Physiological demand responsive control system

• US 20080183287A1
• Filed: 09/30/2003
• Published: 07/31/2008
• Est. Priority Date: 09/30/2002
• Status: Active Grant

• Current Assignee: Heartware,Inc. (Medtronic Plc), HeartWare Pty Ltd. (Medtronic Plc), Thoratec LLC
• Original Assignee: Thoratec LLC
• Inventors: Ayre, Peter
• Granted Patent: US 7,988,728 B2
• Time in Patent Office: Days
• US Class Current: 623/3.28
• CPC Class Codes: A61M 2205/33 Controlling, regulating or measuring
• CPC Class Codes: A61M 2205/3303 Using a biosensor
• CPC Class Codes: A61M 2205/3334 Measuring or controlling the flow rate
• CPC Class Codes: A61M 2230/06 Heartbeat rate only
• CPC Class Codes: A61M 2230/63 Motion, e.g. physical activity
• CPC Class Codes: A61M 60/148 in line with a blood vessel using resection or like techniques, e.g. permanent endovascular heart assist devices
• CPC Class Codes: A61M 60/178 drawing blood from a ventricle and returning the blood to the arterial system via a cannula external to the ventricle, e.g. left or right ventricular assist devices
• CPC Class Codes: A61M 60/232 Centrifugal pumps
• CPC Class Codes: A61M 60/515 Regulation using real-time patient data
• CPC Class Codes: A61M 60/523 using blood flow data, e.g. from blood flow transducers
• CPC Class Codes: A61M 60/538 Regulation using real-time blood pump operational parameter data, e.g. motor current
• CPC Class Codes: A61M 60/562 for making blood flow pulsatile in blood pumps that do not intrinsically create pulsatile flow
• CPC Class Codes: A61M 60/585 User interfaces
• CPC Class Codes: A61M 60/824 Hydrodynamic or fluid film bearings

Abstract

A demand responsive physiological control system for use with a rotary blood pump; said system including a pump controller which is capable of controlling pump speed of said pump; said system further including a physiological controller, and wherein said physiological controller is adapted to analyse input data relating to physiological condition of a user of said pump; and wherein said physiological controller determines appropriate pumping speed and sends a speed control signal to said pump controller to adjust pump speed; said system further including a physiological state detector which provides said input data indicative of at least one physiological state of said user, in use, to said physiological controller.

Claims

1. A demand responsive physiological control system for use with a rotary blood pump;

said system including a pump controller which is capable of controlling pump speed of said pump;

said system further including a physiological controller, and wherein said physiological controller is adapted to analyse input data relating to physiological condition of a user of said pump; and

wherein said physiological controller determines appropriate pumping speed and sends a speed control signal to said pump controller to adjust pump speed;

said system further including a physiological state detector which provides said input data indicative of at least one physiological state of said user, in use, to said physiological controller.

2. The system as in claim 1 wherein the physiological state detector includes an accelerometer to sense motion of the user, when in use.

3. The system as in claim 2 wherein the accelerometer senses motion in at least one axis.

4. The system as in claim 3 wherein the accelerometer senses motion in three orthogonal axes.

5. The system as in claim 4, wherein said system includes a pump monitor that detects information relating to voltage and current of the pump and delivers this information to said physiological controller.

6. The system as in claim 5 wherein the pump monitor detects an instantaneous pump impeller speed of the rotary blood pump through measurements.

7. The system as in claim 6 wherein the pump monitor detects non-invasively.

8. The system as in claim 6 wherein said physiological controller uses said information received from the pump monitor to derive mathematically an appropriate pump speed.

9. The system as in claim 8 wherein the physiological controller assesses flow dynamics and an average flow estimate developed from speed and input power supplied to the pump by the pump controller.

10. The system as in claim 8 wherein the physiological controller mathematically determines a pumping state and if a deleterious state is determined the speed control signal is changed accordingly.

11. The system as in claim 10 wherein the physiological detector includes a means of detecting and quantifying a heart rate of the user, when in use.

12. The system as in claim 11 wherein the physiological detector includes a means of non-invasively detecting and quantifying a heart rate of the user, in use.

13. The system as in claim 12 wherein, the physiological controller can determine a heart rate of the user using power inputted to the pump.

14. The system as in claim 13 wherein the pump is internally implantable within the user.

15. The system as in claim 14 wherein the pump is a ventricle assist device.

16. The system as in claim 14 wherein the pump has a hydrodynamic bearing that produces a relatively flat pump head versus pump flow curve.

17. The system as in claim 16 wherein the physiological controller is capable of manual manipulation by the user.

18. The system as in claim 17 wherein the manual manipulation is within adjustable predefined limits.

19. The system as in claim 18 wherein the physiological controller is adapted for communication with a computer and wherein the physiological controller, is adapted for manipulation by a software user interface.

20. The system as in claim 19 wherein the physiological controller includes an alarm.

21. A process for using physiological demand data to optimize pump speed of a rotary blood pump wherein the process comprises of the following steps:

a heart rate of the user is non-invasively determined;

a level of physiological exertion of the user is determined through non invasive means;

an instantaneous pump speed and input power is used to calculate instantaneous blood flow rate;

a pumping state is mathematically determined;

the heart rate, pumping state and level of physical exertion are compared to the blood flow rate; and

the pumping speed of the rotary blood pump is changed to appropriately supply the user with the correct blood flow rate.

22. A pump control system for a pump for use in a heart assist device;

said system comprising data processing means which receives body motion information and heart rate information thereby to derive a speed control signal for impeller speed of an impeller, of said pump.

23. The system of claim 22 wherein said body, motion information is derived from an accelerometer.

24. The system of claim 23 wherein said accelerometer senses motion in a single axis.

25. The system of claim 23 wherein said accelerometer senses motion in three orthogonal axes.

26. The system of. claim 22 wherein said heart rate information is derived from a non-invasive sensor.

27. The system of claim 26 wherein said heart rate information is derived from voltage and current applied to an electric motor deriving driving said impeller.

28. A physiological demand responsive controller for use with a rotary blood pump implanted within a patient, wherein said controller includes:

an accelerometer, which produces an output signal as an analogue of a patient'"'"'s physical motion;

wherein said accelerometer provides an output signal to the circuits of the controller; and

wherein said controller controls pumping speed setpoints of blood pump using said output signal.

29. The controller of claim 28 wherein said controller determines pumping speed setpoint by use of a mathematical model or algorithm.

30. The controller of claim 28 wherein said circuits of the controller include at least one conditioning circuit.