Intraoperative alignment assessment system and method

This application is a continuation-in-part application of U.S. patent application Ser. No. 16/237,443, filed on Dec. 31, 2018, which is a continuation-in-part of U.S. patent application Ser. No. 16/026,754, filed Jul. 3, 2018, which claims priority to U.S. Provisional Patent Application No. 62/528,390, filed on Jul. 3, 2017, the entire contents of which are incorporated herein by reference. This application also claims priority to U.S. Provisional Patent Application No. 62/884,032, filed Aug. 7, 2019.

Current tools limit a surgeon's ability to quickly and accurately assess the intraoperative alignment of their patient's spine, especially after the spine has been manipulated during a correction. In addition, most of the state-of-the-art options introduce or rely on excessive radiation exposure, inadequate visualization of anatomical landmark(s) of interest, and lengthy disruptions to the surgical workflow.

Accordingly, new systems and methods are needed analyzing and providing a patient's spinal alignment information and therapeutic device data. The method ideally should include obtaining initial patient data, and acquiring spinal alignment contour information, assessing localized anatomical features of the patient, and obtaining anatomical region data. The system and method should include analyzing the localized anatomy and therapeutic device location and contouring resulting in an output including a localized anatomical analysis and a display of therapeutic device contouring data.

Some embodiments include a system comprising at least one dynamic reference frame (DRF) configured so that any fixed or mobile portion of the DRF, or any assembly or component coupled to the DRF can be registered in 3D space using a plurality of trackable markers. In some embodiments, the plurality of trackable markers includes at least one moveable or triggerable marker. Some embodiments include at least one user-actuation trigger or actuator coupled to the at least one moveable or triggerable marker that can trigger or actuate the at least one moveable or triggerable marker. Some further embodiments include at least one 3D tracking camera or imaging system configured to track one or more of the plurality of trackable markers. In some embodiments, the system includes a processor and a memory coupled to the processor, wherein the memory stores instructions executable by the processor to track one or more 3D coordinates of one or more of the plurality of trackable markers.

Some further embodiments include a method of analyzing and providing spinal alignment anatomical information and therapeutic device data, comprising obtaining initial patient data, acquiring alignment contour information, assessing localized anatomical features, obtaining anatomical region data, analyzing localized anatomy, analyzing therapeutic device location and contouring, and/or outputting on a display the localized anatomical analyses and therapeutic device contouring data.

Some further embodiments include an anatomical marking or tracking system comprising a lower fiducial alignment assembly and a complementary upper fiducial alignment assembly. In some embodiments, the lower fiducial alignment assembly is configured to couple to an anatomy, and the upper fiducial alignment assembly is configured to align to at least a portion of the lower fiducial assembly using at least one characteristic of the lower fiducial alignment assembly and the upper fiducial alignment assembly.

Some embodiments include radiopaque markers configured to be visually observable using an X-ray source or imager, where the radiopaque markers are at least partially embedded in at least one of the lower fiducial alignment assembly and a complementary upper fiducial alignment assembly.

In some embodiments, the at least one characteristic comprises at least one magnet. In some embodiments, the at least one characteristic comprises at least one protrusion configured to at least partially insert or mate with at least one mating aperture. In some embodiments, the at least one protrusion comprises at least one protrusion extending from a mating surface of the lower fiducial alignment assembly. In some further embodiments, the at least one mating aperture is positioned through a mating surface of the upper fiducial alignment assembly.

In some embodiments of the invention, the lower fiducial alignment assembly and complementary upper fiducial alignment assembly are configured to be at least partially aligned and coupled at an interface through surgical drapes or towels, where the interface comprises at least a portion of the surgical drapes or towels positioned between at least a portion of the lower fiducial alignment assembly and complementary upper fiducial alignment assembly.

In some further embodiments, the upper fiducial alignment assembly comprises at least one groove positioned in an upper surface, where the at least one groove is configured to be tracked by a tracking probe to determine a unique identity of the system as well as interpret its location and pose in space.

In some embodiments, the at least one groove comprises a “z” geometry configured to accommodate and/or guide a tracking probe. In some further embodiments, the at least one groove comprises a sloped decline configured to facilitate a user tracing a probe from the upper surface of the upper surface of the upper fiducial alignment assembly down to a body surface onto which the system is placed.

In some embodiments, the lower fiducial alignment assembly is configured and arranged to adhere to a skin surface. In some further embodiments, the lower fiducial alignment assembly and/or upper fiducial alignment assembly can comprise a guide indicative of how a user should position the system. In some embodiments, the guide comprises an arrow shape indicative of a position or orientation. In some embodiments of the system, the radiopaque markers comprise three or more markers positioned with respect to each other to enable calculation of 3D pose information.

Some further embodiments comprise a tracking probe configured to couple to at least a portion of the upper fiducial alignment assembly. In some embodiments, the tracking probe is configured to couple to at least one groove of the upper fiducial alignment assembly to determine a unique identity of the system as well as interpret its location and pose in space.

Some embodiments include a tracking system comprising a lower fiducial alignment assembly and a complementary upper fiducial alignment assembly, where the lower fiducial alignment assembly is configured to couple to an anatomy, and the upper fiducial alignment assembly is configured to align to at least a portion of the lower fiducial assembly using at least one characteristic of the lower fiducial alignment assembly and the upper fiducial alignment assembly. In some further embodiments, the radiopaque markers are configured to be visually observable using an X-ray source or imager, and the radiopaque markers are at least partially embedded in at least one of the lower fiducial alignment assembly and a complementary upper fiducial alignment assembly. Some embodiments also include at least one tracking probe assembly configured to couple to at least a portion of the upper fiducial alignment assembly, and at least one groove positioned in the upper fiducial alignment assembly. In some embodiments, the at least one groove is configured to be tracked by the at least one tracking probe assembly to determine a unique identity of the system as well as interpret its location and pose in space.

In some embodiments of the tracking system, the at least one characteristic comprises at least one magnet. In some embodiments of the tracking system, the at least one characteristic comprises at least one protrusion configured to at least partially insert or mate with at least one mating aperture, where the at least one protrusion extends from the mating surface of the lower fiducial alignment assembly, and the at least one mating aperture is positioned through a mating surface of the upper fiducial alignment assembly.

Some embodiments of the tracking system include at least one groove that comprises a “z” geometry configured to accommodate and/or guide the tracking probe. In some embodiments, the at least one groove comprises a sloped decline configured to facilitate a user tracing a probe from the upper surface of the upper surface of the upper fiducial alignment assembly down to a body surface onto which at least the lower fiducial alignment assembly is placed.

Some embodiments include a tracking system comprising a tracking probe assembly comprising a probe shaft with a depressible sliding shaft tip, and a mount with a trackable mobile stray marker at one end of the probe shaft, and a plurality of depth-stops at the opposite end of the probe shaft. Further, some embodiments include a dynamic reference frame coupled to the probe shaft adjacent the mount.

Some embodiments further comprise at least one depth-stop fiducial. In some embodiments, the plurality of depth-stops comprises a series of concentrically-oriented, varying diameter protrusions. In some embodiments, the one or more of the plurality of depth-stops are configured to actuate the depressible sliding shaft tip. Further, in some embodiments, the one or more of the plurality of depth-stops are configured to actuate the depressible sliding shaft tip when forced against a depth-stop fiducial with specific inner diameters, the actuation configured to provide identifiable deflections of the trackable mobile stray marker.

In some embodiments, the probe shaft is spring-loaded. In some embodiments, the dynamic reference frame comprises at least one tracking marker. In some embodiments, the dynamic reference frame comprises four tracking markers, with two of the four tracking markers extending to one side of the probe shaft and two of the four tracking markers extending to an opposite side of the probe shaft. Some embodiments further comprise an asymmetric protruding extrusion configured to engage with a corresponding slot of a depth-stop fiducial.

In some embodiments of the invention, an engagement of the asymmetric protruding extrusion with a corresponding slot of a depth-stop fiducial can enable the system to register a unique orientation of the coordinate axes of the depth-stop fiducial, and/or detect how the depth-stop fiducial rotates and translates in 3D space between one or more registrations.

Some further embodiments comprise a fiduciary assembly comprising a lower fiducial alignment assembly and a complementary upper fiducial alignment assembly, where the lower fiducial alignment assembly is configured to couple to an anatomy, and the upper fiducial alignment assembly is configured to align to at least a portion of the lower fiducial assembly using at least one characteristic of the lower fiducial alignment assembly and the upper fiducial alignment assembly. In some embodiments, the at least one groove is positioned in the upper fiducial alignment assembly, and the at least one groove is configured to be tracked by tracking probe to determine a unique identity of the system as well as interpret its location and pose in space.

In some embodiments, the tracking system comprises radiopaque markers configured to be visually observable using an X-ray source or imager, where the radiopaque markers are at least partially embedded in at least one of the lower fiducial alignment assembly and a complementary upper fiducial alignment assembly. In some embodiments, the at least one characteristic comprises at least one magnet. In some embodiments, the at least one characteristic comprises at least one protrusion configured to at least partially insert into or mate with at least one mating aperture, and the at least one protrusion extends from the mating surface of the lower fiducial alignment assembly, and further, the at least one mating aperture is positioned through a mating surface of the upper fiducial alignment assembly.

Some embodiments include a tracking system comprising a tracking probe assembly comprising a probe shaft with a depressible sliding shaft tip, and a mount with a trackable mobile stray marker at one end of the probe shaft, and a plurality of depth-stops at the opposite end of the probe shaft. Further, some embodiments include a dynamic reference frame coupled to the probe shaft adjacent the mount, and a lower fiducial alignment assembly and a complementary upper fiducial alignment assembly. In some embodiments, the lower fiducial alignment assembly is configured to couple to an anatomy, and the upper fiducial alignment assembly is configured to align to at least a portion of the lower fiducial assembly using an embedded or coupled element of the lower fiducial alignment assembly and the upper fiducial alignment assembly. Further, some embodiments include at least one groove positioned in the upper fiducial alignment assembly, where the at least one groove is configured to be tracked by the tracking probe assembly. Further, some embodiments of the tracking system further comprise radiopaque markers configured to be visually observable using an X-ray source or imager, and where the radiopaque markers are at least partially embedded in at least one of the lower fiducial alignment assembly and a complementary upper fiducial alignment assembly. In some embodiments, the at least one embedded or coupled element comprises at least one magnet. In some embodiments, the at least one embedded or coupled element comprises at least one at least one protrusion configured to at least partially insert or mate with at least one mating aperture, where the at least one protrusion extends from the mating surface of the lower fiducial alignment assembly, and the at least one mating aperture is positioned through a mating surface of the upper fiducial alignment assembly.

Some embodiments include a marker system comprising a lower fiducial alignment assembly and a complementary upper fiducial alignment assembly, where the lower fiducial alignment assembly is configured to couple to an anatomy, and the upper fiducial alignment assembly is configured to align to at least a portion of the lower fiducial assembly, and the radiopaque markers are configured to be visually observable using an X-ray source or imager, and extend from the complementary upper fiducial alignment assembly.

In some embodiments, the radiopaque markers comprise three radiopaque markers. In some further embodiments, the radiopaque markers are positioned on corners of the upper fiducial alignment assembly. In some embodiments, the lower fiducial alignment assembly/or a complementary upper fiducial alignment assembly include slots. In some further embodiments, an upper surface of the upper fiducial alignment assembly comprises a depression or contour configured to be probed by a tracking probe shaft or tip.

In some embodiments, the lower fiducial alignment assembly and complementary upper fiducial alignment assembly are configured to be at least partially aligned and coupled at an interface through surgical drapes or towels, where the interface comprises at least a portion of the surgical drapes or towels positioned between at least a portion of the lower fiducial alignment assembly and complementary upper fiducial alignment assembly.

Some embodiments further comprise a tracking probe assembly comprising a probe shaft and at least one coupled dynamic reference frame including optically trackable markers.

Some embodiments include an anatomy analysis method comprising providing at least one trackable surgical tool including a tool dynamic reference frame and at least one trackable marker, where the at least one trackable surgical tool is configured so that any fixed or mobile portion of the at least one trackable surgical tool can be registered in 3D space. In some embodiments, the method includes providing at least one 3D tracking camera or imaging system configured to track the at least one trackable marker. In some embodiments, the method includes providing a topological optical surface registration system. In some embodiments, the method includes providing a malleable contour element coupled to at least a portion of a patient. In some embodiments, the method includes providing an electromechanical 3D-tracking system, where the electromechanical 3D-tracking provides a system including at least one physically coupled probe, where the at least one physically coupled probe is configured to be tracked in 3D space while coupled to the malleable contour element and/or at least a portion of a patient, and tracing at least a portion of an anatomy of a patient. In some embodiments, the method includes registering the location of one or more fiducial markers inside or outside a surgical site of the patient. In some further embodiments, the method includes registering a contour of at least a portion of the patient using the malleable contour element. In some embodiments, the method includes providing a processor and a memory coupled to the processor, where the memory stores anatomy contour measurement instructions executable by the processor to track 3D coordinates of one or more of the fiducial markers. In some embodiments, the instructions executable by the processor including outputting on a display an anatomical imaging analysis of at least a portion of the patient, and one or more anatomical landmarks registered by the electromechanical 3D-tracking system that are adjusted in position and orientation to the registered contour.

Some embodiments of the invention include a trackable probe assembly comprising a trackable dynamic reference frame coupled or integrated to a probe shaft, where the dynamic reference frame includes at least one marker. Some embodiments include a user actuable marker coupled to a user triggerable assembly including a trigger, and at least one probe tip extending from the probe shaft.

In some embodiments, the trigger comprises a depressible tab positioned at one end of a pivotable arm, where the user actuable marker is coupled to the opposite end of the pivotable arm, the pivotable arm configured and arranged to enable rotation of the user actuable marker. In some further embodiments, the trigger comprises a trigger tab mounted to an extension of a rotatable trigger arm, where the user actuable marker is coupled to the opposite end of the rotatable trigger arm, and is configured and arranged to be rotated in an arc pathway determined by angular displacement of the trigger arm following user actuation of the trigger tab.

In some embodiments, the user triggerable assembly includes a two-link arm link coupled to a slidable shaft, where the user actuable marker is coupled to the slidable shaft, and is configured and arranged to enable movement of the user actuable marker that is coaxial with the probe shaft when the two-link arm link is actuated by user actuation of the trigger.

Some embodiments include an implantable rod analysis system comprising a trackable slider assembly comprising a handle including a dynamic reference frame mounting arm extending from one end, and a rod engagement assembly at an opposite end, the rod engagement assembly configured to slide along a surface of the implantable rod. Some embodiments further comprise a dynamic reference frame (DRF) coupled to the dynamic reference frame mounting arm or configured to be coupled onto the dynamic reference frame mounting arm. Some embodiments include a trackable end cap assembly comprising a rod mounting assembly that can engage and secure one end of the implantable rod, and a dynamic reference frame including trackable markers.

In some embodiments, the system further comprises a 3D tracking camera or imaging system configured to track the at least one trackable marker, and a processor and a memory coupled to the processor, where the memory stores anatomy contour measurement instructions executable by the processor to track 3D coordinates of at least one fixed or mobile marker, and output on a display an anatomical imaging analysis of at least a portion of a patient, and one or more anatomical landmarks and registered contour of the implantable rod.

Some embodiments include an implantable rod adjustment and measurement system comprising a trackable rod bender assembly comprising a roller assembly including three rollers arranged on a pair rotatable handles and at least one trackable marker, where the roller assembly can grip a surface of an implantable rod, slide along a surface of the implantable rod, and/or bend the implantable rod. Some embodiments include a trackable end cap assembly comprising a rod mounting assembly that can engage and secure one end of the implantable rod, and a dynamic reference frame including trackable markers. In some embodiments, at least one of the handles includes a coupled dynamic reference frame including at least one trackable marker. Some further embodiments include a 3D tracking camera or imaging system configured to track the at least one trackable marker, a processor and a memory coupled to the processor, where the memory storing anatomy contour measurement instructions executable by the processor. In some embodiments, the instructions operate a method including tracking 3D coordinates of at least one fixed or mobile marker, and outputting on a display an anatomical imaging analyses of at least a portion of a patient, one or more anatomical landmarks and registered contour of the implantable rod and to display an illustration of a bending of the implantable rod.

Some embodiments include an assembly comprising an adjustable bracket including a fixed shoulder at one end and an adjustable channel at an opposite end, where the adjustable channel extends at least partially to the fixed shoulder. Further, some embodiments include a first side arm extending from the fixed shoulder, and a second side arm extending from the adjustable channel, where the first and second side arms each configured to couple with a pedicle screw. In some embodiments, the second side arm is configured and arranged to be moveable in the adjustable channel enabling the distance between the first and second side arms to be adjusted. Some further embodiments include a handle extending from the adjustable bracket, and at least one dynamic reference frame (DRF) coupled to the handle, where the DRF includes at least one trackable marker.

Some embodiments include a system comprising an assembly comprising an adjustable bracket including a fixed shoulder at one end and an adjustable channel at an opposite end, where the adjustable channel extends at least partially to the fixed shoulder. Some further embodiments include a first side arm extending from the fixed shoulder, and a second side arm extending from the adjustable channel, where the first and second side arms are each configured to couple to a pedicle screw. Some embodiments include a handle extending from the adjustable bracket, and at least one dynamic reference frame (DRF) coupled to the handle, where the DRF includes at least one trackable marker, and where the second side arm is configured and arranged to be moveable in the adjustable channel enabling the distance between the first and second side arms to be adjusted. Further, some embodiments include at least one 3D tracking camera or imaging system configured to track the at least one trackable marker, and a processor and a memory coupled to the processor. In some embodiments, the memory stores instructions executable by the processor to track 3D coordinates of one or more of trackable markers, and output on a display an anatomical imaging analysis of at least a portion of a patient, and one or more anatomical landmarks and representation of at least a portion of the assembly based on the 3D coordinates.

Some embodiments include a fiducial system comprising a probe assembly comprising, and a trackable dynamic reference frame coupled or integrated to a probe shaft. Some embodiments include a moveable post with trackable marker that is slidably positioned in the probe shaft. Some embodiments include at least one probe tip extrusion tab configured and arranged to engage a mating portion of an implantable mating screw. Some embodiments include a spring-loaded plunger movable positioned in the probe shaft, and configured to be actuated against a surface of the mating screw, elevating the moveable post with trackable marker to a triggered state defined by mating of the probe assembly with the mating screw.

Some embodiments of the invention include an an assembly comprising an adjustable bracket including a fixed shoulder at one end and an adjustable channel at an opposite end, where the adjustable channel extending at least partially to the fixed shoulder, and a first side arm extending from the fixed shoulder, and a second side arm extending from the adjustable channel, the first and second side arms each configured to couple with a pedicle screw. Some further embodiments include at least one adjustable screw interface extending from at least one of the first side arm and the second side arm, and including a tool mating tip configured to engage a screw mating attachment comprising a depth-stop, and where the second side arm is configured and arranged to be moveable in the adjustable channel enabling the distance between the first and second side arms to be adjusted.

Some embodiments further comprise a handle extending from the adjustable bracket, and at least one dynamic reference frame (DRF) coupled to the handle, where the DRF includes at least one trackable marker.

In some embodiments, the system comprises an assembly comprising an adjustable bracket including a fixed shoulder at one end and an adjustable channel at an opposite end, where the adjustable channel extends at least partially to the fixed shoulder, and a first side arm extending from the fixed shoulder, and further, a second side arm extending from the adjustable channel, the first and second side arms each configured to couple with a pedicle screw. Some embodiments include at least one adjustable screw interface extending from at least one of the first side arm and the second side arm, where the at least one adjustable screw interface includes a tool mating tip configured to engage a screw mating attachment comprising a depth-stop. Further, some embodiments include a handle extending from the adjustable bracket, and at least one dynamic reference frame (DRF) coupled to the handle, where the DRF includes at least one trackable marker. In some embodiments, the second side arm is configured and arranged to be moveable in the adjustable channel enabling the distance between the first and second side arms to be adjusted. Further, some embodiments include providing at least one 3D tracking camera or imaging system configured to track the at least one trackable marker, and a processor and a memory coupled to the processor. In some embodiments, the memory stores instructions executable by the processor to track 3D coordinates of one or more of trackable markers, and output on a display an anatomical imaging analysis of at least a portion of a patient, and one or more anatomical landmarks and representation of at least a portion of the assembly based on the 3D coordinates.

Some embodiments include a method comprising acquiring at least one X-ray image from a patient, where the patient is positioned with at least one dynamic reference frame and at least one trackable marker enabling any portion of the patient to be registered in 3D space and any portion of the acquired X-ray image to include at least one tracked 3D coordinate. Further, the method includes calculating the position and orientation of at least one portion of the patient from the at least one X-ray image and the at least one tracked 3D coordinate. Further, the method includes calculating and scaling 3D coordinates of the at least one X-ray image to a phantom model. Further, the method includes transforming 3D coordinates to cartesian coordinates of the phantom model. Further, the method includes providing a phantom model mounting assembly including at least one dynamic reference frame. Further, the method includes positioning at least one portion of the phantom model onto the phantom model mounting assembly based on one or more of the cartesian coordinates and a position of the at least one dynamic reference frame.

Some embodiments include a 3D trackable probe system comprising a probe assembly comprising a trackable dynamic reference frame coupled or integrated to a probe shaft, where the dynamic reference frame includes at least one marker. Some embodiments include a user actuable marker coupled to a user triggerable assembly including a trigger, and at least one probe tip extending from the probe shaft, and at least one 3D tracking camera or imaging system configured to track the at least one trackable marker. Some embodiments include a processor and a memory coupled to the processor, where the memory stores instructions executable by the processor to track 3D coordinates of one or more of trackable markers, and calculate a 3D position and pose of the probe assembly.

In some embodiments, the trigger comprises a depressible tab positioned at one end of a pivotable arm, where the user actuable marker is coupled to the opposite end of the pivotable arm, the pivotable arm configured and arranged to enable rotation of the user actuable marker.

In some embodiments, the trigger comprises a trigger tab mounted to an extension of a rotatable trigger arm, where the user actuable marker is coupled to the opposite end of the rotatable trigger arm, and is configured and arranged to be rotated in an arc pathway determined by angular displacement of the trigger arm following user actuation of the trigger tab.

In some embodiments, the user triggerable assembly includes a two-link arm link coupled to a slidable shaft, where the user actuable marker is coupled to the slidable shaft, and is configured and arranged to enable movement of the user actuable marker that is coaxial with the probe shaft when the two-link arm link is actuated by user actuation of the trigger.

Some embodiments include a probe assembly comprising a probe shaft including one or more coaxial depth-stops proximate one end of the probe shaft and a trackable dynamic reference frame integrated or coupled proximate an opposite end of the probe shaft, where the one or more of the coaxial depth-stops are configured to couple or mate with one or more depth-stop fiducials. Some further embodiments include a moveable shaft slidably positioned at least partially within the probe shaft, where the moveable shaft includes a probe tip at one end and a trackable marker at an opposite end.

In some embodiments, the probe assembly is configured and arranged so that during use, coupling of the probe-tip with a body surface with movement of the moveable shaft comprises movement of the trackable marker away from the body to a distance determined by the one or more depth-stop fiducials. In some further embodiments, one or more of the coaxial depth-stops comprise an alignment protrusion configured and arranged to mate, interlock, or couple with a complementary slot, cavity, or receptible of the one or more depth-stop fiducials.

Some embodiments include a system comprising a trackable surgical tool including a tool dynamic reference frame and at least one trackable marker, where the trackable surgical tool is configured so that any fixed or mobile portion of the trackable surgical tool can be registered in 3D space. Some embodiments include a processor and a memory coupled to the processor, where the memory stores instructions executed by the processor to acquire at least one X-ray image from a patient wherein the location and pose of the emitter and detector are known or determined, and using at least one X-ray imager mounted dynamic reference frame, determine a conical imaging volume of an X-ray imager coupled to the processor. Further, in some embodiments, the memory stores instructions executed by the processor to record pose of the trackable surgical tool, and visually display, on an external display or device, in response to a calculated position of the trackable surgical tool in the conical imaging volume, a scaled projection of the trackable surgical tool over at least a portion of the X-ray image displayed on the external display or device.

Some embodiments include a trackable probe comprising at least one trackable dynamic reference frame (DRF) including at least one trackable marker, and at least one movable trackable marker coupled to the DRF. Some embodiments include a mating protrusion extending from the DRF including a mating slot or cavity. Some embodiments include at least one probe extension including a mating element, where the mating element is configured for insertion and/or sliding in the mating slot or cavity.

In some embodiments, the at least one movable trackable marker is positioned coupled to a slidable insert of the mating protrusion. In some embodiments, the at least one movable trackable marker is spring-loaded, where movement of the at least one movable trackable marker is governed by the spring-loading.

Some embodiments include a fiducial patch comprising a body-surface mountable article including a plurality of radiopaque markers arranged between a plurality of radiopaque grid lines. In some embodiments, the radiopaque markers comprise at least one of colors or shades of grey, letters, numbers, symbols, and icons. Some embodiments further comprise adhesive at least partially covering one side of the body-surface mountable article, the one side being a side intended for coupling to a body surface. some embodiments further comprise at least one radiopaque lining that at least partially matches one or more of the plurality of radiopaque markers.

Some embodiments include a probe assembly comprising a trackable probe including a trackable dynamic reference frame integrated or coupled to a first end of the probe, and rod-centering fork positioned at a second end of the probe, the rod-centering fork comprising a bifurcating structure configured to engage an implantable or implanted rod. Some embodiments include a depressible shaft positioned at least partially within the probe, where the depressible shaft includes a probe tip at one end and a trackable marker at an opposite end.

Some embodiments include an adjustable depth-stop positioned adjacent the first end of the probe, where the adjustable depth-stop is configured to control a maximum extension of the depressible shaft and probe tip. Some embodiments include at least one shaft guide configured to prevent rotation of the depressible shaft;

Some embodiments further comprise a spring assembly coupled to the first end of the probe, where the spring assembly is configured to spring-load the depressible shaft. In some embodiments, the trackable dynamic reference frame includes at least one coupled trackable marker.

Some embodiments include an electromechanical 3D tracking system comprising an extensible cord system including two or more extensible cords retractable or extendible from a spool, and two or more ball-in-socket assemblies, where each extensible cord extends from a ball-in-socket assembly. Further, some embodiments include at least one position or movement sensor configured for measuring a position or movement of each ball-in-socket assembly, and at least one sensor configured for determining an extended length of each extensible cord. Some embodiments include a data acquisition system configured to receive sensor data from the at least one position or movement sensor and the at least one sensor, and to calculate movement and/or at least one 3D coordinate of at least a portion of a probe coupled to the extensible cords.

Some embodiments include an implanted rod manipulator comprising a handle, and a dynamic tracking frame positioned extending from a first end of the handle, where the dynamic tracking frame includes at least on trackable marker. Some embodiments include a rod interface head positioned extending from a second end of the handle opposite the first end, where the rod interface head includes a concave surface configured to couple to a surface of an implantable or implanted rod. Further, some embodiments include a moveable sliding tip positioned extending through the rod interface head. In some embodiments, the moveable sliding tip is coupled to a spring-load the depressible shaft.

Some embodiments further comprise a moveable trackable marker coupled to the moveable sliding tip, where a position of the moveable trackable marker relative to the first end of the handle is dependent on at least one of a rod coupled to the rod interface head and the position of the moveable sliding tip in the rod interface head.

Some embodiments include a method comprising positioning a trackable probe in-line and/or parallel to an anatomical alignment of a patient, and triggering the trackable probe to communicate a reference plane initialization. Further, in some embodiments, the method comprises calculating a 3D pose of a dynamic reference frame as analogous for the patient's anatomical planes, and registering three or more points to establish anatomical planes on which to project acquired data.

In some embodiments of the method, the dynamic reference frame is attached to the patient. In some embodiments of the method, the dynamic reference frame is coupled to a surgical table or adjacent surface, where the dynamic reference frame is adjacent to the patient.

Some embodiments include a method of analyzing and providing a patient's spinal alignment information and therapeutic device data. In some embodiments, the method can comprise obtaining initial patient data, and acquiring spinal alignment contour information. In some embodiments, the method can comprise assessing localized anatomical features of the patient, and obtaining anatomical region data. In some embodiments, the method can include analyzing the localized anatomy and therapeutic device location and contouring. In some embodiments, the method can output localized anatomical analyses and therapeutic device contouring data on a display.

FIG. 1 illustrates a system for assessing spinal alignment, local anatomy biomechanics, rod contours, and active contouring of a rod, as well as initialization of fiducials and interactive displays of various outputs in accordance with some embodiments of the invention.

FIG. 2 A shows a representation of a body-surface-mountable fiducial patch in accordance with some embodiments of the invention.

FIG. 2 B displays the radiopaque elements of the fiducial patch of FIG. 2 A as would be visible on an X-ray image of a patient with the patch applied in accordance with some embodiments of the invention.

FIG. 3 A displays a vertebra with a bone-mounted fiducial fastened to the bone in accordance with some embodiments of the invention.

FIG. 3 B shows an assembly view of a vertebra with a bone-mounted fiducial and top fiducial for coupling to the bone-mounted fiducial in accordance with some embodiments of the invention.

FIG. 3 C shows a vertebra with a bone-mounted fiducial coupled with a top fiducial in accordance with some embodiments of the invention.

FIG. 4 A illustrates an assembly or operation process for a skin-surface-mounted fiducial being applied to a patient's posterior skin as they are positioned prone on an operative table in accordance with some embodiments of the invention.

FIG. 4 B illustrates a sample lateral radiograph of skin fiducials applied to an anatomical model in accordance with some embodiments of the invention.

FIG. 4 C illustrates the sample lateral radiograph of FIG. 4 B with annotated vectors in accordance with some embodiments of the invention.

FIG. 4 D illustrates a C-arm based mount a type of an X-ray imaging system that can be utilized for image acquisition and subsequent initialization of fiducial markers in accordance with some embodiments of the invention.

FIG. 4 E illustrates a sample X-ray image of a spine-fiducial pair from a different imaging angle from that of FIGS. 4 A and 4 B in accordance with some embodiments of the invention.

FIG. 4 F illustrates the sample X-ray image of FIG. 4 E including annotated vectors in accordance with some embodiments of the invention.

FIG. 4 G illustrates 3D axes relative to the fiducial origin point onto which displacement vectors drawn over each of the 2D X-rays are able to be added based on input or calculated angle between each X-ray image plane in accordance with some embodiments of the invention.

FIG. 4 H illustrates a system and method of localizing the fiducial in 3D tracking camera coordinates in accordance with some embodiments of the invention.

FIG. 4 I displays the axes of a 3D-acquisition system with which the unique location and pose of the fiducial was registered as of FIG. 4 H in accordance with some embodiments of the invention.

FIG. 5 A illustrates an optical tracking system in accordance with some embodiments of the invention.

FIG. 5 B illustrates an ultrasound probe equipped with a tracked dynamic reference frame in accordance with some embodiments of the invention.

FIG. 5 C illustrates an assembly or process view of a patient's skin surface overlying a cross-sectional view of a vertebra as a representation of a particular region of bony anatomy that could be registered to a skin-mounted fiducial in accordance with some embodiments of the invention.

FIG. 6 A illustrates an assembly or process view for applying a skin-mounted fiducial and its associated over-the drape fiducial in accordance with some embodiments of the invention.

FIG. 6 B illustrates an assembly view of a skin-mounted fiducial and its associated over-the-drape mating fiducial in accordance with some embodiments of the invention.

FIG. 6 C illustrates a skin-mounted fiducial applied to an anatomical phantom in a region that is outside the surgical site but located over regions of underlying anatomy for which their location within 3D-tracking coordinates is desired to be known in accordance with some embodiments of the invention.

FIG. 6 D illustrates a skin-mounted fiducial mating with its over-the-drape fiducial across a surgical drape/towel in accordance with some embodiments of the invention.

FIG. 7 illustrates an assembly view of a fiducial in accordance with some embodiments of the invention.

FIG. 8 illustrates an assembly view of a fiducial in accordance with some embodiments of the invention.

FIG. 9 A illustrates an assembled skin-surface fiducial with mating top surface fiducial in accordance with some embodiments of the invention.

FIG. 9 B illustrates an assembly view of the fiducial of FIG. 9 A in accordance with some embodiments of the invention.

FIG. 10 A illustrates a 3D-trackable probe equipped with a substantially rigidly attached trackable dynamic reference frame in accordance with some embodiments of the invention.

FIG. 10 B illustrates a close-up perspective of an actuating tip and variable height selection depth-stops of the probe of FIG. 10 A in accordance with some embodiments of the invention.

FIG. 10 C illustrates receptacles designed to mate with the probe of FIGS. 10 A- 10 B in accordance with some embodiments of the invention.

FIG. 10 D illustrates the probe of FIG. 10 A mated with a particular receptacle of FIG. 10 C in accordance with some embodiments of the invention.

FIG. 10 E illustrates the probe of FIG. 10 A mated with a receptacle designed to mate with a different height selector of the probe than shown in FIG. 10 D in accordance with some embodiments of the invention.

FIG. 10 F illustrates an assembly view of a portion of a probe in accordance with some embodiments of the invention.

FIG. 10 G illustrates a partially assembled view of the probe of FIG. 10 F in accordance with some embodiments of the invention.

FIG. 11 A illustrates a top perspective assembly view of a skin surface fiducial mated with an over-the-drape fiducial that contains three or more tracked markers in accordance with some embodiments of the invention.

FIG. 11 B illustrates a side perspective assembly view of the fiducial of FIG. 11 A accordance with some embodiments of the invention.

FIG. 12 illustrates a representation of a tracked dynamic reference frame in accordance with some embodiments of the invention.

FIG. 13 illustrates a sample cross-sectional CT scan view of a spine in accordance with some embodiments of the invention.

FIG. 14 A illustrates a tool equipped with a tracked dynamic reference frame in accordance with some embodiments of the invention.

FIGS. 14 B- 14 C illustrate the tool of FIG. 14 A in different arrangements in accordance with some embodiments of the invention.

FIGS. 15 A- 15 C shows a probe equipped with a tracked dynamic reference frame (DRF) in various configurations in accordance with some embodiments of the invention.

FIG. 16 illustrates a rotary encoder in accordance with some embodiments of the invention.

FIG. 17 A illustrates a pulley-gear system for use with the encoder of FIG. 16 in accordance with some embodiments of the invention.

FIG. 17 B illustrates a gear of the pulley-gear system of FIG. 17 A in accordance with some embodiments of the invention.

FIG. 18 A illustrates a perspective view of a cord spool for use in the pulley-gear system of FIG. 17 in accordance with some embodiments of the invention.

FIG. 18 B illustrates a side view of the cord spool for use in the pulley-gear system of FIG. 17 in accordance with some embodiments of the invention.

FIGS. 19 A- 19 C illustrates a ball assembly of a 3D-tracking system of FIG. 23 A in accordance with some embodiments of the invention.

FIGS. 19 D- 19 E illustrate a ball and socket assembly of the 3D-tracking system of FIG. 23 A accordance with some embodiments of the invention.

FIG. 20 illustrates a probe of a 3D tracking system in accordance with some embodiments of the invention.

FIGS. 20 A- 20 E show views of components of the probe of FIG. 20 in accordance with some embodiments of the invention.

FIGS. 21 A- 21 B illustrate assemblies of a 3D tracking system including a probe coupled to cord fixation points in accordance with some embodiments of the invention.

FIG. 22 illustrates an example system enabling 3D tracking of a probe in accordance with some embodiments of the invention.

FIG. 23 A illustrates an example 3D tracking system in accordance with some embodiments of the invention.

FIG. 23 B illustrates 3D tracking system in enclosure in accordance with some embodiments of the invention.

FIG. 23 C shows an exploded assembly view of the 3D tracking system of FIG. 23 B in accordance with some embodiments of the invention.

FIGS. 24 - 26 illustrate systems enabling 3D tracking of a probe in accordance with some embodiments of the invention.

FIGS. 27 A- 27 D includes representations of 3D tracking methods in accordance with some embodiments of the invention.

FIG. 28 A illustrates an example 3D tracking system in accordance with some embodiments of the invention.

FIG. 28 B illustrates a computer system configured for operating and processing components of the system in accordance with some embodiments of the invention.

FIGS. 29 A- 29 B illustrates a screw-head-registering screwdriver equipped with a tracked dynamic reference frame in accordance with some embodiments of the invention.

FIG. 29 C illustrates a close-up perspective view of a screwdriver head and depressible tip of the screwdriver of FIGS. 29 A- 29 B in accordance with some embodiments of the invention.

FIG. 29 D illustrates a cross-sectional view of the screwdriver-screw interface in accordance with some embodiments of the invention.

FIG. 30 A illustrates a 3D-tracking camera system in accordance with some embodiments of the invention.

FIG. 30 B comprises an image of a tracked reference frame accordance with some embodiments of the invention.

FIG. 31 illustrates a body-mounted 3D-tracking camera in accordance with some embodiments of the invention.

FIG. 32 displays a method of interpreting the contour of the posterior elements of the spine in accordance with some embodiments of the invention.

FIG. 33 A illustrates pedicle screw in accordance with some embodiments of the invention.

FIG. 33 B illustrates a pedicle screw in accordance with some embodiments of the invention.

FIG. 33 C illustrates pedicle screw mated with a polyaxial tulip head in accordance with some embodiments of the invention.

FIG. 33 D illustrates a tool designed to interface with the pedicle screw of FIG. 33 B in accordance with some embodiments of the invention.

FIG. 33 E illustrates a visualization of a couple between the tool of FIG. 33 D and the screw of FIG. 33 C in accordance with some embodiments of the invention.

FIG. 33 F illustrates a screwdriver coupled to a pedicle screw in accordance with some embodiments of the invention.

FIG. 33 G illustrates a top view of the screw of FIG. 33 A in accordance with some embodiments of the invention.

FIG. 33 H illustrates a top view of the screw of FIG. 33 B in accordance with some embodiments of the invention.

FIG. 33 I illustrates a top view of the screw of FIG. 33 A in accordance with some embodiments of the invention.

FIG. 34 illustrates a tool for interfacing with a pedicle screw accordance with some embodiments of the invention.

FIGS. 34 A- 34 F illustrate various views of the tool of FIG. 34 in accordance with some embodiments of the invention.

FIGS. 35 A- 35 E illustrate various views of a tool for interfacing with a pedicle screw in accordance with some embodiments of the invention.

FIG. 35 F illustrates a close-up perspective view of the tool of FIGS. 35 A- 35 E without a coupled pedicle screw or tulip head in accordance with some embodiments of the invention.

FIGS. 36 A- 36 G illustrate a tool designed to interface directly with tulip heads of pedicle screws in accordance with some embodiments of the invention.

FIGS. 36 H- 36 I illustrate perspective views of the tool of FIGS. 36 A- 36 G without pedicle screw shaft in accordance with some embodiments of the invention.

FIGS. 37 A- 37 G illustrate various views of a tool for interfacing directly with two implanted pedicle screws in accordance with some embodiments of the invention.

FIG. 38 illustrates a pedicle screw shaft with depth-stop in accordance with some embodiments of the invention.

FIG. 38 A illustrates a top view of the pedicle screw shaft with depth-stop of FIG. 38 in accordance with some embodiments of the invention.

FIG. 38 B illustrates a screw interface region with coupled handle in accordance with some embodiments of the invention.

FIG. 38 C illustrates an example assembly view coupling between the screw interface region of FIG. 38 B and the pedicle screw shaft with depth-stop of FIGS. 38 - 38 A in accordance with some embodiments of the invention.

FIGS. 38 D- 38 G illustrates view of the screw interface region of FIG. 38 B coupled with the pedicle screw shaft with depth-stop of FIGS. 38 - 38 A in accordance with some embodiments of the invention.

FIG. 39 A illustrates a full perspective view of a device used for manipulating bony anatomy and assessing range of motion intraoperatively in accordance with some embodiments of the invention.

FIG. 39 B illustrates some embodiments of the handle of the tool described previously in relation to FIG. 39 A in accordance with some embodiments of the invention.

FIG. 39 C illustrates a bottom view of the embodiment described above in relation to FIGS. 39 A-B in accordance with some embodiments of the invention.

FIG. 39 D displays a cross-sectional side view of the tool as described previously in relation to FIGS. 39 A- 39 C in accordance with some embodiments of the invention.

FIG. 39 E illustrates a bottom view of a width-adjustment mechanism that allows for variation in the distance between screw-interface locations of the tool in accordance with some embodiments of the invention.

FIG. 39 F illustrates a close-up perspective of the width-adjustment mechanism, thread-tightening knobs, and sleeve body of the device as described above in relation to FIGS. 39 A-E in accordance with some embodiments of the invention.

FIG. 40 A illustrates a lateral view of a spine model with a straight curve, and two flexibility assessment tools engaged with the model in accordance with some embodiments of the invention.

FIG. 40 B illustrates two flexibility assessment devices interfacing with a spine model with a lordotic curve in accordance with some embodiments of the invention.

FIG. 40 C illustrates the invention from a 3D-tracking camera perspective in accordance with some embodiments of the invention.

FIG. 41 A illustrates a side view of the screw-interface components of the flexibility assessment device described previously in relation to FIGS. 34 A- 34 F, 35 A- 35 E, and 36 A- 36 G, 39 A- 39 F, and 40 A- 40 C in accordance with some embodiments of the invention.

FIG. 41 B illustrates a front view of the embodiment described above in relation to FIG. 41 A in accordance with some embodiments of the invention.

FIG. 41 C illustrates the device of FIGS. 41 A- 41 B assembled with a flexibility assessment device previously described in relation to FIGS. 39 A- 39 F, and 40 A- 40 C in accordance with some embodiments of the invention.

FIG. 41 D illustrates a perspective assembly view of a detachable screw-interface component displaying release tabs, center-alignment post, peripheral alignment pins, screw-interface rod, side-tab extensions, and spring-loaded snap arm in accordance with some embodiments of the invention.

FIG. 42 A illustrates the flexibly assessment device of FIGS. 39 A- 39 F, and 40 A- 40 C equipped with detachable screw interface components, previously described in FIG. 41 with adjustable cross-linking devices, described below in reference to FIG. 43 A- 43 F in accordance with some embodiments of the invention.

FIG. 42 B illustrates the flexibility assessment device described previously in relation to FIG. 42 A substantially rigidly coupled to the pedicle screws by interfacing with the tulip heads in accordance with some embodiments of the invention.

FIG. 42 C illustrates a second flexibility assessment device interfacing with a spinal level at a user-defined distance from the already mated device described previously in relation to FIGS. 39 A- 39 F, 41 A- 41 D, and 42 A- 42 B in accordance with some embodiments of the invention.

FIG. 42 D illustrates two mated flexibility assessment devices, as previously described in relation to FIGS. 39 A- 39 F, 41 A- 41 D, and 42 A- 42 C in accordance with some embodiments of the invention.

FIG. 42 E illustrates two flexibility assessment devices substantially rigidly attached to the spine as described previously in relation to FIGS. 39 A- 39 F, 41 A- 41 D, and 42 A- 42 D in accordance with some embodiments of the invention.

FIG. 42 F illustrates two flexibility assessment devices substantially rigidly attached to the spine as described previously in relation to FIGS. 39 A- 39 F, 41 A- 41 D, and 42 A- 42 F in accordance with some embodiments of the invention.

FIG. 42 G illustrates an instrumented spine previously described in relation to FIGS. 42 A- 42 F in accordance with some embodiments of the invention.

FIG. 42 H displays an instrumented spine previously described in relation to FIGS. 42 A- 42 G in accordance with some embodiments of the invention.

FIG. 42 I illustrates an instrumented spine previously described in relation to FIGS. 42 A- 42 H in accordance with some embodiments of the invention.

FIG. 42 J illustrates an instrumented spine previously described in relation to FIGS. 42 A- 421 in accordance with some embodiments of the invention.

FIG. 42 K illustrates an instrumented spine previously described in relation to FIGS. 42 A- 42 J in accordance with some embodiments of the invention.

FIGS. 43 A- 43 D includes views of an adjustable cross-linking device in accordance with some embodiments of the invention.

FIGS. 43 E- 43 F illustrate views of an adjustable cross-linking device in accordance with some embodiments of the invention.

FIG. 44 A illustrates a bone-implanted fiducial equipped with a crossbar and substantially rigidly fixed to the lamina of a vertebra as previously described in relation to FIGS. 3 A- 3 C in accordance with some embodiments of the invention.

FIG. 44 B illustrates a process view of a pre-engagement of a bone-implanted fiducial and bone-fiducial mating screwdriver equipped with a tracked DRF and a TMSM coupled to a depressible sliding shaft at the end of the screwdriver in accordance with some embodiments of the invention.

FIG. 44 C illustrates an engagement of a bone-implanted fiducial and bone-fiducial mating screwdriver equipped with a tracked DRF and a TMSM coupled to a depressible sliding shaft at the end of the screwdriver in accordance with some embodiments of the invention.

FIG. 44 D illustrates a bone-implanted fiducia with crossbar and overlying bone-fiducial-mating screwdriver in accordance with some embodiments of the invention.

FIGS. 45 A- 45 B illustrate a vertebra engagement and rendering process in accordance with some embodiments of the invention.

FIGS. 46 A- 46 B illustrate a 3D tracking tool in accordance with some embodiments of the invention.

FIG. 46 C illustrates an X-ray imaging and tracking system in accordance with some embodiments of the invention.

FIG. 46 D illustrates a virtual overlay of a tracked surgical tool positioned close to the X-ray detector on top of an X-ray image of the spine in accordance with some embodiments of the invention.

FIG. 46 E illustrates an X-ray imaging and tracking system in accordance with some embodiments of the invention.

FIG. 46 F illustrates a virtual overlay of a tracked surgical tool positioned close to the emitter as shown in FIG. 46 E in accordance with some embodiments of the invention.

FIG. 46 G illustrates a virtual overlay of a tracked surgical tool that has been turned 90 degrees from the tool position previously described in FIGS. 46 D- 46 F in accordance with some embodiments of the invention.

FIG. 47 A illustrates components of a tracked end cap in accordance with some embodiments of the invention.

FIG. 47 B illustrates components of a tracked slider designed to interface with a rod fixed to a tracked end cap, described previously in relation to FIG. 47 A in accordance with some embodiments of the invention.

FIG. 48 A illustrates a close-up view of a portion of an end cap in accordance with some embodiments of the invention.

FIG. 48 B illustrates a perspective view of an end cap assembled from components of FIG. 47 A in accordance with some embodiments of the invention.

FIG. 48 C illustrates a side view of the end cap of FIG. 48 B in accordance with some embodiments of the invention.

FIGS. 49 A- 49 C illustrates a single-ring rod assessment device assembly in accordance with some embodiments of the invention.

FIG. 49 D illustrates the assembly of FIGS. 49 A- 49 C coupled with a rod and tracked end cap previously described in relation to FIGS. 47 A, and 48 A- 48 B in accordance with some embodiments of the invention.

FIGS. 50 A- 50 D illustrates a fixed-base, variable-ring, mobile rod assessment device in accordance with some embodiments of the invention.

FIG. 50 E illustrates the fixed-base, variable-ring, mobile rod assessment device of FIGS. 50 A- 50 D engaged with a rod coupled to an end cap in accordance with some embodiments of the invention.

FIGS. 51 A- 51 G illustrates various views of a handheld, mobile rod contour assessment device in accordance with some embodiments of the invention.

FIG. 51 H- 51 I illustrates views of a process or method of registering the contour of a rod prior to implantation with the handheld, mobile rod contour assessment device of FIGS. 51 A- 51 G in accordance with some embodiments of the invention.

FIG. 52 A illustrates a component of a TMSM-based, implanted rod contour assessment device in accordance with some embodiments of the invention.

FIG. 52 B illustrates a depressible sliding shaft for coupling to the component of FIG. 52 A in accordance with some embodiments of the invention.

FIG. 52 C illustrates a top view of the component of FIG. 52 A in accordance with some embodiments of the invention.

FIG. 52 D illustrates a close-up perspective view of the depressible sliding shaft of FIG. 52 B in accordance with some embodiments of the invention.

FIG. 53 A illustrates an assembly of components of FIGS. 52 A and 52 B used to assess the contour of a rod after it has been implanted within the surgical site in accordance with some embodiments of the invention.

FIG. 53 B illustrates a close-up rear view of a portion of the assembly of FIG. 53 A in accordance with some embodiments of the invention.

FIG. 53 C illustrates a close-up view of the rod-interface region of the assembly of FIGS. 53 A- 53 B in accordance with some embodiments of the invention.

FIG. 53 D illustrates the assembly of FIGS. 53 A- 53 C interfacing with a rod in accordance with some embodiments of the invention.

FIGS. 53 E- 53 F illustrates close-up views of a trackable DRF portion of the assembly view of FIGS. 53 A- 53 D in accordance with some embodiments of the invention.

FIG. 54 A illustrates a conductivity-based rod contour assessment device in accordance with some embodiments of the invention.

FIG. 54 B illustrates a rod-centering fork and electrical contact pads of the device of FIG. 54 A in accordance with some embodiments of the invention.

FIGS. 54 C- 54 D illustrates the rod-centering fork of FIG. 54 B interacting with a rod in accordance with some embodiments of the invention.

FIGS. 55 A- 55 I illustrates various views of a 3D-tracked, manual mobile rod bender in accordance with some embodiments of the invention.

FIGS. 56 A- 56 F illustrate various views of a tracked DRF-equipped end cap, pre-registered rod, and manual bender equipped with TMSMs accordance with some embodiments of the invention.

FIG. 57 A illustrates a DRF-tracked and trigger-equipped in-situ benders coupled to a rod in accordance with some embodiments of the invention.

FIG. 57 B illustrates a DRF-tracked and trigger-equipped in-situ benders coupled to a rod coupled to a spine in accordance with some embodiments of the invention.

FIG. 57 C illustrates a close-up assembly view of the rod of FIG. 57 A in accordance with some embodiments of the invention.

FIG. 57 D illustrates a close-up view of a rod interface head of the bender shown in FIG. 57 A including a view of a depressible sliding shaft tip in an extended position in accordance with some embodiments of the invention.

FIG. 58 illustrates a workflow to initialize skin-mounted, or percutaneous, fiducials with two or more X-ray images intraoperatively in accordance with some embodiments of the invention.

FIG. 59 illustrates a workflow to initialize one or more bone-mounted fiducials placed intraoperatively with 2 or more X-ray images taken before placement of the bone-mounted fiducials in accordance with some embodiments of the invention.

FIG. 60 shows a workflow to initialize one or more bone-mounted fiducials placed intraoperatively with 2 or more X-ray images taken after placement of the bone-mounted fiducials in accordance with some embodiments of the invention.

FIG. 61 illustrates methods of registering anatomical reference planes intraoperatively in accordance with some embodiments of the invention.

FIG. 62 A illustrates an arrangement for acquiring information regarding the contour of the spine via tracing over body surfaces using a tracked probe in accordance with some embodiments of the invention.

FIG. 62 B illustrates a display of the acquired body surface contours via tracing with a 3D-tracked probe in accordance with some embodiments of the invention.

FIG. 62 C illustrates a display of transformed tracing data in accordance with some embodiments of the invention.

FIG. 62 D illustrates a display of the data of FIGS. 62 B- 62 C with depth translation in accordance with some embodiments of the invention.

FIG. 63 shows a workflow for analog triggering detection of one or more tracked mobile stray marker (TMSM) relative to a tracked tool with a dynamic reference frame (DRF) in accordance with some embodiments of the invention.

FIG. 64 A illustrates a tracking probe assembly in accordance with some embodiments of the invention.

FIG. 64 B illustrates an interpretation and calculation of the position of a rotating TMSM relative to the DRF on a probe as described previously in relation to FIG. 64 A in accordance with some embodiments of the invention.

