INDUCTIVELY RECHARGEABLE EXTERNAL ENERGY SOURCE, CHARGER, SYSTEM AND METHOD FOR A TRANSCUTANEOUS INDUCTIVE CHARGER FOR AN IMPLANTABLE MEDICAL DEVICE

• US 20110022125A1
• Filed: 01/12/2010
• Published: 01/27/2011
• Est. Priority Date: 10/02/2003
• Status: Active Grant

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Olson, David P., Schmeling, Andrew L., Phillips, William C.
• Granted Patent: US 8,554,322 B2
• Time in Patent Office: Days
• US Class Current: 607/61
• CPC Class Codes: A61M 2205/3327 Measuring
• CPC Class Codes: A61M 2205/3368 Temperature
• CPC Class Codes: A61M 2205/52 with memories providing a history of measured variating parameters of apparatus or patient
• CPC Class Codes: A61M 2205/8206 battery-operated
• CPC Class Codes: A61M 2205/8237 Charging means
• CPC Class Codes: A61M 2209/01 Remote controllers for specific apparatus
• CPC Class Codes: A61M 5/142 Pressure infusion, e.g. using pumps
• CPC Class Codes: A61M 5/14276 specially adapted for implantation
• CPC Class Codes: A61M 5/1723 using feedback of body parameters, e.g. blood-sugar, pressure measurement of body parameters A61B5/00
• CPC Class Codes: A61N 1/3655 controlled by body or blood temperature
• CPC Class Codes: A61N 1/3787 from an external energy source
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 50/70 involving the reduction of electric, magnetic or electromagnetic leakage fields
• CPC Class Codes: H02J 7/007192 in response to temperature

Abstract

Techniques for transcutaneous transferral of energy to an implantable medical device are disclosed. An embodiment includes a system comprising an implantable medical device having a secondary coil. An external device is provided to transcutaneously transfer energy to the secondary coil. The external device comprises a housing having a side adapted to be positioned in proximity to the secondary coil when the external device is transferring energy to the secondary coil. A temperature sensor is coupled to the side to determine a temperature indicative of heat to which the patient is being exposed during the transfer of energy. A control circuit is adapted to control the transfer of energy to the secondary coil based on the temperature. For instance, the control circuit may limit transfer of energy by controlling times at which transfer of energy occurs or controlling an amplitude of a signal within the external device.

Claims

1. A system, comprising:

an implantable medical device having a secondary coil and a rechargeable power source;

an external device having a primary coil adapted to inductively couple to the secondary coil to transcutaneously recharge the rechargeable power source, the external device having a surface that assumes a position in proximity to the secondary coil when the primary coil is inductively coupled to the secondary coil; and

a temperature sensor thermally coupled to the surface of the external device.

2. The system of claim 1, further comprising control circuitry operationally-coupled to the temperature sensor to control recharging of the rechargeable power source based on an output from the temperature sensor.

3. The system of claim 2, wherein the control circuitry is adapted to limit energy transfer between the external device and the secondary coil.

4. The system of claim 2, wherein the control circuitry is adapted to control a duty cycle of energy transfer between the external device and the secondary coil for recharging of the rechargeable power source based on the output from the temperature sensor.

5. The system of claim 1, wherein at least a portion of the surface is thermally conductive.

6. The system of claim 1, wherein the external device is adapted to limit at least one of a temperature of the surface and a temperature of a surface of a patient in which the implantable medical device is implanted to no higher than a respective predetermined temperature.

7. The system of claim 1, wherein the external device further comprises an adjustable assembly adapted to adjust efficiency of energy transfer between the primary coil and the secondary coil.

8. The system of claim 1, wherein the external device is adapted to exchange data with the implantable medical device.

9. The system of claim 1, wherein the external device further comprises a circuit adapted to monitor recharging of the rechargeable power source and to provide status of the recharging to a user.

10. A system, comprising:

an implantable medical device adapted to be implanted within a patient, comprising;

a rechargeable power source; and

a secondary coil coupled to the rechargeable power source; and

an external device, comprising;

a housing having a surface adapted to assume a position in proximity to a surface of the patient during recharging of the rechargeable power source;

a primary coil adapted to be transcutaneously coupled to the secondary coil during the recharging; and

a temperature sensor adapted to sense a temperature of the surface of the housing during the recharging.

11. The system of claim 10, wherein the external device further comprises control circuitry to control the recharging based on the temperature of the surface of the housing.

