Granted Patent B2

US 12,297,836 · App. 18/241,433 · Granted May 13, 2025

Inventors: Masamichi Yanai (Ann Arbor, MI); Shunzhou Yu (Ann Arbor, MI); Tao Zhang (Ann Arbor, MI)

Assignee: TC1 LLC

F04D13/064A61M60/232A61M60/237A61M60/422A61M60/538A61M60/82A61M60/824F04D13/0646F04D13/0666F04D29/047F04D29/048A61M2205/3334

Abstract

Claims (68)

1. A blood pump, comprising:

a chamber;

an impeller disposed within the chamber;

a motor that drives rotation of the impeller; and

a control system that controls operation of the motor, wherein the control system is configured to:

deliver a quadrature current to the motor that controls a rotational speed of the impeller; and

adjust a direct current supplied to the motor that controls a magnetic flux of electromagnetic coils of the motor to modify an attractive force on the impeller to move the impeller in an axial direction to alternate the impeller between a first balanced position and a second balanced position.

2. The blood pump of claim 1 , wherein:

the quadrature current and the direct current are decoupled and controlled independently.

3. The blood pump of claim 1 , wherein:

adjusting the direct current comprises:

measuring an instantaneous phase current in two phases of a three phase stator;

estimating a position and a speed of the impeller based on the instantaneous phase currents; and

transforming the instantaneous phase currents into a two-axis coordinate system to generate values in a rotating reference frame for the quadrature current and the direct current.

4. The blood pump of claim 3 , wherein:

adjusting the direct current further comprises:

determining a next quadrature voltage based on a quadrature current error between the value of the quadrature current in the rotating reference frame and a required current for impeller rotation; and

determining a next direct voltage based on a direct current error between the value of the direct current in the rotating reference frame and a required current for attraction force alternation to control an axial position of the impeller.

5. The blood pump of claim 4 , wherein:

adjusting the direct current further comprises:

transforming the next quadrature voltage and the next direct voltage to a stationary reference frame to generate multiphase voltage commands; and

providing the multiphase voltage commands to the motor.

6. The blood pump of claim 3 , wherein:

adjusting the direct current further comprises calculating a current corresponding to a third phase of the three phase stator.

7. The blood pump of claim 1 , wherein:

a target speed of the impeller is provided by a physiological monitor.

8. A method of operating a blood pump, comprising:

delivering a quadrature current to a motor of the blood pump to control a rotational speed of an impeller disposed within a chamber of the blood pump; and

adjusting a direct current supplied to the motor that controls a magnetic flux of electromagnetic coils of the motor to modify an attractive force on the impeller to move the impeller in an axial direction to alternate the impeller between a first balanced position and a second balanced position.

9. The method of operating a blood pump of claim 8 , wherein:

in the first balanced position and the second balanced position, a sum of hydrodynamic forces generated by any hydrodynamic bearings of the blood pump, a combination of permanent magnetic forces acting on the impeller, and a magnetic attraction force generated by the motor is equal to zero.

10. The method of operating a blood pump of claim 8 , wherein:

adjusting the direct current comprises:

measuring an instantaneous phase current in two phases of a three phase stator;

estimating a position and a speed of the impeller based on the instantaneous phase currents; and

transforming the instantaneous phase currents into a two-axis coordinate system to generate values in a rotating reference frame for the quadrature current and the direct current.

11. The method of operating a blood pump of claim 10 , wherein:

adjusting the direct current further comprises:

determining a next quadrature voltage based on a quadrature current error between the value of the quadrature current in the rotating reference frame and a required current for impeller rotation; and

determining a next direct voltage based on a direct current error between the value of the direct current in the rotating reference frame and a required current for attraction force alternation to control an axial position of the impeller.

12. The method of operating a blood pump of claim 11 , wherein:

adjusting the direct current further comprises:

transforming the next quadrature voltage and the next direct voltage to a stationary reference frame to generate multiphase voltage commands; and

providing the multiphase voltage commands to the motor.

13. The method of operating a blood pump of claim 8 , wherein:

an amount of time the impeller spends at each of the first balanced position and the second balanced position is substantially equal.

14. The method of operating a blood pump of claim 8 , wherein:

an amount of time the impeller spends at each of the first balanced position and the second balanced position is inversely proportional to a size of a gap between the impeller and a wall of the chamber.

15. A non-transitory computer-readable medium having instructions stored thereon that, when executed, cause a blood pump control system to perform a method comprising:

delivering a quadrature current to a motor of the blood pump to control a rotational speed of an impeller disposed within a chamber of the blood pump; and

adjusting a direct current supplied to the motor that controls a magnetic flux of electromagnetic coils of the motor to modify an attractive force on the impeller to move the impeller in an axial direction to alternate the impeller between a first balanced position and a second balanced position.

16. The non-transitory computer-readable of claim 15 , wherein:

adjusting the direct current comprises:

measuring an instantaneous phase current in two phases of a three phase stator;

estimating a position and a speed of the impeller based on the instantaneous phase currents; and

transforming the instantaneous phase currents into a two-axis coordinate system to generate values in a rotating reference frame for the quadrature current and the direct current.

17. The non-transitory computer-readable of claim 16 , wherein:

adjusting the direct current further comprises:

determining a next quadrature voltage based on a quadrature current error between the value of the quadrature current in the rotating reference frame and a required current for impeller rotation; and

determining a next direct voltage based on a direct current error between the value of the direct current in the rotating reference frame and a required current for attraction force alternation to control an axial position of the impeller.

18. The non-transitory computer-readable of claim 17 , wherein:

adjusting the direct current further comprises:

transforming the next quadrature voltage and the next direct voltage to a stationary reference frame to generate multiphase voltage commands; and

providing the multiphase voltage commands to the motor.

19. The non-transitory computer-readable of claim 15 , wherein:

movement of the impeller between the first balanced position and the second balanced position is asynchronous with a native heartbeat.

20. The non-transitory computer-readable of claim 15 , wherein:

movement of the impeller between the first balanced position and the second balanced position is synchronous with a native heartbeat.

Assignments (1)

Continuity (5)

References Cited (400)