AUTOMATIC POWER REGULATION FOR TRANSCUTANEOUS ENERGY TRANSFER CHARGING SYSTEM

• US 20130158631A1
• Filed: 12/16/2011
• Published: 06/20/2013
• Est. Priority Date: 12/16/2011
• Status: Active Grant

• Current Assignee: Abiomed, Inc. (Johnson & Johnson)
• Original Assignee: Abiomed, Inc. (Johnson & Johnson)
• Inventors: Shea, Arthur, Ambrosio, Ralph D.
• Granted Patent: US 9,002,468 B2
• Time in Patent Office: Days
• US Class Current: 607/61
• 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 60/216 including a rotating member acting on the blood, e.g. impeller
• CPC Class Codes: A61M 60/873 specially adapted for wireless or transcutaneous energy transfer [TET], e.g. inductive charging
• CPC Class Codes: A61N 1/3787 from an external energy source

Abstract

Methods and systems for controlling power output from an external power source in a transcutaneous energy transfer (TET) system are provided to prevent inadvertent energy transfer when no secondary coil is present. The system operates by transmitting power transcutaneously from an external primary coil and determining whether a response from a secondary coil implanted within a patient is detected. If no response is detected, the power output of the primary coil is decreased. The decrease in power output can be accomplished by operating the primary coil at a lower average power level, which can include variations in power level, duty cycle, etc. The system can also be configured to periodically repeat the process in order to continue searching for a coupled secondary coil.

Claims

1. A method of controlling power output from a primary coil in a transcutaneous energy transfer system, comprising:

transcutaneously transmitting power from the primary coil;

determining whether a response from a secondary coil within a patient is detected; and

if no response is received, decreasing the power output of the primary coil.

2. The method of claim 1, wherein decreasing the power output of the primary coil comprises reducing an average power output of the primary coil.

3. The method of claim 2, wherein reducing the average power output of the primary coil is accomplished by varying the duty cycle of the primary coil.

4. The method of claim 2, wherein reducing the average power output of the primary coil is accomplished by reducing the power output of the primary coil by a percentage value.

5. The method of claim 4, wherein the percentage value is large enough to prevent inadvertent heating of a nearby object.

6. The method of claim 1, wherein the method further comprises waiting a first period of time before determining that no response has been received.

7. The method of claim 1, wherein the method further comprises holding or adjusting the power output of the primary coil in response to the requirements of the secondary coil if a response from the secondary coil is received.

8. The method of claim 6, wherein the first period of time is about 100 milliseconds.

9. The method of claim 1, wherein the power output of the primary coil is reduced to zero after the first period of time elapses.

10. The method of claim 1, wherein the power output of the primary coil is decreased at a linear rate after the first period of time elapses.

11. The method of claim 6, further comprising:

holding the power output of the primary coil at a decreased level for a second period of time if no response is received during the first period of time; and

repeating the method of claim 0 after the second period of time elapses.

12. The method of claim 11, wherein the decreased level of power output is zero.

13. The method of claim 11, wherein the second period of time is about 3 seconds.

14. The method of claim 1, wherein the response from the secondary coil is in the form of one or more detectable feedback indications.

15. An external transcutaneous energy transfer system for use with an implanted medical device, comprising:

a primary coil configured to transcutaneously transmit energy to the implanted medical device; and

controlling circuitry connected to the primary coil;

wherein the controlling circuitry comprises a functionality to detect a response from the implanted medical device and the controlling circuitry is configured to;

(a) transmit power transcutaneously through the primary coil;

(b) determine whether a response from the implanted medical device is detected; and

(c) decrease the transmitted power if no response is received.

16. The system of claim 15, wherein the controlling circuitry is configured to decrease the transmitted power by reducing an average power output of the primary coil.

17. The system of claim 16, wherein the controlling circuitry is configured to reduce the average power output of the primary coil by varying the duty cycle of the primary coil.

18. The system of claim 16, wherein the controlling circuitry is configured to reduce the average power output of the primary coil by reducing the power output of the primary coil by a percentage value.

19. The system of claim 15, wherein the controlling circuitry is further configured to wait a first period of time before determining that no response has been received.

20. The system of claim 15, wherein the controlling circuitry is further configured to hold or adjust the transmitted power in response to the requirements of the implanted medical device if a response from the implanted medical device is received.

21. The system of claim 19, wherein the first period of time is about 100 milliseconds.

22. The system of claim 15, wherein decreasing the transmitted power comprises reducing the transmitted power to zero.

23. The system of claim 15, wherein decreasing the transmitted power comprises reducing the transmitted power at a linear rate.

24. The system of claim 19, wherein the controlling circuitry is further configured to:

hold the transmitted power at a decreased level for a second period of time if no response is received during the first period of time; and

repeat steps (a)-(c) after the second period of time elapses.

25. The system of claim 24, wherein the decreased level is zero.

26. The system of claim 24, wherein the second period of time is about 3 seconds.

27. An external transcutaneous energy transfer system for use with an implanted medical device, comprising:

a primary coil configured to transcutaneously transmit energy to the implanted medical device; and

controlling circuitry connected to the primary coil;

wherein the controlling circuitry comprises a functionality to detect a response from the implanted medical device and the controlling circuitry is configured to operate the primary coil at a lower average power level when no response is detected.

28. The system of claim 27, wherein the response from the implanted medical device is in the form of one or more detectable feedback indications.

29. The system of claim 27, wherein the controlling circuitry achieves the lower average power level by varying the duty cycle of the primary coil.

30. The system of claim 27, wherein the controlling circuitry achieves the lower average power level by reducing the output of the primary coil by a percentage value.

31. The system of claim 27, wherein the lower average power level is zero power.

32. The system of claim 27, wherein the controlling circuitry is configured to periodically repeat a process of transmitting power, detecting a response, and lowering the average power level of the primary coil if no response is detected.

33. A method of controlling power output from a primary coil in a transcutaneous energy transfer system, comprising:

transcutaneously transmitting power from the primary coil;

determining whether a response from a secondary coil within a patient is detected; and

if no response is received, reducing the average power output of the primary coil.

34. The method of claim 33, wherein the response from the implanted medical device is in the form of one or more detectable feedback indications.

35. The method of claim 33, wherein reducing the average power level is accomplished by varying the duty cycle of the primary coil.

36. The method of claim 33, wherein reducing the average power level is accomplished by reducing the output of the primary coil by a percentage value.

37. The method of claim 33, wherein the average power output is reduced to zero power.

38. The method of claim 33, wherein the method steps are repeated.