FIG. 65 A illustrates displays of a discrete body surface or bony surface annotations on cross-sectional images used for initialization of patient-specific interpretation of body and bony surface tracings with a 3D-tracked probe in accordance with some embodiments of the invention.

FIG. 65 B illustrates 3D perspective of cross-sectional annotations from the CT scan in accordance with some embodiments of the invention.

FIG. 65 C illustrates a plot of coronal projected coordinates in accordance with some embodiments of the invention.

FIG. 65 D illustrates a plot of sagittal projected coordinates in accordance with some embodiments of the invention.

FIG. 65 E illustrates computed cross-sectional distances between corresponding anatomical landmarks and vertebral body centroids in accordance with some embodiments of the invention.

FIG. 66 A illustrates a display of cross-sectional slices of vertebra (a) in their relative anatomical axes in accordance with some embodiments of the invention.

FIG. 66 B illustrates a display of a vertebral body calculated via bilaterally traced coordinates and patient initialization data in accordance with some embodiments of the invention.

FIG. 67 illustrates a workflow to calculate spinal alignment parameters based on intraoperative tracing in accordance with some embodiments of the invention.

FIG. 68 illustrates a workflow to acquire a spinal alignment curve using probe-based tracing within only the surgical site in accordance with some embodiments of the invention.

FIG. 69 illustrates a workflow to acquire a spinal alignment curve using probe-based tracing data spanning beyond the surgical site in accordance with some embodiments of the invention.

FIG. 70 illustrates a workflow to assess flexibility of the spine intraoperatively using flexibility assessment device in accordance with some embodiments of the invention.

FIG. 71 illustrates a workflow of producing real-time overlays of surgical instruments over intraoperative X-rays in accordance with some embodiments of the invention.

FIG. 72 shows a workflow to rapidly re-register a surgical navigation system after a navigated/registered screw insertion in accordance with some embodiments of the invention.

FIG. 73 A illustrates a rod-centering fork on the end of a tool shaft in accordance with some embodiments of the invention.

FIG. 73 B illustrates the fork of FIG. 73 A fully engaged with a rod in accordance with some embodiments of the invention.

FIG. 74 illustrates a workflow to assess the contour of a rod prior to implantation using two handheld tracked tools in accordance with some embodiments of the invention.

FIG. 75 illustrates a workflow to assess the contour of a rod prior to implantation using one handheld tracked tool and one substantially rigidly fixed ring in accordance with some embodiments of the invention.

FIG. 76 illustrates a workflow to assess the contour of a rod after implantation in accordance with some embodiments of the invention.

FIGS. 77 A- 77 C illustrate various displays of interpretation of data generated by assessment of a rod contour after a rod has been implanted to tulip heads within a surgical site in accordance with some embodiments of the invention.

FIG. 78 illustrates a workflow for interactive user placement of a registered rod as an overlay on patient images on a display monitor in accordance with some embodiments of the invention.

FIGS. 79 A- 79 G display processes of interpreting and calculating a tracked rod bending device in accordance with some embodiments of the invention.

FIG. 80 illustrates a workflow for manually bending a rod prior to its implantation with real-time feedback of its dynamic contour in accordance with some embodiments of the invention.

FIG. 81 shows a workflow for manually bending a rod prior to its implantation with directed software input to overlay a projection of the dynamic rod contour onto an intraoperative X-ray image in accordance with some embodiments of the invention.

FIGS. 82 A- 82 B illustrates processes or methods of a probe calibration in accordance with some embodiments of the invention.

FIG. 83 illustrates a workflow to utilize a trigger-equipped probe to serve as a laser pointer analog for a user-interface system with a non-tracked display in accordance with some embodiments of the invention.

FIGS. 84 A- 84 B illustrates a workflow to utilize a trigger-equipped probe to serve as a laser pointer analog for a user-interface with a 3D-tracked display monitor in accordance with some embodiments of the invention.

FIG. 85 illustrates a workflow to utilize a trigger-equipped probe to serve as an interface device for a non-tracked display via a user-defined trackpad analog in accordance with some embodiments of the invention.

FIGS. 86 A- 86 D illustrates output displays of alignment assessments in accordance with some embodiments of the invention.

FIG. 87 A illustrates a rod with previously registered contour fixed to a tracked DRF-equipped end cap and interacting with a tracked rod bender in accordance with some embodiments of the invention.

FIG. 87 B illustrates a sagittal projection of the registered rod contour in accordance with some embodiments of the invention.

FIG. 87 C illustrates a coronal projection of the registered rod contour in accordance with some embodiments of the invention.

FIG. 87 D illustrates a display of the location of a rod bender's center rod contouring surface relative to a cross-sectional view of the rod in accordance with some embodiments of the invention.

FIG. 87 E illustrates a display of a sagittal projection of the registered rod contour in accordance with some embodiments of the invention.

FIG. 87 F illustrates a sagittal patient image with an overlay of a registered rod contour as well as an overlay display of the location of a tracked rod bender relative to the previously registered rod in accordance with some embodiments of the invention.

FIG. 87 G illustrates a sagittal patient image adjusted for operative planning with an overlay of a registered rod contour as well as an overlay display of the location of a tracked rod bender relative to the previously registered rod in accordance with some embodiments of the invention.

FIGS. 87 H- 87 I include displays of a rod and rod bender's location on display monitor in accordance with some embodiments of the invention.

FIGS. 87 J- 87 M illustrates a display of a bender and rod in accordance with some embodiments of the invention.

FIG. 88 A illustrates a sagittal projection of a registered rod contour, a display of the current location of the rod bender relative to the registered rod contour, a display of the software-instructed location where the user should place the rod-bender, and anatomical axes labels in accordance with some embodiments of the invention.

FIG. 88 B illustrates a display of FIG. 88 A as applied to the coronal plane in accordance with some embodiments of the invention.

FIG. 88 C illustrates a cross-sectional display of the rod, the current location of the rod bender's center contouring surface, the software-instructed location of where the rod bender's center contouring surface should be placed, and anatomical axes labels in accordance with some embodiments of the invention.

FIG. 88 D illustrates a display representation of the current relative position of the bender's handles, directly related to the degree of bending induced on a rod of known diameter in accordance with some embodiments of the invention.

FIG. 88 E illustrates a display representation of the software-instructed relative position of the bender's handles (k), directly related to the degree of bending induced on a rod of known diameter in accordance with some embodiments of the invention.

FIG. 88 F illustrates a bend angle display gauge in accordance with some embodiments of the invention.

FIG. 89 shows a workflow to match the adjustable benchtop spinal model to mimic alignment parameters from patient-specific imaging in accordance with some embodiments of the invention.

FIG. 90 A illustrates sagittal and coronal patient images with overlaid sagittal and coronal contour tracings of the spine, discrete software-instructed placement of adjustable mounts onto the anatomical model, and instructions for the coordinates of each of those adjustable mounts to be positioned on the adjustable benchtop model in accordance with some embodiments of the invention.

FIG. 90 B illustrates an anatomical model mounting exploded assembly in accordance with some embodiments of the invention.

FIG. 90 C illustrates a fastening interface for anatomical model in accordance with some embodiments of the invention.

FIG. 90 D illustrates a mounted spine anatomical model in accordance with some embodiments of the invention.

FIG. 91 A illustrates a top view of a modular 3D-tracked tool with a straight extension that is fully engaged into the tool's base in accordance with some embodiments of the invention.

FIG. 91 B illustrates a perspective view of a modular 3D-tracked tool with a straight extension that is disengaged with the tool's base as described previously in relation to FIG. 91 A in accordance with some embodiments of the invention.

FIG. 91 C illustrates a perspective view of a modular 3D-tracked tool with a curved extension that is fully engaged into the tool's base as described previously in relation to FIGS. 91 A- 91 B in accordance with some embodiments of the invention.

FIGS. 92 A- 92 B illustrate side views of an adjustable phantom spine model holder with vertebral holders substantially rigidly engaged with select vertebrae and the pelvis of the model in accordance with some embodiments of the invention.

FIG. 92 C illustrates a perspective view of an adjustable phantom spine model holder with vertebral holders substantially rigidly engaged with select vertebrae and the pelvis of the model as described previously in relation to FIGS. 92 A- 92 B in accordance with some embodiments of the invention.

FIG. 92 D illustrates a perspective view of an adjustable phantom spine model holder in an upright position via an adjustable base holder as described previously in relation to FIGS. 92 A- 92 C in accordance with some embodiments of the invention.

FIGS. 92 E- 92 F illustrate perspective assembly views of a DRF and associated mount for attaching the DRF to an adjustable phantom spine model holder's base platform as described previously in relation to FIGS. 92 A- 92 D in accordance with some embodiments of the invention.

FIGS. 92 G- 92 I illustrate perspective assembly views of a base mount and vertical height adjustment for attaching to an adjustable phantom spine model holder as described previously in relation to FIGS. 92 A- 92 F in accordance with some embodiments of the invention.

FIG. 92 J illustrates a perspective view of a vertical height indicator for a base mount of an adjustable phantom spine model holder as described previously in relation to FIGS. 92 A- 92 I in accordance with some embodiments of the invention.

FIG. 92 K illustrates a front view of a vertical height indicator for a base mount of an adjustable phantom spine model holder as described previously in relation to FIGS. 92 A- 92 J in accordance with some embodiments of the invention.

FIG. 92 L illustrates a perspective view of a sagittal angle indicator for a pelvis mount of an adjustable phantom spine model holder as described previously in relation to FIGS. 92 A- 92 K in accordance with some embodiments of the invention.

FIG. 92 M illustrates a front view of a sagittal angle indicator for a pelvis mount of an adjustable phantom spine model holder as described previously in relation to FIGS. 92 A- 92 L in accordance with some embodiments of the invention.

FIG. 92 N illustrates a front view of a sagittal angle indicator for a vertebral holder of an adjustable phantom spine model holder as described previously in relation to FIGS. 92 A- 92 M in accordance with some embodiments of the invention.

FIG. 92 O illustrates a perspective view of a sagittal angle indicator for a vertebral holder of an adjustable phantom spine model holder as described previously in relation to FIGS. 92 A- 92 N in accordance with some embodiments of the invention.

FIGS. 92 P- 92 Q illustrate perspective views of a sagittal angle adjustment component for a vertebral holder of an adjustable phantom spine model holder as described previously in relation to FIGS. 92 A- 920 in accordance with some embodiments of the invention.

FIGS. 92 R- 92 S illustrate perspective views of a sagittal angle adjustment component for a pelvis mount of an adjustable phantom spine model holder as described previously in relation to FIGS. 92 A- 92 Q in accordance with some embodiments of the invention.

FIGS. 92 T- 92 U illustrate perspective views of a pelvic angle adjustment component for a vertebral holder of an adjustable phantom spine model holder as described previously in relation to FIGS. 92 A- 92 S in accordance with some embodiments of the invention.

FIGS. 92 V- 92 X illustrate perspective views of a sagittal angle adjustment component for a vertebral holder of an adjustable phantom spine model holder as described previously in relation to FIGS. 92 A- 92 U in accordance with some embodiments of the invention.

FIG. 92 Y illustrates a front view of a vertebral interface component for a vertebral holder of an adjustable phantom spine model holder as described previously in relation to FIGS. 92 A- 92 X in accordance with some embodiments of the invention.

FIG. 92 Z illustrates a perspective view of a vertebral interface component and sagittal angle adjustment component for a vertebral holder of an adjustable phantom spine model holder as described previously in relation to FIGS. 92 A- 92 Y in accordance with some embodiments of the invention.

FIG. 92 AA illustrates a perspective view of an adjustable vertebral holder substantially rigidly engaged with a phantom spine model holder as described previously in relation to FIGS. 92 A- 92 Z in accordance with some embodiments of the invention.

FIG. 92 AB illustrates a perspective assembly view of an adjustable vertical base holder of an adjustable phantom spine model holder as described previously in relation to FIGS. 92 A- 92 AA in accordance with some embodiments of the invention.

FIG. 92 AC illustrates a front assembly view of an adjustable vertical base holder of an adjustable phantom spine model holder as described previously in relation to FIGS. 92 A- 92 AB in accordance with some embodiments of the invention.

FIG. 92 AD illustrates a front assembly view of a base platform and cross-rails of an adjustable phantom spine model holder as described previously in relation to FIGS. 92 A- 92 AC in accordance with some embodiments of the invention.

FIG. 93 A illustrates a rear view of an adjustable pedicle screw interface base, with one fixed side arm and one side arm with height and angle adjustments, of a flexibility assessment device.

FIG. 93 B illustrates a side view of an adjustable pedicle screw interface base, with one fixed side arm and one side arm with height and angle adjustments, of a flexibility assessment device as described previously in relation to FIG. 93 A in accordance with some embodiments of the invention.

FIG. 93 C illustrates a perspective view of an adjustable pedicle screw interface base, with one fixed side arm and one side arm with height and angle adjustments, of a flexibility assessment device as described previously in relation to FIGS. 93 A- 93 B in accordance with some embodiments of the invention.

FIG. 93 D illustrates a side view of an adjustable pedicle screw interface base, with one fixed side arm and one side arm with height and angle adjustments, of a flexibility assessment device as described previously in relation to FIGS. 93 A- 93 C in accordance with some embodiments of the invention.

FIG. 93 E illustrates a front view of an adjustable pedicle screw interface base, with one fixed side arm and one side arm with height and angle adjustments, of a flexibility assessment device as described previously in relation to FIGS. 93 A- 93 D in accordance with some embodiments of the invention.

FIG. 93 F illustrates a top view of an adjustable pedicle screw interface base, with one fixed side arm and one side arm with height and angle adjustments, of a flexibility assessment device as described previously in relation to FIGS. 93 A- 93 E in accordance with some embodiments of the invention.

FIG. 93 G illustrates an assembly view of an adjustable pedicle screw interface base, with one fixed side arm and one side arm with height and angle adjustments, of a flexibility assessment device as described previously in relation to FIGS. 93 A- 93 F in accordance with some embodiments of the invention.

FIG. 93 H illustrates a perspective view of an adjustable pedicle screw interface base, with one fixed side arm and one side arm with height and angle adjustments, of a flexibility assessment device as described previously in relation to FIGS. 93 A- 93 G in accordance with some embodiments of the invention.

FIG. 93 I illustrates a perspective assembly view of an adjustable pedicle screw interface base, with one fixed side arm and one side arm with height and angle adjustments, of a flexibility assessment device as described previously in relation to FIGS. 93 A- 93 H in accordance with some embodiments of the invention.

FIG. 93 J illustrates a cross-sectional view of the side arm of an adjustable pedicle screw interface base, with one fixed side arm and one side arm with height and angle adjustments, of a flexibility assessment device as described previously in relation to FIGS. 93 A- 93 I in accordance with some embodiments of the invention.

FIG. 94 A illustrates a side view of an adjustable pedicle screw interface base, with one fixed side arm and one side arm with angle adjustment, of a flexibility assessment device in accordance with some embodiments of the invention.

FIG. 94 B illustrates a top view of an adjustable pedicle screw interface base, with one fixed side arm and one side arm with angle adjustment, of a flexibility assessment device as described previously in relation to FIG. 94 A in accordance with some embodiments of the invention.

FIG. 94 C illustrates a front view of an adjustable pedicle screw interface base, with one fixed side arm and one side arm with angle adjustment, of a flexibility assessment device as described previously in relation to FIGS. 94 A- 94 B in accordance with some embodiments of the invention.

FIG. 94 D illustrates a perspective view of an adjustable pedicle screw interface base, with one fixed side arm and one side arm with angle adjustment, of a flexibility assessment device as described previously in relation to FIGS. 94 A- 94 C in accordance with some embodiments of the invention.

FIG. 94 E illustrates a rear view of an adjustable pedicle screw interface base, with one fixed side arm and one side arm with angle adjustment, of a flexibility assessment device as described previously in relation to FIGS. 94 A- 94 D in accordance with some embodiments of the invention.

FIG. 94 F illustrates a side view of an adjustable pedicle screw interface base, with one fixed side arm and one side arm with angle adjustment, of a flexibility assessment device as described previously in relation to FIGS. 94 A- 94 E in accordance with some embodiments of the invention.

FIG. 94 G illustrates a front view of an adjustable pedicle screw interface base, with one fixed side arm without an attached pedicle screw and one side arm with angle adjustment that is attached to a pedicle screw, of a flexibility assessment device as described previously in relation to FIGS. 94 A- 94 F in accordance with some embodiments of the invention.

FIG. 94 H illustrates a perspective view of an adjustable pedicle screw interface base, with one fixed side arm without an attached pedicle screw and one side arm with angle adjustment that is attached to a pedicle screw, of a flexibility assessment device as described previously in relation to FIGS. 94 A- 94 G in accordance with some embodiments of the invention.

FIGS. 95 A- 95 B illustrate front views of a front-facing flexibility assessment device in a triggered and untriggered state in accordance with some embodiments of the invention.

FIGS. 95 C- 95 D illustrate rear views of a front-facing flexibility assessment device in a triggered and untriggered state as described previously in relation to FIGS. 95 A- 95 B in accordance with some embodiments of the invention.

FIGS. 95 E- 95 F illustrate front views of a back-facing flexibility assessment device in a triggered and untriggered state as described previously in relation to FIGS. 95 A- 95 D in accordance with some embodiments of the invention.

FIG. 95 G illustrates a front view of both back-facing and front-facing flexibility assessment devices as described previously in relation to FIGS. 95 A- 95 F in accordance with some embodiments of the invention.

FIG. 95 H illustrates a side view of both back-facing and front-facing flexibility assessment devices as described previously in relation to FIGS. 95 A- 95 G in accordance with some embodiments of the invention.

FIG. 95 I illustrates a cross-sectional view of a triggering mechanism of a handle of a flexibility assessment device as described previously in relation to FIGS. 95 A- 95 H in accordance with some embodiments of the invention.

FIG. 96 A illustrates a front view of both back-facing and front-facing flexibility assessment devices attached to an adjustable pedicle screw interface with accessory pedicle screw mounts in accordance with some embodiments of the invention.

FIG. 96 B illustrates a rear view of both back-facing and front-facing flexibility assessment devices attached to an adjustable pedicle screw interface with accessory pedicle screw mounts as described previously in relation to FIG. 96 A in accordance with some embodiments of the invention.

FIG. 96 C illustrates a perspective view of both back-facing and front-facing flexibility assessment devices attached to an adjustable pedicle screw interface with accessory pedicle screw mounts as described previously in relation to FIGS. 96 A- 96 B in accordance with some embodiments of the invention.

FIG. 96 D illustrates a side view of both back-facing and front-facing flexibility assessment devices attached to an adjustable pedicle screw interface with accessory pedicle screw mounts as described previously in relation to FIGS. 96 A- 96 C in accordance with some embodiments of the invention.

FIG. 96 E illustrates a top view of both back-facing and front-facing flexibility assessment devices attached to an adjustable pedicle screw interface with accessory pedicle screw mounts as described previously in relation to FIGS. 96 A- 96 D in accordance with some embodiments of the invention.

FIGS. 96 F- 96 H illustrate perspective views of an adjustable pedicle screw interface with embedded screw-mating fasteners and accessory pedicle screw mounts as described previously in relation to FIGS. 96 A- 96 E in accordance with some embodiments of the invention.

FIGS. 96 I- 96 J illustrate perspective views of an adjustable pedicle screw interface with embedded screw-mating fasteners and accessory pedicle screw mounts, with the pedicle screw interfaces of the side arms not engaged with a pedicle screw, as described previously in relation to FIGS. 96 A- 96 H in accordance with some embodiments of the invention.

FIGS. 96 K- 96 L illustrate exploded assembly views of an adjustable pedicle screw interface with embedded screw-mating fasteners and accessory pedicle screw mounts, with the pedicle screw interfaces of the distal end of the side arms containing a rod extension for mating with pedicle screw tulip heads, as described previously in relation to FIGS. 96 A- 96 J in accordance with some embodiments of the invention.

FIG. 96 M illustrates a perspective view of an adjustable pedicle screw interface with embedded screw-mating fasteners and accessory pedicle screw mounts, with the pedicle screw interfaces of the distal end of the side arms containing a rod extension for mating with pedicle screw tulip heads, as described previously in relation to FIGS. 96 A- 96 L in accordance with some embodiments of the invention.

FIG. 96 N illustrates a rear view of a back-facing flexibility assessment device in a triggered state with an adjustable pedicle screw interface as described previously in relation to FIGS. 96 A- 96 M in accordance with some embodiments of the invention.

FIG. 96 O illustrates a side view of both back-facing and front-facing flexibility assessment devices with adjustable pedicle screw interfaces that are substantially rigidly fixed in their relative orientations to one another while the devices are substantially rigidly engaged with vertebrae, as described previously in relation to FIGS. 96 A- 96 N in accordance with some embodiments of the invention.

FIG. 96 P illustrates a perspective view of both back-facing and front-facing flexibility assessment devices with adjustable pedicle screw interfaces that are substantially rigidly fixed in their relative orientations to one another, as described previously in relation to FIGS. 96 A- 960 in accordance with some embodiments of the invention.

FIG. 96 Q illustrates a side view of the bottom half side arm components of the flexibility assessment devices that are substantially rigidly linked to one another and engaged with the vertebrae, as described previously in relation to FIGS. 96 A- 96 P in accordance with some embodiments of the invention.

FIG. 96 R illustrates a perspective view of the bottom half side arm components of the flexibility assessment devices that are substantially rigidly linked to one another and engaged with the vertebrae, as described previously in relation to FIGS. 96 A- 96 Q in accordance with some embodiments of the invention.

FIG. 96 S illustrates a top view of the bottom half side arm components of the flexibility assessment devices that are substantially rigidly linked to one another and engaged with the vertebrae, as described previously in relation to FIGS. 96 A- 96 R in accordance with some embodiments of the invention.

FIGS. 97 A- 97 B illustrate side views of an extended side arm of a flexibility assessment device that is substantially rigidly attached and unattached to a pedicle screw in accordance with some embodiments of the invention.

FIG. 97 C illustrates a top view of an extended side arm of a flexibility assessment device as described previously in relation to FIGS. 97 A- 97 B in accordance with some embodiments of the invention.

FIGS. 97 D- 97 E illustrate cross-sectional views of an extended side arm of a flexibility assessment device that is substantially rigidly attached to pedicle screw as described previously in relation to FIGS. 97 A- 97 C in accordance with some embodiments of the invention.

FIG. 97 F illustrates an exploded assembly view of extended, adjustable screw interfaces of the flexibility assessment device that are substantially rigidly attached to pedicle screws as described previously in relation to FIGS. 97 A- 97 E in accordance with some embodiments of the invention.

FIG. 97 G illustrates a side view of extended, adjustable screw interfaces of the flexibility assessment devices that are substantially rigidly attached to pedicle screws as described previously in relation to FIGS. 97 A- 97 F in accordance with some embodiments of the invention.

FIG. 97 H illustrates a perspective view of extended, adjustable screw interfaces of the flexibility assessment devices that are substantially rigidly attached to pedicle screws as described previously in relation to FIGS. 97 A- 97 G in accordance with some embodiments of the invention.

FIG. 97 I illustrates a side view of extended, adjustable screw interfaces of the flexibility assessment devices that are substantially rigidly attached to pedicle screws as described previously in relation to FIGS. 97 A- 97 H in accordance with some embodiments of the invention.

FIG. 97 J illustrates a front view of extended, adjustable screw interfaces of the flexibility assessment devices that are substantially rigidly attached to pedicle screws as described previously in relation to FIGS. 97 A- 97 I in accordance with some embodiments of the invention.

FIG. 97 K illustrates a top view of extended, adjustable screw interfaces of the flexibility assessment devices that are substantially rigidly attached to pedicle screws as described previously in relation to FIGS. 97 A- 97 J in accordance with some embodiments of the invention.

FIG. 97 L illustrates a rear view of extended, adjustable screw interfaces of the flexibility assessment devices that are substantially rigidly attached to pedicle screws as described previously in relation to FIGS. 97 A- 97 K in accordance with some embodiments of the invention.

FIGS. 98 A- 98 B illustrate front views of a rod contour registration tool in an active and inactive triggering state in accordance with some embodiments of the invention.

FIG. 98 C illustrates a side view of a rod contour registration tool as described previously in relation to FIGS. 98 A- 98 B in accordance with some embodiments of the invention.

FIG. 98 D illustrates a perspective view of a rod contour registration tool as described previously in relation to FIGS. 98 A- 98 C in accordance with some embodiments of the invention.

FIGS. 98 E- 98 F illustrate perspective views of a triggering mechanism of a rod contour registration tool as described previously in relation to FIGS. 98 A- 98 D in accordance with some embodiments of the invention.

FIG. 98 G illustrates a side view of a triggering mechanism of a rod contour registration tool as described previously in relation to FIGS. 98 A- 98 F in accordance with some embodiments of the invention.

FIG. 98 H illustrates a side view of a coordinate reference tool in an inactive triggered state as described previously in relation to FIGS. 98 A- 98 G in accordance with some embodiments of the invention.

FIG. 98 I illustrates a side view of a coordinate reference tool in an active triggered state as described previously in relation to FIGS. 98 A- 98 H in accordance with some embodiments of the invention.

FIG. 98 J illustrates a front view of a coordinate reference tool in an inactive triggered state as described previously in relation to FIGS. 98 A- 98 I in accordance with some embodiments of the invention.

FIG. 98 K illustrates a front view of a coordinate reference tool in an active triggered state as described previously in relation to FIGS. 98 A- 98 J in accordance with some embodiments of the invention.

FIG. 98 L illustrates a side view of a coordinate reference tool in an inactive triggered state as described previously in relation to FIGS. 98 A- 98 K in accordance with some embodiments of the invention.

FIG. 98 M illustrates a side view of a coordinate reference tool in an active triggered state as described previously in relation to FIGS. 98 A- 98 L in accordance with some embodiments of the invention.

FIG. 98 N illustrates a cross-sectional view of a coordinate reference tool in an inactive triggered state as described previously in relation to FIGS. 98 A- 98 M in accordance with some embodiments of the invention.

FIGS. 98 O- 98 S illustrate perspective views of a rod attached to a coordinate reference tool and a rod contour registration tool engaged with the rod as described previously in relation to FIGS. 98 A- 98 N in accordance with some embodiments of the invention.

FIGS. 98 T- 98 V illustrate perspective views of a rod contour registration tool with a reversible DRF-mounting mechanism as described previously in relation to FIGS. 98 A- 98 S in accordance with some embodiments of the invention.

FIG. 99 A illustrates a front view of a rod contour registration tool attachment in an inactive triggering state in accordance with some embodiments of the invention.

FIG. 99 B illustrates a front view of a rod contour registration tool attachment in an active triggering state as described previously in relation to FIG. 99 A in accordance with some embodiments of the invention.

FIG. 99 C illustrates a perspective view of a rod contour registration tool attachment in an inactive triggering state as described previously in relation to FIGS. 99 A- 99 B in accordance with some embodiments of the invention.

FIG. 99 D illustrates a side view of a rod contour registration tool attachment as described previously in relation to FIGS. 99 A- 99 C in accordance with some embodiments of the invention.

FIGS. 99 E- 99 F illustrate rear views of a rod bender with a rod contour registration tool attachment mounted onto the rod bender as described previously in relation to FIGS. 99 A- 99 D in accordance with some embodiments of the invention.

FIGS. 99 G- 99 H illustrate back perspective views of a rod bender with a rod contour registration tool attachment mounted onto the rod bender as described previously in relation to FIGS. 99 A- 99 F in accordance with some embodiments of the invention.

FIGS. 99 I- 99 J illustrate side views of a rod bender with a rod contour registration tool attachment mounted onto the rod bender, with the trigger in an active and inactive state as described previously in relation to FIGS. 99 A- 99 H in accordance with some embodiments of the invention.

FIGS. 99 K- 99 L illustrate perspective views of a rod bender with a rod contour registration tool attachment mounted onto the rod bender, with the rod bender actively contouring a rod mounted to a coordinate reference tool, as described previously in relation to FIGS. 99 A- 99 J in accordance with some embodiments of the invention.

FIGS. 99 M- 99 N illustrate perspective views of a rod bender with a rod contour registration tool attachment mounted onto the rod bender, with the rod bender attachment actively tracing the contour of a rod mounted to a coordinate reference tool, as described previously in relation to FIGS. 99 A- 99 L in accordance with some embodiments of the invention.

FIG. 99 O illustrates a side view of a rod bender with a rod contour registration tool attachment mounted onto the rod bender, with the rod bender attachment actively tracing the contour of a rod mounted to a coordinate reference tool, as described previously in relation to FIGS. 99 A- 99 N in accordance with some embodiments of the invention.

FIG. 100 A illustrates a rear view of a 3D-tracked tool with a rotational triggering mechanism and the tool in an inactive state in accordance with some embodiments of the invention.

FIG. 100 B illustrates a side view of a 3D-tracked tool with a rotational triggering mechanism and the tool in an inactive state, as described previously in relation to FIG. 100 A in accordance with some embodiments of the invention.

FIG. 100 C illustrates a front view of a 3D-tracked tool with a rotational triggering mechanism and the tool in an inactive state, as described previously in relation to FIGS. 100 A- 100 B in accordance with some embodiments of the invention.

FIG. 100 D illustrates a rear view of a 3D-tracked tool with a rotational triggering mechanism and the tool in an active state, as described previously in relation to FIGS. 100 A- 100 C in accordance with some embodiments of the invention.

FIG. 100 E illustrates a side view of a 3D-tracked tool with a rotational triggering mechanism and the tool in an active state, as described previously in relation to FIGS. 100 A- 100 D in accordance with some embodiments of the invention.

FIG. 100 F illustrates a front view of a 3D-tracked tool with a rotational triggering mechanism and the tool in an active state, as described previously in relation to FIGS. 100 A- 100 E in accordance with some embodiments of the invention.

FIG. 101 A illustrates a front view of a 3D-tracked tool with a linear triggering mechanism and the tool in an inactive state in accordance with some embodiments of the invention.

FIG. 101 B illustrates a front view of a 3D-tracked tool with a linear triggering mechanism and the tool in an active state, as described previously in relation to FIG. 101 A in accordance with some embodiments of the invention.

FIG. 101 C illustrates a rear view of a 3D-tracked tool with a linear triggering mechanism and the tool in an inactive state, as described previously in relation to FIGS. 101 A- 101 B in accordance with some embodiments of the invention.

FIG. 101 D illustrates a rear view of a 3D-tracked tool with a linear triggering mechanism and the tool in an active state, as described previously in relation to FIGS. 101 A- 101 C in accordance with some embodiments of the invention.

FIG. 101 E illustrates a cross-sectional view of a 3D-tracked tool with a linear triggering mechanism and the tool in an inactive state, as described previously in relation to FIGS. 101 A- 101 D in accordance with some embodiments of the invention.

FIG. 101 F illustrates a cross-sectional view of a 3D-tracked tool with a linear triggering mechanism and the tool in an active state, as described previously in relation to FIGS. 101 A- 101 E in accordance with some embodiments of the invention.

FIG. 101 G illustrates a front view of a 3D-tracked tool without a trigger sleeve and with a linear triggering mechanism (oriented for a left-hand-dominant user) and the tool in an inactive state, as described previously in relation to FIGS. 101 A- 101 F in accordance with some embodiments of the invention.

FIG. 101 H illustrates a rear view of a 3D-tracked tool without a trigger sleeve and with a linear triggering mechanism (oriented for a left-hand-dominant user) and the tool in an inactive state, as described previously in relation to FIGS. 101 A- 101 G in accordance with some embodiments of the invention.

FIG. 101 I illustrates a side view of a 3D-tracked tool with a linear triggering mechanism and the tool in an inactive state, as described previously in relation to FIGS. 101 A- 101 H in accordance with some embodiments of the invention.

FIG. 101 J illustrates a side view of a 3D-tracked tool with a linear triggering mechanism and the tool in an active state, as described previously in relation to FIGS. 101 A- 101 I in accordance with some embodiments of the invention.

FIG. 101 K illustrates an assembly view of a 3D-tracked tool with a linear triggering mechanism as described previously in relation to FIGS. 101 A- 101 J in accordance with some embodiments of the invention.

FIGS. 101 L- 101 O illustrate perspective views of a trigger sleeve of a 3D-tracked tool with a linear triggering mechanism as described previously in relation to FIGS. 101 A- 101 K in accordance with some embodiments of the invention.

FIG. 101 P illustrates an assembly view of a 3D-tracked tool with a linear triggering mechanism, with the trigger sleeve oriented for a left-hand-dominant user, as described previously in relation to FIGS. 101 A- 101 O in accordance with some embodiments of the invention.

FIG. 101 Q illustrates an assembly view of a 3D-tracked tool with a linear triggering mechanism, with the trigger sleeve oriented for a right-hand-dominant user, as described previously in relation to FIGS. 101 A- 101 P in accordance with some embodiments of the invention.

FIG. 102 A illustrates a side view of a 3D-tracked tool engaged with an external-mating bone-mounted fiducial in accordance with some embodiments of the invention.

FIG. 102 B illustrates a rear view of a 3D-tracked tool engaged with an external-mating bone-mounted fiducial as described previously in relation to FIG. 102 A in accordance with some embodiments of the invention.

FIG. 102 C illustrates a side view of a 3D-tracked tool engaged with an external-mating bone-mounted fiducial as described previously in relation to FIGS. 102 A- 102 B in accordance with some embodiments of the invention.

FIG. 102 D illustrates a perspective assembly view of a 3D-tracked tool that is not engaged with an external-mating bone-mounted fiducial as described previously in relation to FIGS. 102 A- 102 C in accordance with some embodiments of the invention.

FIG. 102 E illustrates a side assembly view of a 3D-tracked tool that is not engaged with an external-mating bone-mounted fiducial as described previously in relation to FIGS. 102 A- 102 D in accordance with some embodiments of the invention.

FIG. 102 F illustrates a front assembly view of a 3D-tracked tool that is not engaged with an external-mating bone-mounted fiducial as described previously in relation to FIGS. 102 A- 102 E in accordance with some embodiments of the invention.

FIG. 102 G illustrates a perspective view of an external-mating bone-mounted fiducial as described previously in relation to FIGS. 102 A- 102 F in accordance with some embodiments of the invention.

FIG. 102 H illustrates a side view of an external-mating bone-mounted fiducial as described previously in relation to FIGS. 102 A- 102 G in accordance with some embodiments of the invention.

FIG. 102 I illustrates a perspective view of an external-mating bone-mounted fiducial as described previously in relation to FIGS. 102 A- 102 H in accordance with some embodiments of the invention.

FIG. 102 J illustrates a top view of an external-mating bone-mounted fiducial as described previously in relation to FIGS. 102 A- 102 I in accordance with some embodiments of the invention.

FIG. 102 K illustrates a side view of an external-mating bone-mounted fiducial as described previously in relation to FIGS. 102 A- 102 J in accordance with some embodiments of the invention.

FIG. 102 L illustrates a perspective view of an external-mating bone-mounted fiducial as described previously in relation to FIGS. 102 A- 102 K in accordance with some embodiments of the invention.

FIG. 102 M illustrates a perspective view of a 3D-tracked tool that is not engaged with an external-mating bone-mounted fiducial, as described previously in relation to FIGS. 102 A- 102 L in accordance with some embodiments of the invention.

FIG. 102 N illustrates a cross-sectional view of a 3D-tracked tool's triggering mechanism for engaging with an external-mating bone-mounted fiducial, as described previously in relation to FIGS. 102 A- 102 M in accordance with some embodiments of the invention.

FIGS. 102 O- 102 P illustrate assembly views of a 3D-tracked tool that mates with an external-mating bone-mounted fiducial, as described previously in relation to FIGS. 102 A- 102 N in accordance with some embodiments of the invention.

FIG. 103 A illustrates a front view of a 3D-tracked tool that mates with an internal-mating bone-mounted fiducial in accordance with some embodiments of the invention.

FIG. 103 B illustrates a side view of a 3D-tracked tool that mates with an internal-mating bone-mounted fiducial, as described previously in relation to FIG. 103 A in accordance with some embodiments of the invention.

FIG. 103 C illustrates a rear view of a 3D-tracked tool that mates with an internal-mating bone-mounted fiducial, as described previously in relation to FIGS. 103 A- 103 B in accordance with some embodiments of the invention.

FIGS. 103 D- 103 F illustrate perspective views of a 3D-tracked tool that mates with an internal-mating bone-mounted fiducial, as shown in its various mating trigger states, as described previously in relation to FIGS. 103 A- 103 C in accordance with some embodiments of the invention.

FIG. 103 G illustrates a front view of a 3D-tracked tool that mates with an internal-mating bone-mounted fiducial, as shown with both devices fully mated, as described previously in relation to FIGS. 103 A- 103 F in accordance with some embodiments of the invention.

FIG. 103 H illustrates a side view of a 3D-tracked tool that mates with an internal-mating bone-mounted fiducial, as shown with both devices fully mated, as described previously in relation to FIGS. 103 A- 103 G in accordance with some embodiments of the invention.

FIG. 103 I illustrates a rear view of a 3D-tracked tool that mates with an internal-mating bone-mounted fiducial, as shown with both devices fully mated, as described previously in relation to FIGS. 103 A- 103 H in accordance with some embodiments of the invention.

FIG. 103 J illustrates a perspective view of an internal-mating bone-mounted fiducial's assembly components as described previously in relation to FIGS. 103 A- 103 I in accordance with some embodiments of the invention.

FIG. 103 K illustrates a side view of an internal-mating bone-mounted fiducial, as described previously in relation to FIGS. 103 A- 103 J in accordance with some embodiments of the invention.

FIGS. 103 L- 103 O illustrate perspective views of an internal-mating bone-mounted fiducial, as described previously in relation to FIGS. 103 A- 103 K in accordance with some embodiments of the invention.

FIG. 103 P illustrates a bottom view of a 3D-tracked tool that mates with an internal-mating bone-mounted fiducial, as described previously in relation to FIGS. 103 A- 103 O in accordance with some embodiments of the invention.

FIG. 103 Q illustrates a perspective view of a 3D-tracked tool that mates with an internal-mating bone-mounted fiducial, as described previously in relation to FIGS. 103 A- 103 P in accordance with some embodiments of the invention.

FIG. 104 A illustrates a front view of a 3D-tracked tool that mates with a fastener with a depth-stop interface, with the devices not mated as shown, in accordance with some embodiments of the invention.

FIG. 104 B illustrates a side view of a 3D-tracked tool that mates with a fastener with a depth-stop interface, with the devices not mated as shown, as described previously in relation to FIG. 104 A in accordance with some embodiments of the invention.

FIG. 104 C illustrates a rear view of a 3D-tracked tool that mates with a fastener with a depth-stop interface, with the devices not mated as shown, as described previously in relation to FIGS. 104 A- 104 B in accordance with some embodiments of the invention.

FIG. 104 D illustrates a front view of a 3D-tracked tool that mates with a fastener with a depth-stop interface, with the devices mated as shown, as described previously in relation to FIGS. 104 A- 104 C in accordance with some embodiments of the invention.

FIG. 104 E illustrates a side view of a 3D-tracked tool that mates with a fastener with a depth-stop interface, with the devices mated as shown, as described previously in relation to FIGS. 104 A- 104 D in accordance with some embodiments of the invention.

FIG. 104 F illustrates a rear view of a 3D-tracked tool that mates with a fastener with a depth-stop interface, with the devices mated as shown, as described previously in relation to FIGS. 104 A- 104 E in accordance with some embodiments of the invention.

FIG. 104 G illustrates a perspective view of a 3D-tracked tool that mates with a fastener with a depth-stop interface, with the devices not mated as shown, as described previously in relation to FIGS. 104 A- 104 F in accordance with some embodiments of the invention.

FIG. 104 H illustrates a perspective view of a mating interfaces between a 3D-tracked tool and a fastener with a depth-stop interface, with the devices not mated as shown, as described previously in relation to FIGS. 104 A- 104 G in accordance with some embodiments of the invention.

FIG. 104 I illustrates a perspective view of a 3D-tracked tool that mates with a fastener with a depth-stop interface, with the devices mated as shown, as described previously in relation to FIGS. 104 A- 104 H in accordance with some embodiments of the invention.

FIG. 104 J illustrates a side view of a 3D-tracked tool that mates with a fastener with a depth-stop interface, with the devices mated and engaged to a vertebra with an implanted rod as shown, as described previously in relation to FIGS. 104 A- 104 I in accordance with some embodiments of the invention.

FIG. 105 A illustrates a perspective view of an adjustable pedicle screw interface base, with one fixed side arm and one side arm with height and angle adjustments, and with the device mated with a fastener with depth-stop mating interfaces, of a flexibility assessment device in accordance with some embodiments of the invention.

FIG. 105 B illustrates a front view of an adjustable pedicle screw interface base, with one fixed side arm and one side arm with height and angle adjustments, and with the device mated with a fastener with depth-stop mating interfaces, of a flexibility assessment device as described previously in relation to FIG. 105 A in accordance with some embodiments of the invention.

FIG. 105 C illustrates a rear view of an adjustable pedicle screw interface base, with one fixed side arm and one side arm with height and angle adjustments, and with the device mated with a fastener with depth-stop mating interfaces, of a flexibility assessment device as described previously in relation to FIGS. 105 A- 105 B in accordance with some embodiments of the invention.

FIG. 105 D illustrates a top view of an adjustable pedicle screw interface base, with one fixed side arm and one side arm with height and angle adjustments, and with the device mated with a fastener with depth-stop mating interfaces, of a flexibility assessment device as described previously in relation to FIGS. 105 A- 105 C in accordance with some embodiments of the invention.

FIG. 105 E illustrates a side view of an adjustable pedicle screw interface base, with one fixed side arm and one side arm with height and angle adjustments, and with the device mated with a fastener with depth-stop mating interfaces, of a flexibility assessment device as described previously in relation to FIGS. 105 A- 105 D in accordance with some embodiments of the invention.

FIG. 105 F illustrates a perspective view of an adjustable pedicle screw interface base, with one fixed side arm and one side arm with height and angle adjustments, and with the device mated with one of the displayed fasteners with depth-stop mating interfaces, of a flexibility assessment device as described previously in relation to FIGS. 105 A- 105 E in accordance with some embodiments of the invention.

FIG. 105 G illustrates a perspective view of flexibility assessment devices with adjustable pedicle screw interface bases, with the devices mated with fasteners with depth-stop mating interfaces, the engaged vertebrae substantially rigidly linked via an implanted rod, and the devices substantially rigidly linked via an accessory rod between the screw interface bases, as described previously in relation to FIGS. 105 A- 105 F in accordance with some embodiments of the invention.

FIG. 106 A illustrates a perspective view of a coordinate reference end cap device with a lockable trigger tab in accordance with some embodiments of the invention.

FIG. 106 B illustrates a rear view of a coordinate reference end cap device with a lockable trigger tab, as described previously in relation to FIG. 106 A in accordance with some embodiments of the invention.

FIG. 106 C illustrates a top view of a coordinate reference end cap device with a lockable trigger tab, as described previously in relation to FIGS. 106 A- 106 B in accordance with some embodiments of the invention.

FIG. 106 D illustrates a side cross-sectional view of a coordinate reference end cap device with a lockable trigger tab in its active locking state, as described previously in relation to FIGS. 106 A- 106 C in accordance with some embodiments of the invention.

FIG. 106 E illustrates a side cross-sectional view of a coordinate reference end cap device with a lockable trigger tab in its inactive locking state, as described previously in relation to FIGS. 106 A- 106 D in accordance with some embodiments of the invention.

FIG. 106 F illustrates an assembly view of a coordinate reference end cap device with a lockable trigger tab, as described previously in relation to FIGS. 106 A- 106 E in accordance with some embodiments of the invention.

FIG. 107 A illustrates a display interface for analyzing the contour of patient and illustrating spinal alignment parameters from landmarks of interest, as well as a trackpad display-controlling interface in its active state, in accordance with some embodiments of the invention.

FIG. 107 B illustrates a display interface for analyzing the contour of patient and illustrating spinal alignment parameters from landmarks of interest, as well as a trackpad display-controlling interface in its inactive state, as described previously in relation to FIG. 107 A in accordance with some embodiments of the invention.

FIG. 107 C illustrates a display interface for analyzing the contour of patient and illustrating spinal alignment parameters from landmarks of interest, as well as a trackpad display-controlling interface and overlays of several contour acquisitions, as described previously in relation to FIGS. 107 A- 107 B in accordance with some embodiments of the invention.

FIG. 107 D illustrates a display interface for analyzing the contour of patient and illustrating spinal alignment parameters from landmarks of interest, as well as a trackpad display-controlling interface, overlays of several contour acquisitions, and the latest contour's measurements, as described previously in relation to FIGS. 107 A- 107 C in accordance with some embodiments of the invention.

FIG. 108 A illustrates a display interface for analyzing the position and orientation of flexibility assessment devices in accordance with some embodiments of the invention.

FIGS. 108 B- 108 D illustrate a display interface for analyzing the position and orientation of flexibility assessment devices, with the devices in their active triggering state and displaying the range of the motion of engaged vertebrae across all anatomical planes, as described previously in relation to FIG. 108 A in accordance with some embodiments of the invention.

FIG. 108 E illustrates a display interface for analyzing the position and orientation of flexibility assessment devices, with the devices in their active triggering state and displaying a rendered view of each engaged vertebra, as described previously in relation to FIGS. 108 A- 108 D in accordance with some embodiments of the invention.

FIGS. 108 F- 108 H illustrate a display interface for analyzing the position and orientation of flexibility assessment devices, displaying a summary view across all anatomical planes of the exhibited range of motion of engaged vertebrae during an assessment, as described previously in relation to FIGS. 108 A- 108 E in accordance with some embodiments of the invention.

FIG. 109 A illustrates a display interface for displaying the live location of devices used for the registration of a rod contour in accordance with some embodiments of the invention.

FIG. 109 B illustrates a display interface for displaying the live location of devices used for the registration of a rod contour and a completed tracing of the rod's contour as described previously in relation to FIG. 109 A in accordance with some embodiments of the invention.

FIGS. 109 C- 109 D illustrate a display interface with patient images and the overlay of a registered rod contour that has been adjusted to match the user's goal for the patient's contour, as described previously in relation to FIGS. 109 A- 109 B in accordance with some embodiments of the invention.

FIGS. 110 A- 110 B illustrate a workflow for adjusting the positions of vertebral holders for an adjustable model holder with inputs from patient imaging in accordance with some embodiments of the invention.

FIGS. 111 A- 111 C illustrate a workflow for analyzing and outputting the range of motion results of engaged vertebrae during and after a flexibility assessment in accordance with some embodiments of the invention.

FIGS. 112 A- 112 C illustrate a workflow for registering and overlaying the contour of a rod and subsequent contours of adjusted rods in accordance with some embodiments of the invention.

FIG. 113 illustrates a workflow for filtering stray markers outputted by a 3D-tracking camera, identifying the TMSM(s) of DRF-equipped tools with triggering mechanisms, and analyzing if the TMSMs are in an active triggering state, in accordance with some embodiments of the invention.

FIGS. 114 A- 114 F illustrate a workflow for estimating the contour of a rod during and after it is bent in accordance with some embodiments of the invention.

FIG. 115 A illustrates a front view of a rod contour and roller surfaces of a rod bender in accordance with some embodiments of the invention.

FIGS. 115 B- 115 C illustrate a front view of a rod contour and roller surfaces of a rod bender during the process of contouring an engaged rod, as described previously in relation to FIG. 115 A in accordance with some embodiments of the invention.

FIG. 115 D illustrates a front, close-up view of an adjusted, segmented rod contour against the center rod-contouring surface of a rod bender, as described previously in relation to FIGS. 115 A- 115 C in accordance with some embodiments of the invention.

FIG. 115 E illustrates a front view of an adjusted rod contour with estimated contour corrections while engaged with the center rod-contouring surface of a rod bender, as described previously in relation to FIGS. 115 A- 115 D in accordance with some embodiments of the invention.

FIG. 115 F illustrates a front, close-up view of an adjusted rod contour with estimated contour corrections while engaged with the center rod-contouring surface of a rod bender, as described previously in relation to FIGS. 115 A- 115 E in accordance with some embodiments of the invention.

FIG. 116 A illustrates a perspective view of a skin-mounted fiducial assembly in accordance with some embodiments of the invention.

FIG. 116 B illustrates a side view of a disengaged skin-mounted fiducial assembly as described previously in relation to FIG. 116 A in accordance with some embodiments of the invention.

FIG. 116 C illustrates a side view of an engaged skin-mounted fiducial assembly as described previously in relation to FIGS. 116 A- 116 B in accordance with some embodiments of the invention.

FIG. 116 D illustrates a side, cross-sectional view of an engaged skin-mounted fiducial assembly with an embedded radiopaque sphere as described previously in relation to FIGS. 116 A- 116 C in accordance with some embodiments of the invention.

FIG. 116 E illustrates a bottom view of the top skin-mounted fiducial with five asymmetrically distributed holes for embedding radiopaque spheres as described previously in relation to FIGS. 116 A- 116 D in accordance with some embodiments of the invention.

FIG. 116 F illustrates a cross-sectional view of the top skin-mounted fiducial as described previously in relation to FIGS. 116 A- 116 E in accordance with some embodiments of the invention.

FIG. 116 G illustrates an exploded view of the top skin-mounted fiducial, radiopaque spheres, a surgical drape, and bottom skin-mounted fiducial as described previously in relation to FIGS. 116 A- 116 F in accordance with some embodiments of the invention.

FIG. 116 H illustrates an exploded view of the top skin-mounted fiducial with embedded radiopaque spheres, a surgical drape, and bottom skin-mounted fiducial as described previously in relation to FIGS. 116 A- 116 G in accordance with some embodiments of the invention.

FIG. 116 I illustrates a perspective view of the skin-fiducial assembled over the surgical drape and disengaged as described previously in relation to FIGS. 116 A- 116 H in accordance with some embodiments of the invention.

FIG. 116 J illustrates a perspective view of a 3D-tracked tool with a tool ball-tip adapter engaged with the “Z-pattern” of the skin-mounted fiducial assembly as described previously in relation to FIGS. 116 A- 116 I in accordance with some embodiments of the invention.

FIG. 117 A illustrates a perspective view of an internal-mating bone-mounted fiducial in accordance with some embodiments of the invention.

FIG. 117 B illustrates a top view of an internal-mating bone-mounted fiducial as described previously in relation to FIG. 117 A in accordance with some embodiments of the invention.

FIG. 117 C illustrates perspective views of an internal-mating bone-mounted fiducial and external-mating tool tip adapter of a 3D-tracked tool as described previously in relation to FIGS. 117 A- 117 B in accordance with some embodiments of the invention.

FIG. 117 D illustrates perspective views of a 3D-tracked tool with an external-mating tool tip adapter not engaged with an internal-mating bone-mounted fiducial as described previously in relation to FIGS. 117 A- 117 C in accordance with some embodiments of the invention.

FIG. 117 E illustrates perspective views of a 3D-tracked tool with an external-mating tool tip adapter engaged with an internal-mating bone-mounted fiducial as described previously in relation to FIGS. 117 A- 117 D in accordance with some embodiments of the invention.

FIG. 117 F illustrates perspective views of a 3D-tracked tool with an external-mating tool tip adapter not engaged with an internal-mating bone-mounted fiducial implanted into the sacrum and in an untriggered state as described previously in relation to FIGS. 117 A- 117 E in accordance with some embodiments of the invention.

FIG. 117 G illustrates perspective views of a 3D-tracked tool with an external-mating tool tip adapter engaged with an internal-mating bone-mounted fiducial implanted into the sacrum and in a triggered state as described previously in relation to FIGS. 117 A- 117 F in accordance with some embodiments of the invention.

