Heat management for recharge coils for implantable medical devices

• US 10,322,288 B2
• Filed: 10/28/2011
• Issued: 06/18/2019
• Est. Priority Date: 10/28/2011
• Status: Active Grant

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Kallmyer, Todd A., Kast, John E., Olson, David P., Roles, Randy S., Gaddam, Venkat R.
• Primary Examiner(s): Teitelbaum, David J
• Application Number:
  US13/284,804
• Publication Number:
  US 20130106347A1
• Time in Patent Office: 2,790 Days
• Field of Search: 62 56, 622593, 62530
• CPC Class Codes: A61N 1/36142 for improving safety
• CPC Class Codes: A61N 1/37211 Means for communicating with stimulators
• CPC Class Codes: A61N 1/3787 from an external energy source
• CPC Class Codes: H02J 2310/23 The load being a medical device, a medical implant, or a life supporting device
• CPC Class Codes: H02J 50/005 Mechanical details of housing or structure aiming to accommodate the power transfer means, e.g. mechanical integration of coils, antennas or transducers into emitting or receiving devices
• CPC Class Codes: H02J 50/10 using inductive coupling
• CPC Class Codes: H02J 50/90 involving detection or optimisation of position, e.g. alignment
• CPC Class Codes: H02J 7/00712 the cycle being controlled or terminated in response to electric parameters

Abstract

Devices, systems, and techniques for managing heat generated in coils for wireless energy transmission are disclosed. Inductive coupling between two coils may be used to recharge the power source of an implantable medical device. A phase change material may be thermally coupled to a flexible coil to absorb heat generated during the inductive coupling and reduce temperature increases of the flexible coil. The flexible coil may be configured to at least one of transmit energy to or receive energy from a second coil, and the phase change material may be configured to deform with the flexible coil and absorb heat from the flexible coil. The phase change material may be contained within thermally conductive tubes or channels configured in shapes that promote flexibility of the flexible coil.

Claims

1. A device comprising:

a flexible coil configured to at least one of transmit electrical energy to or receive electrical energy from a second coil via inductive coupling; and

a phase change material configured in one or more shapes that allow the phase change material in a solid state to deform with the flexible coil, wherein the phase change material is configured to absorb heat from the flexible coil.

2. The device of claim 1, further comprising a flexible housing configured to encase the flexible coil and the phase change material.

3. The device of claim 2, wherein the flexible coil is configured to conform to a non-planar skin surface, and wherein the flexible housing is configured to deform with the flexible coil.

4. The device of claim 2, wherein the flexible housing comprises one or more channels configured to contain the phase change material in the one or more shapes.

5. The device of claim 1, further comprising:

a containment structure comprising one or more channels configured to contain the phase change material in the one or more shapes; and

a film configured to be applied to a surface of the containment structure, retain the phase change material within the one or more channels, and contact the flexible coil.

6. The device of claim 1, further comprising one or more flexible tubes configured to contain the phase change material in the one or more shapes at predetermined locations with respect to the flexible coil, wherein the phase change material is disposed within the one or more flexible tubes.

7. The device of claim 6, wherein the one or more flexible tubes are constructed of a thermally conductive elastomer.

8. The device of claim 1, further comprising a woven material, wherein the phase change material is placed in contact with the woven material to retain the phase change material in thermal communication with the flexible coil.

9. The device of claim 1, wherein the phase change material is encapsulated in a plurality of beads distributed adjacent at least one surface of the flexible coil, the plurality of beads comprising the one or more shapes.

10. The device of claim 1, wherein the flexible coil comprises a wire wound as an in-plane spiral.

11. The device of claim 10, wherein the phase change material is disposed in a disk-shaped volume of a second plane adjacent to the in-plane spiral.

12. The device of claim 10, wherein the phase change material is disposed within the in-plane spiral as at least one phase change material spiral, the at least one phase change material spiral comprising at least one shape of the one or more shapes.

13. The device of claim 10, wherein the phase change material is disposed in a plurality of concentric rings in a second plane adjacent to the in-plane spiral, the plurality of concentric rings comprising at least some of the one or more shapes.

14. The device of claim 10, wherein the phase change material is disposed at least one of inside an inner diameter of the in-plane spiral or outside an outer diameter of the in-plane spiral.

