Thermal management for recharge of implantable medical devices

• US 10,258,804 B2
• Filed: 11/04/2016
• Issued: 04/16/2019
• Est. Priority Date: 11/04/2016
• Status: Active Grant

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Scott, Erik R., Paralikar, Kunal
• Primary Examiner(s): Marlen, Tammie K
• Application Number:
  US15/343,949
• Publication Number:
  US 20180126177A1
• Time in Patent Office: 893 Days
• CPC Class Codes: A61B 2560/0219 of externally powered implanted units
• CPC Class Codes: A61B 5/01 Measuring temperature of body parts ; Diagnostic temperature sensing, e.g. for malignant or inflamed tissue clinical contact thermometers G01K13/20
• CPC Class Codes: A61B 5/6867 specially adapted to be attached or implanted in a specific body part A61B5/6847 takes precedence
• CPC Class Codes: A61F 2007/0052 for treatment of skin or hair
• CPC Class Codes: A61F 2007/0096 with a thermometer
• CPC Class Codes: A61F 7/0085 Devices for generating hot or cold treatment fluids
• CPC Class Codes: A61M 2205/3368 Temperature
• CPC Class Codes: A61M 2205/3523 using telemetric means
• CPC Class Codes: A61M 2205/502 User interfaces, e.g. screens or keyboards
• CPC Class Codes: A61M 2205/8206 battery-operated
• CPC Class Codes: A61M 5/14276 specially adapted for implantation
• CPC Class Codes: A61M 5/172 electrical or electronic A61M5/16804, A61M5/16831 take precedence
• CPC Class Codes: A61M 5/44 having means for cooling or heating the devices or media
• CPC Class Codes: A61N 1/3787 from an external energy source
• CPC Class Codes: A61N 2005/007 for cooling the patient
• CPC Class Codes: A61N 2005/0632 Constructional aspects of the apparatus
• CPC Class Codes: A61N 5/0601 Apparatus for use inside the body
• CPC Class Codes: A61N 5/0622 Optical stimulation for exciting neural tissue

Abstract

Devices, systems, and techniques are configured for cooling tissue during recharge of an implantable medical device (IMD) battery. In one example, a method includes charging, by an inductive charger, a rechargeable battery of an implantable medical device (IMD) within a patient, wherein the IMD comprises a housing that houses the rechargeable battery, and wherein a primary coil of the inductive charger is positioned above a region of skin of the patient proximate to the IMD. The example method further includes cooling, by a heat exchanger, the region of skin below a normal ambient surface temperature of the region of skin, wherein the heat exchanger is interposed between the primary coil and the region of skin.

Claims

1. A method comprising:

charging, by an inductive charger, a rechargeable battery of an implantable medical device (IMD) within a patient, wherein the IMD comprises a housing that houses the rechargeable battery, and wherein a primary coil of the inductive charger is positioned above a region of skin of the patient proximate to the IMD; and

cooling, by a heat exchanger, the region of skin to a temperature selected from a range of 5 degrees Celsius to 25 degrees Celsius, wherein an element of the heat exchanger is interposed between the primary coil and the region of skin.

2. The method of claim 1, further comprising measuring, by one or more processors, at least one first temperature of the IMD within the patient, and wherein cooling the region of skin to the temperature selected from the range of 5 degrees Celsius to 25 degrees Celsius comprises cooling the region of skin to the temperature selected from the range of 5 degrees Celsius to 25 degrees Celsius such that the at least one first temperature does not exceed a predetermined temperature.

3. The method of claim 2, wherein the predetermined temperature is selected from a range of 34 degrees Celsius to 39 degrees Celsius.

4. The method of claim 3, wherein the predetermined temperature further comprises a predetermined temperature selected to accommodate a temperature sensitivity of a specific patient.

5. The method of claim 2, wherein:

the housing of the IMD comprises a first surface proximate to the element of the heat exchanger and a second surface distal to the element of the heat exchanger; and

measuring the at least one first temperature of the IMD within the patient comprises measuring a temperature of the second surface of the IMD distal to the element of the heat exchanger.

6. The method of claim 2, wherein measuring the at least one first temperature of the IMD within the patient comprises measuring one temperature of a plurality of temperatures selected from a group comprising:

an external surface temperature of the region of skin;

a temperature of the housing of the IMD;

a temperature of the battery of the IMD; and

a temperature of an internal surgical pocket of tissue of the patient enveloping the IMD.

7. The method of claim 2, wherein measuring the at least one first temperature of the IMD within the patient comprises measuring each temperature of a plurality of temperatures of a group comprising:

an external surface temperature of the region of skin;

a temperature of the housing of the IMD;

a temperature of the battery of the IMD; and

a temperature of an internal surgical pocket of tissue of the patient enveloping the IMD.

8. The method of claim 7, wherein cooling the region of skin to the temperature selected from the range of 5 degrees Celsius to 25 degrees Celsius such that the at least one first temperature does not exceed the predetermined temperature comprises cooling the region of skin to the temperature selected from the range of 5 degrees Celsius to 25 degrees Celsius such that each measured temperature of the plurality of measured temperatures of the group does not exceed the predetermined temperature.

9. The method of claim 7, wherein cooling the region of skin to the temperature selected from the range of 5 degrees Celsius to 25 degrees Celsius such that the at least one first temperature does not exceed the predetermined temperature comprises cooling the region of skin to the temperature selected from the range of 5 degrees Celsius to 25 degrees Celsius such that at least one measured temperature of the plurality of measured temperatures of the group does not exceed the predetermined temperature.

10. The method of claim 1, wherein cooling the region of skin to the temperature selected from the range of 5 degrees Celsius to 25 degrees Celsius comprises cooling the region of skin to a temperature selected from a range of 15 degrees Celsius to 25 degrees Celsius.