FIG. 117 H illustrates a coronal plane view of the spine with bone-mounted fiducials implanted into the sacrum and several laminae as described in relation to FIGS. 117 A- 117 G in accordance with some embodiments of the invention.

FIG. 117 I illustrates perspective views of a 3D-tracked tool with an external-mating tool tip adapter not engaged with internal-mating bone-mounted fiducials implanted into the sacrum and laminae and in an untriggered state as described previously in relation to FIGS. 117 A- 117 H in accordance with some embodiments of the invention.

FIG. 117 J illustrates perspective views of a 3D-tracked tool with an external-mating tool tip adapter engaged with internal-mating bone-mounted fiducials implanted into the sacrum and laminae and in a triggered state as described previously in relation to FIGS. 117 A- 117 I in accordance with some embodiments of the invention.

FIG. 118 A illustrates a perspective view of an external-mating bone-mounted fiducial in accordance with some embodiments of the invention.

FIG. 118 B illustrates a top view of an external-mating bone-mounted fiducial as described previously in relation to FIG. 118 A in accordance with some embodiments of the invention.

FIG. 118 C illustrates perspective views of an external-mating bone-mounted fiducial and internal-mating tool tip adapter of a 3D-tracked tool as described previously in relation to FIGS. 118 A- 118 B in accordance with some embodiments of the invention.

FIG. 118 D illustrates a front view of a 3D-tracked tool with an internal-mating tool tip adapter not engaged with an external-mating bone-mounted fiducial and in an untriggered state as described previously in relation to FIGS. 118 A- 118 C in accordance with some embodiments of the invention.

FIG. 118 E illustrates frontal views of a 3D-tracked tool with an internal-mating tool tip adapter engaged with an external-mating bone-mounted fiducial and in an untriggered state as described previously in relation to FIGS. 118 A- 118 D in accordance with some embodiments of the invention.

FIG. 118 F illustrates frontal views of a 3D-tracked tool with an internal-mating tool tip adapter engaged with an external-mating bone-mounted fiducial and in a triggered state as described previously in relation to FIGS. 118 A- 118 E in accordance with some embodiments of the invention.

FIG. 118 G illustrates perspective views of a 3D-tracked tool with an internal-mating tool tip adapter not engaged with an external-mating bone-mounted fiducial and in an untriggered state as described previously in relation to FIGS. 118 A- 118 F in accordance with some embodiments of the invention.

FIG. 118 H illustrates perspective views of a 3D-tracked tool with an internal-mating tool tip adapter engaged with an external-mating bone-mounted fiducial and in an untriggered state as described previously in relation to FIGS. 118 A- 118 G in accordance with some embodiments of the invention.

FIG. 118 I illustrates perspective views of a 3D-tracked tool with an internal-mating tool tip adapter engaged with an external-mating bone-mounted fiducial and in a triggered state as described previously in relation to FIGS. 118 A- 118 H in accordance with some embodiments of the invention.

FIG. 119 A illustrates a top perspective view of an external-mating bone-mounted fiducial attached to a single-screw plate in accordance with some embodiments of the invention.

FIG. 119 B illustrates a bottom perspective view of an external-mating bone-mounted fiducial attached to a single-screw plate as described previously in relation to FIG. 119 A in accordance with some embodiments of the invention.

FIG. 119 C illustrates a top view of an external-mating bone-mounted fiducial attached to a single-screw plate as described previously in relation to FIGS. 119 A- 119 B in accordance with some embodiments of the invention.

FIG. 119 D illustrates a side view of an external-mating bone-mounted fiducial attached to single-screw plate as described previously in relation to FIGS. 119 A- 119 C in accordance with some embodiments of the invention.

FIG. 119 E illustrates a front view of an external-mating bone-mounted fiducial attached to single-screw plate as described previously in relation to FIGS. 119 A- 119 D in accordance with some embodiments of the invention.

FIG. 119 F illustrates perspective views of an external-mating bone-mounted fiducial attached to a single-screw plate and an internal-mating tool tip adapter of a 3D-tracked tool as described previously in relation to FIGS. 119 A- 119 E in accordance with some embodiments of the invention.

FIG. 119 G illustrates a front view of a 3D-tracked tool with internal-mating tool tip adapter not engaged with an external-mating bone-mounted fiducial attached to a single-screw plate and in an untriggered state as described previously in relation to FIGS. 119 A- 119 F in accordance with some embodiments of the invention.

FIG. 119 H illustrates a side view of a 3D-tracked tool with internal-mating tool tip adapter engaged with an external-mating bone-mounted fiducial attached to a single-screw plate and in an untriggered state as described previously in relation to FIGS. 119 A- 119 G in accordance with some embodiments of the invention.

FIG. 119 I illustrates a side view of a 3D-tracked tool with internal-mating tool tip adapter engaged with an external-mating bone-mounted fiducial attached to a single-screw plate and in a triggered state as described previously in relation to FIGS. 119 A- 119 H in accordance with some embodiments of the invention.

FIG. 119 J illustrates a perspective view of a 3D-tracked tool with internal-mating tool tip adapter not engaged with an external-mating bone-mounted fiducial attached to a single-screw plate and in an untriggered state as described previously in relation to FIGS. 119 A- 119 I in accordance with some embodiments of the invention.

FIG. 119 K illustrates a perspective view of a 3D-tracked tool with internal-mating tool tip adapter engaged with an external-mating bone-mounted fiducial attached to a single-screw plate and in a triggered state as described previously in relation to FIGS. 119 A- 119 . 1 in accordance with some embodiments of the invention.

FIG. 120 A illustrates a top perspective view of an internal-mating bone-mounted fiducial attached to a single-screw plate in accordance with some embodiments of the invention.

FIG. 120 B illustrates a side view of an internal-mating bone-mounted fiducial as described previously in relation to FIG. 120 A in accordance with some embodiments of the invention.

FIG. 120 C illustrates a top view of an internal-mating bone-mounted fiducial as described previously in relation to FIGS. 120 A- 120 B in accordance with some embodiments of the invention.

FIG. 120 D illustrates perspective views of an internal-mating bone-mounted fiducial attached to single-screw plate and an external-mating tool tip adapter of a 3D-tracked tool as described previously in relation to FIGS. 120 A- 120 C in accordance with some embodiments of the invention.

FIG. 120 E illustrates perspective views of an internal-mating bone-mounted fiducial attached to a single-screw plate engaged with an external-mating tool tip adapter of a 3D-tracked tool as described previously in relation to FIGS. 120 A- 120 D in accordance with some embodiments of the invention.

FIG. 120 F illustrates a perspective view of a 3D-tracked tool with external-mating tool tip adapter disengaged with an internal-mating bone-mounted fiducial attached to a single-screw plate and in an untriggered state as described previously in relation to FIGS. 120 A- 120 E in accordance with some embodiments of the invention.

FIG. 120 G illustrates a perspective view of a 3D-tracked tool with external-mating tool tip adapter engaged with an internal-mating bone-mounted fiducial attached to a single-screw plate and in an untriggered state as described previously in relation to FIGS. 120 A- 120 F in accordance with some embodiments of the invention.

FIG. 120 H illustrates a perspective view of a 3D-tracked tool with external-mating tool tip adapter engaged with an internal-mating bone-mounted fiducial attached to a single-screw plate and in a triggered state as described previously in relation to FIGS. 120 A- 120 G in accordance with some embodiments of the invention.

FIG. 121 A illustrates a perspective view of an external-mating bone-mounted fiducial X-Ray adapter with asymmetrically distributed holes for embedding radiopaque spheres in accordance with some embodiments of the invention.

FIG. 121 B illustrates a front view of an external-mating bone-mounted fiducial X-Ray adapter with asymmetrically distributed holes for embedding radiopaque spheres as described previously in relation to FIG. 121 A in accordance with some embodiments of the invention.

FIG. 121 C illustrates a side view of an external-mating bone-mounted fiducial X-Ray adapter with asymmetrically distributed holes for embedding radiopaque spheres as described previously in relation to FIGS. 121 A- 121 B in accordance with some embodiments of the invention.

FIGS. 121 D- 121 F illustrate perspective views of an external-mating bone-mounted fiducial X-Ray adapter embedded with asymmetrically distributed radiopaque spheres disengaged and engaged with an internal-mating bone-mounted fiducial implanted into the sacrum as described previously in relation to FIGS. 121 A- 121 C in accordance with some embodiments of the invention.

FIG. 121 G illustrates an X-Ray image taken from a lateral view visualizing the pelvis and asymmetrically distributed radiopaque spheres of the bone-mounted fiducial X-Ray adapter as described previously in relation to FIGS. 121 A- 121 F in accordance with some embodiments of the invention.

FIG. 121 H illustrates an X-Ray image taken from an AP view visualizing the pelvis and asymmetrically distributed radiopaque spheres of the bone-mounted fiducial X-Ray adapter as described previously in relation to FIGS. 121 A- 121 G in accordance with some embodiments of the invention.

FIGS. 122 A- 122 B illustrate top and bottom perspective views of an internal-mating bone-mounted fiducial X-Ray adapter with asymmetrically distributed holes for embedding radiopaque spheres and arrow indicator for determining anatomical axes and an external-mating bone-mounted fiducial in accordance with some embodiments of the invention.

FIG. 122 C illustrates a perspective view of an internal-mating bone-mounted fiducial X-Ray adapter embedded with asymmetrically distributed radiopaque spheres disengaged with an external-mating bone-mounted fiducial implanted into the sacrum as described previously in relation to FIGS. 122 A- 122 B in accordance with some embodiments of the invention.

FIG. 122 D illustrates a top view of an internal-mating bone-mounted fiducial X-Ray adapter embedded with asymmetrically distributed radiopaque spheres engaged with an external-mating bone-mounted fiducial implanted into the sacrum as described previously in relation to FIGS. 122 A- 122 C in accordance with some embodiments of the invention.

FIG. 123 A illustrates a perspective view of an external-mating bone-mounted fiducial X-Ray adapter with three symmetrically distributed holes for embedding radiopaque spheres with an arrow indicator for determining anatomical axes in accordance with some embodiments of the invention.

FIG. 123 B illustrates a front view of an external-mating bone-mounted fiducial X-Ray adapter with three symmetrically distributed holes for embedding radiopaque spheres with an arrow indicator for determining anatomical axes as described previously in relation to FIG. 123 A in accordance with some embodiments of the invention.

FIG. 123 C illustrates a side view of an external-mating bone-mounted fiducial X-Ray adapter with three symmetrically distributed holes for embedding radiopaque spheres with an arrow indicator for determining anatomical axes as described previously in relation to FIGS. 123 A- 123 B in accordance with some embodiments of the invention.

FIG. 123 D illustrates a side cross-sectional view of an external-mating bone-mounted fiducial X-Ray adapter with three symmetrically distributed radiopaque spheres embedded as described previously in relation to FIGS. 123 A- 123 C in accordance with some embodiments of the invention.

FIG. 123 E illustrates a perspective view of an external-mating bone-mounted fiducial X-Ray adapter with three symmetrically distributed radiopaque spheres engaged with an internal-mating bone-mounted fiducial implanted in the sacrum as described previously in relation to FIGS. 123 A- 123 D in accordance with some embodiments of the invention.

FIG. 124 A illustrates a perspective view of a bone-mounted fiducial with a star-shaped internal-mating mechanism in accordance with some embodiments of the invention.

FIG. 124 B illustrates a top view of a bone-mounted fiducial with a star-shaped internal-mating mechanism as described previously in relation to FIG. 124 A in accordance with some embodiments of the invention.

FIG. 124 C illustrates a side view of a bone-mounted fiducial with a star-shaped internal-mating mechanism as described previously in relation to FIGS. 124 A- 124 B in accordance with some embodiments of the invention.

FIG. 124 D illustrates a perspective view of a 3D-tracked tool with external-mating tool tip adapter disengaged with an internal-mating bone-mounted fiducial implanted in the vertebra as described previously in relation to FIGS. 124 A- 124 C in accordance with some embodiments of the invention.

FIGS. 124 E- 124 F illustrate a perspective view of a 3D-tracked tool with external-mating tool tip adapter engaged with an internal-mating bone-mounted fiducial implanted in the vertebra and in an untriggered and triggered state as described previously in relation to FIGS. 124 A- 124 D in accordance with some embodiments of the invention.

FIG. 124 G illustrates a perspective view of a 3D-tracked tool with external-mating tool tip adapter engaged with an internal-mating bone-mounted fiducial implanted in the vertebra and in an untriggered state as described previously in relation to FIGS. 124 A- 124 F in accordance with some embodiments of the invention.

FIG. 124 H illustrates a perspective view of a 3D-tracked tool with external-mating tool tip adapter engaged with an internal-mating bone-mounted fiducial implanted in the vertebra and in a triggered state as described previously in relation to FIGS. 124 A- 124 G in accordance with some embodiments of the invention.

FIG. 125 A illustrates a perspective view of a 3D-tracked tool with an external-mating tool tip not engaged with internal-mating bone-mounted fiducials in accordance with some embodiments of the invention.

FIG. 125 B illustrates a perspective view of a 3D-tracked tool with an external-mating tool tip engaged in a unique orientation with an internal-mating bone-mounted fiducial and in a triggered state as described previously in relation to FIG. 125 A in accordance with some embodiments of the invention.

FIG. 125 C illustrates a side view of a 3D-tracked tool with an external-mating tool tip not engaged with internal-mating bone-mounted fiducials as described previously in relation to FIGS. 125 A- 125 B in accordance with some embodiments of the invention.

FIG. 125 D illustrates a side view of a 3D-tracked tool with an external-mating tool tip engaged in a unique orientation with an internal-mating bone-mounted fiducial and in a triggered state as described previously in relation to FIGS. 125 A- 125 C in accordance with some embodiments of the invention.

FIG. 126 A illustrates a perspective view of a rod contour registration tool with linear triggering mechanism in accordance with some embodiments of the invention.

FIG. 126 B illustrates a side view of a rod contour registration tool disengaged with a rod and in an untriggered state as described previously in relation to FIG. 126 A in accordance with some embodiments of the invention.

FIG. 126 C illustrates a side view of a rod contour registration tool engaged with a rod and in a triggered state as described previously in relation to FIGS. 126 A- 126 B in accordance with some embodiments of the invention.

FIG. 126 D illustrates a cross-sectional view of a rod contour registration tool disengaged with a rod and in an untriggered state as described previously in relation to FIGS. 126 A- 126 C in accordance with some embodiments of the invention.

FIG. 126 E illustrates a cross-sectional view of a rod contour registration tool engaged with a rod and in a triggered state as described previously in relation to FIGS. 126 A- 126 D in accordance with some embodiments of the invention.

FIG. 126 F illustrates a perspective view of a rod contour registration tool attached to a rod bender as described previously in relation to FIGS. 126 A- 126 E in accordance with some embodiments of the invention.

FIG. 126 G illustrates a back view of a rod contour registration tool attached to a rod bender as described previously in relation to FIGS. 126 A- 126 F in accordance with some embodiments of the invention.

FIG. 126 H illustrates a side view of a rod contour registration tool attached to a rod bender as described previously in relation to FIGS. 126 A- 126 G in accordance with some embodiments of the invention.

FIGS. 126 I- 126 J illustrate perspective views of a rod contour registration tool attached to a rod bender disengaged and engaged with a bent rod attached to a coordinate reference end cap device as described previously in relation to FIGS. 126 A- 126 H in accordance with some embodiments of the invention.

FIG. 127 A illustrates a front view of a front-facing flexibility assessment device in accordance with some embodiments of the invention.

FIG. 127 B illustrates a top view of a front-facing flexibility assessment device as described previously in relation to FIG. 127 A in accordance with some embodiments of the invention.

FIGS. 127 C- 127 D illustrate perspective views of a front-facing and back-facing flexibility assessment devices as described previously in relation to FIG. 127 A- 127 B in accordance with some embodiments of the invention.

FIG. 128 A illustrates a top view of the adjustable pedicle screw interfaces of a flexibility assessment device rigidly engaged with vertebrae and spinal rods in accordance with some embodiments of the invention.

FIG. 128 B illustrates a side view of the adjustable pedicle screw interfaces of a flexibility assessment device rigidly engaged with vertebrae as described previously in relation to FIG. 128 A in accordance with some embodiments of the invention.

FIG. 128 C illustrates a top view of the front-facing and back-facing flexibility assessment devices rigidly engaged with the adjustable pedicle screw interface and corresponding vertebrae as described previously in relation to FIGS. 128 A- 128 B in accordance with some embodiments of the invention.

FIG. 128 D illustrates a side view of the front-facing and back-facing flexibility assessment devices rigidly engaged with the adjustable pedicle screw interface and corresponding vertebrae as described previously in relation to FIGS. 128 A- 128 B in accordance with some embodiments of the invention.

FIG. 129 A illustrates a perspective view of a 3D-tracked tool engaged with a pedicle screw inserted in the lamina in accordance with some embodiments of the invention.

FIG. 129 B illustrates perspective views of a 3D-tracked tool and one side of the adjustable pedicle screw interfaces of the flexibility assessment device attached rigidly to vertebrae as described previously in relation to FIG. 129 A in accordance with some embodiments of the invention.

FIG. 129 C illustrates perspective views of a 3D-tracked tool engaged with a pedicle screw inserted in lamina and one side of the adjustable pedicle screw interfaces of the flexibility assessment device attached rigidly to vertebrae as described previously in relation to FIGS. 129 A- 129 B in accordance with some embodiments of the invention.

FIG. 129 D illustrates a top view of a 3D-tracked tool engaged with a pedicle screw inserted in lamina and one side of the adjustable pedicle screw interfaces of the flexibility assessment device attached rigidly to vertebrae as described previously in relation to FIGS. 129 A- 129 C in accordance with some embodiments of the invention.

FIG. 130 A illustrates a perspective view of a 3D-tracked tool with a tool ball tip adapter engaged with the “Z-pattern” of the top skin-mounted fiducial attached on the skin covering the vertebrae in accordance with some embodiments of the invention.

FIG. 130 B illustrates a perspective view of a 3D-tracked tool with a tool ball tip adapter tracing the laminae region of the vertebrae as described previously in relation to FIG. 130 A in accordance with some embodiments of the invention.

FIG. 130 C illustrates a top view of a 3D-tracked tool with a tool ball tip adapter tracing the sacrum region of the vertebrae as described previously in relation to FIGS. 130 A- 130 B in accordance with some embodiments of the invention.

FIG. 130 D illustrates a zoomed-out view of a 3D-tracked tool with a tool ball tip adapter engaged with the “Z-pattern” of the top skin-mounted fiducial attached on the skin covering the vertebrae as described previously in relation to FIGS. 130 A- 130 C in accordance with some embodiments of the invention.

FIG. 130 E illustrates a zoomed-out view of a 3D-tracked tool with a tool ball tip adapter tracing the laminae region of the vertebrae as described previously in relation to FIGS. 130 A- 130 D in accordance with some embodiments of the invention.

FIG. 130 F illustrates a zoomed-out view of a 3D-tracked tool with a tool ball tip adapter tracing the sacrum region of the vertebrae as described previously in relation to FIGS. 130 A- 130 E in accordance with some embodiments of the invention.

FIG. 131 A illustrates a perspective view of an external-mating bone-mounted fiducial and internal-mating bone-mounted fiducial X-Ray adapter with five asymmetrically distributed holes for embedding radiopaque spheres in accordance with some embodiments of the invention.

FIG. 131 B illustrates a top view of an external-mating bone-mounted fiducial with five asymmetrically distributed holes for embedding radiopaque spheres as described previously in relation to FIG. 131 A in accordance with some embodiments of the invention.

FIGS. 131 C- 131 D illustrate side views of an external-mating bone-mounted fiducial and internal-mating bone-mounted fiducial X-Ray adapter with five asymmetrically distributed holes for embedding radiopaque spheres as described previously in relation to FIGS. 131 A- 131 B in accordance with some embodiments of the invention.

FIG. 131 E illustrates a bottom view of an external-mating bone-mounted fiducial and internal-mating bone-mounted fiducial X-Ray adapter with five asymmetrically distributed holes for embedding radiopaque spheres as described previously in relation to FIGS. 131 A- 131 D in accordance with some embodiments of the invention.

FIG. 131 F illustrates an X-Ray image taken from a lateral view visualizing the pelvis and five radiopaque spheres of the bone-mounted fiducial X-Ray adapter as described previously in relation to FIGS. 131 A- 131 E in accordance with some embodiments of the invention.

FIG. 131 G illustrates an X-Ray image taken from an AP view visualizing the pelvis and five radiopaque spheres of the bone-mounted fiducial X-Ray adapter as described previously in relation to FIGS. 131 A- 131 F in accordance with some embodiments of the invention.

FIG. 132 A illustrates a perspective view of a trackpad display-controlling interface with a DRF attached in accordance with some embodiments of the invention.

FIG. 132 B illustrates a top view of a trackpad display-controlling interface with a DRF attached as described previously in relation to FIG. 132 A in accordance with some embodiments of the invention.

FIG. 132 C illustrates a perspective view of a 3D-tracked tool hovering over the DRF-attached trackpad display-controlling interface in an untriggered state as described previously in relation to FIGS. 132 A- 132 B in accordance with some embodiments of the invention.

FIG. 132 D illustrates a perspective view of a 3D-tracked tool in contact with the DRF-attached trackpad display-controlling interface in a triggered state as described previously in relation to FIGS. 132 A- 132 C in accordance with some embodiments of the invention.

FIGS. 133 A- 133 C illustrate display interfaces for initializing the trackpad display-controlling interface by selecting a bottom left, bottom right, and top right corner of a rectangle that defines the trackpad region in accordance with some embodiments of the invention.

FIG. 133 D illustrates outputs of one initialization step of the trackpad display-controlling interface performed by tracing a diagonal line on any surface using a 3D-tracked probe as described previously in relation to FIGS. 133 A- 133 C in accordance with some embodiments of the invention.

FIG. 133 E illustrates outputs of one initialization step of the trackpad display-controlling interface performed by tracing an L-shaped line on any surface using a 3D-tracked probe as described previously in relation to FIGS. 133 A- 133 D in accordance with some embodiments of the invention.

FIG. 133 F illustrates a display interface of the trackpad display-controlling interface in its active state as described previously in relation to FIGS. 133 A- 133 E in accordance with some embodiments of the invention.

FIG. 133 G illustrates a display interface for the Z-pattern tracing of the skin-mounted fiducial as described previously in relation to FIGS. 133 A- 133 F in accordance with some embodiments of the invention.

FIG. 133 H illustrates outputs of the Z-pattern tracing of the skin-mounted fiducial and the automatic detection of the three corners of the fiducial as well as drop-down to an underlying anatomical landmark as described previously in relation to FIGS. 133 A- 133 G in accordance with some embodiments of the invention.

FIG. 133 I illustrates a display interface for the tracing of one side of the surgically exposed laminae region of the spine as described previously in relation to FIGS. 133 A- 133 H in accordance with some embodiments of the invention.

FIG. 133 J illustrates a display interface for the tracing of contralateral side of the surgically exposed laminae region of the spine as described previously in relation to FIGS. 133 A- 133 J in accordance with some embodiments of the invention.

FIGS. 133 K- 133 L illustrates outputs of the computed coronal and sagittal plane midlines of the 2D-projected bilateral laminae tracings as described previously in relation to FIGS. 133 A- 133 J in accordance with some embodiments of the invention.

FIG. 133 M illustrates an output of the computed 3D midline of the bilateral laminae tracings as described previously in relation to FIGS. 133 A- 133 L in accordance with some embodiments of the invention.

FIG. 133 N illustrates a display interface for computing the midline of the bilateral laminae tracings as described previously in relation to FIGS. 133 A- 133 M in accordance with some embodiments of the invention.

FIG. 133 O illustrates a display interface for computing the sagittal and coronal S1 endplate lines and femoral head centers as described previously in relation to FIGS. 133 A- 133 N in accordance with some embodiments of the invention.

FIG. 133 P illustrates a display interface for computing the desired spinal alignment parameters from available anatomical landmarks described previously in relation to FIGS. 133 A- 1330 in accordance with some embodiments of the invention.

FIG. 133 Q illustrates a display interface for displaying the sagittal plane view of the spine tracing as described previously in relation to FIGS. 133 A- 133 P in accordance with some embodiments of the invention.

FIG. 133 R illustrates a display interface for displaying the coronal plane view of the spine tracing as described previously in relation to FIGS. 133 A- 133 Q in accordance with some embodiments of the invention.

FIG. 133 S illustrates a display interface for displaying the axial plane view of the spine tracing as described previously in relation to FIGS. 133 A- 133 R in accordance with some embodiments of the invention.

FIG. 134 A illustrates a display interface for determining the anatomical axes using the coordinate reference end cap device in accordance with some embodiments of the invention.

FIG. 134 B illustrates a display interface for viewing the 3D locations of pedicle screw tulip-heads acquired using a 3D-tracked probe as described previously in relation to FIG. 134 A in accordance with some embodiments of the invention.

FIGS. 134 C- 134 E illustrate display interfaces for viewing the sagittal and coronal plane projections of the acquired 3D locations of pedicle screw tulip-heads, a completed tracing of the laminae, and a completed tracing of the rod's contour as described previously in relation to FIGS. 134 A- 134 B in accordance with some embodiments of the invention.

FIG. 134 F illustrates a display interface for viewing the sagittal and coronal plane projections of the acquired 3D locations of pedicle screw tulip-heads, a completed tracing of the laminae, a smoothed tracing of the rod's contour, and an indication of screws aligned with the rod as described previously in relation to FIGS. 134 A- 134 E in accordance with some embodiments of the invention.

FIGS. 134 G- 134 H illustrate a display interface for viewing the sagittal and coronal plane projections of the acquired 3D locations of pedicle screw tulip-heads, a completed tracing of the laminae, and a completed tracing of a rod's contour modified to align with more screws as described previously in relation to FIGS. 134 A- 134 F in accordance with some embodiments of the invention.

FIGS. 135 A- 135 F illustrate a display interface for viewing the 3D meshworks of the patient's sacrum and vertebrae registered via a 3D-tracked tool that engages with bone-mounted fiducials in accordance with some embodiments of the invention.

FIGS. 135 G- 135 I illustrate a display interface for displaying the sagittal, coronal, and axial plane views of the patient's sacrum and vertebrae registered via the bone-mounted fiducial as described previously in relation to FIGS. 135 A- 135 F in accordance with some embodiments of the invention.

FIGS. 135 J- 135 L illustrate a display interface for re-registering the patient's sacrum and vertebrae after manipulating their positions in 3D space as described previously in relation to FIGS. 135 A- 135 I in accordance with some embodiments of the invention.

FIGS. 136 A- 136 B illustrate a display interface for viewing the 3D meshworks of vertebrae registered via the flexibility assessment device in a non-measuring and live-measuring state in accordance with some embodiments of the invention.

FIGS. 136 C- 136 D illustrate a display interface for displaying the sagittal plane maximum lordosis and maximum kyphosis angles measured during the live manipulation of the vertebra via the flexibility assessment device as described previously in relation to FIGS. 136 A- 136 B in accordance with some embodiments of the invention.

FIG. 136 E- 136 F illustrate a display interface for displaying the coronal plane maximum left Cobb and maximum right Cobb angles measured during the live manipulation of the vertebra via the flexibility assessment device as described previously in relation to FIGS. 136 A- 136 D in accordance with some embodiments of the invention.

FIG. 136 G- 136 H illustrate a display interface for displaying the axial plane maximum clockwise twist and maximum counter-clockwise twist angles measured during the live manipulation of the vertebra via the flexibility assessment device as described previously in relation to FIGS. 136 A- 136 F in accordance with some embodiments of the invention.

FIG. 136 I illustrates a display interface for displaying the full replay of the live vertebrae manipulation via the flexibility assessment device as described previously in relation to FIGS. 136 A- 136 H in accordance with some embodiments of the invention.

FIG. 136 J illustrates an X-Ray-based initialization of the offset angle between the 3D-tracked handles of the flexibility assessment devices and their engaged vertebrae.

FIG. 137 illustrates a workflow for calculating the 3D midline of acquired 3D bilateral tracings of the laminae of the spine in accordance with some embodiments of the invention.

FIGS. 138 A- 138 E illustrate a workflow for automatically detecting the 3D location and pose of vertebrae from two or more multi-planar X-Ray images of the bone-mounted fiducials implanted in the vertebrae in accordance with some embodiments of the invention.

FIGS. 139 A- 139 B illustrate a workflow for registering the 3D location and pose of vertebrae via bone-mounted fiducials in accordance with some embodiments of the invention.

FIGS. 140 A- 140 C illustrate a workflow for defining a trackpad display-controlling interface on any surface using a 3D-tracked probe in accordance with some embodiments of the invention.

FIGS. 141 A- 141 D illustrate a workflow for making quantitative, 3D, intraoperative global spinal alignment assessments using skin-mounted fiducials, bone-mounted fiducials, and/or bilateral tracings of the spine in accordance with some embodiments of the invention.

FIG. 142 A illustrates a perspective view of a 3D-tracked tool with a tool ball-tip adapter not engaged with a tapered, semi-cylindrical external-mating bone-mounted fiducial and in an untriggered state in accordance with some embodiments of the invention.

FIG. 142 B illustrates a perspective view of a 3D-tracked probe engaged with a tapered, semi-cylindrical external-mating bone-mounted fiducial and in an untriggered state as described previously in relation to FIG. 142 A in accordance with some embodiments of the invention.

FIG. 142 C illustrates a perspective view of a 3D-tracked probe engaged with a tapered, semi-cylindrical external-mating bone-mounted fiducial and in a triggered state as described previously in relation to FIGS. 142 A-B in accordance with some embodiments of the invention.

FIG. 142 D illustrates a perspective view of a tapered, semi-cylindrical external-mating bone-bounted fiducial not engaged with an internal-mating tool tip adapter of a 3D-tracked probe as described previously in relation to FIGS. 142 A-C in accordance with some embodiments of the invention.

FIG. 142 E illustrates a perspective view of a tapered, semi-cylindrical external-mating bone-bounted fiducial engaged with an internal-mating tool tip adapter of a 3D-tracked probe as described previously in relation to FIGS. 142 A-D in accordance with some embodiments of the invention.

FIG. 142 F illustrates a side cross-sectional view of a tapered, semi-cylindrical external-mating bone-bounted fiducial engaged with an internal-mating tool tip adapter of a 3D-tracked probe as described previously in relation to FIGS. 142 A-E in accordance with some embodiments of the invention.

FIG. 142 G illustrates a side view of an external-mating bone-mounted fiducial with a spring-loaded detent as described previously in relation to FIGS. 142 A-F in accordance with some embodiments of the invention.

FIG. 142 H illustrates a side cross-sectional view of an external-mating bone-mounted fiducial with a spring-loaded detent as described previously in relation to FIGS. 142 A-G in accordance with some embodiments of the invention.

FIG. 142 I illustrates a perspective view of an external-mating bone-mounted fiducial with a friction-inducing bone interface as described previously in relation to FIGS. 142 A-H in accordance with some embodiments of the invention.

FIG. 142 J illustrates a side view of an external-mating bone-mounted fiducial with a friction-inducing bone interface as described previously in relation to FIGS. 142 A-I in accordance with some embodiments of the invention.

FIG. 142 K illustrates a perspective view of an external-mating bone-mounted fiducial with extended shaft for percutaneous registration of anatomical landmarks of interest as described previously in relation to FIGS. 142 A-J in accordance with some embodiments of the invention.

FIG. 142 L illustrates a different perspective view of an external-mating bone-mounted fiducial with extended shaft for percutaneous registration of anatomical landmarks of interest as described previously in relation to FIGS. 142 A-K in accordance with some embodiments of the invention.

FIG. 143 A illustrates a perspective view of the spine with an external-mating bone-mounted fiducial implanted into the sacrum and a frame-bump-monitoring, 3D-tracked marker post and 3D-tracked DRF implanted into the pelvis in accordance with some embodiments of the invention.

FIG. 143 B illustrates a perspective view of a 3D-tracked tool not engaged with an external-mating bone-mounted fiducial implanted into the sacrum and in an untriggered state, along with a frame-bump-monitoring, 3D-tracked marker post and 3D-tracked DRF implanted into the pelvis, as described previously in relation to FIG. 143 A in accordance with some embodiments of the invention.

FIG. 143 C illustrates a perspective view of a 3D-tracked tool engaged with an external-mating bone-mounted fiducial implanted into the sacrum and in a triggered state, along with a 3D-tracked iliac screw and 3D-tracked DRF implanted into the pelvis, as described previously in relation to FIGS. 143 A-B in accordance with some embodiments of the invention.

FIG. 144 A illustrates a perspective view of an internal-mating bone-mounted fiducial X-Ray adapter that has a cam-lock mechanism with an undrepressed cam-lever. The adapter is not engaged with an external-mating bone-mounted fiducial in accordance with some embodiments of the invention.

FIG. 144 B illustrates a perspective view of an internal-mating bone-mounted fiducial X-Ray adapter that has a cam-lock mechanism with an undepressed cam-lever. The adapter is engaged with an external-mating bone-mounted fiducial as described previously in relation to FIG. 144 A in accordance with some embodiments of the invention.

FIG. 144 C illustrates a different perspective view of an internal-mating bone-mounted fiducial X-Ray adapter that has a cam-lock mechanism and depressed cam-lever. The adapter is engaged with an external-mating bone-mounted fiducial as described previously in relation to FIGS. 144 A-B in accordance with some embodiments of the invention.

FIG. 144 D illustrates a side cross-sectional view of an internal-mating bone-mounted fiducial X-Ray adapter that has a cam-lock mechanism. The depressed cam-lever applies compression force to the flat interface of an external-mating bone-mounted fiducial to secure it in place, as described previously in relation to FIGS. 144 A-C in accordance with some embodiments of the invention.

FIG. 144 E illustrates a perspective view of an internal-mating bone-mounted fiducial X-Ray adapter that has a cam-lock mechanism. The cam-lever is depressed via a compression spring, which applies compression force to the flat interface of an external-mating bone-mounted fiducial to secure it in place, as described previously in relation to FIGS. 144 A-D in accordance with some embodiments of the invention.

FIG. 144 F illustrates a side cross-sectional view of an internal-mating bone-mounted fiducial X-Ray adapter with a spring-loaded mating mechanism, not engaged with an external-mating bone-mounted fiducial as described previously in relation to FIGS. 144 A-E in accordance with some embodiments of the invention.

FIG. 144 G illustrates a side cross-sectional view of an internal-mating bone-mounted fiducial X-Ray adapter with a spring-loaded mating mechanism, engaged with an external-mating bone-mounted fiducial as described previously in relation to FIGS. 144 A-F in accordance with some embodiments of the invention.

FIG. 144 H illustrates a bottom perspective view of an internal-mating bone-mounted fiducial X-Ray adapter embedded with a larger array of asymmetrically distributed radiopaque spheres, not engaged with an external-mating bone-mounted fiducial as described previously in relation to FIGS. 144 A-G in accordance with some embodiments of the invention.

FIG. 144 I illustrates a top perspective view of an internal-mating bone-mounted fiducial X-Ray adapter embedded with a larger array of asymmetrically distributed radiopaque spheres, not engaged with an external-mating bone-mounted fiducial as described previously in relation to FIGS. 144 A-H in accordance with some embodiments of the invention.

FIG. 144 J illustrates a top view of an internal-mating bone-mounted fiducial X-Ray adapter embedded with a larger array of asymmetrically distributed radiopaque spheres, as described previously in relation to FIGS. 144 A-H in accordance with some embodiments of the invention.

FIG. 145 A illustrates perspective views of an internal-mating bone-mounted fiducial X-Ray adapter embedded with asymmetrically distributed radiopaque spheres not engaged with any of the external-mating bone-mounted fiducials implanted into the sacrum and multiple laminae of the spine in accordance with some embodiments of the invention.

FIG. 145 B illustrates perspective views of an internal-mating bone-mounted fiducial X-Ray adapter embedded with asymmetrically distributed radiopaque spheres engaged with one of the external-mating bone-mounted fiducials implanted into the sacrum and multiple laminae of the spine as described previously in relation to FIG. 145 A in accordance with some embodiments of the invention.

FIG. 145 C illustrates perspective views of an internal-mating bone-mounted fiducial X-Ray adapter embedded with asymmetrically distributed radiopaque spheres and equipped with 3D-tracked markers, engaged with one of the external-mating bone-mounted fiducials implanted into the sacrum and multiple laminae of the spine as described previously in relation to FIGS. 145 A-B in accordance with some embodiments of the invention.

FIG. 145 D illustrates an X-Ray image taken from the sagittal view of the spine with an internal-mating bone-mounted fiducial X-Ray adapter engaged with one of the external-mating bone-mounted fiducials implanted into the sacrum and multiple laminae, as well as line annotations of several vertebral endplates, as described previously in relation to FIGS. 145 A-C in accordance with some embodiments of the invention.

FIG. 145 E illustrates an X-Ray image taken from the coronal view of the spine with an internal-mating bone-mounted fiducial X-Ray adapter engaged with one of the external-mating bone-mounted fiducials implanted into the sacrum and multiple laminae, as well as line annotations of several vertebral endplates, as described previously in relation to FIGS. 145 A-D in accordance with some embodiments of the invention.

FIG. 146 A illustrates perspective views of a front-facing flexibility assessment device rigidly engaged with a vertebra of the spine, as well as an X-Ray adapter not engaged with the male protrusion on the flexibility assessment device, in accordance with some embodiments of the invention.

FIG. 146 B illustrates perspective views of front-facing and back-facing flexibility assessment devices rigidly engaged with vertebrae of the spine, as well as an X-Ray adapter engaged with the male protrusion on the front-facing flexibility assessment device, as described previously in relation to FIG. 146 A in accordance with some embodiments of the invention.

FIG. 146 C illustrates an X-Ray image taken from the sagittal view of the spine with front-facing and back-facing flexibility assessment devices rigidly engaged with vertebrae of the spine, an X-Ray adapter engaged with the male protrusion on the front-facing flexibility assessment device, and line annotations of endplates of the vertebrae with flexibility assessment devices attached, as described previously in relation to FIGS. 146 A-B in accordance with some embodiments of the invention.

FIG. 146 D illustrates an X-Ray image taken from the coronal view of the spine with front-facing and back-facing flexibility assessment devices rigidly engaged with vertebrae of the spine, an X-Ray adapter engaged with the male protrusion on the front-facing flexibility assessment device, and line annotations of endplates of the vertebrae with flexibility assessment devices attached, as described previously in relation to FIGS. 146 A-B in accordance with some embodiments of the invention.

FIG. 147 A illustrates a perspective view of a 3D-tracked implant driver with an implant-attachment tip mechanically linked with a TMSM in an inactive state in accordance with some embodiments of the invention.

FIG. 147 B illustrates a side view of a 3D-tracked implant driver with an implant-attachment tip mechanically linked with a TMSM in an inactive state as described previously in relation to FIG. 147 A in accordance with some embodiments of the invention.

FIG. 147 C illustrates a side view of a 3D-tracked implant driver with an implant-attachment tip mechanically linked with a TMSM in an active state as described previously in relation to FIGS. 147 A-B in accordance with some embodiments of the invention.

FIG. 147 D illustrates a side cross-sectional view of a 3D-tracked implant driver with an implant-attachment tip mechanically linked with a TMSM mount as described previously in relation to FIGS. 147 A-C in accordance with some embodiments of the invention.

FIG. 147 E illustrates a cross-sectional view of a TMSM mount and attached TMSM as described previously in relation to FIGS. 147 A-D in accordance with some embodiments of the invention.

FIG. 147 F illustrates a perspective view of a 3D-tracked implant driver with an implant-attachment tip not engaged with an expandable interbody cage and in an inactive state, as described previously in relation to FIGS. 147 A-E in accordance with some embodiments of the invention.

FIG. 147 G illustrates a side cross-sectional view of a 3D-tracked implant driver with an implant-attachment tip engaged with an expandable interbody cage, as described previously in relation to FIGS. 147 A-F in accordance with some embodiments of the invention.

FIG. 147 H illustrates a side view of a 3D-tracked implant driver with an implant-attachment tip engaged with an expandable interbody cage and in an inactive state, as described previously in relation to FIGS. 147 A-G in accordance with some embodiments of the invention.

FIG. 147 I illustrates a side view of a 3D-tracked implant driver with an implant-attachment tip engaged with an expanded interbody cage and in an active state, as described previously in relation to FIGS. 147 A-H in accordance with some embodiments of the invention.

FIG. 148 A illustrates perspective views of 3D-tracked DRF attachments not engaged with external-mating bone-mounted fiducials, in accordance with some embodiments of the invention.

FIG. 148 B illustrates perspective views of 3D-tracked DRF attachments engaged with external-mating bone-mounted fiducials, as described previously in relation to FIG. 148 A in accordance with some embodiments of the invention.

FIG. 148 C illustrates a top view of the sacrum and L5 vertebra with external-mating bone-mounted fiducials implanted in them, as described previously in relation to FIGS. 148 A-B in accordance with some embodiments of the invention.

FIG. 148 D illustrates perspective views of 3D-tracked DRF attachments engaged with external-mating bone-mounted fiducials implanted in the sacrum and L5 vertebra, as described previously in relation to FIGS. 148 A-C in accordance with some embodiments of the invention.

FIG. 148 E illustrates side views of a 3D-tracked implant driver with an expandable interbody cage. The cage is not inserted between the sacrum and L5 vertebra, which are implanted with external-mating bone-mounted fiducials engaged with 3D-tracked DRF attachments, as described previously in relation to FIGS. 148 A-D in accordance with some embodiments of the invention.

FIG. 148 F illustrates a sagittal view of a 3D-tracked implant driver with an expandable interbody cage. The cage is inserted between the sacrum and L5 vertebra, which are implanted with external-mating bone-mounted fiducials engaged with 3D-tracked DRF attachments. The above components are described previously in relation to FIGS. 148 A-E in accordance with some embodiments of the invention.

FIG. 148 G illustrates a sagittal view of a 3D-tracked implant driver with an expandable interbody cage. The cage is inserted and expanded between the sacrum and L5 vertebra and the implant driver's TMSM is in an active state. The sacrum and L5 vertebra has external-mating bone-mounted fiducials engaged with 3D-tracked DRF attachments. The above components are described previously in relation to FIGS. 148 A-F in accordance with some embodiments of the invention.

FIG. 148 H illustrates an axial view of a 3D-tracked implant driver with an expandable interbody cage. The cage is inserted between the sacrum and L5 vertebra and the implant driver's TMSM is in an inactive state. The sacrum and L5 vertebra has external-mating bone-mounted fiducials engaged with 3D-tracked DRF attachments. The above components are described previously in relation to FIGS. 148 A-G in accordance with some embodiments of the invention.

FIG. 148 I illustrates an axial view of a 3D-tracked implant driver with an expandable interbody cage. The cage is inserted and expanded between the sacrum and L5 vertebra and the implant driver's TMSM is in an active state. The sacrum and L5 vertebra has external-mating bone-mounted fiducials engaged with 3D-tracked DRF attachments. The above components are described previously in relation to FIGS. 148 A-H in accordance with some embodiments of the invention.

FIG. 148 J illustrates a sagittal view of the sacrum and L5 vertebra with an expandable interbody cage inserted and expanded between them, and has external-mating bone-mounted fiducials engaged with 3D-tracked DRF attachments. The 3D-tracked implant driver is disengaged from the interbody cage. The above components are described previously in relation to FIGS. 148 A-I in accordance with some embodiments of the invention.

FIG. 148 K illustrates a top perspective view of the sacrum and L5 vertebra with an interbody cage inserted and expanded between them, as described previously in relation to FIGS. 148 A-J in accordance with some embodiments of the invention.

FIG. 148 L illustrates a side view of the sacrum and L5 vertebra with an interbody cage inserted between them, as described previously in relation to FIGS. 148 A-K in accordance with some embodiments of the invention.

FIG. 149 A illustrates a side view of the sacrum and L5 vertebra with an interbody cage inserted between them, still attached to the 3D-tracked implant driver that is in an inactive state, in accordance with some embodiments of the invention.

FIG. 149 B illustrates a side view of the sacrum and L5 vertebra with an interbody cage inserted and expanded between them, still attached to the 3D-tracked implant driver that is in an active state, as described previously in relation to FIG. 149 A in accordance with some embodiments of the invention.

FIG. 149 C illustrates a perspective view of the sacrum and L5 vertebra with an interbody cage inserted and expanded between them, still attached to the 3D-tracked implant driver that is in an active state. A 3D-tracked tool is not engaged with an external-mating bone-mounted fiducial implanted in the sacrum and is in an inactive state. The above components are described previously in relation to FIGS. 149 A-B in accordance with some embodiments of the invention.

FIG. 149 D illustrates a perspective view of the sacrum and L5 vertebra with an interbody cage inserted and expanded between them, still attached to the 3D-tracked implant driver that is in an active state. A 3D-tracked tool is engaged with an external-mating bone-mounted fiducial implanted in the sacrum and is in an inactive state. The above components are described previously in relation to FIGS. 149 A-C in accordance with some embodiments of the invention.

FIG. 149 E illustrates a perspective view of the sacrum and L5 vertebra with an interbody cage inserted and expanded between them, still attached to the 3D-tracked implant driver that is in an active state. A 3D-tracked tool is engaged with an external-mating bone-mounted fiducial implanted in the sacrum and is in an active state. The above components are described previously in relation to FIGS. 149 A-D in accordance with some embodiments of the invention.

FIG. 150 A illustrates a perspective view of a 3D-tracked bone-clamping fiducial attached to the L4 vertebra in accordance with some embodiments of the invention.

FIG. 150 B illustrates perspective views of the L4 and L5 vertebrae with 3D-tracked bone-clamping fiducial attached. An interbody cage is inserted between them via a 3D-tracked implant driver that is in an inactive state. The above components are described previously in relation to FIG. 150 A in accordance with some embodiments of the invention.

FIG. 150 C illustrates perspective views of the L4 and L5 vertebrae with 3D-tracked bone-clamping fiducial attached. An interbody cage is inserted and expanded between them via a 3D-tracked implant driver that is in an active state. The above components are described previously in relation to FIGS. 150 A-B in accordance with some embodiments of the invention.

FIG. 151 A illustrates perspective views of the L4 and L5 vertebrae with 3D-tracked bone-clamping fiducials attached, and an internal-mating X-Ray adapter not engaged with a male protrusion on one of the bone-clamping fiducials, in accordance with some embodiments of the invention.

FIG. 151 B illustrates perspective views of the L4 and L5 vertebrae with 3D-tracked bone-clamping fiducials attached, and an internal-mating X-Ray adapter engaged with a male protrusion on one of the bone-clamping fiducials, as described previously in relation to FIG. 151 A in accordance with some embodiments of the invention.

FIG. 151 C illustrates sagittal views of the L4 and L5 vertebrae with 3D-tracked bone-clamping fiducials attached, and an internal-mating X-Ray adapter engaged with a male protrusion on one of the bone-clamping fiducials, as described previously in relation to FIGS. 151 A-B in accordance with some embodiments of the invention.

FIG. 151 D illustrates coronal views of the L4 and L5 vertebrae with 3D-tracked bone-clamping fiducials, and an internal-mating X-Ray adapter engaged with a male protrusion on one of the bone-clamping fiducials, as described previously in relation to FIGS. 151 A-C in accordance with some embodiments of the invention.

FIG. 151 E illustrates perspective views of the L4 and L5 vertebrae with 3D-tracked bone-clamping fiducials attached. An interbody cage is inserted between them via a 3D-tracked implant driver that is in an inactive state. The above components are described previously in relation to FIGS. 151 A-D in accordance with some embodiments of the invention.

FIG. 152 A illustrates a perspective view of a single-actuation 3D-tracked implant driver attached to an interbody cage and in an inactive state, in accordance with some embodiments of the invention.

FIG. 152 B illustrates a perspective view of a single-actuation 3D-tracked implant driver attached to a pivoted interbody cage and in an inactive state, as described previously in relation to FIG. 152 A in accordance with some embodiments of the invention.

FIG. 152 C illustrates a perspective view of a single-actuation 3D-tracked implant driver attached to a pivoted and expanded interbody cage, and in an active state as indicated by the sideways movement of the mechanically-linked TMSM, as described previously in relation to FIGS. 152 A-B in accordance with some embodiments of the invention.

FIG. 152 D illustrates a perspective view of a single-actuation 3D-tracked implant driver attached to an expanded interbody cage, and in an active state as indicated by the sideways movement of the mechanically-linked TMSM, as described previously in relation to FIGS. 152 A-C in accordance with some embodiments of the invention.

FIG. 152 E illustrates a perspective view of the orthogonal, geared mechanism for converting cage-expansion motion into orthogonal actuation of the TMSM of the 3D-tracked implant driver as described previously in relation to FIGS. 152 A-D in accordance with some embodiments of the invention.

FIG. 153 A illustrates a side view of a single-actuation 3D-tracked implant driver attached to an interbody cage and in an inactive state, in accordance with some embodiments of the invention.

FIG. 153 B illustrates a side view of a single-actuation 3D-tracked implant driver attached to a pivoted interbody cage and in an inactive state, as described previously in relation to FIG. 153 A in accordance with some embodiments of the invention.

FIG. 153 C illustrates a side perspective view of a single-actuation 3D-tracked implant driver attached to a pivoted interbody cage and in an inactive state, as described previously in relation to FIGS. 153 A-B in accordance with some embodiments of the invention.

FIG. 153 D illustrates another side perspective view of a single-actuation 3D-tracked implant driver attached to a pivoted and expanded interbody cage and in an inactive state, as described previously in relation to FIGS. 153 A-C in accordance with some embodiments of the invention.

FIG. 153 E illustrates a back view of a single-actuation 3D-tracked implant driver attached to an interbody cage and in an inactive state, as described previously in relation to FIGS. 153 A-D in accordance with some embodiments of the invention.

FIG. 153 F illustrates a perspective view of a dual-actuation 3D-tracked implant driver attached to a pivoted interbody cage and in an inactive state, as described previously in relation to FIGS. 153 A-E in accordance with some embodiments of the invention.

FIG. 153 G illustrates a perspective view of a dual-actuation 3D-tracked implant driver attached to a pivoted and expanded interbody cage, and in an active state as indicated by the vertical movement of the mechanically-linked TMSM, as described previously in relation to FIGS. 153 A-F in accordance with some embodiments of the invention.

FIG. 154 A illustrates a perspective view of a dual-actuation 3D-tracked implant driver attached to an interbody cage and in an inactive state, in accordance with some embodiments of the invention.

FIG. 154 B illustrates a perspective view of a dual-actuation 3D-tracked implant driver attached to a pivoted interbody cage and in an inactive state, as described previously in relation to FIG. 154 A in accordance with some embodiments of the invention.

FIG. 154 C illustrates a perspective view of a dual-actuation 3D-tracked implant driver attached to a pivoted and expanded interbody cage, and in an active state as indicated by the vertical movement of the mechanically-linked TMSM, as described previously in relation to FIGS. 154 A-B in accordance with some embodiments of the invention.

FIG. 155 A illustrates perspective views of a single-actuation 3D-tracked implant driver not engaged with a corpectomy cage, in accordance with some embodiments of the invention.

FIG. 155 B illustrates perspective views of a single-actuation 3D-tracked implant driver engaged with a corpectomy cage and in an inactive state, as described previously in relation to FIG. 155 A in accordance with some embodiments of the invention.

FIG. 155 C illustrates perspective views of a single-actuation 3D-tracked implant driver engaged with a corpectomy cage and in an active state as the spring expands, as described previously in relation to FIGS. 155 A-B in accordance with some embodiments of the invention.

