Pressure/flow characteristic modification of a centrifugal pump in a ventricular assist device

Patent metadata

Field	Value
Publication number	US-10117983-B2
Application number	US-201615352141-A
Country	US
Kind code	B2
Filing date	Nov 15, 2016
Priority date	Nov 16, 2015
Publication date	Nov 6, 2018
Grant date	Nov 6, 2018

Abstract

A ventricular assist device is disclosed. The ventricular assist device may include a centrifugal pump and a controller. The controller may be configured to cause the centrifugal pump to operate at a first speed above a predetermined flow rate. The controller may also be configured to cause the centrifugal pump to operate at a second speed below the predetermined flow rate, wherein the predetermined flowrate is indicative of a crossover point between systole and diastole phases of a person's cardiac cycle.

First claim

What is claimed is:

1. A ventricular assist device comprising:
a centrifugal pump having a motor; and
a controller, wherein the controller is configured to at least:
measure a current of the motor;
determine an estimated flow rate through the centrifugal pump based on the current;
cause the motor of the centrifugal pump to operate at a first speed when the estimated flow rate is greater than a predetermined flow rate; and
cause the motor of the centrifugal pump to operate at a second speed when the estimated flow rate is less than the predetermined flow rate, wherein the predetermined flowrate is indicative of an actual flow rate through the pump at a crossover point between systole and diastole phases of a person's cardiac cycle.

2. A method of controlling a centrifugal pump in a ventricular assist device of a person, wherein the method comprises:
measuring a current of a motor of a centrifugal pump in a ventricular assist device:
determining an estimated flow rate through the centrifugal pump based on the current:
causing the motor of the centrifugal pump to operate at a first speed when the estimated flow rate is greater than a predetermined flow rate; and
causing the motor of the centrifugal pump to operate at a second speed when the estimated flow rate is less than the predetermined flow rate, wherein the predetermined flowrate is indicative of an actual flow rate through the pump at a crossover point between systole and diastole phases of a person's cardiac cycle.

3. The method of controlling a centrifugal pump of claim 2 , wherein the first speed comprises a minimum operating speed as set by a clinician.

4. The method of controlling a centrifugal pump of claim 2 , wherein the second speed is greater than the first speed.

5. The method of controlling a centrifugal pump of claim 2 , wherein the second speed comprises a set speed as set by a clinician.

6. The method of controlling a centrifugal pump of claim 2 , wherein when the motor of the centrifugal pump is operating at the second speed, the motor of the centrifugal pump is operating at a constant current.

7. The method of controlling a centrifugal pump of claim 2 , wherein causing the motor of the centrifugal pump to operate at the second speed comprises controlling the motor of the centrifugal pump to maintain a parameter at a substantially constant value, wherein the parameter is selected from a group consisting of: motor current, motor voltage, motor power, back electromotive force, and a combination of the same.

8. The method of controlling a centrifugal pump of claim 2 , wherein the method further comprises:
determining a current flow rate with a flow measurement sensor.

9. The method of controlling a centrifugal pump of claim 8 , wherein the method further comprises:
comparing the current flow rate to the predetermined flow rate.

10. The method of controlling a centrifugal pump of claim 2 , wherein the predetermined flow rate is set by a clinician.

11. The method of controlling a centrifugal pump of claim 2 , wherein the method further comprises:
identifying a suction event in the centrifugal pump and reducing a speed of the motor of the centrifugal pump to alleviate the suction event.

12. A controller for operating a centrifugal pump in a ventricular assist device of a person, wherein the controller comprises:
one or more processors configured to execute instructions stored on a non-transitory medium, the instructions executable by the one or more processors to at least:
measure a current of a motor of a centrifugal pump in a ventricular assist device;
determine an estimated flow rate through the centrifugal pump based on the current;
cause the motor of the centrifugal pump to operate at a first speed when the estimated flow rate is greater than a predetermined flow rate; and
cause the motor of the centrifugal pump to operate at a second speed when the estimated flow rate is less than the predetermined flow rate, wherein the predetermined flowrate is indicative of an actual flow rate through the pump at a crossover point between systole and diastole phases of a person's cardiac cycle.

13. The controller for operating a centrifugal pump of claim 12 , wherein the second speed is greater than the first speed.

14. A non-transitory machine readable medium having instructions stored thereon for operating a centrifugal pump in a ventricular assist device of a person, the instructions executable by one or more processors to at least:
measure a current of a motor of a centrifugal pump in a ventricular assist device;
determine an estimated flow rate through the centrifugal pump based on the current:
cause the motor of the centrifugal pump to operate at a first speed when the estimated flow rate is greater than a predetermined flow rate; and
cause the motor of the centrifugal pump to operate at a second speed when the estimated flow rate is less than the predetermined flow rate, wherein the predetermined flowrate is indicative of an actual flow rate through the pump at a crossover point between systole and diastole phases of a person's cardiac cycle.

15. The non-transitory machine readable medium of claim 14 , wherein the second speed is greater than the first speed.

Assignees

• Tc1 Llc

Inventors

• Medvedev Alexander
• Sami Muhammad

Classifications

• F04D15/0088

  Testing machines · CPC title

• F05D2270/3061

  of the working fluid · CPC title

• F04D13/06

  the pump being electrically driven · CPC title

• A61M2205/3334

  Measuring or controlling the flow rate · CPC title

• F04D29/22

  specially for centrifugal pumps · CPC title