12. The system of claim 11, wherein the control circuitry is adapted to limit energy transfer to the implantable medical device during the recharging based on the temperature of the surface of the housing.

13. The system of claim 12, wherein the control circuitry is adapted to limit energy transfer to the implantable medical device during the recharging by limiting time during which energy is transferred.

14. The system of claim 13, wherein the control circuitry is adapted to switch energy transfer on and off to provide an energy transfer duty cycle.

15. The system of claim 11, wherein the control circuitry is adapted to limit the temperature of the surface of the housing to no more than a predetermined temperature.

16. The system of claim 15, wherein the control circuitry comprises a processor.

17. The system of claim 10, wherein the external device further comprises a circuit to vary a frequency of a recharging signal to substantially optimize efficiency of energy transfer between the primary coil and the secondary coil.

18. The system of claim 10, wherein the external device further comprises thermally conductive material in proximity to the temperature sensor.

19. The system of claim 10, wherein the external device further comprises a telemetry coil adapted to exchange communication signals with the implantable medical device.

20. The system of claim 10, wherein the surface is adapted to contact the patient during recharging of the rechargeable power source;

21. A system, comprising:

an implantable medical device implantable within a patient and comprising a secondary coil; and

an external device to transcutaneously transfer energy to the secondary coil, the external device comprising;

a housing having a side adapted to be positioned in proximity to the secondary coil when the external device is transferring energy to the secondary coil;

a temperature sensor coupled to the side to determine a temperature indicative of heat to which the patient is being exposed during the transfer of energy; and

a control circuit adapted to limit the transfer of energy to the secondary coil based on the temperature.

22. The system of claim 21, wherein the control circuit is adapted to control the transfer of energy so that the temperature does not exceed a predetermined maximum temperature.

23. The system of claim 22, wherein the control circuit is adapted to limit time during which the energy is transferred based on the temperature.

24. The system of claim 22, wherein the external device further comprises a primary coil, and wherein the control circuit is adapted to control amplitude of a signal within the primary coil based on the temperature.

25. The system of claim 22, wherein the temperature sensor is thermally-coupled to a surface of the side of the housing, the surface being in contact with the patient.

26. The system of claim 22, wherein the control circuit further comprises a processor executing programmed instructions, and wherein the predetermined maximum temperature is selectable by the processor.

27. The system of claim 22, wherein the external device further comprises a circuit to vary a frequency of a signal used to transfer energy to the secondary coil to substantially optimize efficiency of the transfer of energy.

28. The system of claim 21, wherein at least a portion of the side of the housing carries a thermally-conductive material.

29. The system of claim 21, wherein the implantable medical device further comprises circuitry to deliver therapy to the patient and magnetic material positioned between the secondary coil and at least a portion of the circuitry.

30. A computer-readable medium comprising instructions that, upon execution, cause a processor to:

control transcutaneous transfer of energy from an external device to a secondary coil of an implantable medical device while a side of the external device assumes a position in proximity to the secondary coil; and

receive output from a temperature sensor that is coupled to the side of the external device and to control the transcutaneous transfer of energy based, at least in part, on the received output.

31. The computer-readable medium of claim 30, further comprising instructions that cause the processor to limit energy transfer between the external device and the secondary coil.

32. The computer-readable medium of claim 30, further comprising instructions that cause the processor to control a duty cycle of energy transfer between the external device and the secondary coil.

33. The computer-readable medium of claim 30, further comprising instructions that cause the processor to limit at least one of a temperature of the side of the external device and a temperature of a surface of a patient in which the implantable medical device is implanted to no higher than a respective predetermined temperature.

34. The computer-readable medium of claim 30, further comprising instructions that cause the processor to adjust efficiency of energy transfer to the secondary coil.

35. The computer-readable medium of claim 34, further comprising instructions that cause the processor to adjust a frequency of the energy transfer to the secondary coil.

36. The computer-readable medium of claim 34, further comprising instructions that cause the processor to switch energy transfer on and off to control the energy transfer to the secondary coil.

37. The computer-readable medium of claim 34, further comprising instructions that cause the processor to provide status of the energy transfer between the external device and the secondary coil to a user.

38. The computer-readable medium of claim 30, wherein the received output reflects a thermal coupling of the temperature sensor to the side of the external device, and further comprising instructions that cause the processor to control the transcutaneous transfer of energy based, at least in part, on the thermal coupling of the temperature sensor to the side of the external device.