FIG. 156 A illustrates perspective views of a 3D-tracked implant driver with no actuation mechanism not engaged with a rigid non-actuating interbody cage in accordance with some embodiments of the invention.

FIG. 156 B illustrates perspective views of a 3D-tracked implant driver with no actuation mechanism engaged with a rigid non-actuating interbody cage, as described previously in relation to FIG. 156 A in accordance with some embodiments of the invention.

FIG. 156 C illustrates side views of a 3D-tracked implant driver with no actuation mechanism engaged with a rigid non-actuating interbody cage and not inserted between the sacrum and L5 vertebra, which are both implanted with bone-mounted fiducials mated with 3D-tracked DRFs, as described previously in relation to FIGS. 156 A-B in accordance with some embodiments of the invention.

FIG. 156 D illustrates side views of a 3D-tracked implant driver with no actuation mechanism engaged with a rigid non-actuating interbody cage inserted between the sacrum and L5 vertebra, which are both implanted with bone-mounted fiducials mated with 3D-tracked DRFs, as described previously in relation to FIGS. 156 A-C in accordance with some embodiments of the invention.

FIG. 156 E illustrates side views of a 3D-tracked implant driver with no actuation mechanism removed from a rigid non-actuating interbody cage inserted between the sacrum and L5 vertebra, which are both implanted with bone-mounted fiducials mated with 3D-tracked DRFs, as described previously in relation to FIGS. 156 A-D in accordance with some embodiments of the invention.

FIG. 156 F illustrates a display interface for illustrating in real-time, the 3D motions of vertebrae, visual representations of their endplates, and their associated spinal alignment parameters in sagittal, coronal, axial, and perspective views, as described previously in relation to FIGS. 156 A-E in accordance with some embodiments of the invention.

FIG. 156 G illustrates a display interface for illustrating in real-time, the 3D motions of vertebrae, visual representations of their endplates, and their associated spinal alignment parameters, as well as the 3D motion of an interbody cage being inserted between the vertebrae, in sagittal, coronal, axial, and perspective views, as described previously in relation to FIGS. 156 A-F in accordance with some embodiments of the invention.

FIG. 156 H illustrates a display interface for illustrating in real-time, the 3D motions of vertebrae, visual representations of their endplates, and their associated spinal alignment parameters, as well as the 3D motion of an interbody cage after insertion between the vertebrae, in sagittal, coronal, axial, and perspective views, as described previously in relation to FIGS. 156 A-G in accordance with some embodiments of the invention.

FIGS. 157 A-J illustrate a workflow for registering the 3D location of anatomical landmarks relative to a bone-mounted fiducial, and using those registered landmarks, in some cases in combination with non-fiducial-based inputs of the patient's anatomy (e.g., bilateral laminae tracings, preoperative planning alignment parameters, patient normative data, etc.), to compute the patient's spinal alignment parameters, in accordance with some embodiments of the invention.

FIGS. 158 A-B illustrate a workflow for registering the 3D location of multiple vertebrae relative to its unique bone-mounted fiducials and using those registered landmarks to compute the patient's spinal alignment parameters, in accordance with some embodiments of the invention.

FIGS. 159 A-G illustrate a workflow for providing real-time, visual and quantitative feedback of implant (e.g. interbody cage) insertion into the spine in accordance with some embodiments of the invention.

FIGS. 160 A-D illustrate a workflow for assessing the 3D range of motion of vertebrae of the spine, and if alignment goals are met, locking the vertebrae in place via a set-and-hold mechanism and securing surgical rods in place, in accordance with some embodiments of the invention.

FIG. 161 illustrates a display interface for illustrating in real-time, the 3D motions of vertebrae attached to flexibility-assessment devices, visual representations of their endplates, and their associated spinal alignment parameters, in sagittal, coronal, axial, and perspective views in accordance with some embodiments of the invention.

FIG. 162 A illustrates a display interface for illustrating the 3D locations and poses of vertebrae (e.g., sacrum and lumbar vertebrae) registered via bone-mounted fiducials, along with visual representations of their endplates in a perspective view in accordance with some embodiments of the invention.

FIG. 162 B illustrates a display interface for illustrating the 3D locations and poses of vertebrae (e.g., sacrum and lumbar vertebrae) registered via bone-mounted fiducials, along with visual representations of their endplates and their associated spinal alignment parameters (e.g., inter-vertebral angles), in a sagittal plane view, as described previously in relation to FIG. 162 A in accordance with some embodiments of the invention.

FIG. 162 C illustrates a display interface for illustrating the 3D locations and poses of vertebrae (e.g., sacrum and lumbar vertebrae) registered via bone-mounted fiducials, along with visual representations of their endplates and their associated spinal alignment parameters (e.g., inter-vertebral angles), in a coronal plane view, as described previously in relation to FIGS. 162 A-B in accordance with some embodiments of the invention.

FIG. 162 D illustrates a display interface for illustrating the 3D locations and poses of vertebrae (e.g., sacrum and lumbar vertebrae) registered via bone-mounted fiducials, along with visual representations of their endplates and their associated spinal alignment parameters (e.g., inter-vertebral angles), in an axial plane view, as described previously in relation to FIGS. 162 A-C in accordance with some embodiments of the invention.

Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. Some embodiments of the invention are configured to be combined with some other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless specified or limited otherwise, in some embodiments, the terms “mounted,” “connected,” “supported,” and “coupled” and variations thereof are used broadly and encompass both direct and indirect mountings, connections, supports, and couplings. Further, in some embodiments, “connected” and “coupled” are not restricted to physical or mechanical connections or couplings.

The following discussion is presented to enable a person skilled in the art to make and use embodiments of the invention. Various modifications to the illustrated embodiments will be readily apparent to those skilled in the art, and the generic principles herein can be applied to some embodiments and applications without departing from embodiments of the invention. Thus, embodiments of the invention are not intended to be limited to embodiments shown, but are to be accorded the widest scope consistent with the principles and features disclosed herein. The following detailed description is to be read with reference to the figures, in which like elements in different figures have like reference numerals. The figures, which are not necessarily to scale, depict selected embodiments and are not intended to limit the scope of embodiments of the invention. Skilled artisans will recognize the examples provided herein have many useful alternatives that fall within the scope of embodiments of the invention.

In some embodiments, “tracked” refers to the ability of a particular object to interface with a tracking device (e.g., such as one or more 3D-tracking optical cameras and/or one or more 3D-tracking electromechanical devices) in at least FIG. 4 H , FIG. 5 B , FIGS. 7 - 8 , FIGS. 10 A- 10 G , FIGS. 11 A- 11 B , FIGS. 14 A- 14 C , FIGS. 15 A- 15 C , FIG. 16 , FIGS. 17 A- 17 B , FIGS. 18 A- 18 B , FIGS. 19 A- 19 E , FIGS. 20 , and 20 A- 20 E , FIGS. 21 A- 21 B , FIG. 22 , FIGS. 23 A- 23 C , FIGS. 24 - 26 , FIGS. 27 A- 27 D , FIGS. 28 A- 28 B , FIGS. 29 A- 29 D , FIG. 30 B , FIG. 31 , FIG. 38 , FIGS. 38 A- 38 G , FIGS. 39 A- 39 F , FIGS. 40 A- 40 C , FIGS. 41 A- 41 D , FIGS. 42 A- 42 K , FIGS. 43 A- 43 F , FIGS. 44 A- 44 D , FIGS. 44 A- 44 B , FIGS. 46 A- 46 G , FIGS. 47 A- 47 B , FIGS. 48 A- 48 C , FIGS. 49 A- 49 D , FIGS. 50 A- 50 E , FIGS. 51 A- 51 I , FIGS. 52 A- 52 D , FIGS. 53 A- 53 F , FIGS. 54 A- 54 D , FIGS. 55 A- 55 I , FIGS. 56 A- 56 F , FIGS. 57 A- 57 D , FIGS. 64 A- 64 B , FIGS. 73 A- 73 B , FIGS. 77 A- 77 C , FIGS. 79 A- 79 G , FIGS. 82 A- 82 B , FIGS. 87 A- 87 K , FIGS. 88 A- 88 F , FIG. 116 J , FIGS. 117 D- 117 G, 117 I- 117 J , FIGS. 118 D- 3 H , FIGS. 119 G- 119 K , FIGS. 120 F- 120 H , FIGS. 124 D- 124 H , FIGS. 125 A- 125 D , FIG. 126 , FIG. 127 , FIGS. 128 C- 128 D , FIGS. 129 A- 129 D , FIG. 130 , FIG. 132 , etc., that tracks the 3D coordinates of the tracked object relative to the tracking system's coordinate system. One example of an object that is “tracked” is when it possesses a substantially rigidly-attached dynamic reference frame that is tracked in 3D space.

In some embodiments, a dynamic reference frame (hereinafter “DRF”) refers to three or more points (markers) that are positioned in a uniquely identifiable configuration such that their discrete locations are associated with an object identity. Some embodiments include uniquely-arranged markers that can allow for the calculation of both the 3D location and pose of a DRF.

Some embodiments can also define a coordinate system relative to the DRF. In some embodiments, a stray marker refers to a 3D-tracked object, typically either light-reflective or light-emitting, which can be visualized by a 3D-tracking camera and is not one of the markers that define a DRF. In some embodiments, a stray marker can be associated with a DRF as well as have its location, pose, and behavior computed relative to one or more DRFs.

In some embodiments, a tracked mobile stray marker (TMSM) refers to a stray marker that is designed to move relative to either other stray markers or to nearby DRFs. In some embodiments, the computation of a TMSM's position and/or motion relative to those other entities can be interpreted to communicate information and/or commands to a computer acquisition system.

In some embodiments, a probe refers and/or defines a device that is tracked in such a way that its location, orientation, and identity are known in 3D space. In some embodiments, the system can extrapolate the location and orientation of other points and/or markers on and/or near the tracked object (e.g., the tip, shaft, unique features, etc.) even if they aren't directly tracked independently.

Some embodiments include a fiducial. In some embodiments, a fiducial can be an object that is used primarily as a reference to another point in space. In some embodiments, a fiducial can be placed near an object/region of interest. In some embodiments, the relative position of the fiducial to the object of interest can be initialized. In some embodiments, the location and orientation of the fiducial can be referenced in the future after initialization. In some embodiments, the precise location of the initialized object/region of interest can be calculated. In some embodiments, fiducials can have unique surface patterns in the form of indentations to be tapped, grooves to be traced, and/or mating features to be coupled. In some embodiments, the fiducial unique surface patterns can interact with a 3D-tracked probe or end-effector. In some embodiments, the fiducial's 3D location and orientation, as well as identity, can be calculated by the acquisition system. In some embodiments, a fiducial can be an object with embedded radiopaque markers, that enable for the fiducial's visualization and registration by radiographic imaging. Some embodiments include, a fiducial marker. In some embodiments, the fiducial maker can be used as an equivalent term to “fiducial”, unless referring specifically to the embedded “radiopaque markers” within the fiducial structure that can be visualized on X-rays.

In some embodiments, the term “3D rigid transform” describes the mathematical operation that involves the computational application of a matrix containing both rotation and translation transformations. In some embodiments, the 3D rigid transform can be utilized when the system needs to transform the relations of an object from one coordinate axes to another, without deformation of the object. In some embodiments, an example can be: instead of having a 3D-tracked tool's location coordinates and orientation values to be in reference to a 3D-tracking acquisition system, the 3D-tracked tool can be substantially rigidly transformed to be in reference to the coordinates and orientation of another 3D-tracked tool or DRF within the scene. Further, some embodiments include “rigid body transform”, a synonym.

Some embodiments include a pedicle screw. Some embodiments include a pedicle screw that can be inserted into the anatomical structure of a spinal vertebra called a pedicle. In some embodiments, the pedicle screw can be referenced. In some embodiments, the pedicle screw can be assumed that the system can be compatible with any other screws, fasteners, and/or other surgical implants (e.g., cages, rods, etc.).

In some embodiments, a tulip-head can be an object that attaches to a screw-head and can be polyaxial or uniaxial in its range of motion. In some embodiments, the tulip-head typically has internal threads that enable a fastener to engage substantially rigidly with the structure. In some embodiments, the tulip-head can have mating features on the external wall/surface that can enable a device to substantially rigidly attach to the tulip-head. In some embodiments, the tulip-heads can be designed to accept the insertion of a rod implant.

In some embodiments, a rod can be any object with a cross-section similar to a circle. Some embodiments include, additional shapes can include a keyhole, semi-circle, and the like. In some embodiments, a rod can be of any length and curvature. In some embodiments, a rod can be coupled to tracked and non-tracked tools. In some embodiments, a rod can be inserted into the cavity of a tulip-head and can be substantially rigidly fixed in-place via a cap screw that is fastened via threads on the interior wall of a tulip-head.

In some embodiments, register or a registration refers to any time a 3D-tracked tool or object signals information to the computer system regarding an object's state, 3D location, 3D orientation, unique identity, relative position to other objects, or other relevant information for the system's algorithms. Some embodiments include, for example: a 3D-tracked probe can register the position and identity of a fiducial, meaning that the 3D-tracked probe can communicate to the computer system that a particular fiducial can have a specific position and orientation in 3D space relative to the 3D-tracking, acquisition system.

In some embodiments, “sagittal” is an anatomical plane that refers the side view of a patient in which the superior portion of the patient (e.g., the head) is on the right or left side and the inferior portion of the patient (e.g., feet) is on the opposite end, depending on which side of the patient the perspective is from, left or right half. In some embodiments, the posterior aspect of the patient will be visible on either the top or bottom of the view, depending on whether the patient is supine or prone.

In some embodiments, “coronal” is an anatomical plane that refers to the top view of a patient in which the superior portion of the patient (e.g., the head) is on the top or bottom and the inferior portion of the patient (e.g., feet) is on the opposite end, depending on which side of the patient the perspective is from, below or above, as well as which side the left or side of the patient appears in view, right or left.

In some embodiments, “axial” is an anatomical plane that refer to the cross-sectional view of a patient in which the posterior portion of the patient is on the top or bottom and the anterior portion of the patient is on the opposite end, depending on which side of the patient the perspective is from, prone or supine. In some embodiments, the patient view can also change depending on whether the view is pointed towards the inferior or superior aspect of the patient. In some embodiments, “transverse” can be used. In some embodiments, transverse can be an equivalent term to “axial”.

In some embodiments, “depressible sliding shaft” or “plunger” refers to a depressible, sometimes spring-loaded, sliding shaft that actuates via pressing against a surface, a spring-loaded button, or other mechanical means of actuation. In some embodiments, a plunger can have a mechanically-linked TMSM that can communicate its position along the plunger relative to the position of a nearby DRF or other tracked stray markers. In some embodiments, the shaft can be coaxial with a 3D-tracked tool. In some embodiments, the shaft does not need to be protruding out of an object. In some embodiments, the shaft can be engaged within an object.

In some embodiments, spinal alignment parameters of an assessment of the segmental and/or full-length spinal alignment can be produced with values for each relevant radiographic alignment parameter (e.g., Cobb angle, lumbar lordosis (LL), thoracic kyphosis (TK), C2-C7 sagittal vertical axis (SVA), C7-S I SVA, C2-S I SVA, central sacral vertical line (CSVL), Tl pelvic angle (TIPA), pelvic tilt (PT), pelvic incidence (PI), chin-brow to vertical angle (CBVA), Tl slope, sacral slope (SS), C1-2 lordosis, C2-C7 lordosis, C0-C2 lordosis, C1-C2 lordosis, PI-LL mismatch, C2-pelvic tilt (CPT), C2-T3 angle, spino-pelvic inclination from Tl (Tl SPi) and T9 (T9SPi), CO slope, mismatch between T-1 slope and cervical lordosis (Tl S-CL), and/or global sagittal angle (GSA)). Additionally, any time alignment assessments or calculation of alignment parameters are mentioned in this document, it can be assumed that any of the above parameters, and others not mentioned but commonly known, can be calculated in that portion of the description.

In some embodiments, a 3D-tracking acquisition system can refer to the use of a 3D-tracking system to acquire points in 3D space and register particular commands via 3D-tracked tools. Some embodiments include, for example: an optical-tracking system that can be used in surgical navigation (e.g., NDI Polaris Spectra stereoscopic camera system, which tracks tools or objects, as depicted in FIG. 126 , FIG. 127 , etc.).

In some embodiments, a 3D-tracked probe is a tool that can be handheld or robot-held, and can be tracked in 3D physical space by any 3D-tracking acquisition system, such as an optical surgical navigation system (e.g., NDI Polaris stereoscopic camera). In some embodiments, relying on an optical surgical navigation system can include a probe with a substantially rigidly-attached, 3D-tracked DRF. Some embodiments can include the inclusion of a mechanically-linked, 3D-tracked mobile stray marker (TMSM) that can be mounted on, or coupled with, a depressible, spring-loaded, and/or user-actuated shaft that can actuate the motion of the TMSM either linearly or rotationally (e.g., about a hinge pivot on the probe).

In some embodiments, an optical, 3D-tracking system can refer to any optical system that can provide a 3D mapping or image of a scene or calculate the location, orientation, and identity of a tracking-compatible object. Some embodiments include, for example: a 3D-tracking system can be a surgical navigation system (e.g., an NDI Polaris Spectra® stereoscopic camera system, from NDI International, 103 Randall Drive, Waterloo, Ontario, Canada N2V 1C5). In some embodiments, similar information can be gathered from any 3D-tracking, optical-based system.

In some embodiments, a skin-mounted fiducial can be mounted directly on the skin surface of a patient, or within the skin in a percutaneous manner. In some embodiments, an over-the-drape-mating fiducial can be used to mate with another fiducial that is beneath a surgical drape, or any other obstructing material.

In some embodiments, a tracked stray marker (“TSM”) refers to an optically-3D-tracked stray marker, which is defined as an independent light-reflective or light-emitting marker that is not registered as part of a DRF. In some embodiments, this particular stray marker does not exhibit direct movement relative to the dynamic reference marker, however, it can be used as a toggle to signal various, unique commands to the acquisition unit.

In some embodiments, a display monitor refers to any display embodiment that can visually depict the output of the system, its feedback systems and instructions, its calculations, and other relevant information or settings that are available.

In some embodiments, a “tracked end cap” refers to a 3D-tracked object that can contain a substantially rigidly-attached, 3D-tracked DRF and can be substantially rigidly attached to a rod or rod-like object. In some embodiments, the end cap can provide a reference frame of the rod in a manner of establishing a dynamic coordinate system for the implant while its contour is traced, structurally manipulated/contoured, or any other assessment. In some embodiments, this term can be used in the form “tracked DRF-equipped end cap”, a synonym.

In some embodiments, a tracked slider refers to a 3D-tracked object that can contain a substantially rigidly-attached, 3D-tracked DRF and can register the contour of a rod via mechanically engaging with its surface and tracing along the length of the rod. In some embodiments, the slider tool can be transformed to output 3D coordinates and orientation values relative to a 3D-tracked end cap tool. In some embodiments, this term can be used in the form “slider tool equipped with a DRF”; typically used for assessing a rod contour.

In some embodiments, an acquisition system is synonymous with the 3D-tracking acquisition system term described above. In some embodiments, this system is a 3D-tracking camera (e.g., NDI Polaris Spectra® stereoscopic camera) and the computer system with which it is communicating.

In some embodiments, an end-effector refers to any component of an object that interfaces with another surface or object in a manner that enables the registration or communication of information including, but not limited to: 3D location, 3D orientation, unique identity, physical or identity-based relations to other objects in a scene, forces applied to an object or forces experienced by an end-effector, and the like. Some embodiments include, for example: a 3D-tracked distal tip of a robotic arm.

In some embodiments, a tracing refers to the method of acquiring discrete or continuous points along a surface via a 3D-traced probe or object.

In some embodiments, an endplate refers to the surface of a spinal vertebra that interfaces with the intervertebral disc and the nearby vertebra coupled on the other side of the intervertebral disc. In some embodiments, the endplate can be a common anatomical landmark used for measuring the spinal alignment parameters of a patient (e.g., Cobb angles), mainly due to the way that an endplate surface X-ray can be utilized to represent an anatomical line segment or vector, from which two or more endplates can be used to calculate relative angles between two or more vertebrae (e.g., LI and SI endplate measurements can be used to calculate the lumbar lordosis angle of the patient's lumbar spine).

In some embodiments, pose refers to the orientation of an object with respect to another object or 3D-tracking acquisition system. In some embodiments, the pose of an object can be redundant from multiple perspectives or it can be unique and identifiable in a way that it distinguishes itself from other objects. In some embodiments, the pose of an object can be outputted via 3D orientation values (e.g., quaternions, Euler angles, rotation matrices, series of vectors, etc.).

In some embodiments, the term “unique” can refer to the distinct identity of an object, or its distinguishable configuration, position, or orientation. In some embodiments, the phrase “unique pattern” can refer to either the I) embedded pattern surface on the ball component in the 3D-tracking system (depicted in FIG. 117 , FIG. 118 , FIG. 119 , FIG. 120 , FIG. 121 , FIG. 122 , FIG. 123 , FIG. 124 , FIG. 125 ); or 2) an asymmetric or identifiable arrangement of objects that can be registered in a manner that the group of objects can be identified uniquely compared to another group of tracked/registered objects.

In some embodiments, “level” refers to a specific spinal vertebra within the span of the vertebrae of the spinal column. In some embodiments, a level can refer to any of the vertebrae (e.g., LS, TIO, Cl, S3, etc.). In some embodiments, the abbreviations of the sections of the spinal vertebrae can be: lumbar (L), thoracic (T), cervical (C), and sacral (S) vertebrae.

In some embodiments, “fully engaged” can be used to describe two or more objects that are completely linked, mated, coupled, adhered, joined, fastened, or aligned. In some embodiments, two or more objects can be fully engaged. In some embodiments, the computer system can record an event, collect information, acquire 3D locations or orientations, determine the identity of one or more objects, receive a command, or output information regarding the engagement. In some embodiments, fully-engaged objects can trigger a communication to the computer system of a particular command or acquisition to store.

In some embodiments, a “trigger” can be used to describe either a button or a moment of communication that signals to the computer or acquisition system to store data, output calculations or other relevant information, interpret a command, or register an object's identity.

Some embodiments can be independent inventions and do not have to be precluded by other inventions or categorical system workflows (e.g., patient initialization, alignment contour acquisition, etc.), as illustrated in FIG. 1 . For example, some embodiments of the invention described herein include devices, assemblies, systems, and methods to assess the intraoperative alignment of the spine, extract information as to the contour or alignment of instrumented hardware, and evaluate some of the biomechanical qualities of the patient's spine. Some embodiments of the overall system are illustrated in FIG. 1 , where a central software system can receive inputs from discrete and/or continuous location data (e.g., inside and/or outside of the surgical site), where the data is gathered by non-radiographic or radiographic systems, algorithmic calculations, or manual user-based interactions, to generate visual and quantitative outputs relating to the intersegmental or full-length alignment, curvature, position, range-of-motion, and biomechanical flexibility of the patient's spine. Some of the embodiments described herein do not have to be within the categorical series of systematic steps (e.g., 3D trace, local anatomy, landmarks, etc.) shown in FIG. 1 , illustrating a system for assessing spinal alignment, local anatomy biomechanics, rod contours, and active contouring of a rod, as well as initialization of fiducials and interactive displays of various outputs in accordance with some embodiments of the invention. The overall system 100 of FIG. 1 can include devices, assemblies, systems, and/or methods described in the following description in reference to one or more of the figures, including processes that utilize one or more software modules 121 of one or more computer-implemented methods according to some embodiments. In some embodiments, the system 100 can comprise devices, assemblies, systems, and methods for patient initialization 107 , alignment contour acquisition 115 , referenced/detected anatomical regions 117 , third-party software integration 119 , assessment of localized anatomy 105 , rod contour assessment 109 , assisted rod contouring 111 , and output display 113 .

Some embodiments of the invention relate to systems and methods for precise placement of skin surface markers or percutaneous access devices that provide the relative position of underlying bony anatomy to a visible surface grid. In some embodiments, the systems and methods described herein can reduce the number of X-rays needed to be taken to verify location of overlying or percutaneous devices relative to bony anatomy. Some embodiments can include a skin-mounted patch that has visible markings with colors in the visible spectrum for a user to see. Further, in some embodiments, the patch can include corresponding radiopaque patterns (e.g., grid lines, letters, numbers, symbols, icons, etc.) embedded in the patch such that when an X-ray is taken, the patch provides a large area of landmarks that can aid a user with percutaneous device placement, the placement of one or more additional surface marker fiducials, and/or with localizing surgical incision sites relative to underlying anatomy. For example, FIG. 2 A shows a representation of a body-surface-mountable fiducial patch 200 in accordance with some embodiments of the invention, where radiopaque grid lines can be visualized on the X-ray image. Other relevant figures and discussions herein can include those related to skin-fiducial marker examples to apply onto a patch such as FIGS. 6 B, 9 A- 9 B , and FIGS. 11 A- 11 B . As shown in FIG. 2 A , some embodiments include a body-surface-mountable fiducial patch 200 that can comprise an array of radiopaque markers with visible and/or radiopaque grid lines 201 . In some embodiments, the shapes or markers defined by the grid lines 201 can be colored and/or marked with an identifier, including, but not limited to, a red-colored grid surface with a radiopaque “R” (label 209 ), a blue-colored grid surface with a radiopaque “B” (label 211 ), a yellow-colored grid surface with a radiopaque “Y” (label 205 ), and/or a green-colored grid surface with radiopaque “G” (label 207 ). In some embodiments, the grid lines can be further apart or closer than shown. In some embodiments, the markers can be larger or smaller, as well as fewer or greater in number, than shown in this non-limiting embodiment. In some embodiments, the body-surface-mounted fiducial patch 200 can enable precise placement of surface-mounted objects or percutaneous devices that require recognition or understanding of the relative location of underlying bony or soft-tissue structures.

It should be noted that in some embodiments, the visible surface of the patch 200 need not be a distribution of colors, but can also consist of any recognizable pattern that is also displayed in a meaningful way on X-ray imaging. In some embodiments, the patch can be adhered to surface anatomy via an adhesive (not shown) or other methods. In some embodiments, one side of the patch 200 can include adhesive (e.g., such as the skin-mounted side). In some embodiments, the size and density of unique identifiable grid sections on the patch can be varied based on a particular application. In some embodiments of the invention, a radiopaque lining can be included that at least partially matches one or more overlying visible markings. In some embodiments, the patch 200 can facilitate a user understanding where each visible marking is and how it corresponds with an underlying anatomical region or element. This can facilitate a user making incisions in known or identified regions of a patient according to some embodiments.

FIG. 2 B displays the radiopaque elements of the fiducial patch of FIG. 2 A as would be visible on an X-ray image of a patient with the patch applied in accordance with some embodiments of the invention. For example, X-ray patient image 225 is shown with radiopaque fiducial grid patch 200 a displayed on the image 225 according to some embodiments. In some embodiments, the image displays the radiopaque elements of the fiducial patch 200 as would be visible on an X-ray image 225 of a patient with the patch 200 applied. In some embodiments, after taking an X-ray of the patch 200 applied to the patient, users can place surface fiducials or direct percutaneous access devices towards the bony anatomy of interest based on the corresponding grid location on the patch that represents the underlying anatomy of interest. In this non-limiting example embodiments, the red-colored grid surface with radiopaque “R” (label 209 ) is shown as 209 a , the blue-colored grid surface with radiopaque “B” (label 211 ) is shown as 211 a . Further, in some embodiments, the yellow-colored grid surface with radiopaque “Y” (label 205 ) is shown as 205 a , and the green-colored grid surface with radiopaque “G” (label 207 ) is shown as 207 a in the X-ray image 225 . In some embodiments, when used in this way, the patch 200 of FIG. 2 A and imaging of FIG. 2 B can aid with the precise selection of correct surgical site access points, ensuring that incisions overlay the desired bony anatomy on which will be operated. Additionally, in some embodiments, this patch 200 can be used to precisely place secondary skin-mounted fiducials such that they superimpose underlying bony anatomy of interest. Some example embodiments of fiducials that can be applied onto the imaged patch include FIG. 6 B , FIGS. 9 A- 9 B , FIGS. 11 A- 11 B . In some embodiments, the patch 200 can be applied to a patient's skin using adhesive or other conventional methods. In some embodiments, the type of identifiable surface marker can be different than some embodiments shown.

FIGS. 3 A- 3 C illustrate a bone-mounted fiducial device that is designed with a crossbar to interface with one or more mating devices that can either help to register the fiducial's location and pose in 3D space (e.g., via tracing, tapping discrete locations, being tracked directly), help initialize the fiducial relative to anatomical structures of interest registered with X-ray images or 3D-tracking acquisition systems, or directly manipulate the fiducial and attached bony anatomy after they are coupled according to some embodiments. In some embodiments, after imaging a fiducial mounted to bony anatomy, the fiducial's relative location in space to an anatomical landmark of interest can be registered, such that when the fiducial is located and registered by 3D-tracked tools in the future, the corresponding bony anatomy elements are also localizable and/or identifiable. The vertebra 300 is shown with a bone-mounted fiducial 320 fastened to the bone. In some embodiments, the fiducial 320 can be fastened to the medial border of the right spinal lamina, but because of its small size and profile, it can be mounted anywhere on the bony anatomy. In some embodiments, the bone-mounted fiducial 320 can contain a threaded or smooth bone-piercing component (not shown) so that it can be substantially rigidly fastened to the anatomy of interest (e.g., the vertebra 300 ). In some embodiments, the bone-piercing component can be significantly miniaturized such that it does not pierce through the opposite side of the bony anatomy, or otherwise harm any sensitive anatomical structures.

In some embodiments, the fiducial 320 can contain one or more rigid crossbars 325 that travel across the fiducial 320 . In some embodiments, the crossbars 325 can be positioned such that there is an open space underlying it to allow for a mating interface of a coupled fiducial accessory 350 to directly engage with it. In this instance, in some embodiments, the fiducial 320 can be substantially rigidly fixed to the accessory fiducial 350 (see FIG. 3 B below) so as to interpret the pose and location of the fiducial 320 in space when accessed by a 3D-tracked device.

In addition, some embodiments involve a patterned perimeter surface ( FIG. 3 B ), including but not limited to groove 327 (not shown) and other identifiable patterns, that can be traced or discrete registered by a 3D-tracked probe. In some embodiments, FIG. 3 B shows an assembly view of a vertebra 300 with a bone-mounted fiducial 320 and accessory fiducial 350 for coupling to the bone-mounted fiducial 320 , illustrating the mating capability of the bone-mounted fiducial 320 such that it can mechanically couple with an accessory fiducial 350 via a variety of mechanisms. For example, in some embodiments, one non-limiting mechanism includes a quarter-turn interlocking mechanism 355 such that the accessory fiducial 350 is tightly pulled into the crossbars 325 of the base bone-fiducial 320 when the accessory fiducial 350 is rotated 90 degrees into the interlocking design of the mechanism 355 . In some embodiments, the structure of the accessory fiducial 350 is such that it can contain surface features, including, but not limited to, asymmetric pattern of three or more identifiable indentations 370 . In some embodiments, the identifiable indentations 370 can enable the registration of the unique position and pose of the fiducial 320 in 3D space by interfacing with 3D-trackable devices, as further described in more detail below in reference to FIG. 3 C , and FIGS. 44 A- 44 D . In some embodiments, other conventional mating mechanisms with the fiducial include, but are not limited to, a quarter-turn, half-turn, internal threads, a clamping device, and/or a spring-loaded snap-in device.

Some embodiments of the uniquely identifiable surface structure of the accessory fiducial 350 that can be used for registration of the orientation of the fiducial 320 in 3D space when interacting with a 3D-tracked probe, can include, but not be limited to, 1.) three or more uniquely spaced indentations, 2.) a uniquely identifiable groove in which a 3D-tracked probe can trace in order to identify the location and pose of the fiducial 320 , 3.) an insert that contains a set of three or more tracked markers whose location in 3D space are able to be tracked by a 3D-tracking camera, 4.) a tracked DRF, 5.) a larger version with radiopaque features to enable its unique pose and location to be identifiable with X-ray imaging, and 6.) interfacing with a tracked probe that can substantially rigidly couple to the fiducial 320 in such a way that it can interpret the location and pose of the fiducial 320 in 3D space, as described below in reference to FIGS. 44 A- 44 D . For example, FIG. 3 C shows a vertebra 300 with a bone-mounted fiducial 320 coupled with a top fiducial (fiducial 350 ) in accordance with some embodiments of the invention. In some embodiments, the bone-mounted fiducial 320 includes an accessory fiducial 350 substantially rigidly attached and demonstrates some embodiments of a uniquely identifiable surface pattern 370 (surface indentations) that can be registered with a 3D-tracked probe. In some embodiments, the three or more discrete indentations that make up the surface pattern 370 can couple with at least a portion of a 3D-tracked probe that can couple with the surface pattern 370 . Consequently, one or more computer systems can then be used to compute the location and unique pose of the fiducial 320 in 3D space according to some embodiments.

FIG. 4 A illustrates an assembly or operation process 450 for a skin-surface-mounted fiducial 400 being applied to a patient 425 in accordance with some embodiments of the invention. The skin-surface-mounted fiducial 400 is applied to the patient's posterior skin as they are positioned prone on an operative table 435 according to some embodiments. In some embodiments, this fiducial 400 can be adhered to the patient's skin via attached adhesive compound, staples, suture, or overlying adhesive draping.

FIG. 4 B illustrates a sample lateral radiograph of the radiopaque markers 444 embedded within a skin-based fiducial 442 applied to an anatomical model 443 , adhered to its skin surface 446 , in accordance with some embodiments of the invention. In some embodiments, the radiopaque elements of the fiducial markers 444 allow the fiducial 442 to be clearly visualized and identified on radiograph images. Additionally, in some embodiments, the known sizing of the radiopaque markers 444 allow for reference scaling within the X-ray image 441 . Furthermore, the nearby anatomical structures that are also within the field of view of the X-ray image 441 can then be initialized such that a displacement vector can be drawn within the plane of the X-ray image 441 as described below in FIG. 4 C and FIG. 4 F . In some embodiments, the arrangement of the radiopaque fiducial markers 444 can be designed in an asymmetric pattern to enable an X-ray image of the fiducial from any perspective to visualize a unique pose of the pattern and to subsequently enable the system to automatically estimate the 3D orientation of the fiducial 442 . For example, FIG. 4 C illustrates the sample lateral radiograph 440 of FIG. 4 B with annotated vectors in accordance with some embodiments of the invention. In some embodiments, FIG. 4 C displays one aspect of the initialization process for fiducials located nearby anatomical elements whose position is desired to be known relative to that of the fiducial 442 . In some embodiments, manual or automated software annotation can enable the identification of the radiopaque markers within the fiducial (shown as vectors 465 and 460 extending between radiopaque markers 444 ).

In some embodiments, given the relative sizing of the fiducial markers 444 to one another as well as their relative orientations to one another, the pose of the fiducial 442 relative to the plane of the X-ray image 440 can be calculated. In some embodiments, the user interfaces with the system to select one or more additional anatomical points to which the displacement vector 470 from the fiducial 442 will be calculated. In some embodiments, in this example, the central region of a particular vertebral body was selected, indicated by a large circle (e.g., shown as 427 ), and the software calculated the pixel distance between each radiopaque marker 444 and the annotated region 427 on the display monitor. In some embodiments, based on the known size of the radiopaque markers 444 that are in or on the fiducial 442 , the image can be scaled such that length measured in pixels can be converted to length measured in distance units (e.g., mm, cm, etc.). In some embodiments, the software can also calculate displacement vectors from the fiducial to any anatomical landmarks of interest, even across several vertebrae.

FIG. 4 D illustrates a C-arm X-ray imaging system 480 that can be utilized for image acquisition and subsequent initialization of fiducial markers 442 in accordance with some embodiments of the invention. In some embodiments, following the first X-ray image that was taken, the relative angle between the patient-fiducial complex and the X-ray emitter is rotated by either a known or unknown amount to take a subsequent image. In some embodiments, the second image allows for added information outside of the plane of the first X-ray image to construct the 3D displacement vector between the fiducial and the bony anatomy of interest. In some embodiments, this X-ray system needs not be a C-arm-based device 480 , but can also consist of other image acquisition systems including but not limited to the O-arm, flat-plate X-rays, CT scan, MRI, and wall or bed-mounted acquisition systems.

FIG. 4 E illustrates a sample X-ray image 485 of a spine-fiducial pair from a different imaging angle from that of FIGS. 4 A and 4 B in accordance with some embodiments of the invention, and illustrates the fiducial radiopaque markers (shown as 487 a , 487 b ) as some embodiments of an arrangement of radiopaque markers in or on the fiducial distributed to enable image scaling and localization to nearby anatomical areas of interest.

FIG. 4 F illustrates the sample X-ray image 485 of FIG. 4 E , including annotated vectors in accordance with some embodiments of the invention. In some embodiments, FIG. 4 F displays the X-ray image initialization process for the fiducial-body pair that was imaged and described above in FIG. 4 E . In some embodiments, the annotated vectors 488 are used to reference the relative position of each of the radiopaque markers ( 487 a , 487 b ) within the fiducial 442 ( FIGS. 4 B- 4 C ) as well as calculate the displacement vector 486 to the user-indicated nearby anatomical region of interest (shown as 489 ), for which the fiducial 442 can serve as a reference point upon future localization of that fiducial. In some embodiments, the arrangement of the radiopaque fiducial markers can be designed in an asymmetric pattern, as seen by the example unique triangular pattern of vectors between the radiopaque markers 487 a , 487 b , to enable an X-ray image of the fiducial from any perspective to visualize a unique pose of the pattern that can enable the system to automatically estimate the 3D orientation of the fiducial. In some embodiments, in this respect, the estimation of the fiducial's orientation enables the system to calculate the 3D vector with respect to the fiducial axes.

FIG. 4 G displays the 3D axes of a fiducial device 442 in coordinates of the X-ray imaging system, in which the unique location and pose of the fiducial 442 was registered in accordance with some embodiments of the invention. In some embodiments, the X-ray imaging system coordinate axes 492 are shown with a 3D-displacement vector 494 a that indicates the relative 3D offset initialized between the fiducial origin 490 a and the triangulated position of the anatomical landmark of interest 491 a , which was annotated previously (annotations 427 and 489 ). In some embodiments, displacement vectors drawn over each of the 2D X-rays are able to be combined based on an input or calculated angle between each X-ray image plane in accordance with some embodiments of the invention. In some embodiments, this input enables the calculation of a rigid body transform between the coordinate axes of the two or more X-ray images of the fiducial 442 , and thus enable for the calculation of a 3D-displacement vector that combines displacement vector inputs from two or more X-ray images. In some embodiments, it must be noted that the series of X-ray images of a fiducial device 442 relative to the anatomical regions of interest, such as 427 or 489 , may not always differ by a purely rotational transformation, and may include a translational transformation, especially if the fiducial 442 is not isocentrically aligned with the volume of the C-arm field-of-view, as it is rotated by its boom (as seen in FIG. 4 D ). In some embodiments, this non-circularity of the C-arm's field of view may be caused by the center of the imaging cone not aligning with the center of the C-arm's axis of rotation.

FIG. 4 H illustrates a system and method of localizing the fiducial in 3D-tracking camera coordinates in accordance with some embodiments of the invention. In some embodiments, shown in the non-limiting embodiment are an identifiable tracing pattern 495 , a tracked probe with triggering capability 496 (shown with the probe in an active tracing state 493 ), and fiducial coordinate axes 497 , relative to the 3D-tracking acquisition system. FIG. 4 H displays one method of localizing the fiducial in 3D-tracking camera coordinates as a non-limiting embodiment. As shown, the fiducial is equipped with a unique groove pattern 495 into which a tracked probe 496 can trace the fiducial's signature pattern. In some embodiments, as described above in relation to FIG. 4 A , the recognizable features of the fiducial are not limited to a uniquely traceable pattern, but also discrete points to tap, mount locations for tracked markers, and substantially rigidly coupling with a tracked probe in a way such that the probe's pose can be used to interpret the fiducial's position and pose. In some embodiments, by tracing the unique surface pattern 495 on the fiducial with a tracked probe 496 , the fiducial's axes 497 and origin are able to then be interpreted with respect to the 3D-tracking acquisition system's coordinate system. In some embodiments, the acquisition system will subsequently be able to interpret the location of the initialized nearby anatomical region (such as 427 and 489 ) as described below in FIG. 4 I .

In some embodiments, FIG. 4 I illustrates the 3D coordinate axes of the fiducial device 498 relative to the 3D-tracking acquisition system. Some embodiments includes the fiducial coordinate axes 498 relative to that of the 3D-tracking acquisition system and the 3D-displacement vector 494 b between the fiducial 442 and the anatomical regions of interest ( 427 and 489 ). The 3D-displacement vector 494 b , between the fiducial origin 490 b and the anatomical region of interest 491 b relative to the coordinates of the 3D-tracking acquisition system, represents the vector 494 a (shown in FIG. 4 G ) after it has undergone a 3D rigid transform, utilizing the calculated transform between the fiducial location and orientation in both the X-ray imaging and 3D-tracking acquisition systems, as depicted in FIGS. 4 C, 4 F, and 4 H . In some embodiments, this resultant 3D-displacement vector enables for the calculation of the location of the anatomical region of interest 491 b (depicted in FIGS. 4 C- 4 G as labels 427 and 489 relative to the X-ray imaging system coordinates) with respect to the fiducial's origin and coordinate axes relative to the coordinate system of the 3D-tracking acquisition system. In some embodiments, this enables localization of the bony anatomy regions of interest by interpreting the location and pose of the fiducial within other 3D-tracking acquisition system axes, as depicted in FIG. 4 H .

In some embodiments, FIGS. 5 A- 5 C display components, systems and methods of initializing a fiducial to serve as a reference point for underlying anatomical regions of interest, as described above in reference to FIGS. 4 A- 4 I . However, in some embodiments, instead of utilizing X-ray images, the methods can utilize an ultrasound-based probe 575 equipped with a tracked DRF 580 so that its location and pose are able to be computed when visualized by a 3D-tracking camera. For example, FIG. 5 A illustrates an optical 3D-tracking system 550 in accordance with some embodiments of the invention, and FIG. 5 B illustrates an ultrasound probe 575 equipped with a tracked DRF 580 in accordance with some embodiments of the invention. Further, FIG. 5 C illustrates an assembly or process view 590 of a patient's skin surface 594 overlying a cross-sectional view of a vertebra 596 as a representation of a particular region of bony anatomy that could be registered to a skin-mounted fiducial 592 in accordance with some embodiments of the invention. In some embodiments of the invention, the optical 3D-tracking camera 550 of FIG. 5 A can be utilized for the 3D-tracking acquisition system referenced throughout this document. In some embodiments, this system utilizes stereoscopic cameras 551 to detect the location of tracked markers that reflect or emit infrared light. In some embodiments, this is one example of a tracking system that can be used for acquisition of 3D coordinates throughout this document, but this can also be achieved by other methods including but not limited to light-emitting markers, electronic communication, etc. Further, in some embodiments, the ultrasound probe 575 of FIG. 5 B is equipped with a tracked DRF 580 that enables the probe's location and pose to be tracked in 3D space using passive, light-reflective markers 585 . In some embodiments, tracking the precise location of the probe allows for recording the relative angles between each cross-sectional imaging plane of an acquisition that can be used for creating the 3D-displacement vector to the anatomical point of interest via the computation of 3D rigid transformations of the relative location and pose of the ultrasound probe 575 between acquisitions of the ultrasound cross-sectional images.

In some embodiments, FIGS. 6 A-D includes depictions of devices, systems and processes of applying a skin-mounted fiducial along with its top-mating component that enables mating across surgical drapes so that the fiducial can be both visualized and referenced during procedures during which a drape is obstructing the surface overlying bony anatomy for which the location is desired to be known.

In some embodiments, FIG. 6 A portrays a sample scenario for which applying a skin-mounted fiducial 625 and its associated over-the-drape-mating fiducial 635 could be used. In some embodiments, with the patient positioned prone on the operative table, skin-mounted fiducials can be applied over regions that will not be surgically exposed but under which contain bony anatomy for which a location is desired to be known relative to other anatomical regions. In some embodiments, after the surgical drape 605 is applied over the skin-mounted fiducial, the over-the-drape-mating fiducial can then be used to interpret the position of the underlying skin-mounted fiducial, described in more detail below in FIGS. 6 B-D . For example, FIG. 6 A illustrates an assembly or process view 600 for applying a skin-mounted fiducial 625 and its associated over-the drape fiducial 635 in accordance with some embodiments of the invention, and FIG. 6 B illustrates an assembly view 650 of a skin-mounted fiducial 625 and its associated over-the-drape mating fiducial 635 in accordance with some embodiments of the invention. In some embodiments, the fiducial 625 can comprise the fiducial 400 and the fiducial 635 can comprise the fiducial 635 .

In reference to FIG. 6 B , detailed components depict a skin-mounted fiducial 625 and its associated over-the-drape-mating fiducial 635 . In some embodiments, the skin-mounted fiducial 625 can include a method of adhering to the skin surface (not shown), including but not limited to adhesive material, looped regions to be sutured or stapled to the skin, percutaneous or bone-piercing screws, pins, wires, or other common fasteners, and/or attached bands to be tightly wrapped around body surfaces. In some embodiments, contained within or on either of the fiducials can be one or more radiopaque markers 608 that are readily visualized on X-ray images of the fiducials. Furthermore, in some embodiments, these radiopaque markers 608 can be positioned relative to one another via shape-specific cutouts 606 and the fiducial body itself in such a way that the markers can be used to identify the pose of the fiducial on 2D X-ray images, as described above in FIG. 4 . In some embodiments, the fiducials can contain magnets (e.g., shown as magnet 604 in the fiducial 625 , and 619 in the fiducial 635 embedded in or on the fiducial surfaces in such a way that it helps to securely fasten the two fiducials when separated by a surgical drape (shown as 605 in FIG. 6 A ). In some embodiments, the magnets can have varying geometry. For example, some embodiments include spherical magnets that can be used to serve both functions of a radiopaque marker as well as feature to help join mating fiducials across drapes. In some embodiments, the skin-mounted fiducial can also be equipped with protrusions to serve as mechanical alignment mates (shown as 602 a and 602 b ). In some embodiments, the mates can protrude from one fiducial (e.g., 625 as shown and/or alternatively from both fiducial 625 and fiducial 635 ) and have complementary mating cutouts, such as 617 a , 617 b , within the opposite fiducial to help ensure both fiducials are properly aligned relative to one another. The protrusions are conical in shape in FIG. 6 B , but can also be created with other tapered or non-tapered geometry in some embodiments.

In some embodiments, FIG. 6 C illustrates a skin-mounted fiducial applied to an anatomical phantom in a region that is outside the surgical site but located over regions of underlying anatomy for which their location within coordinates of the 3D-tracking acquisition system is desired to be known in accordance with some embodiments of the invention. Further, FIG. 6 D illustrates some embodiments of a skin-mounted fiducial mating with its over-the-drape fiducial across a surgical drape/towel in accordance with some embodiments of the invention. In reference to FIG. 6 C , in some embodiments, the skin-mounted fiducial 625 can be applied to an anatomical phantom 677 in a region that is outside the surgical site 681 . For example, FIG. 6 D illustrates some embodiments of a skin-mounted fiducial mating 625 with its over-the-drape fiducial 635 across a surgical drape/towel 679 in accordance with some embodiments of the invention. In some embodiments, because the over-the-drape-mating fiducial 635 is mechanically mated in a predictable fashion with the skin-surface fiducial 625 , the location and pose of the over-the-drape-mating fiducial 635 can be used to compute the location and pose of the underlying skin-mounted fiducial 625 . Furthermore, in some embodiments, if the skin-mounted fiducial 625 had been previously initialized to nearby anatomical structures, as described above in relation to FIGS. 4 A- 4 I , the location and pose of the over-the-drape-mating fiducial 635 can then be used as a surrogate reference point for the underlying anatomy of interest 681 .

FIG. 7 illustrates an assembly view 700 of a fiducial 740 in accordance with some embodiments of the invention that enables unique identification of one fiducial to another. In some embodiments, this can be applied to scenarios when more than one fiducial is used, and the identity of the fiducial is required. In some embodiments, an interfacing probe 703 is shown designed with electrodes 735 to mate with the fiducial 740 . In some embodiments, the electrodes can be coupled to or inserted into the fiducial 740 , and based on the circuit characteristics built into the fiducial material (e.g., electrical resistance, capacitance, etc.), the fiducial's unique identity can be made known by the mating probe. As shown, in some embodiments, the probe 703 can include a probe shaft 705 coupled to a tracked DRF 715 with 3D-trackable markers 725 . Further, in some embodiments, the fiducial 740 can include two electrodes built-in, and can possess identifying circuit components (e.g., resistors, capacitors, etc.) embedded between electrodes. In some embodiments, in this way, a probe 703 equipped with a tracked DRF 715 can be designed such that it has mating electrodes 735 that can interface with the fiducial 740 , measuring the unique electrical characteristics of the fiducial 740 , while simultaneously identifying the location and pose of the fiducial 740 in 3D space. Thus, in some embodiments described above can enable identification of unique fiducials, which can be useful when multiple fiducials are being deployed.

FIG. 8 illustrates an assembly view 800 of a fiducial in accordance with some embodiments of the invention, and enables unique identification of one fiducial compared to another. In some embodiments, this can be applied to scenarios when there is more than one fiducial used, and the unique identity of the fiducial is desired to be known. In this design, in some embodiments, a probe equipped with an RFID-reading circuit interfaces with a spring-embedded RFID-tag circuit within the fiducial. In some embodiments, in this way, the probe 803 is able to simultaneously communicate that the fiducial has been accessed by a depressed spring-loaded momentary push button, and can also acquire information as to which fiducial has been referenced. As shown, the probe 803 can comprise a tracked DRF 715 with trackable markers 725 configured to be coupled to an embedded RFID reader 850 including a spring-loaded button 855 . In some embodiments, the tip 707 of the shaft 705 can couple with the surface 858 of the button 855 , compressing the spring 864 , and eventually enabling contact of the terminals 862 with the RFID tag 870 . In some embodiments, if accessed by a probe 803 equipped with an RFID reader 850 in addition to a tracked DRF 715 , a probe 803 that depresses the spring 864 can simultaneously perform three tasks 1.) trigger that it has approximated the fiducial, 2.) interpret the location of the fiducial surface, and 3.) interpret the unique identity of the fiducial based on its embedded RFID tag.

In some embodiments, FIG. 9 A displays some embodiments of a skin-surface fiducial described previously in relation to FIGS. 6 A- 6 B . In some embodiments, the assembled skin-surface fiducial 900 includes a mating top-surface fiducial 905 coupled to a skin-mountable fiducial. For example, FIG. 9 A displays an assembled skin-surface fiducial 930 with its over-the-drape-mating fiducial 905 according to some embodiments. In some embodiments, the bottom surface fiducial 930 is equipped with a mechanism (not shown) of adhering to the skin surface. In some embodiments, the fiducial pair 905 , 930 joins together at an interface 925 designed to accommodate surgical drapes or towels, while maintaining a predictable mating configuration. In some embodiments, the top fiducial contains a groove (tracing pattern 910 ) in a unique geometry (e.g., “z” geometry shown here) such that a 3D-tracked probe (e.g., any of the 3D-tracked probes described herein) can trace the pattern, as depicted previously in relation to FIG. 4 H , and from that information interpret the unique identity of the fiducial, as well as interpret its location and pose in space, enabling the identification of a fiducial-based axes as described previously in relation to FIGS. 4 A- 4 I .

