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

• US 20110301667A1
• Filed: 08/16/2011
• Published: 12/08/2011
• 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., Phillips, William C., Schmeling, Andrew L.
• Granted Patent: US 8,725,262 B2
• Time in Patent Office: Days
• US Class Current: 607/59
• 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

A mechanism for transferring energy from an external power source to an implantable medical device is disclosed. A sensor may be used to measure a parameter that correlates to a temperature of the system that occurs during the transcutaneous coupling of energy. For example, the sensor may measure temperature of a surface of an antenna of the external power source. The measured parameter may then be compared to a programmable limit. A control circuit such as may be provided by the external power source may then control the temperature based on the comparison. The programmable limit may be, for example, under software control so that the temperature occurring during transcutaneous coupling of energy may be modified to fit then-current circumstances.

Claims

1. A medical system, comprising:

an implantable medical device;

an external device configured for transcutaneously coupling energy into the implantable medical device;

a sensor configured for measuring a temperature generated by the external device during coupling of the energy into the implantable medical device; and

a control circuit configured to compare the measured temperature to a programmable limit and to control the temperature based on the comparison.

2. The system of claim 1, wherein the external device is an external charging device.

3. The system of claim 1, further comprising a memory to store the programmable limit.

4. The system of claim 1, wherein the external device comprises an external antenna and wherein the sensor is carried by the external antenna.

5. The system of claim 4, wherein the sensor is thermally-coupled to a surface of the external antenna to measure a temperature to which a patient is being exposed.

6. The system of claim 1, wherein the control circuit includes a processor.

7. The system of claim 1, wherein the control circuit is configured for controlling the temperature by adjusting a rate at which energy is coupled into the implantable medical device.

8. The system of claim 1, further comprising a primary coil, and wherein the control circuit is adapted to control the temperature by limiting the current driving the primary coil.

9. The system of claim 1, wherein the control circuit is adapted to control the temperature by limiting the time during which energy is transferred to the implantable medical device.

10. The system of claim 1, wherein the control circuit is adapted to control the temperature by alternatively terminating and initiating the transcutaneous coupling of energy into the implantable medical device.

11. An external device for providing energy to an implantable medical device, comprising:

an alternating current (AC) coil configured for transcutaneously conveying the energy to the implantable medical device;

a sensor configured for measuring a parameter correlated to a temperature generated by the external device during the transcutaneous conveyance of the energy to the implantable medical device;

a memory configured for storing a programmable limit;

a control circuit configured for controlling the temperature based on the measured parameter and the programmable limit; and

a housing containing one or more of the AC coil, sensor, memory, and control circuit.

12. The external device of claim 11, wherein the measured parameter is the temperature.

13. The external device of claim 11, wherein the sensor is a temperature sensor located in proximity to the AC coil.

14. The external device of claim 13, further comprising a thermally conductive material located in proximity to the temperature sensor.

15. The external device of claim 11, further comprising an antenna housing the AC coil, and wherein the sensor is thermally-coupled to a surface of the antenna to provide an indication of a temperature of the surface of the antenna.

16. The external device of claim 11, wherein the control circuit includes a processor.

17. The external device of claim 11, wherein the control circuit is adapted to control the temperature by adjusting a charge rate of the implantable medical device.

18. The external device of claim 11, wherein the control circuit is adapted to control the temperature by limiting the current driving the AC coil.

19. The external device of claim 11, wherein the control circuit is adapted to control the temperature by alternatively terminating and initiating the transcutaneous conveying of the energy to the implantable medical device.

20. The external device of claim 11, further comprising a magnetic core to focus energy provided from the AC coil to the implantable medical device.

21. The external device of claim 11, further comprising a source of electrical power for providing the energy to the AC coil.

22. The external device of claim 11, wherein the housing is portable to allow a patient in which the implantable medical device is implanted to be ambulatory while energy is being provided to the implantable medical device.

23. The external device of claim 11, wherein the programmable limit is selected to be a temperature of not more than forty-one degrees Centigrade.

24. The external device of claim 11, further including means for modifying the programmable limit to fit then-current circumstances.

25. A method for regulating a temperature generated by an external device, comprising:

transcutaneously coupling energy from the external device to a medical device implanted within a patient;

measuring a parameter correlated to the temperature during the transcutaneous coupling of the energy to the medical device;

obtaining a programmable limit;

comparing the measured parameter to the programmable limit; and

controlling the temperature based on the comparison.

26. The method of claim 25, wherein the external device is an external charging device, wherein the medical device comprises a rechargeable power source, and further comprising transcutaneous coupling energy from the external charging device to charge the rechargeable power source.

27. The method of claim 25, wherein the measured parameter is the temperature.

28. The method of claim 25, wherein measuring a parameter correlated to the temperature comprises measuring a temperature of the external device during the transcutaneous coupling of the energy to the medical device.

29. The method of claim 28, wherein measuring a temperature of the external device comprises measuring a temperature of a surface of the external device during transcutaneous coupling of the energy to the medical device.

30. The method of claim 25, further comprising controlling the temperature by adjusting a charge rate of the implantable medical device.

31. The method of claim 25, wherein transcutaneously coupling energy from the external device to the medical device comprises transcutaneously coupling energy from a primary coil of the external device to the medical device and further comprising controlling the temperature by limiting the current driving the primary coil.

32. The method of claim 25, further comprising controlling the temperature by limiting the time during which energy is transferred to the implantable medical device.

33. The method of claim 25, further comprising controlling the temperature by alternatively terminating and initiating the transcutaneous coupling of energy into the implantable medical device.

34. The method of claim 25, further comprising modifying the programmable limit to fit then-current circumstances associated with the transcutaneous coupling of energy.

35. A medical system, comprising:

an implantable medical device;

an external device configured for transcutaneously coupling energy into the implantable medical device;

a sensor configured for measuring a parameter correlated to a temperature generated by the external device during coupling of the energy into the implantable medical device;

a memory configured for storing a programmable limit; and

a control circuit configured to compare the measured parameter to the programmable limit and to control the temperature based on the comparison.

36. The system of claim 35, wherein the measured parameter is the temperature.

37. The system of claim 35, wherein the external device comprises an external antenna and wherein the sensor is carried by the external antenna.

38. The system of claim 35, wherein the control circuit is configured for controlling the temperature by adjusting a charge rate of the implantable medical device.

39. The system of claim 35, further comprising a primary coil, and wherein the control circuit is adapted for controlling the temperature by limiting the current driving the primary coil.

40. The system of claim 35, wherein the control circuit is adapted to control the temperature by limiting the time during which energy is transferred to the implantable medical device.

41. The system of claim 35, wherein the control circuit is adapted to control the temperature by alternatively terminating and initiating the transcutaneous coupling of energy into the implantable medical device.