15. The device of claim 10, wherein the phase change material is disposed in a zigzag pattern adjacent to the in-plane spiral and configured to promote curvature of the flexible coil in predetermined directions, the zigzag pattern comprising at least one of the one or more shapes.

16. The device of claim 1, wherein the phase change material is disposed on opposing sides of the flexible coil.

17. The device of claim 1, wherein the phase change material comprises a melting point temperature between approximately 35 degrees Celsius and 43 degrees Celsius.

18. The device of claim 1, wherein the flexible coil is coupled to a charging device configured to transcutaneously charge a rechargeable power source of an implantable medical device via inductive coupling between the flexible coil and the second coil, and wherein the implantable medical device comprises the second coil.

19. A device comprising:

a flexible coil configured to at least one of transmit electrical energy to or receive electrical energy from a second coil via inductive coupling; and

means for absorbing heat from the flexible coil, wherein the means for absorbing heat is configured in one or more shapes that allows the means for absorbing heat in a solid state to deform with the flexible coil.

20. The device of claim 19, further comprising means for encasing the flexible coil and the means for absorbing the heat from the flexible coil.

21. The device of claim 20, wherein the flexible coil is configured to conform to a non-planar skin surface, and wherein the means for encasing the flexible coil is configured to deform with the flexible coil.

22. The device of claim 20, further comprising means for containing the means for absorbing heat in the one or more shapes at predetermined locations with respect to the flexible coil.

23. The device of claim 19, wherein the containing means comprises one or more channels as the one or more shapes.

24. The device of claim 19, wherein the containing means comprises one or more flexible tubes that contain the means for absorbing heat in the one or more shapes, wherein the phase change material is disposed within the one or more flexible tubes.

25. The device of claim 19, further comprising means for encapsulating the means for absorbing heat at a plurality of isolated locations distributed adjacent to at least one surface of the flexible coil, the means for encapsulating the means for absorbing heat comprising the one or more shapes.

26. The device of claim 19, wherein the flexible coil comprises a wire wound as an in-plane spiral.

27. The device of claim 19, wherein the means for absorbing heat is disposed on opposing sides of the flexible coil.

28. The device of claim 19, wherein the means for absorbing heat comprises a melting point temperature between approximately 35 degrees Celsius and 43 degrees Celsius.

29. A system comprising:

an implantable medical device comprising a first coil;

a flexible coil configured to transmit electrical energy to the first coil of the implantable medical device via inductive coupling, wherein the flexible coil is configured to conform to a non-planar exterior skin surface;

a phase change material disposed in one or more shapes selected to allow the phase change material in a solid state to deform with the flexible coil when the phase change material is disposed at one or more positions adjacent to the flexible coil, wherein the phase change material is configured to absorb heat from the flexible coil; and

a flexible housing configured to encase the flexible coil and the phase change material.

30. The system of claim 29, wherein the flexible housing comprises one or more channels configured to contain the phase change material in the one or more shapes.

31. The system of claim 29, further comprising:

a containment structure comprising one or more channels configured to contain the phase change material in the one or more shapes; and

a film configured to be applied to a surface of the containment structure, retain the phase change material within the one or more channels, and contact the flexible coil.

32. The system of claim 29, further comprising one or more flexible tubes configured to contain the phase change material in the one or more shapes at the one or more positions, wherein the phase change material is disposed within the one or more flexible tubes.

33. The system of claim 29, wherein the phase change material is disposed on opposing sides of the flexible coil.

34. A method comprising:

transmitting electrical energy from a flexible primary coil associated with an external recharge device to a secondary coil of an implantable medical device; and

absorbing heat from the flexible primary coil via a phase change material configured in one or more shapes that allow the phase change material in a solid state to deform with the flexible primary coil.

35. A system comprising:

an implantable medical device comprising a first coil and a rechargeable power source; and

an external charging device comprising;

a flexible coil configured to transmit electrical energy to the first coil of the implantable medical device via inductive coupling; and

a phase change material configured in one or more shapes that allow the phase change material in a solid state to deform with the flexible coil, wherein the phase change material is configured to absorb heat from the flexible coil, wherein the external charging device is configured to transcutaneously charge the rechargeable power source of the implantable medical device via inductive coupling between the flexible coil and the first coil.