The external design of the fiducial 900 is configured to communicate information to the user as embedded instructions according to some embodiments. Some embodiments of the fiducial possesses an external arrow appearance ( FIG. 9 A depicts an example of fiducial 900 assembled as an arrow) that can be used to indicate how the user should place the fiducial (e.g., position the fiducial on the skin such that the arrow points away from the surgical site). In some embodiments, a sloped decline 920 of known geometry on the bottom fiducial, as well as a curved decline 915 on the top fiducial, can be implemented to facilitate a user tracing a probe from the groove surface 910 of the top-half fiducial 905 down to the bottom surface of the bottom-half fiducial 930 , which transitions to skin or drape-covered skin, onto which the top-half fiducial 905 is placed. In some embodiments, the framed structure of the fiducial 900 can allow for more predictable tracing over the transition from the fiducial groove 910 to the underlying surface. Additionally, in some embodiments, it allows for the ability to calculate the location of the underlying body surface given the known geometry of the fiducial slope design.

FIG. 9 B illustrates an assembly view of the fiducial 900 of FIG. 9 A in accordance with some embodiments of the invention. In some embodiments, the skin-mounted fiducial 930 contains male alignment-aiding protrusions 940 , similar to those described previously in relation to FIG. 6 B . Further, in some embodiments, the protrusions have a flattened top 922 to accommodate added volume of an overlying material, as in the case of a surgical drape. In some embodiments, in this way, the structure allows for close approximation of the two fiducial mates in the presence of a sandwiched drape by avoiding tenting of the drape in between the two fiducial halves. In some embodiments, the fiducials 905 , 930 are equipped with cutouts 924 to accommodate both radiopaque markers and/or magnets, which can also act as radiopaque markers, as described previously in relation to FIG. 6 B . In some embodiments, the cutouts 924 involves an asymmetric geometric pattern that substantially rigidly embeds the radiopaque markers in a relative configuration that enable unique pose estimations at any radiographic viewing angle. Instead of magnets used to help approximate the two fiducials, some embodiments can include protrusions with a quarter-turn or twisting mechanism that allows for tight mechanical linking across surgical drapes. In some embodiments, the over-the-drape-mating fiducial 905 is equipped with female alignment-aiding cutouts 908 configured to mate with the location of the protrusions 940 , 922 on the skin-mounted fiducial 930 . In some embodiments, it should be noted that the location, size, and geometry of these protrusions and mating cutouts can vary and that this is just some embodiments. Furthermore, in some embodiments, it is not necessary for the protrusions to only be located on the skin-mounted fiducial, and the cutouts on the over-the-drape-mating fiducial can include varying combinations of shapes and size.

In place of magnets, some embodiments can include a “clamp-over-drape” feature (e.g., tabs on the top fiducial to clamp down over the lower fiducial sides, while grabbing the drape in between). In some embodiments, this invention includes two or more clamping arms equipped on the over-the-drape fiducial designed to snap onto corresponding regions of the lower fiducial for ensuring proper alignment when separated by a surgical drape.

In some embodiments, the fiducial 905 can be equipped with other components mentioned throughout the document, such as the depth-stop-based fiducial and probe combination described later in reference to FIGS. 10 A- 10 G . In some embodiments, of the fiducial that enable it to be uniquely identifiable include detents of discrete depths designed to mate with a probe equipped with depth-sensing technology, as described below in reference to FIGS. 10 A- 10 G , such that the fiducial and unique location of the detent relative to the fiducial can be determined based on the distribution of measured detent depths.

In some embodiments, the bottom fiducial 930 can have a flexible component to enable it to successfully adhere and/or conform to the uneven surface contour of patient's skin.

Some embodiments of the invention described in FIGS. 10 A- 10 G include a 3D-tracked probe coupled with an actuating TMSM that indicates the depth of depression of a spring-loaded sliding shaft, as well as complementary mating fiducials that are designed to interface with and deflect the shaft by discrete amounts. In some embodiments, the purpose of this design is multifactorial. For example, FIG. 10 A illustrates a 3D-trackable probe 1000 equipped with a substantially rigidly-attached, 3D tracked DRF 1020 in accordance with some embodiments of the invention. In some embodiments, the actuated TMSM 1030 on the tracked probe 1000 allows for analog communication between the probe 1000 and an acquisition system, as will be described below in reference to at least FIGS. 15 A- 15 C and 63 . In some embodiments, the actuated TMSM 1030 conveys information about the depth of deflection of the shaft 1049 at the tip 1049 b of the probe 1000 . Further, in some embodiments, when coupled with mating fiducials that are designed to deflect the shaft tip 1049 b by set heights when fully-engaged, the probe 1000 can convey the following three things: 1.) when it is fully engaged with a mating fiducial, 2.) the location and pose of the mating fiducial, and 3.) the unique identity of the mating fiducial based on the designed depression depth that the fiducial will deflect the sliding shaft 1049 . As shown, in some embodiments, the tracked DRF 1020 includes fixed 3D-tracked markers 1025 a , 1025 b , 1025 c , 1025 d . Some or all of the markers 1025 a , 1025 b , 1025 c , 1025 d shown in the DRF frame 1020 can be used in any of the DRFs described herein. In some embodiments, any of the DRFs described herein can use these markers, or may use fewer markers. In some embodiments, any of the DRFs described herein may use more markers similar or identical to any of the markers 1025 a , 1025 b , 1025 c , and/or 1025 d . In some embodiments, any of the probes or DRFs described herein can include any of the markers 1025 a , 1025 b , 1025 c , and/or 1025 d but with different geometries and/or shapes (e.g., the markers can be smaller or larger than shown, or can be placed at different distances from the probe shaft).

Some embodiments includes a 3D-tracked probe equipped with a substantially rigidly-attached 3D-tracked DRF 1020 . In addition, a TMSM 1030 is substantially rigidly attached to a spring-loaded shaft 1049 that is coaxial with the probe 1000 and actuates within a through-hole down the length of the probe shaft 1010 of the probe 1000 . In some embodiments, the sliding shaft 1049 can be actuated via a depressible tip 1049 b that translates the shaft along with a mount 1005 for the TMSM 1030 . In some embodiments, the probe also contains a series of concentrically-oriented, varying-diameter, protrusions 1040 near the probe tip 1049 b . In some embodiments, these varying diameter protrusions 1040 can serve as variable-depth-stop selections ( 1041 , 1045 , 1047 ) when mating with depth-stop fiducials, as described below in reference to FIG. 10 C , designed with varying inner diameters for mating with specific depth-stops 1040 on the probe 1000 . For example, in some embodiments, FIG. 10 B displays a more detailed perspective of the probe 1000 with actuating tip and variable depth-stops as described previously in FIG. 10 A . In some embodiments, the tracked probe shaft 1010 includes coaxial cylindrical extrusions 1040 of various heights that act as a depth-stops to the actuation of the depressible sliding shaft tip 1049 b , and its associated TMSM 1030 , to different heights ( 1041 , 1045 , 1047 ) for unique trigger signals that are communicated to the computer system.

In some embodiments, FIG. 10 C displays depth-stop fiducials designed to mate with the probe previously described above in relation to FIGS. 10 A- 10 B . These depth-stop fiducials ( 1050 , 1052 ) have variable inner diameters and/or heights such that they can couple with varying depth-stops on the probe. In some embodiments, in addition to having variable inner diameters to mate with defined depth-stops on the probe (e.g., such as probe 1000 ), which can lead to identifiable deflections of the TMSM 1030 relative to the DRF 1020 . Further, some embodiments of these depth-stop fiducials also contain variable floor depths, such that the sliding probe tip 1049 b can be actuating by varying amounts despite mating with depth-stop fiducials with matching inner diameters. In some embodiments, in this way, these depth-stop fiducials ( 1050 , 1052 ) can be distinguished from one another and their mating inner diameters and/or depth-stops provide for additional, unique identifiers. In some embodiments, these depth-stop fiducials can therefore be coupled as probe-interface components coupled to fiducials previously described in relation to FIGS. 3 A- 3 B, 6 A- 6 D, and 9 A- 9 B .

In some embodiments, FIG. 10 D displays the probe 1000 , previously described in relation to FIGS. 10 A- 10 B , mated with a particular depth-stop fiducial 1050 , previously described in relation to FIG. 10 C . In some embodiments, with these two components coupled in this way, the TMSM 1030 can be actuated coaxially with the probe shaft 1010 and based on the known geometry of both the probe and its mating depth-stop fiducial, the deflection can be measured relative to the tracked DRF and compared to what deflection amounts are anticipated based on particular mates to the probe's depth-stop heights 1061 (previously shown as 1041 in FIG. 10 A ). In some embodiments, the measured deflection (“M”) of the sliding tip and attached TMSM 1030 to the sliding shaft is able to serve as a unique identifier of when the probe (e.g., 1000 and/or 1001 ) is fully engaged with a specific depth-stop fiducial 1060 (previously shown as 1050 in FIG. 10 C ).

In some embodiments, FIG. 10 E displays a probe 1002 , as previously described in relation to FIG. 10 A , mated with a depth-stop fiducial 1084 (previously shown as 1052 in FIG. 10 C ) designed to mate with a unique depth-stop 1082 (previously shown as 1045 in FIG. 10 A ) of the probe 1000 than was shown previously in relation to FIG. 10 D . In some embodiments, as compared to FIG. 10 D , this figure displays the different region of mating 1080 on the probe's unique depth-stop 1082 along with the associated difference in deflection height (“P”) of the TMSM 1030 , indicating the different depression depth of the sliding probe tip (compare “P” in FIG. 10 E with “M” in FIG. 10 D ).

FIG. 10 F illustrates an assembly view 1099 of a portion of the probe 1000 in accordance with some embodiments of the invention. In some embodiments, the 3D-tracked probe 1000 , as described previously in relation to FIG. 10 A , contains an asymmetric, protruding extrusion 1091 that can engage with any of the depth-stop fiducials, as described previously in relation to FIG. 10 C , where a corresponding slot 1093 of a depth-stop fiducial mates with the probe's extrusion 1091 . In some embodiments, the probe can only mate in one orientation with the depth-stop fiducial due to the asymmetrical design of the slot cutout 1093 . In some embodiments, this asymmetric alignment enables the probe 1099 to register the unique orientation of the coordinate axes of the fiducial 1095 , and thus detect how the fiducial 1095 rotates and translates in 3D space between registrations. In some embodiments, FIG. 10 G illustrates a perspective view of the depth-stop fiducial 1095 partially engaged with the depth-stop-equipped, 3D-tracking probe 1000 , both previously depicted in relation to FIG. 10 F .

In some embodiments, FIGS. 11 A- 11 B displays skin-surface and mating fiducial design as previously described in FIGS. 6 A- 6 B and FIGS. 9 A- 9 B . In some embodiments, the primary difference in this design is that there are tracked markers mounted to the top fiducial such that its location, pose, and identity are all able to be registered by a 3D-tracking acquisition system without the need for the fiducial to interface with a tracked probe. In some embodiments, the fiducial's information is constantly being registered provided it is in line of sight of the 3D-tracking camera system. In some embodiments, the assembled fiducial can serve the same purpose as previously described in that once initialized, it serves as a surface reference point for the 3D location in space of underlying anatomical structures. For example, in some embodiments, FIG. 11 A displays a top view assembly view 1100 of a skin-surface fiducial 1155 mated with an over-the-drape-mating fiducial 1105 that contains three or more tracked markers 1135 . In some embodiments, these markers 1135 are arranged in a predetermined configuration to form a DRF object, such that a camera acquisition system can recognize them as a unique entity related to the fiducial. In some embodiments, these tracked markers 1135 allow for the constant registration of the fiducial's location and pose in 3D space provided that they are within line of sight of the camera. In some embodiments, in the event that these tracked markers 1135 are not within line of sight of the camera, the top fiducial component 1105 also contains a surface contour 1110 that can be accessed and traced and/or tapped by a 3D-tracked probe. In some embodiments, the fiducial assembly ( 1105 , 1155 ) is designed with redundancy to ensure it can be registered in 3D space, regardless of whether the line of sight of the tracked markers is obstructed or not.

In some embodiments, the markers mounted on the fiducial can be placed in a way to enable unique identification of the fiducial. In some embodiments, include three or more 3D-tracked markers that are arranged in a unique, identifiable pattern (e.g., asymmetric triangle).

Some embodiments include embedding the unique pattern, depicted in FIGS. 27 A- 27 B , on a fiducial depicted in FIGS. 6 A- 6 D, 9 A- 9 B, 11 A- 11 B , in order to enable enhanced X-ray imaging fusion with optical systems to provide localization features across two coordinate systems. In some embodiments, a unique pattern (e.g., CALTag/ARtag) can be applied to a fiducial patch or a skin-based fiducial. This design involves a radiopaque, unique-pattern surface (e.g., CALTag) that can be easily visualized in both 3D-tracking camera space and 2D or 3D X-ray imaging space according to some embodiments. Some embodiments involve using the absolute location of the C-arm relative to the unique-pattern surface to calculate the relative location and pose between separate X-ray images and enable a robust stitching algorithm to understand their spatial relationships and overlaps. In some embodiments, this invention could be used with a corresponding optical sensor that is mounted to the X-ray imaging device, and the system knows the relative geometric relationship between the camera and X-ray imaging device's emitter or detector. In some embodiments, this system can enable stitching, unique 3D pose detection, absolute location relations, and should be robust with X-ray images that are acquired with a rotated/oblique X-ray imaging system. In some embodiments, the unique-pattern surface visualized in the X-ray image could enable automated scaling of the image into physical units (e.g., millimeters), as well as automatically detect the pose of the fiducial relative to anatomical landmark of interest, and relative to the X-ray imaging device.

FIG. 11 B displays another view of a fiducial equipped with tracked markers on the over-the-drape-mating fiducial 1105 coupled with a skin-mounted fiducial 1155 that is mounted to the patient skin via an adhesive backing 1157 according to some embodiments. Some embodiments can also contain insert slots for inserted radiopaque magnets and/or electronics 1125 , 1160 . It should be noted that although not shown in FIGS. 11 A- 11 B , this fiducial 1100 can also be equipped with protrusions and mating cutouts for alignment as previously described in relation to FIGS. 6 A- 6 D and FIGS. 9 A- 9 B according to some embodiments.

Some embodiments of the invention depicted in FIG. 12 include a tracked DRF that is equipped with indications of the relative anatomical reference planes. In this instance, the functional aspects reside in the external indication methods to inform the user how to best orient a tracked DRF for it to indicate to the acquisition system how to interpret camera coordinates relative to anatomical axes coordinates according to some embodiments. In some embodiments, FIG. 12 displays a representation 1200 of a tracked DRF 1250 with built-in indication for communicating relative referenced anatomical axes. In some embodiments, this design includes four 3D-tracked markers 1275 that define a DRF, but also an overlying body outline reference 1225 to help instruct the user how to appropriately position the DRF nearby the patient. In some embodiments, attached to this device is an adjustable mounting surface (marked as 1280 as being under the frame 1250 ) that allows the user to rotate the device until it is aligned with the patient's orientation and then lock it into place via any common fastening mechanism. In some embodiments, this device allows the acquisition system to register not only a DRF, but also define anatomical reference planes relative to the known geometry of the dynamic reference plane. In some embodiments, by utilizing this device, it allows for the acquisition system to display data to the user onto anatomical reference planes (e.g., sagittal, coronal, axial) rather than camera coordinates which often appear skewed and challenging to interpret by a user depending on the camera's orientation relative to the subject. In some embodiments, it should be noted that the methods of indicating anatomical reference axes on this device are not limited to the human body overlay as shown in this figure. In some embodiments, other methods include but are not limited to written text displaying the associated anatomical axes, images of discrete body parts to represent anatomical orientations, and alphanumeric or unique pattern labels for regions that should be aligned with particular anatomical axes so that software interfaces can walk the user through orienting the DRF relative to the patient appropriately. In some embodiments, of note is that the reference frame can be mounted almost anywhere and does not need to have an adjustable mount, and could be rigid/orthogonal relative to the patient or surgical table. For example, in some embodiments, involve the reference frame being mounted substantially rigidly in one orientation to the surgical table, or any rigid surface, or substantially rigidly mounted directly to the patient anatomy (e.g., spinous process of the spine).

Some embodiments of the invention include a cross-sectional CT scan view of a spine and highlights a few anatomical regions of interest that may be used to initialize patient data prior to performing assessments of the contour of the spine via tracing methods that will be described in more detail below in reference to FIGS. 65 A- 65 E and FIGS. 66 A- 65 B . In some embodiments, this can be used to interpret the cross-sectional displacement vectors between certain regions (e.g., the skin surface, lamina, transverse process) and other regions of interest (e.g., centroid of the vertebral body, anterior segment of the vertebral body, etc.). In some embodiments, using a CT scan to initialize a patient prior to intraoperative assessments of spinal alignment enables software to better interpret localization of exposed regions (e.g., lamina) as a surrogate for the location of other regions (e.g., vertebral body centroid). In some embodiments, in doing this, intraoperative interpretation of acquired data can be performed with or without the use of fiducial landmarks as described previously in relation to FIGS. 3 A- 3 B, 4 A- 4 I, 6 A- 6 B, 9 A- 9 B, and 11 A- 11 B . In some embodiments, for example, FIG. 13 displays a sample cross-sectional CT image 1300 of a patient in which particular anatomical regions are visible including posterior skin surface 1335 , and cross-sectional view of the vertebral landmarks 1338 and many of its bony elements. In some embodiments, from CT image sets, it is possible to initialize a patient's anatomy by calculating displacement vectors 1325 from particular regions of interest to another (e.g., skin midpoint to vertebral body centroid, and lamina to vertebral body centroid). In some embodiments, after initialization, it is possible for software to interpret the location of one region in terms of its relative location to other initialized regions of interest. In some embodiments, although the location of the centroid of the vertebral body may be most advantageous for interpreting spinal alignment parameters, if the skin or lamina is all that is exposed during surgery, the coordinates of the exposed elements can be gathered and then interpreted, based on pre-operative and/or intraoperative initialization data, to represent the location of unexposed regions (e.g., vertebral body centroid).

Some embodiments of the invention include an assembly with an arrangement of 3D-tracked markers that can be utilized for discrete signaling to an acquisition system. In some embodiments, four tracked markers that make up a dynamic reference frame (DRF), and two tracked stray markers (TSMs) are included in the assembly. In some embodiments, the center of the assembly can include a rotating shield that can be positioned to cover select TSMs, or none at all. In some embodiments, with the tools geometry known, the acquisition system software can interpret which TSMs are exposed, and based on pre-programmed combinations, the tool is able to communicate discrete messages with the acquisition system. In some embodiments, for example, if a first TSM is covered, this can indicate the system is in a particular state as opposed to if a second TSM is covered, which would indicate another state. In some embodiments, because the tool contains a DRF, its location and pose can be interpreted by a 3D-tracking camera, and the arrangement of covered and uncovered stray markers can then be used for communication particular commands or device states.

In some embodiments, FIG. 14 A displays a tool equipped with a tracked DRF 1401 with markers ( 1420 , 1424 ), two TSMs identified as 1422 a (not visible) and 1422 b . In some embodiments, the tool is also equipped with a rotating shield 1415 that is currently positioned to cover visibility of a TSM 1422 a . In some embodiments, because it is equipped with a DRF, a 3D-tracking camera is able to locate the location and pose of tool 1400 in 3D space, as well as distinguish between the four markers serving as a DRF and those serving as TSMs. In some embodiments, the tool can be programmed to communicate with the acquisition system via having varying combinations of the TSMs visible or invisible. In some embodiments, when the 1422 a is covered, the system indicates that it is in a certain state, that is different than if 1422 b is covered, as is shown in FIG. 14 B , which is also different from the state communicated by neither of the TSMs being covered, as is shown in FIG. 14 C . In some embodiments, it should be noted that there can be any combination of one or more TSMs associated with this tool, and there can also be any permutation of covering or uncovering individual or combinations of TSMs to communicate various states to the acquisition system. In some embodiments, the static, known location of the TSMs relative to the registered DRF enable the computer system to robustly filter out any phantom markers or additional stray markers not associated with this tool as the computer algorithms can determine which stray markers visible to the camera possess locations relative to the tool ( 1400 , 1425 , 1450 ) that match the pre-set locations of the TSMs via the design of the tool base mount. In some embodiments, the rotating shield shown in this figure is only how to block the 3D-tracking camera's visualization of the TSMs. Some embodiments of blocking visualization include but are not limited to spring-loaded rotational wipers, linear-motion sliders, actuating the TSMs such that they move from covered to uncovered positions, and rotating shields with multiple panels such that varying combinations of TSMs can be covered or uncovered. In some embodiments, it should be noted that this technology of signaling through covering and uncovering TSMs can also be combined with actuating TSMs as was previously described in reference to FIGS. 10 A- 10 G and as will be described in more detail below in relation to FIGS. 15 A- 15 C, 63 , and 64 A- 64 B .

FIGS. 14 B- 14 C illustrate the tool of FIG. 14 A in different arrangements in accordance with some embodiments of the invention. For example, in some embodiments, FIG. 14 B displays a tool previously discussed in relation to FIG. 14 A , but in this arrangement, the rotating shield 1415 is covering visualization of the TSM 1422 b , and the TSM 1422 a is uncovered. In some embodiments, this combination can be used to communicate its unique state to the acquisition system software. Further, in some embodiments, FIG. 14 C displays a tool previously discussed in relation to FIG. 14 A , but in this arrangement, the rotating shield 1415 is positioned such that both TSMs 1422 a and 1422 b are visible, which is used to communicate a unique state to the acquisition system software.

Some embodiments of the invention include a 3D-tracked probe, equipped with a tracked DRF and a tracked mobile stray marker (TMSM) that can be actuated by a user and utilized to indicate analog and/or binary information to the acquisition system software. For example, FIGS. 15 A- 15 C shows a probe equipped with a tracked dynamic reference frame (DRF) in various configurations in accordance with some embodiments of the invention. In some embodiments, by the user actuating a tracked mobile stray marker that rotates about a pivot point in the probe shaft, the location of the tracked mobile stray marker can be computed relative to the DRF, and when visualized in certain positions, can be used to communicate varying messages to the acquisition system's software. In some embodiments, in reference to FIG. 15 A , a probe 1500 can be equipped with a tracked DRF 1510 , which is coupled to a mount 1512 that provides structural integrity to the DRF's attachment to the probe 1505 , a TMSM 1525 coupled to an arm 1530 that rotates about a pivot hinge 1550 on a hexagonal extruded probe shaft 1505 . The arm 1530 is spring-loaded (via spring 1578 ) via spanning external spring mounts 1580 , 1575 that allow for a depressible tab 1570 to be actuated by a user depressing it inward towards the coaxial probe shaft. In some embodiments, the probe 1500 shown has a blunt semi-spherical tip 1560 to avoid damaging sensitive anatomical structures, and also has a hexagonal extruded probe shaft 1505 for added grip by the user. In some embodiments, this probe 1500 is designed to have the TMSM 1525 rotate about the pivot hinge 1550 when a user depresses or releases the depressible tab 1570 . In some embodiments, the location and relative angle of the TMSM 1525 to the DRF 1510 is computed by the acquisition software of any of the disclosed systems, and can be used for both binary or analog communication with the system, as will be described in more detail in relation to FIGS. 63 and 64 A- 64 B .

In some embodiments, it should be noted that with regards to the type of motion of components of the TMSM 1525 , the TMSM 1525 can move linearly, as described previously in relation to FIGS. 10 A- 10 E , rotationally, as will be described in more detail in relation to FIGS. 63 and 64 A- 64 B , or a combination of the two types of motion. In some embodiments, with regards to the actuation method, includes a user-depressible tab 1570 as shown here but it can also consist of user sliding buttons, rotating buttons, and depressible sliding shafts as described previously in relation to FIG. 10 A- 10 B . In some embodiments, with regards to the spring location, an external compression spring 1578 can also include but is not limited to torsion springs, internal compression springs, deformable materials with shape memory. With regards to the probe shaft 1505 , the hexagonal extrusion shape as shown is only one embodiment and some embodiments include, but are not limited to, circular, triangular, rectangular, pentagonal extrusions and non-uniform revolved profiles for both user grip and probe placement within limited-access environments. The probe shaft 1505 need not be linear or symmetric according to some embodiments. With regards to the depressible tab 1570 , the location of the tab 1570 can also be positioned anywhere on the body of the tool 1500 according to some embodiments. With regards to the probe tip 1560 , the blunted semi-spherical design is only some embodiments as it can also comprise varying shapes and degrees of sharpness of point at the tip 1560 . In some embodiments, can include motion type, linear/rotational, and include other actuation methods. Some embodiments include a user button, slider, or depressible sliding shaft (shown before in FIGS. 10 A- 10 B ). Some embodiments include a different spring location, internal or external placement, a torsion spring, a compressible spring or a non-compressible spring. Some embodiments include alternative tip shape and size, blunt or sharp. Some further embodiments include a mating tip as shown in other fastening devices such as FIGS. 33 D- 33 F and 44 B- 44 D .

In some embodiments, referring to FIG. 15 B , the tracked probe 1500 with a rotating TMSM 1525 can be used for analog and/or binary communication previously described in relation to FIG. 15 A . In some embodiments displays the location of the TMSM 1525 when the depressible tab 1570 is in its undepressed location and the spring 1578 in its most compressed state. In some embodiments, the location and angle of the TMSM 1525 relative to the DRF 1510 can be calculated as will be described in more detail in relation to FIG. 63 and FIGS. 64 A- 64 B .

FIG. 15 C displays some embodiments of a tracked probe 1500 with a rotating TMSM 1525 used for analog communication previously described in relation to FIG. 15 A . Some embodiments display the location of the TMSM 1525 when the depressible tab 1570 is in its depressed location 1525 a , and the spring 1578 in its most extended state. In some embodiments, the arc that is traveled by the tracked mobile stray marker (marked as 1509 ) can be visualized and computed by the computer system by comparing the location of the TMSM 1525 relative to the tracked DRF 1510 as it is actuated via the depressible tab 1570 , with examples depicted in FIGS. 15 A- 15 C . In some embodiments, the location and angle of the tracked mobile stray marker 1525 relative to the DRF 1510 can be calculated as will be described in more detail in relation to FIGS. 63 and 64 A- 64 B .

Some embodiments of the invention utilize rotary encoders that are used to measure the precise length of an extensible cord that is retracted outside of the electromechanical, 3D-tracking system (e.g., such as the system depicted in FIGS. 23 A- 23 C ). In some embodiments, this length calculation is accomplished by the encoder measuring the amount of rotation a mechanically-linked cord causes due to retraction. In some embodiments, the rotary encoder is mechanically linked either directly with the traversing cord or linked with a spool that stores several revolutions of the cord. In some embodiments, this component of the electromechanical tracking system provides accurate length measurements of the extensible cord between the acquisition unit and the probe. In some embodiments, the rotation measurement system of the electromechanical tracking system consists of a system that is capable of measuring the degree of rotation, and any supporting mechanical systems to enable or enhance the rotation measurement process. In some embodiments, the rotation measurement system interfaces mechanically with an extensible cord and/or a retracting spool/tension system to measure the linear distance of extensible cord that has interfaced with the encoder. For example, some embodiments of the rotation measurement system is a rotary encoder 1600 shown in FIG. 16 . A rotary encoder is an electromechanical device, which converts the position or motion of a shaft 1630 about the body 1610 to an electrical signal. In some embodiments, the electrical interface 1650 of the rotary encoder is dependent on the type of rotary encoder and the manufacturer. In some embodiments, internal circuitry inside the rotary encoder 1600 can automatically calculate the amount of shaft rotation, the direction of shaft rotation, or communicate the measurement data over a digital or analog interface. In some embodiments, the method and interface over which the rotation measurement data is communicated is of no significance to the encoder system. In some embodiments, only the degree and direction of shaft 1630 rotation is of importance to the calculation of linear distance. In some embodiments, potentiometers can also be used to measure rotation, specifically absolute rotation, which can eliminate the need for length calibrations in order to measure the length of the extensible cord that is actively being retracted outside the electromechanical, 3D-tracking system.

In some embodiments, FIG. 17 A illustrates a pulley-gear system 1701 for use with the encoder 1600 of FIG. 16 in accordance with some embodiments of the invention, and FIG. 17 B illustrates a gear 1710 of the pulley-gear system 1701 of FIG. 17 A in accordance with some embodiments of the invention. In some embodiments, this component of the electromechanical, 3D-tracking system depicted in FIGS. 23 A- 23 B enables for the increased accuracy of length measurements of the extensible cord that transverses through the enclosure and extends beyond the system to the probe 2000 illustrated in FIG. 20 . In some embodiments, the pulley-gear embodiment 1701 enables for a gear-based actuation of the encoder shaft 1630 , depicted in FIG. 16 , in a manner that multiplies the sensitivity of rotational measurements made by the encoder by a factor nearly equal to the gear-ratio between the set of gears that are mechanically arranged between the cord-interfacing pulley 1710 and the encoder-shaft gear 1715 .

Some embodiments involve a pulley-gear system that is installed between the encoder shaft, the retracting spool/tension system, and/or the extensible cord to increase the accuracy of the rotation measurement system depicted in FIG. 16 . In some embodiments, the pulley-gear system is shown in FIG. 17 A . Linear movement of the extensible cord 1705 is coupled to the pulley-gear 1710 using surface friction between the extensible cord 1705 , passive pulleys 1707 that help wrap the cord 1705 around the pulley-gear 1710 to maximize friction and avoid cord slippage, and the high-friction O-ring 1748 that surrounds the internal diameter of the pulley. In some embodiments, the pulley-gear 1710 (shown in detail in FIG. 17 B ) mechanically interfaces with a rotary encoder shaft gear 1715 , and during linear movement of the extensible cord 1705 , any rotation of the pulley-gear 1710 corresponds to a greater degree of rotation of the rotary encoder shaft gear 1715 , with the relationship of the corresponding rotations being determined by the gear ratio between 1710 and 1715 . In some embodiments, the resolution of the rotary encoder 1720 can been increased by a fixed quantity using the described pulley-gear system 1701 , and leads to an increase in the measurement accuracy of the extensible cord length. In some embodiments, the described pulley-gear 1710 can be designed with a notch 1745 to allow for the simple removal of the O-ring, and a cutout 1740 placed at the center of the pulley-gear 1710 is designed to allow for the insertion of a bearing that enables for the minimally-frictional rotation of the pulley-gear 1710 about its center axis, which can have a significant effect on the ease-of-use of the system for the user to retract the probe in a responsive manner.

Some embodiments of the surface of the pulley-gear 1710 that interface mechanically with the extensible cord 1705 can involve specific geometric cross-sectional contours that enhance the friction between the extensible cord 1705 and the pulley-gear 1710 surface. Some embodiments includes a v-shaped groove that the pinches on the surface of the cord 1705 , and this design forms a tight-tolerance fit between the cord and the pulley-gear 1710 when the overall system is placed under tension. Some embodiments can include the linkage of the pulley-gear system directly with a tensioned spool system, (described in more detail below in reference to FIG. 18 A- 18 B ), that stores multiple revolutions of the extensible cord.

FIG. 18 A shows a perspective view of a cord spool for use in the pulley-gear system of FIG. 17 in accordance with some embodiments of the invention, and FIG. 18 B shows a side view. This component of the electromechanical, 3D-tracking system, depicted in FIG. 23 C , involves the spiral storage of extensible cord to be exchanged in and out of the spool at pre-defined cord lengths/circumferences per revolution. Some embodiments involve the spool directly interfacing mechanically with a rotary encoder, depicted in FIG. 16 , in a coaxial manner between the spool and encoder shaft, to measure the number of revolutions of cord that are extended away from the enclosure at any time.

Some embodiments of the spool system involves a linkage with a tension system that provides an opposing force to the extensible cord 1705 to maximize coupling in the pulley-gear system depicted in FIG. 17 A and/or the rotary encoder 1600 depicted in FIG. 16 . In some embodiments, the tension system can be pre-loaded with cord and tuned in tension to ensure that there is no slack along the extensible cord. In some embodiments, if slack develops on the cord, accurate measurement of the degree of rotation about the encoder system is less optimal. In some embodiments, the retracting spool/tensioning system is a spring-based system that provides tension to the extensible cord. In some embodiments, the retracting spool/tensioning system can include a sub-system to allow variable degrees of tension of the extensible cord to a user's specification. In some embodiments, the retracting spool/tensioning system can include a mechanism that slows and/or stops the motion of the spool to prevent the extensible cord from traveling at dangerously high speeds, in the event that the pre-tensioned extensible cord is suddenly released.

In some embodiments, the retracting spool provides a system by which the extensible cord can be contained within. In some embodiments, a cord spool 1800 , illustrated in FIGS. 18 A- 18 B , is composed of a cylindrical disc 1805 with a cord entry slot 1840 removed from the side such that the cord 1705 can be rotated about center of the spool in set revolution increments. Some embodiments may have the cord entry slot 1840 with a thickness much larger than the diameter of the cord. Some embodiments can have the cord entry slot 1840 be the approximate diameter of the cord, such that the cord is forced to spiral outward from the spool's center in a single-revolution-thick spiral stack. Some embodiments can have the inner cord spool radius 1820 be a fixed value. Some embodiments may have the inner cord spool radius 1820 may be represented by an equation. In some embodiments, the radial distance of the Archimedean spiral is equal to the diameter of the cord such that the extensible cord spools continuously around itself as described by an Archimedes spiral, which simplifies the calculation of the distance between the center of the spool and the center of the cord, in addition to the calculation of the linear cord distance.

Some embodiments involves the cord beginning its fixation to the spool at a known radius set by the designed mount point 1830 of the spool 1805 . Some embodiments involves the cord wrapping around inner cord spool surface (defined by inner radius 1820 ) until the cord length is completely contained within the spool 1800 or when the cord reaches the outer spool edge (defined by outer radius 1810 ). In some embodiments, the larger the outer spool edge, the more torque that can be applied by the movement of the cord and the less resistance the user will feel when engaging the retraction of the cord tensioning system. In some embodiments, the large inner radius surface leads to a less accurate measurement by increasing the length of cord contained with a single resolution step of the encoder's rotational sensitivity.

In some embodiments, in the rotational measurement system described herein, the extensible cord 1705 provides a mechanical connection between the retracting spool and the rotation measurement sensor. In some embodiments, the extensible cord 1705 provides a mechanical connection between the probe ( FIGS. 20 A- 20 E ) and the encoder system 1600 ( FIG. 16 ), allowing for the three-dimensional measurement of the probe tip location as the probe moves through space. In some embodiments, the generic embodiment of the extensible cord 1705 is a thin-diameter, low-stretch cord. In some embodiments, the extensible cord is a metal cable, with some embodiments containing special coatings, such as a nylon coating. Some embodiments of the extensible cord is a Kevlar cable.

FIGS. 19 A- 19 C illustrates a ball assembly 1900 of a 3D-tracking system of FIG. 23 A in accordance with some embodiments of the invention. In some embodiments, this component of the electromechanical, 3D-tracking system depicted in FIGS. 23 B- 23 C , involves a ball-and-socket interface that is manipulated via the traversing motion of an extensible cord 1705 that passes through the center of the ball. In some embodiments, an extensible cord (e.g., such as cord 1705 shown in FIG. 17 A , cord 2120 shown in FIG. 21 A , or cord 2150 shown in FIG. 21 B ) can traverse through the ball-and-socket system via entry to the cord insertion point (cord entry passage 1903 ) through the central barrel. In some embodiments, the entry point for the cord is designed to intersect with the center of the spherical structure, and subsequently aligned with the sphere's center of rotation. In some embodiments, this alignment of the cord entry point 1903 enables the movement of the cord to be mathematically separated into two sections, the straight line between the cord storage system (e.g., spool depicted in FIGS. 18 A- 18 B ) and the center of the ball 1903 , as well as the straight line between the center of the ball 1903 and the mounting posts on a probe (e.g., probe depicted in FIG. 20 ). In some embodiments, the barrel is supported by mechanical structures added to minimize undesired forces and torques imposed by the cord, which can deflect the barrel during movement of the cord. In some embodiments, the ball assembly can include barrel support structures 1940 of ball (or sphere) 1901 . In some embodiments, as the barrel exits the front of the ball, the barrel is supported internally by a reinforced wall 1902 . In some embodiments, to minimize barrel deflection at the cord entry location, support bars 1940 provide mechanical rigidity to the barrel to minimize deflection created during cord movement.

In some embodiments, the sphere includes a cylindrical groove 1950 extruded out of the top of the spherical surface, which allows for the installation of an image, or any unique pattern, without any spherical distortion of the pattern surface. In some embodiments, an imaging sensor can thus be used to visualize and measure the ball's rotation in the spherical coordinates, theta and phi, by examining how the pattern on the cylindrical groove 1950 rotates and translates relative to an imaging sensor. In some embodiments, in order to maintain the cylindrical groove's alignment with the center of the ball 1901 and imaging sensor, the ball 1901 includes an orthogonal extrusion (roll-prevention rod 1920 ) relative to the cylindrical window, that prevents the rotation of the ball about the barrel structure when inserted into a complementary mating slot that limits the movement of the roll-prevention rod to a linear arc that is orthogonal to the cylindrical groove 1950 .

In some embodiments, as shown in FIGS. 19 B and 19 D , the ball 1901 contains a cylindrical barrel 1930 , which begins inside the ball 1901 and extends radially to a fixed distance in front of the ball 1901 . In some embodiments, the cord (e.g., such as cord 1705 ) can pass through the extrusion in the back of the ball, enters the barrel at the cord insertion point (shown as 1903 ), passing through and exiting the barrel in front of the ball (through barrel 1930 ). In some embodiments, the barrel 1930 contains a plethora of holes (barrel fenestrations 1922 ) to reduce the surface contact area between the inside of the barrel 1931 and the outside of the cord, which helps to ensure smooth cord movement through the barrel 1930 . In some embodiments, the barrel design provides the encoder (e.g., such as encoder 1600 ) with a fixed exit point that is required to calculate of linear cord distance. In some embodiments, as the barrel 1930 extends from the front of the ball 1901 , the barrel 1930 is supported externally by a reinforced wall by the barrel shaft base fillet (barrel tip fillet 1924 ). Further, in some embodiments, the cylindrical groove 1950 provides a cross-sectionally-flat surface from which an imaging sensor can calculate the degree of spherical ball rotation without requiring additional transformations caused by distortion (e.g., barrel distortion) of the pattern. In some embodiments, in reference to FIG. 19 C , a cylindrical groove (groove 1950 ) is extruded out of the top of the spherical surface, and allows for the installation of an image, or any unique pattern, without any spherical distortion of the pattern surface. In some embodiments, the support structures illustrated to reinforce the rigidity of the barrel are not required in the final manufactured product, and can include components for prototypes created via 3D printing with fragile materials.

In some embodiments, FIGS. 19 D- 19 E illustrate a ball and socket assembly of the 3D-tracking system of FIG. 23 A accordance with some embodiments of the invention. In some embodiments, the socket enclosure 1950 for the ball 1901 provides a joint surface to rotate within due to traversing motions and trajectory changes in the extensible cord. In some embodiments, the socket contains a window cutout 1980 that restricts the movement of the barrel 1930 to within a defined range-of-motion (in window 1932 ). In some embodiments, the window's boundaries can help maintain the optimal tracking volume for the electromechanical, 3D-tracking system without having multiple ball-and-socket systems allowing for cord to intersect or obstruct each other. In some embodiments, the system also contains a complementary roll-prevention channel 1976 that allows for the restricted movement of a rod extrusion 1920 from the ball to travel along a path that prevents the rotation of the ball 1901 about its barrel 1930 . In some embodiments, the roll-restriction feature ( 1920 , 1976 ) of the system provides assurance that the cylindrical window is in constant view within the sensor's preview window 1999 , such that any movement of the pattern will always be visible to an imaging sensor. In some embodiments, multiple socket regions 1998 are removed from the top and bottom of the socket structure to minimize surface friction between the outside of the ball and the inside of the socket. In some embodiments, as noted multiple times, the need to minimize friction between the socket, ball, and cord is paramount to the functionality of three-dimensional tracking system. Some embodiments include a layer of ball bearings installed between the ball and the socket surfaces. Some embodiments include some form of lubricant placed in between the ball and the socket surfaces. Some embodiments may include some form of lubricant placed in between the barrel and the cord surfaces. In some embodiments, a high-strength and high-durability material is required to maintain the structural integrity of the ball and socket. In some embodiments, the ball-and-socket system may be comprised of metals, polymers, and/or plastics.

FIG. 20 illustrates a probe 2000 of a 3D-tracking, electromechanical system in accordance with some embodiments of the invention. FIGS. 20 A- 20 E show views of components of the probe 2000 of FIG. 20 in accordance with some embodiments of the invention. In some embodiments, this component of the electromechanical, 3D-tracking system, depicted in FIGS. 23 B- 23 C , involves a probe that is used to register 3D points in space while the tracking system dynamically registers the probe's 3D location and orientation with respect to the tracking system's coordinate system. In some embodiments, the probe 2000 contains two freely-rotating fixation points 2010 where extensible cord (e.g., 1705 ) distal ends that are tracked in 3D space mount at a fixed distance apart. In some embodiments, the probe 2000 can comprise a probe shaft 2025 . In some embodiments, the probe 2000 provides various functions to the electromechanical, 3D-tracking system. First, in some embodiments, the probe 2000 enables the user to trace along a 3D-surface. Second, in some embodiments, the probe provides a fixed mechanical interface to each encoder's extensible cord. In some embodiments, the 3D pose of the probe 2000 can be derived from the calculated linear cord distances from each encoder, the rotational values (spherical coordinates) of the previously described ball 1901 within its ball-and-socket joint, the fixed distance between each cord connection point, and trigonometric identities. In some embodiments, with the pose of the probe 2000 and the linear cord distances, the exact location of the probe tip 2024 can be extrapolated in 3D-space. Third, in some embodiments, the probe 2000 has the ability to identify interactions with multiple materials through electrical, mechanical, optical, and/or electro-mechanical interfaces. Fourth, in some embodiments, the probe 2000 has a grip area 2025 that allows the user to hold the probe 2000 and trace a three-dimensional surface without interfering with the cords or any additional measurement system.

Some embodiments of a probe 2000 is shown in FIG. 20 , has mount points 2010 for two cords. In some embodiments, the cords from an encoder (such as described earlier in FIG. 16 ) can couple to the cord fixation mounts 2010 , each of which is mechanically coupled to individual bearings 2044 that are separated by a cord-mount spacer 2001 coupled to the probe shaft 2025 , with each bearing's internal surface linked substantially rigidly to an internal rod structure (not shown) coaxial within the probe enclosure. In some embodiments, the spacer 2001 and bearings 2044 are coaxial with an internal rod that is fixed to the probe half 2025 that the user can grip (e.g., see bearing 2044 ). In some embodiments, the internal rod structure is maintained within the probe enclosure via a rigid cap 2005 . However, in some embodiments, it should be noted that several components, including, but not limited to, the probe cap 2005 , are not required for the device's function. In some embodiments, the cord mount and bearing system allows the probe 2000 to move freely in any direction without affecting the accuracy of the measurement system of the encoder embodiment. In some embodiments, the probe grip area (on shaft 2025 ) provides spacing for the user to trace in three-dimensions.

Some embodiments include a component of the electromechanical, 3D-tracking system, depicted in FIGS. 23 A- 23 C , that involves a probe that is mechanically linked to two 3D-tracked cord fixation points that are spaced by adjustable distance via mechanical actuation between the two fixation points. For example, in some embodiments, FIGS. 21 A- 21 B illustrate assemblies of a 3D tracking system including probes 2100 a and 2100 b coupled to cord fixation points (see extensible cord 2120 , 2150 extending from the probes 2100 a , 2100 b ). In some embodiments, the probes comprise probe handle 2130 a , 2130 b with depressible sliding shaft 2115 a , 2115 b , and spring-loaded trigger 2140 (of probe 2100 b ). In some embodiments, each 3D-tracked probe 2100 a , 2100 b includes an embedded mechanical system such that the distance between the extensible cord fixation mounts is selectively changed when the depressible shaft (spring-loaded; spring not shown) 2115 a linked to the probe 2100 a is pressed against a surface, or manually actuated by the user via a spring-loaded button 2140 on the shaft 2130 b of the probe 2100 b , which increases distance between the dynamic cord-fixation mount ( 2135 a for probe 2100 a ; 2135 b for probe 2100 b ) and the static cord-fixation mount ( 2136 a for probe 2100 a ; 2136 b for probe 2100 b ). In some embodiments, the extensible cords 2120 , 2150 are mechanically linked to the electromechanical, 3D-tracking system (sample embodiments shown in FIG. 23 A- 23 C ).

In some embodiments, a processing algorithm detects the changes in the relative distance between cord mounts and signals to the electromechanical, 3D-tracking system that it should actively register points at the probe tip, or interpret a specific command that designates what type of measurement the probe is performing, or the object identity the probe is interacting with. In some embodiments, the distance between the two dynamic cord fixation mounts can be calculated with respect to the axes of the probe by substantially rigidly transforming the 3D cord fixation mount coordinates with respect to the probe tip coordinates and pose. In some embodiments, the 3D distance between the cord fixation mounts can be calculated without variability in calculations caused by the changing relationship between a cord fixation mount and its relative distance to the electromechanical, 3D-tracking system, in comparison with that of the other cord fixation mount.

FIG. 22 illustrates an example system enabling 3D tracking of a probe in accordance with some embodiments of the invention. In some embodiments, this component of the electromechanical, 3D-tracking system depicted in FIGS. 23 A- 23 C , involves a system of active and passive components that communicate to enable the 3D tracking of the probe's location and orientation. In some embodiments, a number of embodiments exist for the probe linked to the electromechanical, 3D-tracking system, with FIG. 22 depicting the interface between a system of components that communicate with each other to enable the 3D tracking of a probe. Some embodiments include a probe with no electrical or mechanical feedback systems for which the encoder embodiment and processing software to detect during tracing, as described in the above embodiment. In some embodiments, a probe with embedded electrical subsystems ( FIG. 22 ) can contain a plethora of user-controlled toggle switches that allow the user to control the registration of points and active tracking of the probe ( FIGS. 21 A- 21 B ). Some embodiments include a method of communication to a microcontroller or a computer processing system that can be transmitted through a wireless electromagnetic radiation (RF), light-emitting devices. In some embodiments, cords can be mechanically linked to the docked tracking system. Some embodiments include a method of delivering power to the probe through a voltage applied across two cords that are mechanically linked to the probe for positional tracking. In some embodiments, a battery system or equivalent energy source, such as a capacitor, that is capable of being recharged can be included. In some embodiments, an electrical connection that exists between the probe and the enclosure to provide energy during non-use when the probe is located on the enclosure. In some embodiments, a plurality of sensors of a sensing system can be a plurality of inertial measurement unit, accelerometers, and/or gyroscopes to measure the motion and/or pose of the probe. In some embodiments, this may negate the necessity for mechanical linkages with an encoder or extensible cord. Some embodiments can be a tilt sensor. Some embodiments can be a sensor to measure the rotation of the cord mounts on the probe. Some embodiments can be a system to measure mechanical force applied to the probe and/or the probe tip. In some embodiments, a radiofrequency identification (RFID) tag and/or reader placed at a fixed location on the probe can include an RFID is an RFID reader placed in the probe that reads an RFID tag to begin or halt the registration of points and active tracking of the probe tip in 3D. Some embodiments of RFID is an RFID reader placed in the probe that reads an RFID tag placed at specific locations to identify the locations with specific identities during use of the probe. For example, in some embodiments, see power storage 2212 , power interface 2214 , communication system 2216 , microcontroller 2218 , sensors 2220 , and RFID 2222 of the probe 2210 , cord 2230 coupled to encoder 2226 , cord 2232 coupled to encoder 2228 , digital signals 2234 a (from encoder 2226 ) and digital signals 2234 b (from encoder 2228 ). Further, in some embodiments, see data acquisition controller 2224 coupled to a data storage and processing software in computer system 2238 coupled through interface 2236 .

Some embodiments of the invention include an enclosure of the electromechanical, 3D-tracking system that houses all of the components of the tracking system in a compact form that can be mounted onto a multitude of various surfaces. For example, FIG. 23 A illustrates an example 3D-tracking system 2300 in accordance with some embodiments of the invention, including extensible cords 2350 extending from ball-in-socket structures 2320 (e.g., such as those described earlier in related to FIGS. 19 A- 19 E ), a coupled probe 2340 , and a rigid surface mount 2305 coupled to structures 2310 , 2330 . As shown, some embodiments contain an interface for fastening mounting mechanisms enabling it to be utilized in a variety of settings. Fastening mounting mechanisms 2305 may include, but are not limited to, a suction cup mount or fastener holes for mating to rigid structures (e.g., such as 2310 , 2330 ). Some embodiments of the mounting mechanism 2305 include hooks and clamps to interface with surgical tables, beds, anesthesia poles, a removable instrument tray on a movable stand that is configured to be positioned over or adjacent to a surgical site of a patient (e.g., a Mayo stand), the patient's anatomy, and/or any other rigid structure. Some embodiments involve extensible cords (shown as 2350 ) retracted out by the user via the use of a probe 2340 to collected discrete and continuous tracing registrations.

In some embodiments, the components of the electromechanical, 3D-tracking system can be compiled into a compact design and surrounded by an enclosure device 2350 . For example, FIG. 23 B illustrates a 3D-tracking system in an enclosure 2360 in accordance with some embodiments of the invention. In some embodiments, the enclosure 2360 is shown with extensible cords 2370 extending from barrel 2367 , 2372 of spheres 2374 , 2365 (with the cord coupling to a probe, such as probe 2000 of FIG. 20 ). In some embodiments, the enclosure 2360 can shield internal components from debris, trauma, bodily fluids, and light exposure. Further, the enclosure 2360 can contains an external probe mounting system to substantially rigidly fix the probe (e.g., such as the probe 2000 shown in FIG. 20 ) to the enclosure 2360 for when the extensible probe system is not in use. In some embodiments, the enclosure also houses the spool system (as shown previously in FIGS. 17 A- 17 B, 18 A- 18 B ) which outputs two extensible cords to attach to the probe, and each cord 2370 passes through the barrel structure 2367 , 2372 of each sphere 2365 , 2374 to enable the electro-mechanical triangulation of the probe (e.g., the probe 2000 shown in FIG. 20 ).

Some embodiments include internal light sources to prevent variability in lighting for the camera system. Some embodiments include an electrical interface over which power and/or data can be transmitted to and/or received from the probe when it is docked. Some embodiments of the electrical interface can be metal contacts extending from the probe mounting system to couple to electrical contacts on the probe.

FIG. 23 C shows an exploded assembly view of the 3D-tracking, electromechanical system of FIG. 23 B in accordance with some embodiments of the invention. For example, some embodiments include enclosure 2361 housing a rotary encoder 2399 , a fixed spring-tensioner arm 2390 for spool spring (not shown), a spool 2392 , a bottom half of a socket 2394 , a top half of a socket 2395 (reference FIGS. 19 D- 19 E ), an embedded, unique pattern 2383 , a ball 2374 (reference FIGS. 19 A- 19 C ), a barrel of ball 2365 , and enclosure lid 2362 with embedded optical sensors (not shown). In some embodiments, FIG. 23 C illustrates the compilation of components from the electromechanical, 3D-tracking system. In some embodiments, each of the two rotary encoders 2399 measure the length of an extensible cord coupled to the probe (not shown). In some embodiments, each extensible cord (not shown) is stored and retracted from the spool 2392 that is being tensioned via a spring (not shown) that is fixed at one end by a spring tensioning arm 2390 , which is mounted to the rigid enclosure 2361 . In some embodiments, each extensible cord passes through a ball 2374 , that can rotate within a socket ( 2394 , 2395 ) with viewing windows (not shown; as seen in FIGS. 19 D- 19 E ), via a barrel 2365 that originates at the center of the ball 2374 to enable controlled movement of the cord during rotation of the ball. In some embodiments, the rotation of the ball is measured via an embedded pattern 2383 on the ball surface 2374 that is aligned above the center of the ball and able to mirror the phi and theta rotation of the ball in spherical coordinates for visualization via an above imaging sensor. In some embodiments, the enclosure includes a lid 2362 that couples with the bottom-component of the enclosure 2361 can help to create a protected environment while also housing the optical sensors (not shown), lights (not shown), and microcontrollers (not shown), for recording and analyzing the visual and electrical outputs from the embedded optical sensors and rotary encoders. In some embodiments, wireless communication components (not shown) are also included within the enclosure.