11. The method of claim 10, wherein the temperature selected from a range of 15 degrees Celsius to 25 degrees Celsius comprises a temperature selected to accommodate a temperature sensitivity of a specific patient.

12. The method of claim 1, wherein cooling, by the heat exchanger, the region of skin comprises circulating, by the heat exchanger, a coolant through a heat sink chamber in contact with the region of skin.

13. The method of claim 12, wherein the heat sink chamber comprises a magnetically permeable polymer.

14. The method of claim 12, wherein the coolant is a fluid that comprises at least one of water or propylene glycol.

15. The method of claim 1, wherein the element of the heat exchanger is affixed to a housing of the primary coil.

16. A system comprising:

an implantable medical device (IMD) implantable within a surgical pocket of a patient, comprising;

a housing; and

a rechargeable battery within the housing;

an inductive charger configured to charge the rechargeable battery of the IMD, wherein the inductive charger comprises a primary coil configured to be positioned above a region of skin of the patient proximate to the IMD;

an element of a heat exchanger configured to be interposed between the primary coil and the region of skin; and

one or more processors configured to control the heat exchanger to cool the region of skin to a temperature selected from a range of 5 degrees Celsius to 25 degrees Celsius.

17. The system of claim 16, wherein the one or more processors are further configured to:

measure at least one first temperature of the IMD within the patient, and

control the heat exchanger to cool the region of skin to the temperature selected from the range of 5 degrees Celsius to 25 degrees Celsius such that the at least one first temperature does not exceed a predetermined temperature.

18. The system of claim 17, wherein the predetermined temperature is selected from a range of 34 degrees Celsius to 39 degrees Celsius.

19. The system of claim 18, wherein the predetermined temperature further comprises a predetermined temperature selected to accommodate a temperature sensitivity of a specific patient.

20. The system of claim 17, wherein:

the housing of the IMD comprises a first surface proximate to the element of the heat exchanger and a second surface distal to the heat exchanger; and

the one or more processors configured to measure the at least one first temperature of the IMD within the patient are further configured to measure a temperature of the second surface of the IMD distal to the element of the heat exchanger.

21. The system of claim 17, wherein the one or more processors configured to measure the at least one first temperature of the IMD within the patient are further configured to measure one temperature of a plurality of temperatures selected from a group comprising:

an external surface temperature of the region of skin;

a temperature of the housing of the IMD;

a temperature of the battery of the IMD; and

a temperature of an internal surgical pocket of tissue of the patient enveloping the IMD.

22. The system of claim 17, wherein the one or more processors configured to measure the at least one first temperature of the IMD within the patient are further configured to measure each temperature of a plurality of temperatures selected from a group comprising:

an external surface temperature of the region of skin;

a temperature of the housing of the IMD;

a temperature of the battery of the IMD; and

a temperature of an internal surgical pocket of tissue of the patient enveloping the IMD.

23. The system of claim 22, wherein the one or more processors configured to control the heat exchanger to cool the region of skin to the temperature selected from the range of 5 degrees Celsius to 25 degrees Celsius such that the at least one first temperature does not exceed the predetermined temperature are further configured to control the heat exchanger to cool the region of skin to the temperature selected from the range of 5 degrees Celsius to 25 degrees Celsius such that each measured temperature of the plurality of measured temperatures of the group does not exceed the predetermined temperature.

24. The system of claim 16, wherein the one or more processors configured to control the heat exchanger to cool the region of skin to the temperature selected from the range of 5 degrees Celsius to 25 degrees Celsius are further configured to control the heat exchanger to cool the region of skin to a temperature selected from a range of 15 degrees Celsius to 25 degrees Celsius.

25. The system of claim 24, wherein the temperature selected from a range of 15 degrees Celsius to 25 degrees Celsius comprises a temperature selected to accommodate a temperature sensitivity of a specific patient.

26. The system of claim 16, wherein the one or more processors configured to control the heat exchanger to cool the region of skin are further configured to control the heat exchanger to circulate a coolant through a heat sink chamber in contact with the region of skin.

27. The system of claim 26, wherein the heat sink chamber comprises a magnetically permeable polymer.

28. The system of claim 26, wherein the coolant is a fluid that comprises at least one of water or propylene glycol.

29. The system of claim 16, wherein the element of the heat exchanger is affixed to a housing of the primary coil.

30. A system comprising:

an implantable medical device (IMD) implantable within a surgical pocket of a patient, comprising;

a housing; and

a rechargeable battery within the housing;

means for charging the rechargeable battery of the IMD, wherein the means for charging the rechargeable battery of the IMD is configured to be positioned above a region of skin of the patient proximate to the IMD;

means for cooling skin between the means for charging and the IMD; and

one or more processors configured to control the means for cooling the skin to cool the skin between the means for charging and the IMD to a temperature selected from a range of 5 degrees Celsius to 25 degrees Celsius.

31. The system of claim 30, wherein the one or more processors are further configured to:

measure at least one first temperature of the IMD within the patient, and

control the means for cooling skin to cool the skin between the means for charging and the IMD to the temperature selected from the range of 5 degrees Celsius to 25 degrees Celsius such that the at least one first temperature does not exceed a predetermined temperature.

32. The system of claim 30, wherein the one or more processors configured to control the means for cooling the skin to cool the skin between the means for charging and the IMD to the temperature selected from the range of 5 degrees Celsius to 25 degrees Celsius are further configured to control the means for cooling the skin to cool the skin between the means for charging and the IMD to a temperature selected from a range of 15 degrees Celsius to 25 degrees Celsius.