Active magnetic bearing system for blood pump

A rotary blood pump, comprising: a pump housing; a rotor mounted for rotation within said housing, said rotor having an impeller; a rotor motor, said motor including a plurality of permanent magnets carried by said impeller and a motor stator including electrically conductive coils and pole pieces located within said housing; said motor being operable to transmit torque and also to provide an axial magnetic force that acts as an axial bearing.

A rotary blood pump, comprising: a pump housing; a rotor mounted for rotation within said housing, said rotor having an impeller; a rotor motor, said motor including a plurality of permanent magnets carried by said impeller, a first motor stator positioned on one side of said impeller and a second motor stator positioned on an opposite side of said impeller; said motor stators each including electrically conductive coils and pole pieces located within said housing; said motor being operable to transmit torque and also to provide an axial magnetic force that acts as an axial bearing.

A rotary blood pump, comprising: a pump housing; a rotor mounted for rotation within said housing, said rotor having an impeller; a plurality of permanent magnets carried by said impeller; a first motor stator on one side of said impeller for coaction with said permanent magnets carried by said impeller; a second motor stator located on the opposite side of said impeller for coaction with said permanent magnets carried by said impeller; said first motor stator comprising a first plurality of coils and pole pieces; said second stator comprising a second plurality of coils and pole pieces; a circuit for energizing said first and second stators; a detector for detecting a position of said impeller; the energization of said stators being responsive to said detector for varying the position of said impeller in response to an output from said detector.

A method for controlling a rotary blood pump, which comprises the steps of: providing a pump housing; providing a rotor mounted for rotation within said housing, said rotor having an impeller; providing a rotor motor which includes a plurality of permanent magnets carried by said impeller and a motor stator; and operating said motor to transmit torque and also to provide an axial magnetic force that acts as an axial bearing.

A method for controlling a rotary blood pump, which comprises the steps of: providing a pump housing; providing a rotor mounted for rotation within said housing, said rotor having a shaft portion and an impeller carried by said shaft portion; providing a rotor motor, said motor including a plurality of permanent magnets carried by said impeller, a first motor stator positioned on one side of said impeller and a second motor stator positioned on an opposite side of said impeller; operating said motor to transmit torque and also to provide an axial magnetic force that acts as an axial bearing; detecting axial movement of said impeller; and providing current to said stators in response to said detection step.

A method of controlling a rotary blood pump, which comprises the steps of: providing a pump housing; providing a rotor for rotation within said housing, said rotor having an impeller; providing a plurality of permanent magnets carried by said impeller; providing a first motor stator on one side of said impeller for coaction with said permanent magnets carried by said impeller; providing a second motor stator located on the opposite side of said impeller for coaction with said permanent magnets carried by said impeller; energizing said first and second stators; detecting the axial position of said impeller; energizing said stators in response to said detection of said axial position of said impeller to vary the position of said impeller.

A method for controlling a rotary blood pump, which comprises the steps of: providing a pump housing; providing a rotor for rotation within said housing, said rotor having an impeller; providing a plurality of permanent magnets carried by said impeller; providing a first motor stator on one side of said impeller for coaction with said permanent magnets carried by said impeller; providing a second motor stator located on the opposite side of said impeller for coaction with said permanent magnets carried by said impeller; detecting the axial position of said impeller; and unbalancing the currents to the two stators in response to the detecting step for providing a magnetic restoring force to move the impeller axially .