FIG. 24 illustrates a system enabling 3D tracking of a probe in accordance with some embodiments of the invention. Some embodiments depicts a system of components that enable for the electromechanical localization of a 3D point at the tip of a probe (e.g., such as any of the probes described herein). In some embodiments, three extensible cords ( 2428 , 2430 , 2432 ) mechanically link to the probe tip 2421 of probe 2420 via connections extending from three separate rotary encoders 2422 , 2424 , 2426 that measure the length of each cord, from which the software system calculates the 3D point of the probe tip via triangulation geometric equations. In some embodiments, the encoder (such as those of the encoders 2422 , 2424 , 2426 ) is represented by a spool wound with an extensible cord (e.g., 2428 , 2430 , 2432 ), a spring-loaded retractor system (not shown), which can be represented by any system that provides a tensioning force, and a rotary encoder, which can be represented by other sensors used to detect the degree of rotation. In some embodiments, the three encoder embodiments are placed at fixed distances relative to each other. In some embodiments, the probe 2420 contains a single cord mount connection at the probe tip 2421 , through which all cords 2428 , 2430 , 2432 interface to the probe 2420 . As the probe 2420 is moved in 3D space, the individual, distinct cord lengths are measured via rotary encoders 2422 , 2424 , 2426 (e.g., as illustrated in FIG. 16 ), however other sensors can be used to detect the length of the extended cord. In some embodiments, with the known distance between each encoder 2422 , 2424 , 2426 , the measured cord lengths to the probe tip 2421 , the system's triangulation algorithm can process the data through a geometric relationship to calculate the 3D location of the probe tip 2421 . In some embodiments, the three-cord encoder system requires at least three encoders to calculate the 3D position of the probe 2420 .

In some embodiments, the electromechanical, 3D-tracking system, illustrated in FIG. 23 B- 23 C , can contain in the system of components shown in FIG. 25 , where the ball-and-socket movement is sensed by mechanically-linked rotary encoders that measure the phi and theta movement of the ball in spherical coordinates (e.g., using two encoders per ball and socket system or assembly). In some embodiments, the encoder-based 3D-tracking system shown in FIG. 25 includes probe 2510 , cords 2520 , 2522 , encoders 2514 , 2526 , mechanical linkage and measurement 2518 , 2512 , 2528 , 2530 , ball and socket 2516 , 2524 , digital signals from encoders 2515 , 2527 , digital signals from mechanical linkage and measurement 2517 , 2529 , 2513 , 2531 , data acquisition controllers 2550 , 2555 , and computer 2560 . Each ball-and-socket 2516 , 2524 is mechanically linked to two encoders 2514 , 2526 . In some embodiments, an extensible cord 2520 , 2522 passes radially through the barrel located at the center of the ball and connects to a probe 2510 , allowing the barrel to follow the location of the extensible cord. Since the barrel is fixed at the center of the ball and the ball's axis of rotation is fixed by a rod seated in a slot on the socket, the ball is unable to rotate radially about the barrel's axis and the barrel can track the location of the probe. In some embodiments, measurement of the ball's rotation in the socket allows for the calculation of the angular takeoff of the barrel in spherical coordinates as the probe is moved through 3D space. In some embodiments, the cord length is measured via rotary encoders 2514 , 2526 as described in relation to FIG. 16 , however other sensors can be used to detect the length of the extended cord. In some embodiments, the measurement of cord length and angular takeoff provide sufficient data to calculate the 3D location of the probe in the spherical coordinate system.

Some embodiments of the measurement system used to calculate the angular takeoff is a mechanical linkage between the surface of the ball and a rotary encoder, however other sensors can be used to detect the degree of rotation. In some embodiments, as the ball rotates in the theta and phi directions due to probe translation, a mechanical linkage ( 2512 , 2518 , 2528 , 2530 ) rotates the shaft of a rotary encoder ( 2514 , 2526 ), and the degree of a ball's rotation in each spherical coordinate plane can be calculated.

In some embodiments, one possible mechanical linkage is a spherically or cylindrically-shaped coupling object fixed radially to a rotation measurement system as described in FIG. 16 . Some embodiments of a rotation measurement device could be a rotary encoder. In some embodiments, the position of the rotary encoder is fixed such that the cylindrically shaped object makes physical contact with the ball and is mechanically secured to the rotary encoder shaft. Any movement of the probe results in rotation of the ball, rotation of the cylindrically-shaped object, and thus rotation of the rotary encoder shaft. In some embodiments, the described mechanical linkage ( 2512 , 2518 , 2528 , 2530 ), oriented orthogonal to each other, are required to calculate the rotation of the ball's barrel in theta and phi directions.

In some embodiments, algorithms calculate the degree of ball rotation in theta and phi from the radius of the cylindrically shaped object, the rotation measured by the rotary encoder, and the radius of the ball. In some embodiments, after calculating phi and theta of the barrel, the system then uses spherical coordinate formulas to calculate a vector from the center of the ball to the location of the first cord as it mates with the probe. In some embodiments, the same process is repeated for the second ball-and-socket pair, also using a mechanical linkage to sense the spherical rotation of the ball. In some embodiments, the second ball-and-socket system calculates a 3D vector from the center of the ball to the end location of the second cord as it mates with the probe.

In some embodiments, the pose of the probe is then calculated from the vector subtraction of two calculated cord vectors. In some embodiments, the three-dimensional position and orientation of the probe tip can be extrapolated given the known dimensions of the probe and the distance between the cord fixation points on the probe.

In some embodiments, the electromechanical, 3D-tracking system, illustrated in FIGS. 23 A- 23 C , can contain the system of components shown in FIG. 26 , where the ball-and-socket movement is sensed by optical sensors that interpret the rotation and relative location of the ball-mounted pattern with respect to the image sensor. In some embodiments, the system measures the phi and theta movement of the ball in spherical coordinates. In some embodiments, the combined mechanical, electrical, electro-mechanical, and optical components of the system 2600 shown in FIG. 26 that enable for the 3D-tracking of a probe's location and pose include a probe 2610 , coupled cords 2612 , 2614 , coupled ball and socket 2616 , 2620 , embedded, unique patterns 2617 , 2621 on the ball surfaces, encoders 2618 , 2622 , cameras 2624 , 2628 processor or controller 2626 , 2630 , data acquisition 2632 , computer 2634 , and modem 2636 . Two encoders are able to measure length of the cord, and the two ball-and-socket assemblies enable measurements of cord trajectory for cord that is past the center of the ball (see FIGS. 19 A- 19 E ). In some embodiments, one optical-sensing and unique pattern per ball-and-socket embodiment for measuring the spherical rotation of the ball (depicted in FIGS. 27 A- 27 D ). In some embodiments, one probe to link the 3D-tracked, extensible cords in 3D space and provide the user a medium for acquiring 3D points (as depicted in FIG. 20 ).

In some embodiments, an extensible cord passes through the center of rotation of a sphere and exits via a radial barrel that follows the location of the extensible cord end that is mounted to the probe. In some embodiments, the location of the center of the sphere is fixed by the sphere being constrained by a socket with a slot to allow for the free movement of the barrel to track the exiting cord. In some embodiments, the socket ensures that the sphere cannot rotate about its barrel shaft via a radial slot in the socket that receives a complementary rod tip that is mounted to the sphere and is concentric with the center of the sphere.

In some embodiments, the cord length is measured via rotary encoders, however other sensors can be used to detect the change in length of the cord during use (e.g., potentiometers). In some embodiments, since the portion of the extensible cord that has exceeded the center of the sphere is no longer always coaxial with the starting portion of the extensible cord near the encoder, a measurement must be made of the angular takeoff of the sphere's barrel, through which the cord passes, to produce the spherical coordinates needed calculate the 3D location of the cord end that is mounted to the probe.

Some embodiments to calculate the angular takeoff of the sphere's barrel is to embed a pattern on the sphere's cylindrical window such that while the sphere moves due to the translation of the cord in space, the pattern rotates about the center of the sphere in a manner that mimics the phi and theta angles produced by the barrel relative to the coordinate system of the center of the sphere.

In some embodiments, one possible pattern is a checkerboard that has a unique black-and-white tag pattern (as shown by labels 2617 , 2621 in FIG. 26 ), similar to that used in augmented reality registration markers, in each square of the board. In some embodiments, the unique checkerboard has an established x-y coordinate system, such that one corner of the checkerboard is the origin and each square represents one unit of known size.

In some embodiments, an optical sensor embedded in the socket, with the sensor located concentrically to both the center of the sphere and the preview window of the socket, records the viewable portion of the overall pattern that can be seen through the preview window of the socket. In some embodiments, the optical sensor transmits image frames to the processing software to utilize computer vision algorithms to detect all visible corners of checkerboard pattern, identify the signature of each visible square, and reference each square's known location within the overall pattern. In some embodiments, the pixels in the image frame are converted into millimeters, or any other physical unit, by calculating the ratio between pixels and millimeters for a known side length of one of the visible squares of the pattern surface. In some embodiments, the center of the image frame represents the center of the sphere.

In some embodiments, the algorithms then calculate the absolute location of the center of the image along the unique pattern, identifying the exact location in the units of the physical pattern. In some embodiments, the vertical location of the image center is used to calculate the theta of the barrel by identifying the arc length between the current image center in the active image frame and the location on the pattern surface that aligns with the image center when the barrel is concentric with the side window of the socket, producing a theta of zero. In some embodiments, the arc length input is combined with the known radius of the pattern surface relative to the center of the sphere, and then theta is calculated using the arc length formula that extrapolates the angle of the arc section. In some embodiments, the theta angle of the barrel represents the up and down motion of the barrel.

In addition, in some embodiments, a vector is calculated between the checkerboard corner closest to the image center and a corner nearest that first corner that is vertically in-line with respect to each other in the coordinate system of the pattern. In some embodiments, a second vector is calculated along the vertical axis of the image, passing through the image center. In some embodiments, the algorithms calculate the relative angle between these two vectors by calculating the inverse cosine of the cross product of the two vectors; this calculation can also be done several different ways using known geometry formulas. In some embodiments, the angle between these vectors represents the phi angle of the barrel, which indicates the left and right motion of the barrel. In some embodiments, after calculating phi and theta of the barrel via the location of the image center on the unique pattern and the pose of the pattern relative to the optical sensor, the system then uses spherical coordinate formulas to calculate the end location of the cord end that mates with the probe tip, given the input length of the cord that exists past the center of the sphere. In some embodiments, given two cord fixation points with known, calculated 3D locations on the probe shaft, the system can calculate the 3D vector between the two fixation mounts, and then extrapolates the 3D location of the probe tip, given the known dimensions of the probe, and calculating the offset between the probe tip and the 3D line.

In some embodiments, the same process is repeated for the second ball-and-socket pair, which also have an embedded pattern and optical sensor combination, to calculate the 3D location of the second extensible cord end that mounts to the probe. Some embodiments of the electromechanical, 3D-tracking system involves using an optical sensor to measure the spherical rotation of a ball in correspondence with the movement of an extensible cord that transverses through the center of the ball's rotation. In some embodiments, as the barrel translates left and right in the phi plane of the spherical coordinate system of the ball, the embedded pattern also rotates by the same angle, since the pattern viewable to the camera is aligned to be above the center of the ball. In some embodiments, the system thus measures the angle of the pattern with respect to the optical sensor to calculate the phi angle 2710 of the barrel in spherical coordinates. Some embodiments of the electromechanical, 3D-tracking system, illustrated in FIGS. 23 A- 23 C , can involve the use of unique patterns embedded on the ball surface, as shown in FIGS. 27 A- 27 D (and discussed earlier with respect to 2383 of FIG. 23 C ), where the ball-and-socket movement is sensed by optical sensors that interpret the rotation and relative location of the ball-mounted pattern 2701 with respect to the image sensor. In some embodiments, the unique pattern enables for the computer vision algorithms of the system to calculate the absolute position of the center of the image sensor with respect to coordinate system of the grid-based pattern. In some embodiments, the system measures the phi 2710 and theta 2715 movement of the ball 2705 in spherical coordinates. In some embodiments, unlike a typical optical sensor used in a computer mouse, this system does not lose its sense of position with respect to the pattern if image frames are lost or not able to be calculated for any reason, since the pattern provides the system an ability to calculate absolute position on its surface. In some embodiments, as shown, barrel phi rotation 2710 , ball 2705 , and pattern 2701 .

In some embodiments, in reference to FIG. 27 B , and barrel theta rotation 2715 , the electromechanical, 3D-tracking system involves using an optical sensor to measure the spherical rotation of a ball in correspondence with the movement of an extensible cord that transverses through the center of the ball's rotation. In some embodiments, as the barrel translates up and down vertically in the theta plane of the spherical coordinate system of the ball, the embedded pattern translates away from the center of the image sensor as the ball rotates about the y-axis. In some embodiments, subsequently, the system measures the location of the image center with respect to the grid coordinate system to calculate the translation along the vertical portion of the grid, and then using the known radius between the ball center and pattern surface, the system calculates the theta angle 2715 of the barrel in spherical coordinates.

In some embodiments, in reference to FIGS. 27 C- 27 D , a vector is calculated between the checkerboard corner closest to the image center and a corner nearest that first corner that is vertically in-line with respect to each other in the coordinate system of the pattern. In some embodiments, a second vector is calculated along the vertical axis of the image, passing through the image center. In some embodiments, the algorithms calculate the relative angle between these two vectors, by calculating the inverse cosine of the cross product of the two vectors; this calculation can also be done several different ways using known geometry formulas. In some embodiments, the angle is calculated using one vector from each of the grid axes 2721 a and camera axes 2719 a , selecting the two vectors with the closest angles to the zero-phi angle. In some embodiments, the angle between these vectors represents the phi angle of the barrel, which indicates the left and right motion of the barrel. In some embodiments, after calculating phi and theta of the barrel via the location of the image center on the unique pattern and the pose of the pattern relative to the optical sensor, the system then uses spherical coordinate formulas to calculate the end location of the cord end that mates with the probe tip, given the input length of the cord that exists past the center of the sphere. In some embodiments, the theta angle of the barrel represents the up and down motion of the barrel. In some embodiments, the system algorithms calculate the absolute location of the center of the image along the unique pattern, identifying the exact location in the units of the physical pattern. First, 2 in some embodiments, the grid axes 2721 b rotation is identified and then the image center 2722 relative to the camera axes 2719 b . Next, in some embodiments, the projected length of the vector between the grid axes origin 2723 and the image sensor center 2722 is calculated. In some embodiments, this arc length input is combined with the known radius of the pattern surface relative to the center of the sphere, and then theta is calculated using the arc length formula that extrapolates the angle of the arc section.

Some embodiment of the electromechanical, 3D-tracking system, illustrated in FIGS. 23 A- 23 C , can contain the system of components shown in FIG. 28 A , where the ball-and-socket movement is sensed by optical sensors that interpret the relative translation of the ball surface with respect to the image sensor as the ball rotates due movement of the barrel. In some embodiments, this system measures the phi and theta movement of the ball in spherical coordinates. In some embodiments, the system 2800 can include encoders to measure length of the cord, two ball-and-socket assemblies to enable measurements of cord trajectory for cord that is past the center of the ball, two optical sensors per ball-and-socket assembly for measuring the translation of the ball surface with respect to the image sensor to calculate the spherical rotation of the ball, and one probe assembly to link the 3D-tracked, extensible cords in space and provide the user a medium for acquiring 3D points. For example, in some embodiments, the system 2800 can include couple components comprising probe 2802 with probe tip 2803 , cords 2804 , 2805 , ball and sockets 2809 , 2815 , optically-coupled sensor and processing boards 2807 , 2813 , 2819 , and 2821 , coupled encoders 2811 , 2817 , data acquisition microcontrollers 2823 , 2825 , and computer system 2827 with data storage and processing software.

In some embodiments, for each ball-and-socket there is one encoder and two optical sensor. In some embodiments, an extensible cord passes radially through the barrel located at the center of the ball and connects to a probe, allowing the barrel to follow the location of the extensible cord. In some embodiments, since the barrel is fixed at the center of the ball and the ball's axis of rotation is fixed by a rod seated in a slot on the socket, the ball is unable to rotate radially about the barrel's axis and the barrel can track the location of the probe. In some embodiments, measurement of the ball's rotation in the socket allows for the calculation of the angular takeoff of the barrel as the probe is moved through three-dimensional space. In some embodiments, the cord length is measured via rotary encoders as described in FIG. 16 , however other sensors can be used to detect the length of the extended cord. In some embodiments, the measurement of cord length and angular takeoff provide sufficient data to calculate the 3D location of the probe in the spherical coordinate system.

Some embodiments of the measurement system used to calculate the angular takeoff is a pair of optical sensors oriented normal to the ball and socket and orthogonal to each other, each one aligned with the theta and phi spherical coordinate planes of the ball system.

In some embodiments, a light-emitting device emits light in a finite spectrum that is reflected off the surface of the ball and is converted to electrical signals via a photodetector array. In some embodiments, the converted data is then processed using an algorithm to transform the photodetector array data into translational changes of the ball surface with respect to the camera. In some embodiments, a data acquisition and computing system converts the translational data from cartesian to spherical coordinates, and subsequently calculates the theta and phi rotation of the sphere, based on the known radius of the ball that is being sensed. Some embodiments of the system may include a laser diode and photodiode array, light-emitting diode and photodiode array, and/or an imaging sensor. In some embodiments, a pattern or image installed on the cylindrical window of the ball to increase the contrast, reflectivity, or sensitivity of the optical signal, as well as to produce higher signal-to-noise ratios, and increase the accuracy of theta and phi spherical coordinate calculations. In some embodiments, the pattern or image may contain repeating variations of patterned and/or colors, and may be manufactured with a reflective surface, which maximizes the optical coupling between the light-emitting device and the photodetector array.

Some embodiments involves a surface pattern that is etched on the ball surface during the manufacturing process, and the surface pattern enhances the sensitivity of optical signals to change at the slightest of translational changes of the ball surface with respect to the image sensor.

Some embodiments can involve additional lighting sources that provide lighting on the ball surface at any possible finite spectrum of light, from which certain light source frequencies provide an optimal sensitivity for the system to have a high-resolution sensing of rotational changes, but not erroneously estimating movement that is not actually occurring, but rather just artifacts of optical noise.

FIG. 28 B illustrates a computer system 2829 configured for operating and processing components of the any of the systems disclosed herein according to some embodiments. For example, in some embodiments, the computer system 2829 can operate and/or process computer-executable code of one or more software modules of any of the systems shown in one or more of the figures herein, including, but not limited to FIGS. 24 - 26 , and 28 A . In some embodiments, the system 2829 can comprise at least one computing device including at least one processor 2832 . In some embodiments, at least one processor 2832 can include a processor residing in, or coupled to, one or more server platforms. In some embodiments, the system 2829 can include a network interface 2835 a and an application interface 2835 b coupled to the least one processor 2832 capable of processing at least one operating system 2834 . Further, in some embodiments, the interfaces 2835 a , 2835 b coupled to at least one processor 2832 can be configured to process one or more of the software modules 2838 (e.g., such as enterprise applications). In some embodiments, the software modules 2838 can include server-based software and/or can operate to host at least one user account and/or at least one client account, and operating to transfer data between one or more of these accounts using the at least one processor 2832 .

In some embodiments, the invention can employ various computer-implemented operations involving data stored in computer systems. Moreover, in some embodiments, the above-described databases and models throughout the system 2829 can store analytical models and other data on computer-readable storage media within the system 2829 and on computer-readable storage media coupled to the system 2829 . In addition, in some embodiments, the above-described applications of the 2829 system can be stored on computer-readable storage media within the system 2829 and on computer-readable storage media coupled to the system 2829 . In some embodiments, these operations are those requiring physical manipulation of physical quantities. Usually, though not necessarily, in some embodiments, these quantities take the form of electrical, electromagnetic, or magnetic signals, optical or magneto-optical form capable of being stored, transferred, combined, compared and otherwise manipulated. In some embodiments of the invention, the system 2829 can comprise at least one computer readable medium 2836 coupled to at least one data source 2837 a , and/or at least one data storage device 2837 b , and/or at least one input/output device 2837 c . In some embodiments, the invention can be embodied as computer readable code on a computer readable medium 2836 . In some embodiments, the computer readable medium 2836 can be any data storage device that can store data, which can thereafter be read by a computer system (such as the system 2829 ). In some embodiments, the computer readable medium 2836 can be any physical or material medium that can be used to tangibly store the desired information or data or instructions and which can be accessed by a computer or processor 2832 . In some embodiments, the computer readable medium 2836 can include hard drives, network attached storage (NAS), read-only memory, random-access memory, FLASH based memory, CD-ROMs, CD-Rs, CD-RWs, DVDs, magnetic tapes, other optical and non-optical data storage devices. In some embodiments, various other forms of computer-readable media 2836 can transmit or carry instructions to a computer 2840 and/or at least one user 2831 , including a router, private or public network, or other transmission device or channel, both wired and wireless. In some embodiments, the software modules 2838 can be configured to send and receive data from a database (e.g., from a computer readable medium 2836 including data sources 2837 a and data storage 2837 b that can comprise a database), and data can be received by the software modules 2838 from at least one other source. In some embodiments, at least one of the software modules 2838 can be configured within the system to output data to at least one user 2831 via at least one graphical user interface rendered on at least one digital display.

In some embodiments of the invention, the computer readable medium 2836 can be distributed over a conventional computer network via the network interface 2835 a where the 2829 system embodied by the computer readable code can be stored and executed in a distributed fashion. For example, in some embodiments, one or more components of the system 2829 can be coupled to send and/or receive data through a local area network (“LAN”) 2839 a and/or an internet coupled network 2839 b (e.g., such as a wireless internet). In some further embodiments, the networks 2839 a , 2839 b can include wide area networks (“WAN”), direct connections (e.g., through a universal serial bus port), or other forms of computer-readable media 2836 , or any combination thereof.

In some embodiments, components of the networks 2839 a , 2839 b can include any number of user devices such as personal computers including for example desktop computers, and/or laptop computers, or any fixed, generally non-mobile internet appliances coupled through the LAN 2839 a . For example, some embodiments include personal computers 2840 coupled through the LAN 2839 a that can be configured for any type of user including an administrator. Some embodiments can include personal computers coupled through network 2839 b . In some embodiments, one or more components of the system 2829 can be coupled to send or receive data through an internet network (e.g., such as network 2839 b ). For example, some embodiments include at least one user 2831 coupled wirelessly and accessing one or more software modules of the system including at least one enterprise application 2838 via an input and output (“I/O”) device 2837 c . In some embodiments, the system 2829 can enable at least one user 2831 to be coupled to access enterprise applications 2838 via an I/O device 2837 c through LAN 2839 a . In some embodiments, the user 2831 can comprise a user 2831 a coupled to the system 2829 using a desktop computer, and/or laptop computers, or any fixed, generally non-mobile internet appliances coupled through the internet 2839 b . In some further embodiments, the user 2831 can comprise a mobile user 2831 b coupled to the system 2829 . In some embodiments, the user 2831 b can use any mobile computing device 2831 c to wireless coupled to the system 2829 , including, but not limited to, personal digital assistants, and/or cellular phones 2831 c , mobile phones, or smart phones, and/or pagers, and/or digital tablets, and/or fixed or mobile internet appliances.

In some embodiments of the invention, the system 2829 can enable one or more users 2831 coupled to receive, analyze, input, modify, create and send data to and from the system 2829 , including to and from one or more enterprise applications 2838 running on the system 2829 . In some embodiments, at least one software application 2838 running on one or more processors 2832 can be configured to be coupled for communication over networks 2839 a , 2839 b through the internet 2839 b . In some embodiments, one or more wired or wirelessly coupled components of the network 2839 a , 2839 b can include one or more resources for data storage. For example, in some embodiments, this can include any other form of computer readable media in addition to the computer readable media 2836 for storing information, and can include any form of computer readable media for communicating information from one electronic device to another electronic device.

FIGS. 29 A- 29 B illustrates a screw-head-registering screwdriver 2900 equipped with a tracked dynamic reference frame in accordance with some embodiments of the invention. FIG. 29 C illustrates a close-up perspective view of a screwdriver head and depressible tip 2957 of the screwdriver of FIGS. 29 A- 29 B in accordance with some embodiments of the invention. Further, FIG. 29 D illustrates a cross-sectional view of the screwdriver-screw interface in accordance with some embodiments of the invention. FIG. 29 A- 29 B displays a tool that serves three functions: 1.) it registers the 3D position and pose of the screw shaft, 2.) fully engages in the screw head interface, and 3.) signals when it is fully engaged via a depressible sliding shaft 2957 that extends from the probe shaft 2910 of the tool 2900 and is coupled to a tracked mobile stray marker that is actuated when the tool is fully engaged with the mating screw according to some embodiments. In some embodiments, the overall purpose of this invention is to identify the location and pose of a screw via a coupling mechanism with the screw head, and to have a triggering system via the TMSM 2945 to indicate to the acquisition system when the tool is fully engaged with the screw. In some embodiments, this tool 2900 can be applied when there is not a rod seated in the screw obstructing the tool's interface with the screw head. In some embodiments, as shown in FIG. 29 A , the tool can comprise tracked DRF 2929 (with markers 2930 ), a probe shaft 2910 , a TMSM (undepressed) 2945 , handle 2940 , screwdriver head 2950 , depressible sliding shaft (undepressed) 2957 , pedicle screw shaft 2960 , pedicle screw tulip head 2955 , and coupling mechanism 2905 .

In some embodiments, this tool (screwdriver) 2900 is designed to interface with a pedicle screw shaft 2960 in such a way that it can engage with the head of the screw to both tighten and loosen the screw, but furthermore, that when the tool 2900 is fully engaged in the screw head 2955 , its 2910 is fixed in one orientation relative to the screw shaft 2960 . In some embodiments, this tool 2900 can be used to quickly register both the location and pose of the screw shaft 2960 by only accessing the screw head 2955 of the screw shaft 2960 . In some embodiments, as shown in FIG. 29 A , the TMSM 2945 is in the position corresponding with an undepressed, and therefore unengaged, screwdriver depressible shaft 2957 . In some embodiments, this possesses a similar design of actuating a TMSM 2945 via a depressible tip 2957 as described previously in relation to FIG. 10 A- 10 G . In some embodiments, it should be noted that the depressible tip 2957 and the screw head interface component 2950 of the tool 2900 can have many different configurations.

In some embodiments, the sliding shaft (tip 2957 ) can be structured such that it always remains within the shaft of the tool or screwdriver, and the screw head 2960 is designed with a center protrusion to deflect the inner sliding shaft of the screwdriver. In this way, in some embodiments, the tip 2957 of the sliding shaft is unable to be actuated by any object that cannot fit inside the shaft 2950 . In some embodiments, when the tracked mobile stray marker 2945 is actuated, the acquisition system's software detects its motion (shown as linear) and is able to distinguish when it is fully or partially engaged with a screw head by the known geometry of the tool and interfacing screw as described in more detail below in reference to FIG. 63 . It should be noted that the motion of the TMSM 2945 can be linear, rotational, or any combination thereof according to some embodiments. Further, in some embodiments, the mechanism of detecting the motion of the TMSMs can also consist of covering and uncovering a particular stray marker with actuation of the sliding shaft as described previously in relation to FIG. 14 . In some embodiments, additionally, the design of the screwdriver head 2950 can be such that it also has components that allow for ensuring it will mechanically couple with the screw shaft 2960 such that it can only achieve one unique orientation when fully engaged. In some embodiments, structures to help with engaging in a unique configuration include, but are not limited to, expanding screwdriver heads, a depth-stop flange to help the screwdriver head align with the screw head, and screws designed with screw heads of increased depth to ensure the screwdriver shaft firmly engages in one orientation when fully seated into the head. In addition, in some embodiments, since the depicted location of the tracked DRF 2929 is not the only manner to substantially rigidly attached the DRF, it must be noted that the DRF 2929 can be placed anywhere on the surgical tool screwdriver 2900 as long as it can be substantially rigidly attached, even on adjustable joints.

FIG. 29 B displays some embodiments of the tool shown previously in reference to FIG. 29 A , except in this image, the tool 2900 is fully engaged with the screw head 2960 , highlighting the new position of the TMSM 2945 to indicate to the acquisition software system that the screwdriver head 2950 and depressible shaft 2957 is fully seated and the location and pose of the screw shaft 2960 can subsequently be calculated from that position according to some embodiments.

FIG. 29 C illustrates a close-up perspective view of a screwdriver head 2950 and depressible tip 2957 of the screwdriver 2900 of FIGS. 29 A- 29 B in accordance with some embodiments of the invention, and shows the aforementioned depressible sliding shaft 2957 in an undepressed position according to some embodiments. FIG. 29 C shows a more detailed perspective of the screwdriver head 2950 and the depressible tip 2957 of the screwdriver tool 2900 previously described in relation to FIGS. 29 A- 29 B , and its interface 2905 with a pedicle screw head 2960 according to some embodiments. In some embodiments, in this view it is possible to see the interface of the screwdriver head 2950 and the top of the screw head 2960 , as well as the depressible tip 2957 , shown undepressed. Some embodiments involve a depressible sliding shaft that is contained within the screwdriver head. In some embodiments, this spring-loaded, depressible shaft can only be engaged when a male protrusion in the screw head engages the screwhead coaxially, and then the depressible shaft 2957 is pushed up, actuating the TMSM 2945 attached to the depressible shaft 2957 , to signal that the 3D-tracked tool 2900 and the screw shaft 2960 are fully engaged and coaxial, and thus ready to be registered in 3D space.

FIG. 29 D illustrates a cross-sectional view of the screwdriver-screw interface 2905 in accordance with some embodiments of the invention, and shows the depressible sliding shaft tip (partially depressed) 2965 . As shown in figure FIG. 29 D , the screwdriver tool 2900 would not signal to the acquisition system that it is fully engaged with the screw head 2960 , as the partially-depressed depressible shaft 2965 and its mechanically-linked TMSM 2945 would not be fully-actuated relative to the tracked DRF 2929 according to some embodiments.

In some embodiments, the tracked DRF does not have to be substantially rigidly attached to the tool's shaft, but can be allowed to rotate about the tool shaft (e.g., linked with a bearing) and adjust its relative position to the tool (still able to be substantially rigidly locked when desired). As it shown in the simplified drawings FIG. 29 A- 29 B , it makes it very challenging for users to use the tool as a screwdriver if the DRF 2929 gets in the way according to some embodiments. It should be noted that in some embodiments, the tracked DRF 2929 is both located and attached to the screwdriver in different ways that better facilitates the user interface of the handle while maintaining visualization of the DRF 2929 according to some embodiments.

For instance, in some embodiments, the tracked DRF 2929 is coupled to the screwdriver shaft 2910 via a bearing (which can be coupled with or without a lockable ratcheting mechanism), such that it is allowed to rotate about the long-axis of the screw driver shaft. In some embodiments it is positioned above the handle with or without bearings to enable it to rotate about the screwdriver shaft axis.

In some embodiments of the invention, as seen in FIG. 30 A- 30 C , a pedicle screw insert cap 3060 with an attached series of 3D-tracked markers 3070 , which form a DRF, couples to the tulip head 2955 of a pedicle screw. In this way, in some embodiments, the tulip head can be tracked in 3D space whenever the markers 3070 are within line of sight of the camera 3000 , and do not require a probe to interface with them to register their position in space. FIG. 30 A displays an optical, 3D-tracking system 3000 that can be used as the acquisition device for these and any other tracked markers throughout this document according to some embodiments. FIG. 30 B displays a tracked DRF with 3D-tracked markers 3070 on a cap device equipped with a mating mechanism 3060 to substantially rigidly mount to the tulip head 2955 of a pedicle screw 2960 (not visible; instrumented into spinal vertebrae 3055 in FIG. 30 B ) according to some embodiments. In some embodiments, with this tracked reference frame of markers 3070 coupled to the screw 2960 , the location of the pedicle screw 2960 can be tracked in 3D space, provided it is in line of sight of the 3D-tracking camera 3000 . In some embodiments, the interface 3060 between the DRF markers 3070 and the tulip head 2955 can consist of an array of mechanisms, described in more detail below in reference to FIGS. 34 A- 34 F, 35 A- 35 E, 36 A- 36 I, and 37 A- 37 G .

FIG. 31 illustrates a body-mounted 3D-tracking camera in accordance with some embodiments of the invention, and operates in a way to avoid line of sight obstruction between a 3D-tracking camera and a surgical site, or any other area of visualization interest according to some embodiments. In some embodiments, this design involves a user equipped with a body-mounted tracked DRF 3125 substantially rigidly fixed to a body-mounted 3D-tracking camera 3135 such that information can be fused between the user's field of view and the external 3D-tracking camera (not shown) because the location and pose of the body-mounted camera 3135 will typically be visible and known to the larger field-of-view 3D-tracking camera (not shown). FIG. 31 displays the body-mounted 3D-tracking sensor 3135 equipped with a tracked DRF 3125 according to some embodiments. Some embodiments for the mounting mechanism of the 3D-tracking sensor 3135 to the body is via a head-mounted fastener with adjustable components 3110 , 3105 . In some embodiments, surgical areas that are typically obstructed from the line of sight of a large field-of-view camera can be visualized via the body-mounted, 3D-tracking optical sensor 3135 . In some embodiments, since the body-mounted, optical sensor 3135 is equipped with a substantially rigidly-mounted tracked DRF 3125 , the larger-field-of-view camera (not shown) can register the body-mounted, optical sensor's location and pose in 3D space, and with that information, interpret the scene visualized by the headset-mounted, 3D-tracking optical sensor 3135 to create a dynamic, 3D stitched mapping of the global coordinate system relative to the large field-of-view camera coordinate system. In some embodiments, the fusion of the coordinate systems of the body-mounted camera 3135 and the larger field-of-view camera (not shown) will be computed via a 3D rigid transform, which will be applied to 3D data collected by the body-mounted camera 3135 for all frames of its acquisition. Thus, in some embodiments, the computation of 3D positions and poses of objects of interest (e.g., 3D-trackable tools, DRFs, anatomical landmarks, fiducials, surgical accessories, other optical or electromagnetic sensors, etc.) within the field of view of the body-mounted camera 3135 , which is being tracked by the larger field-of-view camera (not shown).

FIG. 32 displays a method of interpreting the contour of the posterior elements of the spine by placing a malleable object over the surgically-exposed bony elements such that it matches the contour of the exposed spine, and then the malleable object is removed and its contour registered with optical systems, including stereoscopic cameras, and from that information about the surface contour of the malleable object which now serves as a surrogate for the contour of the posterior elements of the spine, the spinal alignment parameters of the contour-matched spine can be calculated according to some embodiments. In some embodiments, other relevant other figures (relating to the calculation of spinal alignment parameters and the location of other anatomical landmarks of interest processed by software algorithms) include FIGS. 65 A- 65 E, 66 A- 66 B, and 68 . FIG. 32 displays the system 3200 where a malleable rod 3215 that is placed over the surgically exposed elements of the spine 3230 with an adjustable clip 3210 to register a particular spinal level for software interpretation according to some embodiments. In some embodiments, after the rod 3215 is inserted into the surgical site, the malleable rod 3215 is conformed to match the contour 3225 of the exposed spinal elements, and one or more mounted clips 3220 are aligned along the rod 3215 with nearby anatomical landmarks of interest. In some embodiments, this malleable rod 3215 then undergoes topological registration 3240 by one or more imaging sensors 3241 to interpret the 3D contour of the rod 3215 that matches the contour 3225 of the spinal column 3230 . In some embodiments, the 3D contour of the malleable rod 3215 is then processed by software algorithms described in detail below in reference to FIGS. 65 A-E , 66 A-B, and 68 . In some embodiments, the optical registration system 3241 can be any optical system to register 3D surface contours including, but not limited to, one or more depth sensors, stereoscopic vision cameras, and structured light systems, with the rod fixed onto a stationary or movable platform base. In some embodiments, based on some embodiments for registering the 3D contour of the malleable rod 3215 using optical methods, and the associated clip 3210 that indicates spinal levels, the system can calculate the spinal alignment parameters 3250 of each anatomical plane of the rod 3215 an interpret the relative alignment and contour of the spine 3230 .

Some embodiments of the invention seen in FIGS. 33 A- 33 I , include a screw and screwdriver combination that allows for the ability to mechanically couple both devices such that the screwdriver becomes coaxial with the screw shaft, and also has the ability to then substantially rigidly manipulate the screw shaft, which if fixed in bone has the ability to then manipulate the associated bony structures. For example, FIG. 33 A illustrates a pedicle screw design in accordance with some embodiments of the invention, and FIG. 33 B illustrates a pedicle screw in accordance with some embodiments of the invention. Further, FIG. 33 C illustrates a pedicle screw mated with a polyaxial tulip head in accordance with some embodiments of the invention, and FIG. 33 D illustrates a tool designed to interface with the pedicle screw of FIG. 33 B in accordance with some embodiments of the invention. FIG. 33 E illustrates a visualization of a couple between the tool of FIG. 33 D , and the screw of FIG. 33 C in accordance with some embodiments of the invention. Further, FIG. 33 F illustrates the coupling tool, depicted in FIG. 33 D , coupled to a pedicle screw, as seen in FIG. 33 C , in accordance with some embodiments of the invention, FIG. 33 G illustrates a top view of the screw of FIG. 33 A in accordance with some embodiments of the invention, and FIG. 33 H illustrates a top view of the screw of FIG. 33 B in accordance with some embodiments of the invention. As shown, some embodiments include an Allen key inset 3325 , rigid single crossbar 3320 , coupled threaded shaft 3305 , and a curved screw head 3315 . FIG. 33 A and FIG. 33 I displays some embodiments of a screw that consists of an Allen key inset 3325 , a rigid crossbar 3320 that spans across the sidewalls of the screw head 3315 but allows for a gap above the inset, a threaded shaft 3305 and a curved screw head 3315 to accommodate mating with a tulip head (seen in FIG. 33 C as label 3365 ) according to some embodiments. FIG. 33 B displays some embodiments of the screw described in detail above in relation to FIG. 33 A . Some embodiments displays the screw head 3345 with two intersecting crossbars 3350 , to enable interfacing with a different tool depicted in FIG. 33 D . It should be noted that the examples of screws portrayed in these figures only represent some embodiments of the invention. In some embodiments, the crossbars 3350 can be of varying contour, number, and relative arrangement for each screw head. FIG. 33 C displays an some embodiments of the screw described previously in relation to FIG. 33 B mated with a polyaxial tulip head 3365 with a cutout 3375 to interface with a rod, and a thread 3370 to receive a tightening cap according to some embodiments.

FIG. 33 D displays some embodiments of a tool designed to interface with the screw previously described in detail in relation to FIG. 33 B . In some embodiments, this tool consists of four mechanically-coupling extensions 3390 designed to engage with the screw head cross-bars via a quarter-turn mechanism. In some embodiments, after performing a quarter-turn, the tool becomes substantially rigidly fixed to a screw head and shaft, as depicted in FIG. 33 B . In some embodiments, the end of the center shaft of the screw has a depressible sliding shaft 3393 that can be coupled to a TMSM (not shown) to indicate full engagement of the tool 3390 and screw, as depicted in FIG. 33 B , in a communication method previously described in detail in relation to FIGS. 10 A- 10 E and FIGS. 29 A- 29 C . In some embodiments, it should be noted that the center of the tip 3393 of this tool can also consist of a threaded shaft that is tightened down at the top segment (not shown) of the tool 3390 to push a sliding rod against the rigid cross bars of the screw head. In some embodiments, in this way, the tool has increased fixation strength at the screw head interface. In some embodiments, this threaded middle shaft can also be attached to a TMSM (not shown) to indicate its position relative to a tracked DRF (not shown) mounted to the screwdriver. Further, in some embodiments, FIG. 33 E displays a transparency view of the interface between the screw head, its crossbars, and the screwdriver coupling end effector, previously discussed in relation to FIGS. 33 A- 33 I . From this view, in some embodiments, the threaded screw shaft 3391 , curved screw head walls 3318 , and the mechanically-coupling extensions 3390 of the tool are visible as the two tools engage with one another. Further, in some embodiments, unlike FIG. 33 E , FIG. 33 F displays a different perspective of the screwdriver ( 3392 ) and crossbar-equipped screw 3395 interfacing with one another. From this perspective, in some embodiments, the coaxial alignment of the screwdriver shaft with the screw shaft is appreciable. FIG. 33 G displays an underside view of the cross-bar-equipped screw previously described in relation to FIG. 33 B and this view highlights the circular cutout 3380 of the tulip head interfacing with the curved walls of the screw head ( 3318 , 3345 ; not shown) according to some embodiments.

Some embodiments include a tool or assembly to interface directly with the tulip heads of pedicle screws, in such a way that it substantially rigidly fixes the rotating tulip head relative to the pedicle screw shaft, to then enable measurement and manipulation devices to act on the coupled spinal elements to aid with alignment measurements and fixation as will be described in more detail below in reference to FIGS. 39 A- 39 F, and 42 A- 42 K .

FIG. 34 illustrates a tool for interfacing with a pedicle screw accordance with some embodiments of the invention. FIG. 34 A displays a cross-sectional view interfacing directly with the threaded inserts of the tulip heads of pedicle screws according to some embodiments. In some embodiments, this figure displays a pedicle screw shaft 3410 (threading not shown), its associated tulip head 3420 , the interfacing device's thread-tightening knob 3440 , its sleeve body 3425 , device body connection 3430 , protruding tip 3423 to substantially rigidly push towards the screw head, and inner shaft threading 3422 of the device. In some embodiments, tightening of the device through the thread-tightening knob 3440 leads the inner shaft threading 3422 to interface directly with the tulip head threads to cause the protruding tip 3423 to push against the screw head. In some embodiments, tightening in this way provides a rigid connection between the device, tulip head, and pedicle screw, such that the motion of the polyaxial tulip head has been restricted and all three parts coupled to one another. In some embodiments, the device body connection 3430 displayed in this figure is designed to interface with a larger tool that will be described in more detail below in reference to FIGS. 39 A- 39 D, 40 A- 40 C, 41 C , 42 A 42 -F. Some embodiments include but are not limited to cylindrical extrusion, spherical tip, and a non-rigid cylindrical extrusion coaxial or perpendicular to the inner shaft and coupled via rivet or other mechanism that enables its rotation about the axis of the inner shaft according to some embodiments.

FIGS. 34 B- 34 C display a non-cross-sectional, side view of the device described in relation to FIG. 34 interfacing with a pedicle screw according to some embodiments. In some embodiments, visible are side-tab extensions 3421 that extend over the tulip head cutouts. In some embodiments, these side tabs extensions provide additional rigid interfacing between the device and the tulip head of the screw, further helping to substantially rigidly fix the device, tulip head, and screw to one another.

FIG. 34 D displays a cross-sectional view of the device described in relation to FIG. 34 A interfacing with a pedicle screw according to some embodiments. FIG. 34 E displays a non-cross-sectional, rendered side view of the device described in relation to FIG. 34 A interfacing with a pedicle screw according to some embodiments. FIG. 34 F displays a non-cross-sectional, rendered front view of the device described in relation to FIG. 34 A interfacing with a pedicle screw according to some embodiments.

FIGS. 35 A- 35 F display an assembly or tool 3500 designed to interface directly with the tulip heads of pedicle screws, in such a way that it substantially rigidly fixes the rotating tulip head relative to the pedicle screw shaft, to then enable measurement and manipulation devices to act on the spinal elements to aid with alignment measurements and fixation as will be described in more detail below in reference to FIGS. 39 A- 39 F, and 42 A- 42 K according to some embodiments. As shown, in some embodiments, the tool 3500 comprises pedicle screw shaft 3510 , tulip head 3503 , drafted shaft advancement knob 3540 , sleeve body 3525 , device body connection 3530 , protruding tip 3504 , outer shaft threading 3535 , protruding-tip advancement knob 3545 , drafted pin 3546 , retaining ring 3502 , and expanding teeth 3527 . In some embodiments, in operations, after interfacing directly with the tulip head 3503 , the drafted pin advancement knob 3540 leads the outer shaft threading 3535 to drive the expansion of the expanding teeth 3527 to interface directly with the tulip head threads. In some embodiments, the retaining ring 3502 limits expansion of the device to prevent over stress, and the protruding tip advancement knob 3545 can then be tightened to increase the tension on the expanded teeth with the tulip head threads and thereby substantially rigidly fix the device, tulip head, and screw shaft together. In some embodiments, the device body connection 3530 displayed in this figure is designed to interface with a larger tool that will be described in more detail below in reference to FIGS. 39 A- 39 F, and 42 A- 42 K .

FIG. 35 B displays a non-cross-sectional, front view of the device described in relation to FIG. 35 A interfacing with a pedicle screw according to some embodiments. Visible in this figure are side-tab extensions 3529 that extend over the tulip head cutouts according to some embodiments. In some embodiments, these side tabs provide additional rigid interfacing between the device and the tulip head of the screw, further helping to substantially rigidly fix the device, tulip head, and screw to one another. FIG. 35 C displays a non-cross-sectional, perspective view of the device described in relation to FIG. 35 A interfacing with a pedicle screw according to some embodiments. FIG. 35 D displays a cross-sectional, rendered view of the device described in relation to FIG. 35 A interfacing with a pedicle screw according to some embodiments. FIG. 35 E displays a non-cross-sectional, rendered front view of the device described in relation to FIG. 35 A interfacing with a pedicle screw according to some embodiments. FIG. 35 F illustrates a close-up perspective view of the tool of FIGS. 35 A- 35 E without a coupled pedicle screw or tulip head in accordance with some embodiments of the invention. FIG. 35 F displays a non-cross-sectional, rendered front view of the device described in relation to FIG. 35 A without the interfacing pedicle screw and tulip head according to some embodiments. In this view, the expanding teeth and side tab extensions are more clearly visual according to some embodiments.

Some further embodiments of the invention include a tool or assembly able to interface directly with the tulip heads of pedicle screws via a quarter-turn mechanism, in such a way that it substantially rigidly fixes the rotating tulip head relative to the pedicle screw shaft, to then enable measurement and manipulation devices to act on the spinal elements to aid with alignment measurements and fixation as will be described in more detail below in reference to FIGS. 39 A- 39 F , and 42 A- 42 K. For example, in some embodiments, FIG. 36 A displays a cross-sectional view of an invention for interfacing directly with the threaded inserts of the tulip heads of pedicle screws via a quarter-turn mechanism. In some embodiments, this figure displays a pedicle screw shaft 3610 (threading not shown), its associated tulip head 3620 , the quarter-turn knob 3635 , its sleeve body 3640 , device body connection 3645 , protruding tip 3650 to substantially rigidly push towards the screw head, protruding tip advancement knob 3637 , side-tab extensions 3695 , and quarter-turn retainer 3699 . In some embodiments, after inserting the device into the tulip head such that the threads are not engaged, the quarter-turn knob is rotated 90 degrees to engage the quarter-turn threads with the threads of the tulip head. In some embodiments, after rotating 90 degrees, the quarter-turn retainer prevents excess rotation, to ensure the threading is engaged prior to increasing tension on the threads via tightening the protruding tip advancement knob. In some embodiments, by tightening the protruding tip advancement knob, the protruding tip is driven directly against the head of the screw and increasing tension on the quarter-turn threads, thereby removing tolerance from thy polyaxial tulip head. In this way, in some embodiments, this device substantially rigidly fixes the tulip head and screw shaft together. In some embodiments, the device body connection 3645 displayed in this figure is designed to interface with a larger tool that will be described in more detail below in reference to FIGS. 39 A- 39 F, and 42 A- 42 K .

FIG. 36 B displays a non-cross-sectional, front view of the device described in relation to FIG. 36 A interfacing with a pedicle screw according to some embodiments. More clearly visible in this figure are side-tab extensions 3695 , previously described in detail in relation to FIG. 35 B according to some embodiments. Also, more clearly visualized in this figure is the quarter-turn retainer 3699 , previously described in detail in relation to FIG. 36 A according to some embodiments. Further, FIG. 36 C displays a side view of the device described in relation to FIG. 36 A interfacing with a pedicle screw, and FIG. 36 D displays a non-cross-sectional, perspective view of the device described in relation to FIG. 36 A interfacing with a pedicle screw according to some embodiments. FIG. 36 E displays a non-cross-sectional, perspective view of the device described in relation to FIG. 36 A interfacing with a pedicle screw, and FIG. 36 F displays a cross-sectional, rendered view of the device described in relation to FIG. 36 A interfacing with a pedicle screw according to some embodiments. In some embodiments, this figure displays the quarter-turn threads engaged with the tulip head threads. FIG. 36 G displays a cross-sectional, rendered view of the device described in relation to FIG. 36 A interfacing with a pedicle screw according to some embodiments. In some embodiments, this figure displays the quarter-turn threads disengaged from the tulip head threads. FIG. 36 H displays a non-cross-sectional, rendered side view of the device described in relation to FIG. 36 A interfacing with a tulip head (pedicle screw shaft not shown) according to some embodiments. FIG. 36 I displays a non-cross-sectional, rendered front view of the device described in relation to FIG. 36 A interfacing with a tulip head (pedicle screw shaft not shown) according to some embodiments.

Some embodiments of the invention include a device for interfacing directly with two implanted pedicle screws in such a way that it substantially rigidly connects to the tulip head and removes tolerance between a polyaxial tulip head and pedicle screw such that the device is mechanically linked to a vertebra or other bony anatomy in which the screw(s) is/are inserted. For clarity, in some embodiments, FIGS. 37 A- 37 G do not include a tracked DRF and triggering mechanism, although they can be attached to this device to allow it to provide quantitative data to the user while manipulating or holding the spinal elements, as will be described in more detail in reference to FIGS. 39 A- 39 F, and 42 A- 42 K . In some embodiments, the invention comprising the assemblies of FIGS. 37 A- 37 G may include various coupled components including a tightening knob 3740 , handle 3705 , width-adjustment mechanism 3707 , guide rail (×2) 3723 , tulip head side rests 3727 , spring mechanism 3728 for fastening protrusions, tensioning lever 3732 that presses up against internal spring (not shown) when device is actively clamped, footplate 3710 , and/or clamp release lever 3750 . For example, FIG. 37 A displays a front view of the invention designed to substantially rigidly interface two screws already implanted into the spine or other bony elements according to some embodiments. In some embodiments, this embodiment is equipped with a tightening knob 3740 , handle 3705 , width-adjustment mechanism 3707 , two guide rails 3723 , tulip head rests 3727 to approximate the sidewall of the tulip heads, footplates 3710 to slide under the tulip head, and a clamp release lever 3750 . In some embodiments, not shown (for clarity purposes) are tracked DRF, and tracked stray markers that can be applied to the device to make assessments of the tool's position and motion during use, as described in detail below in reference to FIGS. 39 A- 39 F, and 42 A- 42 K . Further, FIG. 37 B displays a rear view of some embodiments of the invention previously described in FIG. 37 A . Visible from this perspective is the width-adjustment knob 3709 , used to adjust the distance between the handle and the tulip head side rests according to some embodiments. In some embodiments, this viewpoint also provides the front perspective of the width-adjustment mechanism that enables the tulip head side rests to be drawn closer to or farther away from one another. Further, some embodiments include a screw-head interface protrusion 3760 , and clamp 3749 . For example, FIG. 37 C displays a perspective view of the invention previously described in FIG. 37 A in the closed position according to some embodiments. Visible from this perspective is the screw-head interface protrusions 3760 , the clamp 3749 used to securely fasten the device to the pedicle screws, and footplate 3710 to slide underneath the tulip head according to some embodiments. In some embodiments, this viewpoint displays a better view point of the guide rails 3723 , which connects the handle and screw-interfacing arms. Further, FIG. 37 E displays a rendered oblique side view of the invention previously described in FIG. 37 A in the open position, and FIG. 37 D displays a side perspective view of the invention previously described in FIG. 37 A in the closed position according to some embodiments. Visible from this perspective is the spring 3728 and over center spring structure 3732 in its collapsed position according to some embodiments.

FIG. 37 F displays a rendered oblique side view of the invention previously described in FIG. 37 A in the closed position with detailed view of the device interfacing on one side with a tulip head 3770 attached to a pedicle screw shaft 3790 (threads not shown) according to some embodiments. From this perspective, the screw-head interface protrusion is seen engaging with the screw, and by tightly driving the screw head down while the footplate is pulling the tulip head upwards, the tolerance between a polyaxial tulip head and pedicle screw shaft is reduced, resulting in rigid fixation between the three structures according to some embodiments. It should be noted that the design and geometry of the screw-head interface protrusion can have a cylindrical extrusion, spherical head, and a pivoting lever arm according to some embodiments.

FIG. 37 G displays a rendered bottom view of the invention previously described in FIG. 37 A according to some embodiments. This perspective does not include the width-adjustment mechanism, to aid in visibility of the guide rails, and their cutout groove to enable applying a torque between the tulip head side rests and the screw-head interface protrusion according to some embodiments. It should be noted that because the width-adjustment mechanism is not shown in this figure, the handle is not centered between the two screw head interfacing components of the device according to some embodiments. In some embodiments of this device previously described, the width-selector mechanism ensures that the handle remains centered between the screw head interfacing components.

In reference to FIG. 38 , and FIGS. 38 A- 38 G , some embodiments include FIG. 38 include a pedicle screw shaft (represented without threads) with depth-stop in accordance with some embodiments of the invention. Some embodiments enable assessment of the screw shaft location and pose when equipped with a polyaxial tulip head and with or without the presence of an already-implanted rod seated into the tulip head. In some embodiments, the first aspect of the embodiment is a screw designed with a depth-stop ring substantially rigidly attached to the screw shaft at a location beneath the tulip head that still enables full mobility of the attached polyaxial tulip head. In some embodiments, the depth-stop possesses a particular pattern that will interface with the second aspect of the embodiment, a tracked depth-stop assessment tool, in such a way that it allows for the interpretation of the screw shaft location and pose in 3D space, as well as indicate when the assessment tool is fully seated in the depth-stop, to ensure assessment of the screw shaft location is only made when the tool is properly engaged. In some embodiments, the indication method shown is via actuation of a TMSM, as previously described in detail in relation to FIGS. 10 A- 10 G, 14 A- 14 C, and 29 A- 29 C , but can also be achieved by other methods including, but not limited to, hand actuation of a TMSM, covering or uncovering of a tracked stray marker, and electronic communication.

FIG. 38 A illustrates a top view of the pedicle screw shaft with depth-stop of FIG. 38 in accordance with some embodiments of the invention. For example, some embodiments include a pedicle screw with a shaft 3810 (threads not shown), a depth-stop 3815 substantially rigidly attached to the screw shaft 3805 and designed with a depth-stop mating pattern 3818 , depth-stop mating holes 3817 , as well as an interface for a polyaxial tulip head (not shown). In some embodiments, the depth-stop distance from the tulip head interface 3820 is designed to stop the screw against bony anatomy such that the polyaxial head maintains full mobility about its ball joint on the screw. In some embodiments, the depth-stop as shown can be circular but can be designed to be of many shapes including interrupted and partial shapes to allow for better fitting within tight anatomical areas. In some embodiments, the mating pattern 3818 and mating holes on the depth-stop 3815 are designed such that an assessment tool, described in detail below in relation to FIGS. 38 B- 38 G , is able to interface with the depth-stop-screw device 3810 and interpret the screw shaft location and pose, irrespective of the position of the tulip head relative to the screw.

FIG. 38 B illustrates a screw interface region with coupled handle, with a partial view of an assessment tool designed to mate with the screw previously described in detail in relation to FIG. 38 A according to some embodiments. In some embodiments, the tool consists of a handle 3825 , partial-cylinder screw interface region 3827 , mating protrusions 3828 , and spring-loaded (not shown) mating pins 3829 . Further, in some embodiments, FIG. 38 C illustrates an example assembly view coupling between the screw interface region of FIG. 38 B and the pedicle screw shaft with depth-stop of FIGS. 38 - 38 A in accordance with some embodiments of the invention, and FIG. 38 C displays the closer perspective of the screw, described previously in relation to FIG. 38 A with the assessment tool, described previously in relation to FIG. 38 B , aligned and ready to engage with the mating depth-stop. In this image, the tulip head 3804 is visible attached to the top of the screw and an implanted rod 3803 is displayed engaged within the tulip head. In the position displayed, the assessment tool is not engaged with the rigid depth-stop and therefore the mating pins are not depressed according to some embodiments. It is not until the assessment device fully is seated into the depth-stop that the spring-loaded mating pins are depressed and an associated tracked mobile stray marker (not shown) can be actuated to communication to the acquisition system according to some embodiments.

Some further embodiments involve a combination of staggered heights and shapes of the depth-stop protrusions providing several unique permutations of height changes of TMSM linked to the probe. In some embodiments, this could involve two or more TMSMs on the probe. In some embodiments, the depth-stop design can be comprised of a radially-repeating pattern of two or more unique depth heights. In some embodiments, this unique combination of heights, which is also sensitive to direction/order of height changes will interact with two or more mating pins 3830 of the probe and those will interact with one or more TMSMs 3875 that are subsequently actuated to specific heights along the probe shaft, each height signaling a unique screw identity or anatomical identity. In some embodiments, instead of two TMSMs, the two mating pins that get engaged at different depth-stops can add up their depth differences mechanically against one lever that subsequently actuates a single TMSM to unique, identifiable height along the probe shaft.

FIG. 38 D displays a front view of the screw, described previously in relation to FIG. 38 A with the assessment tool, described previously in relation to FIG. 38 B , aligned and fully engaged with the mating pattern on the depth-stop according to some embodiments. From this view it is apparent that the partial-cylinder screw-interface region 3827 allows for engagement of the assessment device with the screw, regardless of the position of the polyaxial tulip head 3804 and/or attached rod 3803 according to some embodiments. FIG. 38 E displays a rear view of the screw, described previously in relation to FIG. 38 A with the assessment tool, described previously in relation to FIG. 38 B , aligned and fully engaged with the mating pattern on the depth-stop according to some embodiments. FIG. 38 F displays a side view of the screw, described previously in relation to FIG. 38 A with the assessment tool, described previously in relation to FIG. 38 B , aligned and fully engaged with the mating pattern on the depth-stop according to some embodiments.

FIG. 38 G displays a perspective view of the screw, described previously in relation to FIG. 38 A with the full assessment tool, described previously in relation to FIG. 38 B , aligned but unengaged with the depth-stop of the screw according to some embodiments. Visible in this figure is the tracked DRF 3870 attached to the tool handle 3825 for a 3D-tracking camera (not shown) to acquire the 3D location and pose of the assessment tool, a TMSM 3875 and a groove 3885 for the sliding shaft 3880 coupled to the mating pins to slide up and down to actuate the TMSM 3875 according to some embodiments. Some embodiments for the linear actuation mechanism for the mating pin depressible shaft 3880 coupled to the TMSM 3875 is a slot 3885 for the TMSM 3875 above, below, and/or near the handle 3825 . It should be noted that the location of the TMSM can be positioned anywhere on body of the tool and actuation related to the mating pins 3880 can be achieved via linear motion (as shown), rotational motion, or a combination thereof according to some embodiments. It should also be noted that some embodiments of the device can contain more than one TMSMs, paired to individual spring-loaded mating pins to indicate tool engagement with the screw or to communicate other states to the acquisition system according to some embodiments. In some embodiments, the assessment tool is firmly engaged with the screw depth-stop mating pattern 3815 , signaling to the acquisition system to calculate the 3D location and pose of the screw based on the screw's known geometry and the known mating geometry of the tool-screw combination.

Some embodiments of the invention include a device that can be used to assess the intraoperative flexibility of the spine with one or more mountings to substantially rigidly interface with implanted pedicle screws, (as previously described in relation to FIGS. 33 A- 33 H , FIG. 34 , FIGS. 35 A- 35 F , and FIGS. 36 A- 36 I ). In some embodiments, after substantially rigidly fixing two tools, each to individual spinal levels, the spine can be manipulated via directly pushing on body surfaces or indirectly by interacting with the tool's handles to establish a range of motion between the spinal levels onto which the tools are engaged. In some embodiments, the range of motion can be displayed to the user on a display monitor via a 3D view or 2D projections onto relevant anatomical planes, as described in more detail below in reference to FIG. 70 . Furthermore, in some embodiments, after adjusting two or more spinal levels to a desired relative orientation using this tool, some embodiments will be described in which the tools can lock together to temporarily hold the anatomy in that configuration prior to the insertion of a rod, as will be described in more detail in reference to FIGS. 42 A- 42 K .

FIG. 39 A displays a full perspective view of a device 3900 used for manipulating bony anatomy and assessing range of motion intraoperatively according to some embodiments. In some embodiments, two devices 3900 can be used at once, such that each securely fasten onto a level of the spine and move each level relative to one another while being tracked in 3D space to assess the achievable ranges of alignment between the two or more spinal segments with coupled devices. Some embodiments of the device consists of a tracked DRF 3905 (with markers 3907 ) for a 3D-tracking camera (not shown) to interpret its location and pose in 3D space, an adjustable handle 3910 , width-adjustment knob 3911 equipped with a TSM 3913 to enable the acquisition system software to interpret the angle of the handle relative to the tool end-effectors based on distance between the tracked DRF and this TSM, width-adjustment mechanism 3920 , a retractable spring plunger 3915 to allow for the handle to lock into discrete preset angles, sleeve bodies 3930 for housing the screw-interface component of the tool, thread-tightening knobs 3909 for tightly interfacing with tulip heads as described in detail previously in relation to FIGS. 34 , 34 A- 34 F, 35 A- 35 E, and 36 A- 36 G , and TSM 3908 for indicating the location and/or pose of the screw interface component 3930 of the device. It should be noted that this is the device and that in some embodiments the angle of the sleeve bodies relative to the width-adjustment mechanism can either be adjustable or fixed at varying angles to accommodate the pedicle screws with which the tool will interface according to some embodiments. It should also be noted that the handle of the tool can be outfitted with a spring-loaded trigger to actuate the motion of the TMSM, used to indicate its active state and/or signal a command to the acquisition system, as will be described in more detail in reference to FIG. 39 B according to some embodiments. It should also be noted that some embodiments of the tool can possess varying numbers of TSMs on and/or near the width-adjustment knob 3911 or screw-interface component 3930 of the tool according to some embodiments.

FIG. 39 B displays some embodiments of the handle of the tool described previously in relation to FIG. 39 A in which it is equipped with a TMSM 3956 coupled to a spring-loaded trigger 3950 via a sliding shaft 3959 according to some embodiments. In some embodiments, the user is able to communicate to the acquisition system that the probe is in an active state, during which its coordinates can be recorded, by actuating the TMSM relative to the tracked DRF on the tool, as described previously in detail in relation to FIGS. 10 A- 10 G and 29 A- 29 D . Additionally, some embodiments of this tool are designed for it to be used with one or more additional flexibility assessment devices, each equipped with uniquely identifiable tracked DRFs, so that their relative motion can be independently recorded while adjusting patient positioning, as described below in reference to FIGS. 40 A- 40 C, and 42 A- 42 K .

FIG. 39 C displays a bottom view of the embodiment described above in relation to FIGS. 39 A- 39 B according to some embodiments. In some embodiments, from this view, the width-adjustment mechanism 3920 is visualized with linear gears 3922 , 3924 , which allow for adjustment of the distance between the screw-interface components 3930 of the device to accommodate varying anatomical locations of screws with which it will interface. In some embodiments, FIG. 39 D displays a cross-sectional side view of the tool describe previously in relation to FIGS. 39 A- 39 C . In some embodiments, from this perspective, the retractable spring plunger 3933 is visualized, engaged within one of the detents 3934 at discrete angles, within the central device connection body 3915 , for adjusting the angle of the tool's handle 3910 . In some embodiments, in this way, the tool handle 3910 can be adjusted such that it does not interfere with additional tools placed within the surgical site, as described below in relation to FIGS. 40 A- 40 C and 42 A- 42 K . It should be noted that this is only the handle 3910 , in which it is joined at the middle of the width adjustment mechanism. In some embodiments, the tool's handle is joined at an off-center location on the width-selection mechanism, and in some embodiments, the tool's handle projects at non-orthogonal angles to the width-adjustment mechanism to allow for enhanced tracking-camera visibility of the tracked DRF markers ( 3907 , 3954 ) and TMSM 3956 on each tool.

FIG. 39 E displays a bottom view of the width-adjustment mechanism 3920 that allows for variation in the distance between screw-interface locations of the tool according to some embodiments. Further, FIG. 39 F illustrates a close-up perspective of the width-adjustment mechanism 3920 , thread-tightening knobs 3909 , and sleeve body 3930 of the device as described above in relation to FIGS. 39 A- 39 E in accordance with some embodiments of the invention.

Some embodiments can be equipped with the quarter-turn tip as described in relation to FIGS. 36 A- 36 I to mate with the screws described. Some embodiments of the device include variations in the screw interface components such that they are able to mate with crossbar-equipped screws, as previously described. For some embodiments interfacing with screws of this design, the screw-interface components are designed with the quarter-turn mechanism previously described in relation to FIGS. 3 B, 33 D- 33 F, and 44 D .

FIGS. 40 A- 40 C display the application of the flexibility assessment device previously described in detail in relation to FIGS. 39 A- 39 E , as applied to an anatomical model of the spine according to some embodiments. In some embodiments, the figures show the application of the device as applied across spinal levels L1-S1, an example assessment region. In some embodiments, because the assessment device tools both contain tracked DRFs, their location and pose are tracked during manipulation of the spine such that the maximum and minimum angles as well as positions of the assessment devices can be recorded and the calculations displayed to the user. Furthermore, some embodiments of this device allow for the relative position of two or more of these devices to lock to one another and allow for the insertion of hardware to fix the spine into that conformation, as described below in reference to FIGS. 41 A- 41 C, and 42 A- 42 K .

FIG. 40 A illustrates a lateral view of a spine model with a straight curve, and two flexibility assessment tools engaged with the model in accordance with some embodiments of the invention. FIG. 40 A displays a straight curve 4010 a , and two flexibility assessment tools ( 4077 a , 4077 b ) engaged with the model and screw-interface components 4015 , 4018 according to some embodiments. In some embodiments, the user's hand 4008 interfaces with the handle of each assessment tool 4077 a , 4077 b and each tool is equipped with a unique tracked DRF ( 4076 a , 4076 b ) to enable tracking of the device's location and pose in 3D space by a 3D-tracking camera (not shown). In some embodiments, the width and height between the screw-interface components are fixed. In some embodiments, when the assessment devices are activated, their relative 3D angles ( 4075 a , 4075 b ) can be calculated, and projected onto anatomical reference planes. In FIG. 40 A , the angle between handles shown is 10 degrees, which can be displayed to a user as the maximum limit of spine flexion.

FIG. 40 B displays two flexibility assessment devices ( 4077 a , 4077 b ) interfacing with a spine model with a lordotic curve 4010 b according to some embodiments. In some embodiments, 3D-tracking acquisition systems can display relative angles ( 4075 a , 4075 b ) and positions to a user, as described above in relation to FIG. 40 A , and as applied to this embodiment, can display the maximum limit of spine extension to be 45 degrees. Further, FIG. 40 C displays the invention from a 3D-tracking camera (not shown) perspective according to some embodiments. In some embodiments, both tool's unique tracked DRFs 4076 a , 4076 b are shown, as well as the mirrored angles of the handles relative to the screw-interface components of the device. Some embodiments of the device position the handles at varying angles to the width adjustment mechanism, and also possess spring-loaded triggers (not shown), to communicate the probe's active state to the acquisition system, as described above in relation to FIG. 39 B .

FIGS. 41 A- 41 D displays the flexibility assessment device, described previously in detail in relation to FIGS. 39 A- 39 F and 40 A- 40 C , equipped with detachable components to allow for the removal of the tool handle and body without detaching the screw-interface components according to some embodiments. In some embodiments, the removal of the handle allows for retaining rigid fixation on the screws while regaining workable space within the surgical site. In some embodiments, it also enables utilization with locking the alignment into a certain configuration on one side, removing the handle and body of the device, and then placing a rod to secure the spine in that configuration, as will be described in detail below in FIGS. 42 A- 42 K .

Referring to FIG. 41 A , illustrating a side view of the screw-interface components of the flexibility assessment device described previously, where a detachable component of the screw-interface devices mates with the bottom component via spring-loaded snap arms 4105 that can be released by pressing the release tabs 4110 according to some embodiments. In some embodiments, the top component contains a post 4115 for the thread-tightening knob (not shown) previously described in relation to FIGS. 34 , 34 A- 34 F, 35 A- 35 F, and 36 A- 36 I . In some embodiments, the mating interface of the two components contains a center-alignment post 4120 and peripheral alignment pins 4125 to facilitate alignment and enable rigid mating of the components.

FIG. 41 B displays a front view of the embodiment described above in relation to FIG. 41 A according to some embodiments. This view of the embodiment displays the screw-interface rod 4130 intended to interface with the top surface of the pedicle screw head while the device threads 4135 interface with the tulip head threads (not shown), side-tab extensions 4140 , snap-arm mating detent 4145 , and spring-loaded snap arm 4105 . Further, FIG. 41 C illustrates the device of FIGS. 41 A- 41 B assembled with a flexibility assessment device previously described in relation to FIGS. 39 A- 39 F, and 40 A- 40 C in accordance with some embodiments of the invention. For example, FIG. 41 C displays the device in which the detachable screw-interface components previously described in relation to FIGS. 41 A-B are assembled with a flexibility assessment device previously described according to some embodiments. In some embodiments, one side of the flexibility assessment device is equipped with a detachable screw-interface component, and the other is equipped with a non-detachable component, as described in FIGS. 34 , 34 A- 34 F, 35 A- 35 E , and 36 A- 36 I. For example, in some embodiments, the screw-interface rod 4130 is visible on the non-detachable screw interface component, as is the thread 4135 to interface tulip heads. In some embodiments, the side-tab extension 4140 , snap-arm mating detent 4145 , and spring-loaded snap arm 4105 are visualized on the detachable screw-interface component. Further, in some embodiments, on the flexibility assessment device, previously described in relation to FIGS. 39 A- 39 B and 40 A- 40 C , the tracked DRF 4150 , handle 4160 , retractable spring plunger 4165 , width-adjustment knob 4170 , TSM 4175 for width-adjustment knob 4170 , thread-tightening knob 4178 , TSM 4182 for thread tightening knob 4178 , width-adjustment mechanism 4184 , and sleeve body 4186 are all displayed. Additionally, in some embodiments, the detachable screw interface component is shown interfacing with a tulip head 4192 attached to a pedicle screw (threads not shown) shaft 4188 .

FIG. 41 D displays a perspective assembly view of the detachable screw-interface component displaying the release tabs 4110 , center-alignment post 4120 , peripheral alignment pins 4125 , screw-interface rod 4130 , side-tab extensions 4140 , and spring-loaded snap arm 4105 according to some embodiments.

Some embodiments include an assessment device equipped with detachable screw interface components and adjustable cross-linking devices. For example, in reference to FIGS. 42 A- 42 C , some embodiments include a spinal flexibility assessment device as described above in relation to FIGS. 39 A- 39 F, 40 A- 40 C, and 41 A- 41 D , equipped with a fixation mechanism, described below in reference to FIGS. 43 A- 43 F , that allows for the flexibility assessment devices to be locked in a particular position, and removed from one side to accommodate the placement of a fixation rod on the contralateral side. In this way, the user can position the spine into a desired conformation with feedback from the 3D tracking acquisition system tracking the location of each flexibility assessment device according to some embodiments. It should be noted that the feedback displayed to the user can either be relative positioning of the tools, or relative positioning of initialized vertebra, as described in detail below in reference to FIG. 70 according to some embodiments.

FIG. 42 A , shows the flexibility assessment device 4200 , as described previously equipped with detachable screw interface components with adjustable cross-linking devices according to some embodiments. In some embodiments, the device includes a width-adjustment mechanism 4205 (e.g., 4170 of FIG. 41 C ) to match the distance between screw-interface components with the distance between implanted pedicle screws and their associated tulip heads 4225 . In some embodiments, this is intended to be used after the pedicle screws have been placed into the spine 4210 during surgery. In some embodiments, this device can be equipped with a bone-clamping mechanism that enables it to substantially rigidly fix to the spine in the absence of pedicle screw and tulip heads with which to interface.

Further, FIG. 42 B illustrates the flexibility assessment device described previously in relation to FIG. 42 A substantially rigidly coupled to the pedicle screws by interfacing with the tulip heads in accordance with some embodiments of the invention, and shows thread-tightening knob 4209 according to some embodiments. In some embodiments, illustrated is the flexibility assessment device, where the screw interface components can substantially rigidly couple to the tulip heads via the thread-tightening-knobs 4209 . In some embodiments, when they are tightly coupled to the tulip heads, the tolerance between the pedicle screw shaft and polyaxial tulip head is removed, thus resulting in a substantially rigidly fixed system between the screw shaft, tulip head, and flexibility assessment device.

Further, FIG. 42 C displays a second flexibility assessment device 4202 interfacing with a spinal level at a user-defined distance from the already mated device 4201 described previously according to some embodiments. In some embodiments, because both assessment devices possess unique tracked DRFs 4226 a , 4226 b , the 3D-tracking acquisition system is able to distinguish them from one another. Further FIG. 42 D displays the two mated flexibility assessment devices 4201 , 4202 according to some embodiments. In some embodiments, after the devices are substantially rigidly attached to the spine, their handles can be adjusted relative to their screw-interface components by releasing and subsequently re-engaging the retractable spring plunger 4165 to enable greater degrees of freedom without the devices obstructing one another. In some embodiments, the 3D acquisition system interprets the position of the handle by comparing the individual tool's tracked DRF to the location and/or of the TSMs located over the corresponding tools' width-adjustment mechanism or screw-interface components. Furthermore, in some embodiments, after the assessment devices are substantially rigidly fixed to the spine 4210 through mating with screws 4225 , they can be placed in an active state by user-triggering (trigger 3950 as seen previously in relation to FIG. 39 B ) of a TMSM 3956 coupled to a depressible shaft 3959 within each device handle 4201 , 4202 , and then manipulate the contour of the spine until the user is satisfied with the software-displayed measurements. In some embodiments, the relative contour of the spine between devices can then be held in place by utilization of adjustable cross-linking devices, described below in reference to FIGS. 42 E- 421 , and 43 A- 43 D .

FIG. 42 E displays two flexibility assessment devices substantially rigidly attached to the spine as described previously in relation to FIGS. 39 A- 39 F, 41 A- 41 D, and 42 A- 42 D . When the devices are positioned in a way such that the spine 4210 is held in a desirable contour, they can be locked together utilizing adjustable cross-linking devices 4250 attached to the width-adjustment devices 4201 , 4202 according to some embodiments. Further, FIG. 42 F illustrates two flexibility assessment devices 4201 , 4202 substantially rigidly attached to the spine 4210 , further including an adjustable cross-linking device 4250 for screw-interface device 4255 according to some embodiments. For example, in some embodiments, in addition to substantially rigidly connecting the devices between the width-adjustment mechanisms, the screw-interface components can also be substantially rigidly fixed to one another via the adjustable cross-linking devices 4255 . FIG. 42 G illustrates an instrumented spine 4210 previously described in relation to FIGS. 42 A-F in accordance with some embodiments of the invention, and shows adjustable cross-linking device for screw-interface device 4255 coupled to the spine 4210 according to some embodiments. In this instance, the detachable screw-interface components, as described enable the body and one screw-interface component of the assessment device to be removed to leave behind two screw-interface components, held in place by the coupled, adjustable cross-linking device 4255 according to some embodiments.

FIG. 42 H displays an instrumented spine 4210 previously described in relation to FIGS. 42 A- 42 G according to some embodiments. In some embodiments, rith the spine 4210 held in a fixed contour, the removed components of the flexibility assessment devices allow for the placement of a rod 4269 within the exposed set of contralateral screws. Further, FIG. 42 I illustrates an instrumented spine previously described in relation to FIGS. 42 A- 42 H in accordance with some embodiments of the invention. In some embodiments, the rod 4269 placed within the exposed set of pedicle screws is secured in place with cap screws 4271 . In some embodiments, with the rod 4269 holding the spine 4210 in the desired contour, the remaining screw-interface components are now able to be removed. Further, FIG. 42 J displays an instrumented spine 4210 previously described in relation to FIGS. 42 A- 421 according to some embodiments. In some embodiments, with the contour of the spine held in place with the already-secured rod 4269 b , the remaining components of the flexibility assessment device shown in FIG. 42 I are removed, enabling placement of a second rod 4269 a within the screws. Further, in some embodiments, FIG. 42 K displays an instrumented spine previously described in relation to FIGS. 42 A- 42 J . In some embodiments, this figure displays the final step of securing the adjusted alignment of the spine achieved with the lockable pair of flexibility assessment devices. In some embodiments, during this step, the second rod is secured with cap screws 4271 .

FIG. 43 A displays a top view of the device 4300 which is an adjustable cross-linking device, as described above in relation to FIGS. 42 A- 42 K , mates with components of the flexibility assessment device, as described previously in relation to FIGS. 39 A- 39 F, 40 A- 40 C, 41 A- 41 D, and 42 A- 42 K according to some embodiments. Some embodiments consists of an outer-slider ball socket 4301 designed to mate with protruding balls on components of the flexibility assessment device including the width-adjustment mechanism, as described previously in relation to FIGS. 39 A- 39 F, 40 A- 40 C, 41 A- 41 D, and 42 A- 42 K , and the screw-interface components of the device, as described previously in relation to FIGS. 34 - 36 , 41 A- 41 D . Some embodiments also contain a retractable spring plunger 4303 with teeth that engages with an internal rack with teeth 4304 . Additionally, in some embodiments, there is an inner-slider ball socket 4306 designed to mate with a secondary flexibility assessment device component, as described previously in FIGS. 42 A- 42 K .

FIG. 43 B displays a bottom view of the device 4300 , shown previously in FIG. 43 A , which is an adjustable cross-linking device, a described above in relation to FIGS. 42 A- 42 K according to some embodiments. In some embodiments, from this perspective, the outer-slider ball socket 4301 , internal rack with teeth 4304 and inner-slider ball socket 4306 are all visible. In some embodiments, in order to adjust the length of the adjustable cross-linking device, a user depresses the retractable spring plunger with teeth such that it disengages from the internal rack with teeth. In some embodiments, when the length is as desired, the user releases the retractable spring plunger with teeth such that it re-engages with the internal rack with teeth 4304 . FIG. 43 D illustrates a retractable spring plunger 4303 with teeth 4304 , outer-slider set screw 4320 , and inner-slider set screw 4322 according to some embodiments.

FIGS. 43 E and 43 F shows an adjustable cross-linking device 4333 , described previously in relation to FIGS. 42 A- 43 K, 43 A- 43 D , engaged with detachable screw-interface components (shown here as 4335 a , 4335 b , and adjustably coupled through coupler 4380 , with rotation balls or joints 4381 ) of the flexibility device previously described in relation to FIGS. 41 A- 41 C according to some embodiments. As shown, in some embodiments, coupled components can include fixation ball 4330 a , 4330 b , snap-arm mating location 4345 a , 4345 b (e.g., shown previously in relation to FIG. 41 B as snap-arm mating detent 4145 ), peripheral alignment pin(s) 4350 a , 4350 b , pedicle screw shaft 4355 a , 4355 b , and tulip heads 4360 a , 4360 b . In some embodiments, the detachable screw-interface devices 4335 a , 4335 b possess a fixation ball 4330 a , 4330 b to interface with the inner and outer-slider ball sockets, a snap-arm mating locations 4345 a , 4345 b , and peripheral alignment pins 4350 a , 4350 b . Further, in some embodiments, screw-interface components are engaged with the tulip heads 4360 a , 4360 b of pedicle screw (threads not shown) shafts 4355 a , 4355 b.

Some embodiments of the invention include a bone-implanted fiducial equipped with a rigid crossbar that substantially rigidly mates with a tracked probe equipped with a TMSM to indicate to the acquisition system when it is fully engaged. In some embodiments, because the probe is only able to mate with the fiducial in one conformation, when the tracked probe fully engages with the fiducial, the location and pose of the fiducial can be interpreted. In some embodiments, if the fiducial has been previously initialized to the vertebra, reassessing the location and pose of the fiducial enables re-registration of the location and pose of the vertebra. Furthermore, in some embodiments, if the fiducial is placed under surgical navigation, interfacing the probe with the fiducial enables rapid re-registration of bony anatomy for surgical navigation cases, providing value when anatomy moves relative to a reference DRF or when the anatomy changes conformation from when its imaging was last registered for surgical navigation. In some embodiments, in this way, the bone fiducial serves as another method of rapid re-registration of anatomy, as similarly described in FIGS. 38 , and 38 A- 38 G . For example, FIG. 44 A illustrates a bone-implanted fiducial equipped with a crossbar and substantially rigidly fixed to the lamina of a vertebra as previously described in relation to FIGS. 3 A- 3 C in accordance with some embodiments of the invention. In some embodiments, the bone-implanted fiducial 4410 is equipped with a rigid crossbar 4412 and substantially rigidly fixed to the lamina 4401 of a vertebra 4400 as previously described. Further, FIG. 44 B illustrates a process view of a pre-engagement of a bone-implanted fiducial 4410 and bone-fiducial mating screwdriver 4450 equipped with a tracked DRF 4420 (composed of 3D-tracked markers 4425 ) and a TMSM 4415 coupled to a depressible sliding shaft (shown later as 4450 b ) at the end of the screwdriver in accordance with some embodiments of the invention. Some embodiments are an alternative to some embodiments used to interpret the location and pose of a vertebra in space, as previously described in FIGS. 3 A- 3 C, 29 A- 29 C, 33 A- 33 H, and 38 , 38 A- 38 G . In some embodiments, the probe tip 4450 a is equipped with a quarter-turn mechanism to tightly engage with the bone-implanted fiducial. In some embodiments, by fully engaging with the crossbar 4412 on the fiducial, the depressible sliding shaft is mechanically actuated to move the linked TMSM 4415 and thereby signal to the 3D-tracking acquisition system to record the coordinates of the screwdriver, and calculate the location and pose of the implanted-bone fiducial, and associated vertebra if it has been initialized. For example, in some embodiments, FIG. 44 C illustrates an engagement of a bone-implanted fiducial and bone-fiducial mating screwdriver equipped with a tracked DRF 4420 and a TMSM 4415 coupled to a depressible sliding shaft 4450 b at the end of the screwdriver 4450 , and FIG. 44 C displays the bone-fiducial mating screwdriver 4450 engaged with the bone-implanted fiducial 4410 . When fully engaged, as shown the bone-fiducial mating screwdriver 4450 is aligned coaxially with the bone-implanted fiducial 4410 , and the TMSM 4415 is actuated, indicating to the acquisition system that the screwdriver tip 4450 b is fully engaged with the bone-implanted fiducial according to some embodiments. Further, FIG. 44 D illustrates a bone-implanted fiducial with crossbar and overlying bone-fiducial-mating screwdriver in accordance with some embodiments of the invention. In some embodiments, a quarter-turn mating tip 4455 and depressible sliding shaft 4450 b . In some embodiments, the quarter-turn mating tip 4455 is shown as is the depressible sliding shaft 4450 b which is depressed upon complete engagement between the screwdriver 4450 and fiducial 4410 (engaging around cross-bar 4412 ). It should be noted that in some embodiments, the acquisition system can be triggered to calculate the location of the fiducial, based on user-input to the software, hand-triggering a TMSM or electronic communication system, and can be used for rapid re-registration of a vertebra's location within camera coordinates prior to rod implantation, as described below in FIGS. 45 A- 45 B and 72 .

Some embodiments of the invention include rapid re-registration with depth-stop-screws and depth-stop-engaging screw-assessment tool. For example, some embodiments include a system and method to enable rapid re-registration and 3D-rendering of a vertebra's relative location in space by utilizing a depth-stop equipped pedicle screw and depth-stop engaging assessment tool, as previously described in relation to FIGS. 38 , and 38 A- 38 G . In some embodiments, the depth-stop attached to the screw can be accessed by the depth-stop engaging assessment tool, with or without an implanted rod present, to accurately calculate the location and pose of the screw in 3D-tracking camera coordinates. In some embodiments, if screws were initially placed under image guidance, the acquisition system has already stored and recorded the relative position of each screw to the vertebra in which they are implanted. In some embodiments, with this information, after re-registering the new location of both screws in space, the acquisition software is able to reconstruct the location of the vertebra in which they are inserted. In some embodiments, if a surgical navigation system becomes decoupled from the patient's anatomy, either through movement of the tracked DRF serving as a patient reference or through change in contour of the spine from the time the image was acquired, the system can be rapidly re-registered to the patient's current position in space.

FIG. 45 A displays the invention in which two vertebra 4525 a , 4525 b are instrumented with depth-stop-equipped pedicle screws 4540 , described previously in relation to FIGS. 38 , 38 A- 38 G , which can be registered in 3D space by having the depth-stop-engaging 3D-tracked tool 4505 interfaces with each screw on each vertebra. In some embodiments, the 3D-tracked tool 4505 for registering the position and orientation of the screws comprises of a handle 4510 , a depressible sliding shaft that mates with the screw depth-stop interface that actuates a TMSM 4511 to change the triggering state of the tool to active, and a 3D-trackable DRF 4515 of 3D-tracked markers in a unique configuration. In some embodiments, if the screws were initially placed under surgical navigation, and the position of the screw shafts relative to the vertebrae are known, then assessment of screw shafts' location and pose for each vertebra, is able to yield a 3D rendering of each vertebra (shown as representations 4561 , 4562 ) in space relative to one another. It should be noted that utilizing depth-stop-equipped pedicle screws and their associated assessment tool, is not the only way of obtaining the information needed for the software to make this assessment according to some embodiments. Some embodiments include mating directly with screw heads coaxially to interpret their location and pose, as previously described in FIGS. 29 A- 29 C , and FIGS. 33 A- 33 H . In some embodiments, in cases when an assessment of the screw, and thereby vertebrae locations, are desired after implantation of a rod, the depth-stop-equipped pedicle screws preserve access to the screw shaft with the depicted assessment tool. Further, in some embodiments, FIG. 45 B shows the invention previously described in FIG. 45 A , in which case the position of vertebra # 1 4525 c has changed relative to that of vertebra # 2 4525 b . In some embodiments, by engaging the depth-stop-equipped tracked assessment tool, into both depth-stop-equipped pedicle screws 4540 in vertebra 4525 c and vertebra 4525 b , the acquisition system's software can then reconstruct an updated rendering 4563 on the display monitor of each vertebra in their relative 3D position and orientation to one another.

In some embodiments, the probe depicted in FIG. 38 , used to update 3D renderings of a vertebra via re-registration of screws can also be updated via mating with a bone fiducial, depicted in FIGS. 3 A- 3 C and 44 A- 44 D . Some embodiments include mating directly with bone-mounted, percutaneous, or skin-mounted fiducials that are initialized to anatomical landmark(s) of interest for 3D renderings.

Some embodiments of the invention can enable significantly reduced X-ray and radiation exposure during minimally invasive, as well as open, surgeries and procedures. In some embodiments, tracked surgical tools are able to be placed in the field of view of previously-acquired X-ray images, such that their projected outline can be displayed over anatomy visualized in a previously-acquired X-ray image. In some embodiments, the acquisition software interprets the location of the tool surface relative to the X-ray emitter/detector and using that information is able to accurately display a real-time overlay of the tools' position on the previously acquired X-ray image, accounting for the appropriate size scaling of the tool's outline, as described below in reference to FIG. 71 .

FIGS. 46 A- 46 B illustrate a 3D tracking tool in accordance with some embodiments of the invention. In some embodiments, a 3D-tracked tool 4600 includes a handle 4610 , tracked DRF 4605 (with markers 4607 ) and tool tip 4620 (which is often a coupled implant). It should be noted that in some embodiments of this invention, each mobile component of the surgical tool that is used, requires 3D-tracking relative to each of the other components within said tool. FIG. 46 C displays the invention in which an X-ray emitter 4684 is equipped with a tracked DRF 4686 positioned in a known location relative to the emitter, and the X-ray detector 4682 can also be equipped with a tracked DRF 4699 positioned in a known location relative to the detector. In some embodiments, with the X-ray system imaging a spine 4691 resting on an operative table 4683 , the X-ray emitter produces a conical volume of its X-ray beam 4695 . In some embodiments, all objects within this conical volume are then projected onto the X-ray detector 4682 . In some embodiments, with known geometry of the X-ray system 4680 , the location and pose of this conical volume 4695 is known relative to either of the tracked DRFs ( 4686 , 4699 ) mounted to the X-ray system. In some embodiments, with a 3D-tracking camera having recorded the location of the emitter, and thereby the conical imaging volume, when an X-ray is taken, the acquisition system can determine when any component of the tracked surgical tool enters within the volume. In some embodiments, when the surgical tool 4689 is positioned within the volume, its virtual projection can be overlaid on the previously-acquired x-ray image, as shown in FIG. 46 D . In some embodiments, the proximity of the tracked tool's surface to the emitter, enables the acquisition software to determine its relative size scaling in the overlay image, as described below in reference to FIG. 71 .

FIG. 46 D illustrates a virtual overlay of a tracked surgical tool positioned close to the X-ray detector on top of an X-ray image of the spine in accordance with some embodiments of the invention. As shown, in some embodiments, the X-ray image of spine 4601 includes an overlay image of surgical tool close to detector 4615 a . In some embodiments, this virtual overlay is updated in real-time as the tool moves relative to the previously acquired X-ray's conical volume as described below in reference to FIG. 71 . FIG. 46 E displays some embodiments of the invention previously described in FIG. 46 C , with the tracked surgical tool 4689 positioned closer to the X-ray emitter according to some embodiments. Further, FIG. 46 F displays a virtual overlay of a tracked surgical tool in the X-ray image 4602 , with the tool 4620 a positioned close to the emitter, as shown in FIG. 46 E according to some embodiments. In some embodiments, because the tool's surface is located closer to the X-ray emitter, its virtual projection is scaled to be larger to match the case of if a real X-ray image was acquired of the tool in that position. In some embodiments, the software interpretation of the tool's relative scaling size is described below in reference to FIG. 71 . Further, FIG. 46 G displays an X-ray image 4603 with a virtual overlay of a tracked surgical tool 4620 b close to the emitter, turned 90 degrees, from the tool position previously described in FIGS. 46 E- 46 F according to some embodiments. In some embodiments, the tool's real-time location in space relative to the previously acquired X-ray volume, can be displayed via an overlay onto the previously acquired X-ray image. In some embodiments, the virtually-overlaid tool 4689 can also be simultaneously overlaid or interfaced with other 3D-tracked surgical tools that are within, or outside of, the field of view of the X-ray volume 4695 . In some embodiments, if 3D-tracked DRFs are mounted onto anatomical landmarks of interest that are also in the X-ray image, the 3D-tracked location and pose of the surgical tool 4689 can be overlaid while the anatomical structures in image also become virtually adjusted to reflect their movements relative to the C-arm DRFs ( 4699 , 4684 ) and the main surgical tool 4689 (e.g., when the surgical tool 4689 with a coupled implant, such as a cage) is inserted between two vertebrae, with mechanically-linked DRFs, and the corresponding X-ray image virtual overlay adapts the position and orientation of the imaged vertebrae to reflect their approximate real-world positions and orientations relative to one another.

Some embodiments of the invention include components that make up the two-part system for a handheld mechanism of assessing the contour of the rod prior to implantation. For example, FIG. 47 A displays components of a tracked end cap, used to substantially rigidly hold a rod, define anatomical reference planes relative to the 3D-tracking camera, and establish the coordinate system within which all coordinates of the rod's location will be recorded according to some embodiments. Further, FIG. 47 B displays components of a tracked slider tool, used in combination with the tracked end cap, to slide along the surface of a rod and interpret its coordinates within the coordinate system established by the tracked end cap, as described in detail below in reference to FIG. 74 according to some embodiments. As shown, some embodiments include an end cap handle 4720 , mount 4722 for interfacing with the mount-mate 4714 containing anatomical axes reference arrow labels consisting of, but not limited to inferior 4718 and posterior 4719 . Some embodiments also consists of a rod mount hole 4712 to insert a rod and a threaded hole 4716 for a set screw to secure the rod in place relative to the end cap, a mounting platform 4710 for a tracked DRF, a tracked DRF 4730 , and fasteners 4740 . Some embodiments utilize a separate, tracked DRF. In some embodiments, the DRF-based markers mount directly into the tool surface itself, as described below in reference to FIGS. 52 A- 52 B, and 53 A- 53 F . Furthermore, some embodiments of this invention are shown below in reference to FIGS. 48 A- 48 B, 49 D, 50 E, 51 A- 51 C, 51 H- 51 I, and 56 A- 56 F according to some embodiments.

FIG. 47 B displays the components of a tracked slider, designed to interface with a rod fixed to a tracked end cap, described previously in relation to FIG. 47 A according to some embodiments. Some embodiments of the slider consists of a handle 4770 , mount 4772 for joining with the mount-mate 4797 , a rod-centering fork 4798 designed to straddle and center the rod during acquisition of the rod's contour, a through hole 4784 for receiving a depressible sliding shaft 4786 that mates with a TMSM mount 4754 via a fastener 4790 and is spring-loaded 4795 . Some embodiments also consists of a DRF mount 4760 to receive a tracked DRF 4780 and a TMSM 4753 attached to its corresponding mount. Some embodiments of this device are described below in reference to FIGS. 51 D- 51 I . It should be noted that some embodiments of the rod-centering fork component, meant to interface with the rod, are ring-shaped designs meant to accommodate specific rod diameters, adjustable diameter rings, U-shaped designs, and polygonal-shaped designs including but not limited to triangular, rectangular, pentagonal, etc. according to some embodiments.

FIGS. 48 A- 48 C relate to the tracked end cap previously described in relation to FIG. 47 A according to some embodiments. Some embodiments are equipped with a spring-loaded TMSM actuated by a trigger on the handle used to communicate with the 3D-tracking acquisition system. Additionally, in some embodiments, it contains an alternative method of fixing the rod than a set screw which was previously described in FIG. 47 A . In some embodiments, the rod mount hole is split and tightened by the combination of a cam lever and threaded fastener for more rapid exchange and fixation of rods with the end cap, as well as maintaining the center alignment of the rod after fixation. For example, in some embodiments, FIG. 48 A illustrates a close-up view of a portion of an end cap in accordance with some embodiments of the invention, showing an assembly comprising a rod mount hole 4824 , rod 4805 , end cap handle 4830 , cam lever 4823 , hinge pin 4821 , and threaded fastener 4825 . In some embodiments, the rod 4805 is inserted into the rod mount hole 4824 and secured in place by a cam lever 4823 rotating about a hinge pin 4821 to tighten against a threaded fastener 4825 .

FIG. 48 B illustrates a perspective view of an end cap 4800 assembled from components of FIG. 47 A in accordance with some embodiments of the invention, and shows a rod 4805 , trigger 4833 , spring-loaded hinge 4831 , trigger arm ( 4832 , 4841 ), TMSM 4819 , and end cap tracked DRF 4815 (with 3D-tracked markers 4817 ). In some embodiments, the perspective shows the end cap previously shown in FIG. 47 A , in which a rod 4805 is fixed. Some embodiments also contain a hand-actuated trigger 4833 that rotates about a spring-loaded hinge 4831 inside the handle 4830 , to actuate a trigger arm 4841 with a coupled TMSM 4819 . Some embodiments also contain a tracked DRF 4815 used to interpret the location of the end cap and its attached rod via a 3D-tracking camera (not shown). In some embodiments, the location of the TMSM actuated by the trigger on this embodiment is compared to the location of the tracked DRF by the acquisition software, to determine if the user is triggering the device, as described in more detail below in reference to FIGS. 64 A- 64 B and 65 A- 65 E . It should be noted that in some embodiments of this device, the trigger can be actuated via other mechanisms such as covering or uncovering a tracked marker, as described previously in relation to FIG. 14 , using linear motion rather than rotational, as described previously in relation to FIGS. 10 A- 10 G, 29 A- 29 D, 38 , 38 A- 38 G, 39 A- 39 F, 42 A- 42 K, 44 A- 44 D, and 45 A- 45 B , using electronic communication, or via direct user-input to a display monitor interface according to some embodiments. Further, FIG. 48 C illustrates a side view of the end cap 4800 of FIG. 48 B in accordance with some embodiments of the invention. In some embodiments, this perspective shows a rod 4805 fixed inside the end cap handle 4830 , equipped with a trigger 4833 rotating on a spring-loaded hinge 4831 and mounting a TMSM 4819 on the trigger arm 4841 . In some embodiments, this figure also displays the tracked DRF 4815 used for interpreting the end caps location and pose in 3D space, and two relative anatomical axes indicators with inferior 4849 and posterior 4843 shown. Some embodiment can be applied to any application mentioned below with regards to a tracked DRF-equipped end cap, in reference to FIGS. 49 D, 50 E, 51 H- 51 I, 56 , and 87 A .

Some embodiments of the invention can be used to assess the contour of a rod prior to implantation via coupling a tracked end cap, previously described in FIGS. 47 A and 48 A- 48 C , with a fixed-base, single-ring assessment device. In some embodiments, rather than utilizing two handheld tools to assess the rod contour, as previously described, this device enables rod contour assessments via mounting the rod to one handheld end cap and passing the rod through a substantially rigidly-fixed ring device. In some embodiments, because the diameter of the ring is designed or adjusted to be closely matching the diameter of the rod, this embodiment forces the portion of the rod engaged with the ring to be nearly concentric with the ring. In some embodiments, to compute the contour of the rod from this embodiment, the acquisition system interprets the path traveled by the end cap, rather than the path traveled by the slider relative to the end cap, as previously described. In some embodiments, the software interpretation of this invention is described in detail below in reference to FIG. 75 .

FIG. 49 A displays assembly 4900 used to assess the contour of the rod prior to implantation, applied to when a rod is attached to a tracked end cap according to some embodiments. Some embodiments consists of a fixed base 4905 with a coupled post 4915 holding a rod-receiving ring 4910 designed for a rod of set diameter to pass through. In some embodiments, attached to the ring is a TSM 4903 as well as a hinge 4907 about which a hinged flap 4909 , shown in the closed position, rotates. In some embodiments, a TMSM 4920 is attached to the hinged flap and used to signal to the acquisition system when a rod is engaged with the ring 4910 via the TMSM 4920 attached to the hinged flap 4909 moving relative to the TSM 4903 attached to the ring. In some embodiments, the software interpretation of this motion is completed by simply comparing the distances between the TSM 4903 and the TMSM 4920 when the hinge 4907 is closed versus opened. In some embodiments, the hinged flap 4909 stays closed in the absence of a rod through the force of gravity acting on the TMSM 4920 attached to the hinged flap 4909 . In some embodiments, the hinged flap can also be spring loaded. It should be noted that in some embodiments of this design, the fixed base 4905 can be resting on a surface, or mounted to a rigid surface including a component of a robot according to some embodiments.

FIG. 49 B displays the invention described previously in FIG. 49 A , except with the hinged flap 4909 and its attached TMSM 4920 in the open position, analogous to its position when a rod 4960 is inserted into the ring 4910 and pushing up on the hinged flap 4909 . FIG. 49 C displays a different view of some embodiments of the invention described previously in FIGS. 49 A-B , with the hinged flap 4909 and its attached TMSM 4920 in the open position, and direct visualization of the rod-receiving ring 4910 , held up from the base 4905 by a rigid post 4915 . FIG. 49 D illustrates the assembly of FIGS. 49 A- 49 C coupled with a rod and tracked end cap previously described in relation to FIGS. 47 A, and 48 A- 48 B in accordance with some embodiments of the invention.

FIG. 49 D displays the fixed-base, single-ring rod assessment device as previously described in FIGS. 49 A-C , coupled with a rod 4960 and tracked end cap 4990 , previously described in FIGS. 47 A and 48 according to some embodiments. Some embodiments show the rod 4960 pushing the hinged flap 4909 out of the way and by doing so, actuating the TMSM 4920 attached to the hinged flap 4909 . In some embodiments, when the software acquisition system detects the distance between the TSM 4903 and the TMSM 4920 closer than that when the hinged flap is closed, it is triggered to record the coordinates of the end cap. In some embodiments, the recorded coordinates of the end cap's path can then be used to calculate the contour of the rod, as described in detail in FIG. 75 . In some embodiments, the user can trigger the acquisition via other triggering methods described previously in relation to FIG. 48 B . Following registration of the contour of a rod attached to a tracked end cap, the tracked end cap can be used for the user to directly interface with the display monitor portraying the rod contour, as described in detail below in reference to FIG. 78 .

FIGS. 50 A- 50 D illustrates embodiments of a fixed-base, variable-ring, mobile rod assessment device in accordance with some embodiments of the invention. In some embodiments, the device assembly is described in FIGS. 49 A- 49 D , in which it is able to accommodate the contour assessment of a series of rod diameters via a variable-ring-size selector component. In some embodiments, after the user rotates the appropriate diameter ring in front of the hinged flap by using the retractable spring plunger, a rod of corresponding diameter attached to a tracked end cap can then be passed through the ring and have its contour interpreted in the same method previously described in relation to FIGS. 49 A- 49 D .

Referring initially, FIG. 50 A , illustrating a front view of an embodiment 5000 , fixed base 5001 coupled to post 5005 is shown to which a revolving rod-width selector 5007 containing multiple rod-receiving rings 5009 of varying diameter is coupled via a fastener 5011 and can be rotated into preset angles via a retractable spring plunger 5013 , and a TSM 5017 fixed to the post 5005 according to some embodiments. In some embodiments, the rod-width selector 5007 containing rings of varying diameter is designed to enable this embodiment of the device to accommodate varying diameter rods rather than necessitating multiple devices.

FIG. 50 B displays an oblique view 5001 of the device shown in FIG. 50 A with the rotating rod-width selector 5007 , retractable spring plunger 5013 , and fastener removed according to some embodiments. In some embodiments, discrete-angle detents 5015 receive the retractable spring plunger 5013 at set angles. In some embodiments, a hinge 5019 interfaces with a hinged flap 5021 , shown in the closed position, and with an attached TMSM 5023 , as previously described in relation to FIGS. 49 A- 49 D . FIG. 50 C displays a rear view 5002 of the invention shown in FIG. 50 B . FIG. 50 D displays an embodiment 5003 of the invention as described previously in relation to FIGS. 50 A-C , interfacing with a rod 4960 passing through one of the fixed rings and pushing the hinged flap 5021 and its attached TMSM 5023 to the open position according to some embodiments.

FIG. 50 E illustrates the fixed-base, variable-ring, mobile rod assessment device of FIGS. 50 A- 50 D engaged with a rod 4960 coupled to an end cap 5095 in accordance with some embodiments of the invention. In some embodiments, as described previously in FIG. 49 D , the end cap 5095 is used to track the path of the end of the rod 4960 as its length is passed through the fixed ring. In some embodiments, the software to calculate the rod's contour from this interaction is described below in reference to FIG. 75 . Some embodiments include a linearly-actuated TMSM 5023 that is moved when the rod 4960 is passed through the fixed ring. In some embodiments, following registration of the contour of a rod attached to a tracked end cap, the tracked end cap can be used for the user to directly interface with the display monitor portraying the rod contour, as described in detail below in reference to FIG. 78 .

Some embodiments of the invention include a handheld, mobile rod contour assessment device. In reference to FIGS. 51 A- 51 I , some embodiments include a method of using two handheld tracked devices to assess the contour of a rod prior to implantation. In some embodiments, to utilize some embodiments to register the contour of a rod, the rod is substantially rigidly fixed within the tracked end cap, as previously described in FIGS. 48 A-C , 49 D and 50 E, and then the tracked slider, previously described in FIG. 47 B , is slid over the surface of the rod one or more times. For example, FIG. 51 A displays a side view of 5100 of the invention which is a tracked end cap, previously described in FIGS. 47 A, 48 , 49 D, and 50 E according to some embodiments. In some embodiments, it consists of a handle 5101 , rod mount hole 5103 , anatomical axes reference labels ( 5105 , 5107 ), a tracked DRF 5189 (made of 3D-trackable markers 5188 in a unique configuration), a set screw 5108 to fasten the DRF mount to the handle 5101 , and a set screw 5109 for substantially rigidly fixing the rod in place. In some embodiments, when inserted and fixed within this device, the rod is interpreted by the acquisition software relative to the anatomical labels contained on the device. FIG. 51 B displays a front view of the invention, a tracked end cap, shown previously in FIG. 51 A . FIG. 51 C displays a rear view of the invention, a tracked end cap, shown previously in FIGS. 51 A- 51 B according to some embodiments.

FIG. 51 D displays an assembled view of the invention, a tracked slider, described previously in relation to FIG. 47 B , consisting of a handle 5129 , rod-centering fork 5130 , tracked DRF 5136 (made of 3D-trackable markers 3135 ), spring-loaded depressible shaft 5140 , and shaft-mounted TMSM 5145 according to some embodiments. In some embodiments, when used with a rod fixed to the tracked end cap previously described in relation to FIGS. 51 A- 51 C , this embodiment is able to register the coordinates of the rod by sliding along its surface. In some embodiments, when it is fully engaged with the surface of the rod, the sliding shaft and attached TMSM are actuated, and the acquisition system is triggered to record the coordinates corresponding to the center of the rod. In some embodiments, the software to calculate the coordinates of the rod is described below in reference to FIGS. 73 A- 73 B, and 74 . Some embodiments include a coupled ring as previously described in reference to FIGS. 49 A- 49 D, and 50 A- 50 E . Additionally, in some embodiments, linearly actuating a TMSM is only one method of triggering to the acquisition system that the slider is fully engaged with the rod. Some embodiments include, but are not limited to, rotational motion of a TMSM, handheld triggering on the tracked slider or tracked end cap, electronic communication from embedded electronics on the tracked end cap or tracked slider, or direct user input via software interface.

FIG. 51 E displays a rear view of the embodiment shown previously in FIG. 51 D displaying the depressible shaft 5140 , rod-centering fork 5130 , and tracked DRF 5136 . FIG. 51 F displays a closeup view of some embodiment shown previously in FIGS. 51 D- 51 E in which the tracked DRF 5136 , spring 5150 and spring-loaded depressible shaft tip 5140 , and its attached TMSM 5145 are visible. In some embodiments, the sliding shaft 5140 and its mounted TMSM are in the extended position, indicating that the tracked slider is not engaged with a rod.

FIG. 51 G displays a closeup view of the embodiment shown previously in FIGS. 51 D-F in which the engaged depressible shaft 5155 and its mounted TMSM 5160 are in the depressed location, which if at a preset height corresponding to the rod diameter being used, would indicate to the acquisition software that the tracked slider is firmly engaged with a rod and its coordinates should be recorded according to some embodiments. Further, FIG. 51 H displays the invention which is a mechanism of registering the contour of a rod prior to implantation by substantially rigidly fixing a rod 5170 in a tracked end cap and sliding the tracked slider over the rod one or more times according to some embodiments. Following registration of the contour of a rod attached to a tracked end cap, the tracked end cap can be used for the user to directly interface with the display monitor portraying the rod contour, as described in detail below in reference to FIG. 78 . FIG. 51 I displays another view of some embodiments of the invention previously shown in FIG. 51 H .

Some embodiments of the invention include a TMSM-based, implanted rod contour assessment device. Some embodiments are used to assess the contour of a rod after it has been implanted into a patient. Some embodiments utilize the rod-centering fork design with a sliding shaft and spring-loaded TMSM, previously described in FIGS. 47 A and 51 D- 51 I on the end of a tracked probe, such that it can fit into the surgical site and trace over the implanted rod. In some embodiments, the probe is able to skip over any obstructing hardware without its coordinates being recorded because the acquisition system is only triggered to record when the TMSM is in the position corresponding to the sliding shaft being depressed by a rod of a preset diameter. In some embodiments, the software for calculating and interpreting the rod contour is described below in relation to FIGS. 76 , and 77 A- 77 C .

FIG. 52 A illustrates a component of a TMSM-based, implanted rod contour assessment device 5200 in accordance with some embodiments of the invention. In some embodiments, the device 5200 comprises a probe shaft 5210 , rod-centering fork 5230 , 5235 for interfacing with a rod, mounts 5215 for tracked DRF markers (not shown) to be inserted, mounts 5225 for spring(s), a depth-stop for a sliding shaft 5220 and sliding shaft guides 5205 to prevent the inserted shaft (not shown) from rotating. Some embodiments are intended to be coupled with the embodiment described below in reference to FIG. 52 B .

FIG. 52 B illustrates a depressible sliding shaft for coupling to the component of FIG. 52 A comprising a depressible sliding shaft 5250 with rounded tip 5264 , mounts 5260 for springs, threaded hole 5268 for adjustable depth-stop, mount 5209 for a TMSM, and a guide-fitting profile 5252 to prevent rotation when inserted within its complementary probe described above in relation to FIG. 52 A according to some embodiments.

FIG. 52 C illustrates a top view of the component of FIG. 52 A in accordance with some embodiments of the invention, and shows spring mount 5225 , and sliding shaft through-hole 5229 , able to accommodate the sliding shaft 5250 in relation to FIG. 52 B . FIG. 52 D displays another view of the embodiment shown previously in FIG. 52 B , enabling closer visualization of the depressible sliding shaft 5250 , spring mounts 5260 , threaded hole 5268 for an adjustable depth-stop, mount 5209 for a TMSM, and a guide-fitting profile 5252 .

FIG. 53 A displays some embodiments of a device 5300 configured to assess the contour of a rod after it has been implanted within the surgical site. In some embodiments, the this figure comprises an assembly of the components described previously in relation to FIGS. 52 A- 52 D . In some embodiments, the device 5300 comprises a tracked probe 5310 with a rod-centering fork 5315 , through-hole (not shown) to accommodate a depressible sliding shaft 5335 , with a coupled TMSM 5325 , and tracked DRF 5320 (made of several 3D-trackable markers 5330 ). In some embodiments, this is used to engage with an implanted rod (not shown) such that the rod depresses the depressible sliding shaft 5335 , thereby moving the attached TMSM 5325 relative to the attached tracked DRF 5320 . In some embodiments, when the TMSM 5325 moves relative to the tracked DRF 5320 by a preset amount based on the rod diameter, the acquisition system is triggered to record the coordinates corresponding to the center of the rod, as described below in reference to FIGS. 76 - 77 . Further, FIG. 53 B illustrates a close-up rear view of a portion 5301 of the assembly of FIG. 53 A in accordance with some embodiments of the invention. Further, FIG. 53 B displays a rear view of the embodiment of the invention shown previously in 53 A, visualizing the depressible sliding shaft 5335 , its attached TMSM 5325 , the tracked DRF 5320 , springs 5354 , depth-stop 5356 for sliding shaft, and depth-stop set screw 5352 used to adjust the maximum protrusion length of the sliding shaft tip beyond the bifurcation of the fork according to some embodiments. Some embodiments do not possess a mechanism of adjusting the maximum protrusion length of the sliding shaft. Additionally, in some embodiments, the external springs referenced in this embodiment can consist of internal compressible springs, torsion springs, and memory-embedded materials within some embodiments. In some embodiments, this figure displays how the sliding shaft guides prevent rotation of the sliding shaft, restricting the TMSM 5325 to linear motion relative to the tracked DRF 5320 .

FIG. 53 C displays a closer view of the rod-interface region of the embodiment shown previously in FIGS. 53 A- 53 B according to some embodiments. In some embodiments, the spring-loaded depressible sliding shaft 5335 a is in its extended position. In this position the acquisition system is not triggered to record the coordinates of the probe, as it is not indicating that it is interfacing with a rod to be measured. Further, FIG. 53 D displays a view of the embodiment described previously in FIGS. 53 A- 53 C interfacing with a rod 5367 within the rod-centering fork 5315 and depressing the sliding shaft 5335 b into the depressed position causing the attached TMSM (not shown) to move relative to the probe's attached DRF (not shown), indicating for the acquisition system to record 3D coordinates corresponding to the center of the rod's cross-section according to some embodiments.

FIG. 53 E displays a closer view of the tracked DRF portion of the device embodiment described previously in relation to FIGS. 53 A- 53 D according to some embodiments. In some embodiments, the location of the TMSM 5325 a relative to the tracked DRF 5320 as shown, corresponds to the depressible shaft being in the extended position, as shown in FIG. 53 C . In some embodiments, in this configuration, the acquisition software is not triggered to record the probe's coordinates. FIG. 53 F displays a closer view of the tracked DRF 5320 portion of the device embodiment described previously in relation to FIGS. 53 A-E showing sliding shaft guide 5329 according to some embodiments. In some embodiments, the location of the TMSM 5325 b relative to the tracked DRF 5320 as shown, corresponds to the depressible shaft 5335 being in the depressed position, as shown in FIG. 53 D . In some embodiments, the acquisition software is triggered to record the location of the probe, from which the rod's coordinates can be calculated as described below in reference to FIGS. 76 - 77 .

Some embodiments of the invention include a conductivity-based, implanted rod contour assessment device. Some embodiments are intended to assess the contour of a rod after it has been implanted within the surgical site. Some embodiments differ from those previously described in relation to FIGS. 52 A- 52 D, and 53 A- 53 F , in that it possesses electrical contact terminals on the inside walls of the rod-centering fork. In some embodiments, these electrically-isolated terminals are used then to sense conductivity between them. In some embodiments, in the absence of a rod touching both terminals, no current flows between them. In some embodiments, when a rod is fully engaged within the fork however, current flows from one contact to another, indicating that the device is fully engaged with the rod, and the contour assessment device electrically communicates, either wirelessly or through a wire, with the 3D-tracking acquisition system that it should record the coordinates of the device. Therefore, in some embodiments, embedded in the probe is a small power supply via battery or capacitor, and circuit components to communicate with the acquisition system. For example, FIG. 54 A displays the invention (assembly 5400 ) which includes a probe shaft 5410 equipped with a rod-centering fork 5425 on one end and a tracked DRF 5415 on the other according to some embodiments. Some embodiments can be applied to an already-implanted spinal rod and used to assess its 3D contour by sliding the internal sides of the fork 5425 along the exposed surfaces of the rod 5440 . In some embodiments, this device fork possesses electrical contact terminals, described below in reference to FIG. 54 B , on the inside surfaces of the rod-centering fork 5425 , and internal electronics within the rod (not shown) that detect when current flows between them. In some embodiments, when current flows between the terminals, the contour assessment tool signals for the acquisition system to record its location in space. Some embodiments of the probe's communication method with the acquisition system include but are not limited to wireless radiofrequency transmission, optical signaling via infrared or visible light illumination of elements on the probe that are detected by the system, and wired signal transmission. In some embodiments, the process of interpreting the rod's location and contour relative to the probe is described below in reference to FIGS. 76 , and 77 A- 77 C .

FIG. 54 B illustrates a rod-centering fork and electrical contact pads of the device of FIG. 54 A in accordance with some embodiments of the invention. FIG. 54 B provides better visualization of the rod-centering fork 5425 and electrical contact pads 5427 a , 5427 b located on the inner surface of each arm of the fork according to some embodiments. In some embodiments, the probe is unable to signal that it is active, unless an electrical conductor connects both contact terminals. It should be noted that the shape of the contact terminals can be different in some embodiments, including but not limited to cylindrical, semi-cylindrical, flat, and curved surfaces with variation in their distance of protrusion from the inside surface of the fork.

FIG. 54 C displays the embodiment previously described in relation to FIGS. 54 A- 54 B interacting with a rod 5440 that is not fully seated within the fork according to some embodiments. In this configuration, in some embodiments, the rod 5440 is not approximating both electrical contact plates, and therefore the assessment device is in the inactive, non-tracking state. Further, FIG. 54 D displays the embodiment previously described in relation to FIGS. 54 A- 54 C interacting with a rod 5440 that is fully engaged within the fork according to some embodiments. In this configuration, in some embodiments, the metal rod is approximating both electrical contact pads ( 5427 a , 5427 b of FIG. 54 B ) of the fork and therefore conducting a current across it. In some embodiments, when current is being conducted, the probe then signals to the 3D-tracking acquisition system that it is in the active state and its coordinates are recorded to be used for computing the rod contour as described below in reference to FIGS. 76 , and 77 A- 77 C .

Some embodiments include a 3D-tracked, manual mobile rod bender. Some embodiments can be utilized with an already-registered rod attached to a tracked end cap, to both bend and re-register the updated contour of the rod during bending. Some embodiments also allows for visualization of the precise position of the tracked handheld rod bender relative to a previously registered rod on a display monitor. Additionally, in some embodiments, this system also allows for software-assisted and software-directed bending, instructing the user where to place and how to maneuver a tracked, handheld rod bender, to contour the rod to a pre-determined shape. In some embodiments, the capabilities of this embodiment and its variations are described in more detail below in reference to FIGS. 56 A- 56 F, 79 A- 79 G, and 81 .

FIG. 55 A displays the invention, which is a handheld rod bender 5501 consisting of two handles with handle # 1 5507 a , containing the center rod contouring surface 5503 , and left outer roller 5505 and handle # 2 5507 b containing the right outer roller 5506 according to some embodiments. Some embodiments shown is interfacing with a straight rod 5511 a approximating both rollers and center bend surface, as the bender handles ( 5507 a , 5507 b ) are positioned at an open angle to one another. Further, FIG. 55 B displays the embodiment of the invention described in relation to FIG. 55 A , with the rod bender's handles approximated, resulting in a bent rod 5511 b contour according to some embodiments. FIG. 55 C displays a closer view of the rod-interface points of the bender 5501 , shown previously in FIG. 55 B interfacing with a bent rod 5511 b according to some embodiments.

FIG. 55 D displays the invention which consists of a handheld rod bender coupled to rod 5511 a , previously described in relation to FIGS. 55 A- 55 C , equipped with a tracked DRF 5550 fixed to handle # 1 5507 a , a roller mount 5508 on outer roller 5506 and a TMSM 5540 fixed to the roller mount 5508 according to some embodiments. In some embodiments, as displayed, the rod bender 5501 is interfacing with a straight rod 5511 a , necessitating that the bender's handles 5507 a , 5507 b are positioned at a wide angle from one another to accommodate the straight rod. In some embodiments, with the tracked DRF 5550 mounted to handle # 1 5507 a , the 3D-tracking acquisition system can register the location and pose of both the center rod contouring surface and the left outer roller. In some embodiments, with the TMSM 5540 attached to the right outer-roller 5506 , it enables the acquisition system to then register the location of the right outer roller relative to the two-other rod-interface points of the bender. In some embodiments, with the ability to locate all three rod-interface points on the bender in 3D space, the acquisition system can interpret the relative angle between the bend handles, and with known rod diameter, the degree of bending induced into a rod. In some embodiments, when this embodiment of the invention is coupled to a previously registered rod, fixed to a tracked end cap, as described previously in relation to FIGS. 49 D, 50 E, 51 H- 51 I , the acquisition system is able to interpret when the three rod-interface points on the tracked bender are engaged with the previously registered rod. In some embodiments, when that is the case, the software system is able to provide live tracking of the bender relative to the rod, real-time updates of the rod contour during bending, and software-assisted bending instructions, as described below in reference to FIGS. 56 A- 56 F, 79 A- 79 G, 80 - 81 , 87 A- 87 K, and 88 A- 88 F . Further, FIG. 55 E displays the device 5501 as previously described in FIG. 55 D , except with the rod bender handles 5507 a , 5507 b coupled, resulting in a bent rod 5511 b according to some embodiments. Further, FIG. 55 F displays another view of the embodiment shown in FIG. 55 E and described previously in relation to FIG. 55 D according to some embodiments. In some embodiments, this perspective enables visualization of the mounting post 5551 for the tracked DRF 5550 attached to handle # 1 5507 a . It should be noted that in some embodiments, the tracked DRF 5550 is coupled to varying locations on handle # 1 5507 a and at varying angles and offset heights from the handle. In some embodiments, this figure displays only the relative positioning of the tracked DRF 5550 to the rod bender handle. In some embodiments, the same variation applies for the relative positioning of the TMSM 5508 (as marked in FIG. 55 D ) to handle # 2 5507 b . In some embodiments, it is located directly over the right outer roller 5506 , it can be positioned anywhere on handle # 2 5507 b to provide the input information the software needs to calculate the aforementioned embodiments of the invention.

Some embodiments include a spring-loaded TMSM attached to the center rod contouring surface of the rod bender such that it moves the stray marker only when the rod is fully pressed up against the surface of the center rod contouring surface, and thereby serving as an indicator of when the rod is fully engaged with the bender (i.e., only when the rod is “being bent” or “engaged”). For example, some embodiments include a spring-loaded (not shown) TMSM (not shown), coupled to the center rod-contouring surface 5503 in such a way that it is fully deflected only when the rod is fully approximated against the center rod-contouring surface 5503 of the rod bender. In this way, in some embodiments, the acquisition system has an additional method of indicating when the contour of the rod is actively being bent.

In reference to FIGS. 55 A- 55 I, and 56 A- 56 F , in some embodiments, the tracked bender can be a universal adapter design such that it can be applied to other user-operating rod benders, especially table-top benders that are used in the operating room. Further, in some embodiments, it is also essential to note that rod cutters can also be equipped with tracking accessories in a similar manner in order to see where the digital overlay of the rod will be cut. It should be noted that some embodiments can also be applied to other user-operating rod benders that involve two or more contact points with a rod to induce curvature. In some embodiments, these principles are applied to instruments used for rod cutting, such that the location of the cutter relative to a previously registered rod can be visualized.

FIG. 55 G displays an alternative bender embodiment of the invention from that described previously in relation to FIGS. 55 D- 55 F , in which the rod bender is equipped with two TMSMs on handle # 1 5507 a (shown as 5571 , 5572 ), and one TMSM 5573 on handle # 2 5507 b according to some embodiments. In some embodiments, the three TMSMs 5571 , 5572 , 5573 are utilized to localize the position of each rod-interface point on the bender. In some embodiments, because the three TMSM mounting points shown are directly over the three rod-interface points of the rod bender, the acquisition software can localize the plane of the rod bender defined by the three markers 5571 , 5572 , 5573 , and then offset it by a known amount based on the known offset between the TMSMs and the rod-interface points on the bender. In some embodiments, the acquisition system is able to reliably interpret the direction of offset from the plane defined by the three TMSMs, based on the viewing angle restrictions of a single optical 3D-tracking system, which defines the normal vector the TMSM plane as that which is less than 90 degrees from the vector drawn from the center of the three markers to the 3D-tracking camera. In some embodiments, in this configuration, the tracked bender is able to achieve the same functionality as described previously in relation to FIG. 55 D . Some embodiments include attaching more than three TMSMs to the bender, as well as placing the TMSMs in alternative locations than directly over the rod-interface components of the rod bender. In some embodiments, as shown in this figure, the tracked bender is interfacing with a straight rod 5511 a , necessitating that the angle between the bender handles be positioned at a wide angle relative to one another. In some embodiments, in this configuration, because the distance from the center bend surface to each of the outer rollers is the same, the angle between bender handles, and thereby the degree of bending, can be calculated based on the angle between the two equally-spaced TMSMs 5572 , 5573 from the center TMSM 5571 .

FIG. 55 H displays the invention as previously described in FIG. 55 G , except with the rod bender handles approximated, resulting in a bent rod 5511 b according to some embodiments. FIG. 55 I displays another view of the embodiment shown in FIG. 55 H and described previously in relation to FIG. 55 G according to some embodiments.

FIGS. 56 A- 56 F further describe the invention previously described in relation to FIGS. 55 A- 55 I according to some embodiments. In some embodiments, depicted are the necessary components of the invention to track bending in real-time, as well as utilize software-assisted instructed bending are all displayed. Furthermore, in some embodiments, an additional embodiment of the device is introduced within this figure, that enables the ability to account for shape memory that rod material may experience during and after bending when computing the real-time tracking of bending and computing the re-registered rod. For example, FIG. 56 A displays the device 5600 previously described in relation to FIGS. 55 G- 55 I , in which a pre-registered rod 5610 is fixed within a tracked DRF-equipped end cap 5605 , and a tracked rod bender 5501 b is equipped with three TMSMs interfaces with the rod according to some embodiments. In this configuration, in some embodiments, the acquisition software can interpret the location of the tracked rod bender relative to the previously-registered rod 5610 within the tracked end cap's relative coordinate system. With this configuration, in some embodiments, the acquisition system can provide live tracking of the bender relative to the rod, real-time updates of the rod contour during bending, and software-assisted bending instructions, as described below in reference to FIGS. 79 A- 79 G, 81 , 87 A- 87 G, and 88 A- 88 F .

FIG. 56 B shows another configuration of the embodiment previously described in relation to FIG. 56 A , in which the tracked rod bender 5600 is engaged with an alternative location of the rod that is bent, displaying how the angle between the handles and associated TMSMs changes from when the bender is interfacing with a straight portion of the rod, as shown in FIG. 56 A according to some embodiments.

FIG. 56 C displays the device (assembly 5602 ) previously described in relation to FIGS. 55 D- 55 F , in which a pre-registered rod 5610 is fixed within a tracked-DRF-equipped end cap 5605 and a tracked rod bender (assembly 5602 with end cap 5605 and rod bender 5601 ) is equipped with a tracked DRF 5550 on one handle and a TMSM 5573 on the other according to some embodiments. In some embodiments, with this configuration, the acquisition system is able to provide live tracking of the bender relative to the rod, real-time updates of the rod 5610 contour during bending, and software-assisted bending instructions, as described below in reference to FIGS. 79 A- 79 G, 81 , 87 A- 87 K, and 88 A- 88 F .

FIG. 56 D shows another configuration of some embodiments 5602 previously described in relation to FIG. 56 C , in which the tracked rod bender 5601 is engaged with an alternative location of the rod that is bent 5610 , displaying how the angle between the handles and associated TMSM 5573 relative to the tracked DRF 5550 changes from when the bender is interfacing with a straight portion of the rod 5610 , as shown in FIG. 56 C .

FIG. 56 E displays some embodiments of 5600 , which consists of a tracked DRF-equipped end cap 5605 , fixed to a pre-registered rod 5610 , non-tracked manual bender 5501 c , and a rod cap 5690 with a TMSM 5695 mounted to it. Some embodiments represent an alternative mechanism and method of updating the previously-registered contour of a rod while it is being bent with a handheld bender. In some embodiments, because the bender is not tracked, the location of the TMSM is detected relative to the tracked end cap to which the rod is fixed. In some embodiments, whenever the system detects relative motion between the TMSM 5695 and the tracked DRF on the end cap 5605 , the acquisition system records the path traveled by the TMSM 5695 relative to the end cap 5605 . In some embodiments, with known geometry of the rod bender's center bend surface, the path of the TMSM is used to calculate the location and curvature of each bend, as described below in reference to FIG. 80 .

FIG. 56 F displays 5601 comprising a tracked DRF-equipped end cap 5605 , fixed to a pre-registered rod 5610 , tracked manual bender 5501 equipped with a tracked DRF 5550 and one TMSM, and rod cap 5690 with a TMSM 5695 mounted to it according to some embodiments. In some embodiments, the contour of the previously-registered rod is updated during bending by the combination of tracking both the rod bender's conformation at interfacing regions of the rod, as described previously in relation to FIGS. 55 D- 55 F , as well as the motion of the TMSM-equipped rod cap relative to the tracked end cap to which the rod is fixed. In this configuration, in some embodiments, the acquisition system is able to account for shape memory within the rod material, that previously described embodiments without the TMSM-mounted rod cap were not. In some embodiments, because the end of the rod opposite to the DRF-equipped end cap is tracked in this embodiment, after the rod bender achieves its minimum angle between handles when interfacing with a particular region of the rod, if the rod material retains some of its shape memory and recoils, the TMSM-equipped rod cap will move relative to the DRF-equipped end cap, and the acquisition system software can now account for this memory when recomputing the rod's contour as described in more detail in relation to FIG. 80 . As with some embodiments described in FIGS. 56 A- 56 E , this configuration also enables software-assisted bending and interfacing with display monitor, as described below in reference to FIGS. 79 A- 79 G, 80 - 81 , 87 A- 87 G, and 88 A- 88 F .

Some embodiments of the invention include a 3D-tracked, manual implanted rod bending system which enables the ability to track the bending of a rod that has already been implanted within the surgical site. In some embodiments, the user interfaces with an implanted rod using DRF-tracked and trigger-equipped in-situ benders after already registering the contour of the implanted rod via mechanisms described previously in relation to FIGS. 52 A- 52 D, 53 A- 53 F, and 54 A- 54 B . For example, some embodiments include DRF-tracked and trigger-equipped in-situ benders coupled to a rod in accordance with some embodiments of the invention. In some embodiments, two tracked in-situ benders, each equipped with unique tracked DRFs ( 5705 a , 5705 b ), can interface with a pre-registered rod to alter its contour after implantation. In some embodiments, because the tracked in-situ benders interface with an already-registered rod 5711 , their position relative to the registered rod can be displayed via display monitor. Additionally, in some embodiments, because they are equipped with depressible sliding shafts 5735 to serve as triggers indicating when they are fully engaged with the rod, their movement will not result in alteration in the software-recorded-contour of the registered rod unless two or more in-situ benders are triggered simultaneously and moved relative to one another while triggered. For example, FIG. 57 A displays 5700 of the invention consisting of a tracked in-situ bender with handle 5710 a , 5710 b , rod interface head 5725 a , 5725 b equipped with depressible sliding shaft tip (not shown) coupled to pre-registered rod 5711 , TMSM 5707 a , 5707 b mounted to depressible sliding shaft, and tracked DRF 5705 a , 5705 b according to some embodiments. Further, in reference to FIG. 57 B , showing some embodiments 5701 with a spine 5713 with instrumented pedicle screw shafts 5718 , tulip heads 5739 , an implanted pre-registered rod 5750 , and cap screws 5738 , in some embodiments, both triggers on the benders can be depressed, actuating the TMSMs ( 5707 a , 5707 b ) relative to the associated DRFs ( 5705 a , 5705 b ), indicating to the acquisition system that they are fully engaged with the rods.

FIG. 57 C illustrates a close-up view of the rod (marked as 5711 ) of FIG. 57 A in accordance with some embodiments of the invention, and FIG. 57 C displays another view of some embodiments shown in FIG. 57 A engaging with a pre-registered rod 5711 . FIG. 57 D illustrates a close-up view of a rod-interface head 5725 of the bender show in in FIG. 57 A including a view of a depressible sliding shaft 5735 with depressible sliding shaft tip 5735 a in an extended position towards the surface 5730 that can accept the rod 5711 in this assembly view according to some embodiments. In some embodiments, at least a portion of the surface 5730 can comprise a curved or concave surface 5730 a that can complement and/or maximize engagement and/or surface contact with a curved surface of a rod (e.g., such as rod 5711 ).

Some embodiments of the invention enable the use of skin-mounted fiducial markers to serve as surrogate markers from which the location of the underlying anatomical landmarks can be calculated. For example, FIG. 58 illustrates a workflow 5800 to initialize skin-mounted, or percutaneous, fiducials with two or more X-ray images intraoperatively in accordance with some embodiments of the invention. In some embodiments, this figure describes the process of the user and acquisition system interfacing to initialize and calculate the 3D-displacement vector between a fiducial marker and the anatomical region of interest. In some embodiments, some figures relevant to the process include X-ray initialization of 3D-displacement vector with multi-planar X-rays ( FIGS. 4 A- 4 G , FIG. 13 ), feedback on fiducial placement on or in a patient's skin surface ( FIGS. 2 A- 2 B ), a trans-drape, two-halves fiducial design ( FIGS. 6 A- 6 D , and FIGS. 9 A- 9 B ), registration of a fiducial in camera coordinates+determining its unique identity ( FIGS. 4 H- 4 I , FIG. 5 , and FIGS. 7 - 8 , FIGS. 10 A- 10 D , and FIGS. 11 A- 11 B ).

In some embodiments, one or more steps of the workflow 5800 can be utilized for the registration of a 3D-displacement vector between a skin-mounted or percutaneous fiducial marker and the anatomical landmark of interest. In some embodiments, following a step 5802 of positioning a patient on an operative table, step 5804 can include the placement of a fiducial on or inside the soft tissue within the anatomical region of interest. For example, some embodiments involve the user placing the fiducial on or inside the general region of interest. Some embodiments of the invention can involve the user receiving feedback on the placement of a fiducial marker via a radiopaque patch that identifies the optimal location on the surface to place or insert the fiducial device; this was previously depicted and discussed in related to FIGS. 2 A and 2 B .

Some embodiments involve the mating of a second-half fiducial to the original fiducial marker placed on or inside soft tissue to maintain access to the fiducial after the introduction of surgical drapes and other obstructing materials outside of the surgical site. Some embodiments to accomplish one or more embodiments of this invention are depicted in FIGS. 6 A- 6 D , and FIGS. 9 A- 9 B . In some embodiments, step 5806 can include obtaining a first X-ray image containing fiducial and desired bone anatomy to be identified with the fiducial. Further, step 5808 can include rotation of the X-ray emitter, and step 5810 can include obtaining a second X-ray image containing fiducial and desired bone anatomy to be identified with the fiducial according to some embodiments.

Some embodiments further include the process of annotating 2D vectors between the fiducial marker and the anatomical landmark of interest for each image acquired from a unique perspective relative to the fiducial. In some embodiments, this displacement vector initialization process is depicted and discussed in reference to FIGS. 4 A- 4 F . In some embodiments, the overall goal of the initialization process can be visualized in the cross-sectional view depicted previously in FIG. 13 . Some embodiments include the process of using the relative rotational and translational offset information between two or more X-ray images of the fiducial to calculate the 3D-displacement vector between the fiducial marker and the anatomical landmark of interest using the 2D-displacement vectors for each image as inputs into the calculation. In some embodiments, this process of calculating the 3D-displacement vector based on a rigid transformation between multiple 2D-displacement vectors is previously depicted in FIG. 4 G . For example, step 5812 can include annotation of X-ray images with desired bony anatomy locations, and step 5814 can include calibration of X-ray image distances by known size of the radiopaque markers on the fiducials according to some embodiments. Further, step 5816 can include draw a scaled displacement vector on X-ray images from fiducial origin to indicated bony anatomy of interest, and step 5818 can include input or compute displacement angle between X-ray images according to some embodiments. Further, step 5820 can include adding displacement vectors to produce 3D displacement vector from fiducial origin to annotated regions according to some embodiments.

In some embodiments, steps 5822 - 5830 describe the process of using 3D-tracked devices to register the location and orientation of the fiducial marker relative to the coordinate system of the 3D-tracking acquisition unit, and then applying the acquired positional information as a rigid transformation to the X-ray-based 3D-displacement vector to convert the vector from imaging units into units of the 3D-tracked acquisition system. In some embodiments, this process can be depicted in FIGS. 4 H, 4 I, 5 , 7 - 8 , 10 A- 10 D, and 11 A- 11 B . In addition, these previous figures depict some of the embodiments for determining the unique identity of a fiducial marker in order for the system to be able to utilize several fiducial markers at once and understanding which fiducial is associated with specific mathematical relationships to a unique anatomical landmark of interest. For example, step 5822 can include interpretation of fiducial origin into camera coordinate, and step 5824 can include tracing or tapping the fiducial with tracked probe in discrete points to indicate fiducial pose according to some embodiments. Further, step 5826 can include mechanical mating or coupling of tracked probe with fiducial to obtain fiducial pose, and step 5828 can include directly tracking markers mounted on fiducial, and with step 5830 including access to fiducial which then serves as a reference point to initialized nearby bony points of interest according to some embodiments.

In some embodiments, any of the above processes, methods, or procedures related to the workflow 5800 can include or be accomplished with one or more of steps or processes 5802 , 5804 , 5806 , 5808 , 5810 , 5812 , 5814 , 5816 , 5818 , 5820 , 5822 , 5824 , 5826 , 5828 , and 5830 . In some embodiments, the steps of workflow 5800 can proceed in the order as shown. In some embodiments, any of the steps of the workflow 5800 can proceed out of the order as shown. In some embodiments, one or more of the steps of the workflow 5800 can be skipped.

Some embodiments of the invention enable the registration of bone-mounted fiducial markers to represent anatomical landmarks that are located within or nearby the bony anatomy that the marker is substantially rigidly attached to. For example, FIG. 59 illustrates a workflow 5900 to initialize one or more bone-mounted fiducial placed intraoperatively with two or more X-ray images taken before placement of one or more bone-mounted fiducials in accordance with some embodiments of the invention. In some embodiments, this figure describes the process of the back-end system to use prior X-ray initialization of a skin-based fiducial and its 3D-displacement vector to the anatomical landmark of interest and transform the bone-mounted fiducial location and pose relative to the camera-based registration coordinates of the prior 3D-displacement vector to describe the relationship between the bone-mounted fiducial marker and the anatomical region of interest. In some embodiments, other relevant figures can include some embodiments for bone-mounted fiducial design and coupling to an additional fiducial (see FIGS. 3 A- 3 C ), and registration of a fiducial in camera coordinates and determining its unique identity ( FIGS. 10 A- 10 D , and FIGS. 44 A- 44 D ).

In some embodiments, the steps 5910 , 5912 of this process can involve the steps described in the workflow of FIG. 58 , which outline the process for registering the 3D-displacement vector for a skin-based or percutaneous fiducial in imaging coordinates as well as units of the 3D-tracking acquisition unit. In some embodiments, if the registered fiducial marker has to be removed due to the location of the surgical site requiring access to the that location of the anatomy, then the user can utilize the process to reinstate access to the 3D-displacement vector that provides information about other anatomical landmarks of interest. In some embodiments, step 5914 can include removal of the skin fiducial, and step 5916 can include skin incision and exposure of the surgical site.

In some embodiments, step 5918 and 5920 can involve the user implanting the miniature fiducial marker into the bony anatomy and then registering its location and orientation relative to a 3D-tracking acquisition unit via a 3D-tracked probe. Some embodiments of this process are depicted in FIGS. 3 A- 3 B , and FIGS. 4 A- 4 D .

Some embodiments, described in steps 5922 , and/or 5924 , and/or 5926 , and/or 5928 can involve the 3D-tracked probe tracing the fiducial surface or tapping discrete points on the fiducial to register the fiducial's 3D location and orientation with respect to the coordinates of the 3D-tracking acquisition unit. Some embodiments are depicted in FIGS. 10 A- 10 D .

In some embodiments, step 5930 can include comparing the location and orientation of the registered bone-mounted fiducial to that of the registered landmarks initialized via the prior 3D-displacement vector converted into coordinates of the 3D-tracking acquisition system via initialization of the skin-based fiducial before the incision of the surgical site. Further, in some embodiments, steps 5932 and 5934 can include utilizing the relationship calculated in step 5930 as in input for the rigid transformation applied to the registered anatomical landmarks with coordinates from the 3D-tracking acquisition system.

In some embodiments, any of the above processes, methods, or procedures related to the workflow 5900 can include or be accomplished with one or more of steps or processes 5910 , 5912 , 5914 , 5916 , 5918 , 5920 , 5922 , 5924 , 5926 , 5928 , 5930 , 5932 , and 5934 . In some embodiments, the steps of workflow 5900 can proceed in the order as shown. In some embodiments, any of the steps of the workflow 5900 can proceed out of the order as shown. In some embodiments, one or more of the steps of the workflow 5900 can be skipped.

Similar to embodiments depicted in FIGS. 58 and 59 , FIG. 60 shows a workflow to initialize bone-mounted fiducials placed intraoperatively with two or more X-ray images taken after placement of bone-mounted fiducials in accordance with some embodiments of the invention. In some embodiments, once the user has created a surgical site and exposed the bony anatomy, the user can implant the miniature fiducial marker into the bony anatomy surface until it is substantially rigidly fixed to the anatomy. Examples of this bone fiducial embodiment are depicted in FIGS. 3 A and 3 B according to some embodiments. Some embodiments involve the use of a larger fiducial marker that mates to the surface of the bone-mounted fiducial marker to enhance its visualization in X-ray images for the purpose of annotating the 3D-displacement vector to the anatomical landmark of interest. An example of this embodiment is depicted in FIG. 3 C .

In some embodiments, in step 6002 , incise skin and expose the surgical site, and step 6004 , fasten bone-mounted fiducial to spinal level of interest at accessible location, and further, in step 6006 , attach mating device (optional) to bone-mounted fiducial to aid with X-ray initialization. In some embodiments, steps 6012 , 6010 , 6008 , 6014 , 6016 , 6018 , 6020 , 6022 , and 6024 can include the X-ray-based registration of the fiducial marker as described in FIG. 58 to produce a 3D-displacement vector in imaging coordinates between the bone-mounted fiducial marker and the anatomical landmark of interest. Some embodiments then register the bone-mounted fiducial's 3D-displacement vector to the anatomical landmark of interest in the coordinates of the 3D-tracking acquisition system via acquiring the location and orientation of the fiducial marker with respect to the coordinates of 3D-tracking acquisition system. Examples of this process are depicted in FIGS. 4 H- 4 I , FIGS. 10 A- 10 D , and further in FIGS. 44 A- 44 D .

In some embodiments, once the bone-mounted fiducial is registered in both the X-ray imaging system and the 3D-tracking acquisition system, every time the user returns to register the updated location and orientation, the relative relationship between its current position and that of the prior registration are calculated and applied via a rigid transformation to calculate the most accurate location of the anatomical landmark of interest as they currently exist in relation to the fiducial marker in 3D space. For example, in step 6026 , the process can include assess location and pose of initialized fiducial, including, but not limited to step 6028 including trace a unique pattern imprinted over fiducial with tracked probe, step 6030 substantially rigidly couple tracked mating probe to fiducial, step 6032 , substantially rigidly coupling tracked markers to fiducial, and step 6034 , tap discrete points on fiducial or on fiducial mating attachment with tracked probe according to some embodiments.

In some embodiments, any of the above processes, methods, or procedures related to the workflow 6000 can include or be accomplished with one or more of steps or processes 6002 , 6004 , 6006 , 6012 , 6010 , 6008 , 6014 , 6016 , 6018 , 6020 , 6022 , 6024 , 6026 , 6028 , 6030 , 6032 , 6034 , and 6036 . In some embodiments, any of the steps of the workflow 6000 can proceed out of the order as shown. In some embodiments, one or more of the steps of the workflow 6000 can be skipped.

Some embodiments of this invention pertain to the initialization of the patient's anatomical planes in relation to the coordinates of the 3D-tracking acquisition system to enable the measurements made during a procedure to be accurately referenced to the dimensions of the anatomy being assessed. For example, FIG. 61 illustrates methods of registering anatomical reference planes intraoperatively in accordance with some embodiments of the invention. In some embodiments, if a user has already established the coordinates of the measurement system via the initialization process of surgical navigation technologies, then coordinates of the data outputted by the 3D-tracking acquisition system are already referenced in relation to the anatomical planes of the patient. In some embodiments, if the user has not already established the coordinates of the measurement system via the initialization process of surgical navigation technologies, then the user will utilize a few of the embodiments described in FIG. 61 to initialize the 3D-tracking data outputs with respect to the patient's anatomical planes.

Some embodiments include utilizing a tracked DRF (e.g., FIG. 12 ) and its associated 3D orientation and location in relation to the 3D-tracking acquisition system as inputs to a 3D rigid transformation of the measurements that are outputted by the 3D-tracked devices to reference the anatomical planes of the patient. In some embodiments, one example of this process of transforming measurements outputted by 3D-tracked devices to be relative to the patient anatomical planes, via a tracked dynamic reference aligned with the patient anatomical planes, is depicted in FIGS. 62 A- 62 C .

Some embodiments for initializing the patient anatomical planes can involve acquiring two or more data points in space with a 3D-tracked probe to define the direction, location, and orientation of the anatomical planes of the patient relative to the 3D-tracking acquisition system. Some further embodiments can involve holding the probe in particular orientation and location in space and registering that position relative to the 3D-tracking acquisition system as the new coordinates system of all acquired measurements outputted by 3D-tracked devices.

In some embodiments, a decision step 6102 can include a determination of whether patient anatomy/imaging has been registered relative to a 3D tracking camera axis. In some embodiments, for a positive answer, the process can include step 6104 including a tracked DRF that serves as a reference for patient cross-sectional imaging fusion with a navigation camera, step 6106 , including where the orientation of anatomical planes is interpreted, and step 6126 that can include camera coordinates interpreted within anatomical axis.

In some embodiments, a negative for step 6102 can lead to step 6108 where the position of anatomical planes is indicated relative to camera axis, including, but not limited to step 6110 , including adjusting position of a DRF such that it's reference plane labels align with the patient's anatomical planes. Further, step 6112 including tapping two points in space with a tracked probe to represent each anatomical axis aligned with the patient. Further, step 6114 , includes temporarily holding a tracked probe in instructed orientation according to some embodiments. In some embodiments, step 6116 (reached from step 6110 or decision step 6118 from a positive) can include substantially rigidly transforming camera axis to the DRF-referenced anatomical axes, and to step 6126 , where camera coordinates are interpreted with anatomical axes.

In some embodiments, from decision step 6118 , including checking if a dedicated DRF is used to indicate patient anatomy, a negative can proceed to step 6120 of substantially rigidly transforming camera axes to referenced anatomical axes and to decision step 6122 . From step 6122 , a positive can lead to step 6124 including a return to step 6108 , and a negative can include moving to step 6126 (described above).

In some embodiments, any of the above processes, methods, or procedures related to the workflow 6200 can include or be accomplished with one or more of steps or processes 6102 , 6104 , 6106 , 6108 , 6110 , 6112 , 6114 , 6116 , 6118 , 6120 , 6122 , 6124 , and 6126 . In some embodiments, at least one of the steps can include a decision step (e.g., such as step 6102 or 6122 ), where one or more following steps depend on a status, decision, state, or other condition. In some embodiments, the steps of workflow 6100 can proceed in the order as shown. In some embodiments, any of the steps of the workflow 6100 can proceed out of the order as shown. In some embodiments, one or more of the steps of the workflow 6100 can be skipped.

Some embodiments of the invention in the acquisition and interpretation of spinal contour via tracing body surfaces with a 3D-tracked probe and interfacing with previously initialized skin fiducial markers as described previously. In some embodiments, the tracing can be performed with a trigger-equipped probe, as described previously in relation to FIGS. 10 A- 10 G , and FIGS. 15 A- 15 C , to indicate the body surface type that is being traced (e.g., skin, lamina, etc.) and to ensure the probe is only in an active state when in contact with body surfaces as described below in reference to FIG. 69 . In some embodiments, the acquired tracing data obtained from this embodiment can then be used to automatically compute spinal alignment parameters as described below in reference to FIGS. 66 A- 66 B, and 67 .

FIG. 62 A displays some embodiments of the invention which consists of acquiring information regarding the contour of the spine via tracing over body surfaces using a tracked probe. Some embodiments consist of spine bony anatomy 6211 , overlying skin 6215 interrupted to represent a surgical site 6220 , skin-mounted fiducials 6226 , 6228 applied to two regions outside of the surgical site with overlying surgical drapes 6208 and over-the-drape-mating fiducials 6225 , 6227 . In some embodiments, using a 3D-tracked probe, tracing coordinates are acquired over the skin of the cervicothoracic spine 6202 , surgical site anatomy 6204 , and skin of the lumbosacral spine 6205 . In some embodiments, after acquiring this traced data, the acquisition system software can interpret it with the aid of fiducial initialization data, previously described in relation to FIGS. 4 A- 4 I and 58 to represent one complete bony surface contour from which spinal alignment parameters can be calculated, as described below in reference to FIGS. 67 , and 69 .

FIG. 62 B displays on embodiment of the invention which is a display of the acquired body surface contours via tracing with a 3D-tracked probe within the optical 3D-tracking camera's axes, containing the 3D coordinates of the over-the-drape-mating fiducials 6251 , cervicothoracic skin tracing 6253 , surgical site tracing 6255 , and lumbosacral skin tracing 6257 according to some embodiments. In some embodiments, in order to properly interpret this data, the acquisition software has to substantially rigidly transform the data such that it is represented within anatomical reference axes rather than camera axes. In some embodiments, the mechanism of establishing anatomical reference axes was previously described in relation to FIGS. 12 and 61 and the transformed data is shown below in reference to FIG. 62 C .

FIG. 62 C displays the invention which is applying a 3D rigid transform to the acquired tracing data as described previously in relation to FIGS. 62 A- 62 B , to be interpreted and displayed within anatomical reference axes including the coordinates of the over-the-drape-mating fiducials 6261 , cervicothoracic skin tracing 6263 , surgical site tracing 6265 , and lumbosacral skin tracing 6267 according to some embodiments. Interpreting and displaying the acquired 3D-tracing data in this way enables subsequent manipulation and calculations as described below in relation to FIGS. 62 D and 67 according to some embodiments.

FIG. 62 D displays the invention which is the translation of the acquired tracing data previously described in relation to FIGS. 62 A- 62 C according to some embodiments. In some embodiments, based on the displacement vector between the initialized skin fiducial and anatomical regions of interest, and based on the displacement vectors between the skin tracing locations most closely approximating the surgical site tracing and the end points of the surgical site tracing, any skin-surface tracing is translated to represent one continuous tracing of bony anatomy. As shown in the figure, some embodiments consist of the translated coordinates for the cervical fiducial 6281 , cervicothoracic skin tracing 6283 , lumbosacral skin tracing 6285 , and lumbosacral fiducial 6287 . In some embodiments, from the data coupling the translated tracings to the surgical site tracing (if applicable), spinal alignment parameters can then be calculated as described below in reference to FIG. 67 . Additionally, in some embodiments, if a quantitative assessment of aligning is desired for the surgical site only, that is also achievable with the acquired data in this embodiment, as described in more detail below in reference to FIG. 68 .

Some embodiments of this invention include the use of a tracked mobile stray marker (TMSM) to communicate particular commands to the computer system via its tracked dynamic motion relative to the 3D-tracked tool's end effector and/or DRF. For example, FIG. 63 shows a workflow 6300 for analog triggering detection of one or more TMSMs relative to a tracked tool with a DRF in accordance with some embodiments of the invention. In some embodiments, other relevant figures related to linear actuation of the TMSM relative to the probe shaft can include, but not be limited to, FIGS. 10 A- 10 E , FIGS. 29 A- 29 C , FIGS. 38 C, 38 G , FIGS. 39 A- 39 B , FIGS. 44 B- 44 D , FIGS. 45 A- 45 B , FIGS. 51 E- 51 H , FIGS. 53 A, 53 C- 53 D , and FIGS. 57 A- 57 B . In some embodiments, other relevant figures related to rotational actuation of the TMSM on a rigid arm relative to the probe shaft can include, but not be limited to, FIG. 4 H , FIGS. 15 A- 15 C , FIGS. 48 B- 48 C , FIGS. 49 A- 49 D , FIGS. 50 A- 50 E , and FIGS. 82 A- 82 B . In some embodiments, some relevant figures related to calculation of angle of TMSM with respect to the probe shaft can include, but not be limited to, FIGS. 64 A- 64 B .

Some embodiments of the invention involve the use of a TMSM that is mechanically linked to a 3D-tracked tool and tracking its dynamic position relative to the coordinates of the 3D-tracked tool, which is defined by a coupled DRF and its associated tool definition file. Some embodiments involve the use of a depressible tip that actuates a rod that is coaxial to the shaft of a 3D-tracked tool. In some embodiments, the TMSM is attached to the depressible rod and subsequently its distance from the tip of the 3D-tracked tool, or any other defined component relative to the DRF of the tool, can dynamically change upon actuation of the depressible tip, following a linear path of motion. Some embodiments of the system use the 3D location of the TMSM and apply to it a 3D rigid transformation of the 3D location and orientation of the 3D-tracked tool relative to the 3D-tracking acquisition unit. In some embodiments, the TMSM location data is now transformed to be relative to the coordinate system of the 3D-tracked tool, and thus does not perturb with respect to moving the 3D-tracked tool in space without triggering the depressible tip to change the location of the TMSM relative to the 3D-tracked tool. In some embodiments, the resulting magnitude of the vector between the transformed TMSM and the 3D-tracked tool end effector is the mathematical output that is tracked for the system to detect when an event has occurred to note information or store data produced by the position and/or behavior of the 3D-tracked tool.

In some embodiments, the dynamic change of the magnitude of the vector between transformed TMSM coordinates and the coordinates of the 3D-tracked tool's end effector can be analyzed for detecting specific thresholds of magnitude for a binary system behavior, or also analyzed at various levels of magnitude across the possible range of motion of the TMSM relative to the 3D-tracked tool's end effector, representing a more analog system behavior. Some example embodiments are depicted in FIGS. 10 A- 10 B, 10 D, 10 E , FIGS. 29 A- 29 C , FIGS. 38 C, 38 G , FIGS. 39 A- 39 B , FIGS. 44 B- 44 D , FIGS. 45 A- 45 B , FIGS. 51 E- 51 H , FIGS. 53 A, 53 C- 53 D , and FIGS. 57 A- 57 B . In addition, some embodiments of the system can calculate the angle between two vectors to communicate when the behavior of the TMSM is used to communicate a specific command (e.g., such as the vector between the 3D-tracked tool's end effector and the rotation axis of the arm), which is mechanically linked to the 3D-tracked tool, that the TMSM is substantially rigidly attached to, and the vector between the TMSM and the rotation axis of the arm, which is mechanically linked to the 3D-tracked tool, that the TMSM is substantially rigidly attached to. In some embodiments, the system calculates the angle between these two vectors during the use of the 3D-tracked tool and constantly analyzes the angle of the vectors that are defined with respect to the coordinates of the 3D-tracked tool. In some embodiments, this dynamic angle calculation, such as the example described in FIG. 64 A and FIG. 65 B , can also be sensed in a binary or analog manner such as described above to enable various commands to be communicated to the 3D-tracking acquisition unit for a variety of applications. Some embodiments involve the use of a 3D-tracked tool with a rotationally-actuating TMSM to trace the spine at select regions and communicate to the system to only store location and orientation data of the 3D-tracked tool while the TMSM-based angle has reached a certain threshold via the actuation of a button on the 3D-tracked tool. Some example embodiments are depicted in FIG. 4 H , FIG. 15 A , FIG. 15 B , FIG. 15 C ,