Temperature regulated implant

• US 7,751,897 B2
• Filed: 08/04/2004
• Issued: 07/06/2010
• Est. Priority Date: 08/04/2003
• Status: Expired due to Fees

• Current Assignee: Cochlear Limited
• Original Assignee: Cochlear Limited
• Inventors: Single, Peter
• Primary Examiner(s): Getzow; Scott M
• Application Number:
  US10/910,589
• Publication Number:
  US 20050033382A1
• Time in Patent Office: 2,162 Days
• Field of Search: 607 55- 57, 607/63
• US Class Current: 607/57
• CPC Class Codes: A61N 1/36038 Cochlear stimulation
• CPC Class Codes: A61N 1/375 Constructional arrangements, e.g. casings

Abstract

One disclosed embodiment of the present invention is a medical device having an electronic assembly and battery contained within a housing. Sealed in the housing is a heat absorption medium for regulating the temperature of the medial device, wherein said heat absorption medium undergoes a state change at a state change temperature of 36° Celsius or greater.

Claims

1. An implantable medical device comprising:

a biocompatible housing comprising at least one fluidically sealing and thermally conductive divider integrally formed therein, said divider configured to divide the inside of said housing into two or more substantially fluidically sealed and thermally conductive compartments;

an electronic assembly for processing sound into stimulation signals mounted in said housing;

a power source mounted in a first of said fluidically sealed and thermally conductive compartments; and

a heat absorption medium, sealed within a second of said fluidically sealed and thermally conductive compartments, thermally coupled to said power source, wherein said divider is configured to allow absorption of heat from said power source through said divider during a state change of said heat absorption medium.

2. The implantable medical device of claim 1, wherein said electronic assembly comprises a speech processor.

3. The implantable medical device of claim 1, wherein said heat absorption medium is configured to undergo state change at a temperature of approximately 34°

Celsius or greater.

4. The implantable medical device of claim 1, wherein said maximum device temperature threshold is equal to or less than approximately 37°

Celsius.

5. The implantable medical device of claim 1, wherein said heat absorption medium is configured to undergo said state change at a temperature between approximately 36°

Celsius and approximately 43°

Celsius.

6. The implantable medical device of claim 1, wherein said heat absorption medium is configured to undergo said state change at a temperature between approximately 39°

Celsius and approximately 41°

Celsius.

7. The implantable medical device of claim 1, wherein said heat absorption medium is configured to absorb at least 480 Joules of energy during said state change.

8. The implantable medical device of claim 1, wherein said heat absorption medium is configured to absorb at least 470 Joules of energy during said state change.

9. The implantable medical device of claim 1, wherein a state change temperature for said heat absorption medium is approximately equal to said maximum device threshold temperature.

10. The implantable medical device of claim 1, wherein said heat absorption medium comprises n-heneicosane.

11. The implantable medical device of claim 1, wherein said heat absorption medium is electrically non-conductive.

12. The implantable medical device of claim 1, wherein said power source comprises at least two batteries.

13. The implantable medical device of claim 1, wherein said implantable medical device is a tissue stimulating device.

14. The implantable medical device of claim 13, wherein said implantable medical device is a prosthetic hearing device.

15. The implantable medical device of claim 14, wherein said prosthetic hearing device is configured to be totally implantable.

16. The implantable medical device of claim 1, wherein said housing is hermetically sealed.

17. The implantable medical device of claim 1, wherein said device is adapted to be at least partially implanted in a recipient.

18. The implantable medical device of claim 1, wherein said device is adapted to be entirely implanted in a recipient.

19. The implantable medical device of claim 1, wherein said power source comprises a rechargeable battery.

38. The implantable medical device of claim 1, wherein said biocompatible housing is configured so that said thermally conductive compartment is in direct contact with an exterior surface of said power source.

39. The implantable medical device of claim 1, wherein said biocompatible housing further comprises:

a conductor configured to thermally conductively couple said power source to said thermally conductive compartment.

42. The implantable medical device of claim 1, wherein said state change is from a substantially solid state to a substantially liquid state.

44. The implantable medical device of claim 1, wherein said heat absorption medium is configured to undergo said state change to prevent said electronic assembly from exceeding a maximum device temperature threshold.

20. A device comprising:

a housing;

a heat generating electronic assembly for processing sound into stimulation signals contained at least partially disposed within said housing;

a heat absorption capsule disposed within said housing, wherein the exterior of said heat absorption capsule is constructed of a fluidically sealing and thermally conductive capsule exterior material; and

a heat absorption medium sealed entirely within said capsule, wherein said heat absorption medium is separated from said electronic assembly by said fluidically sealing and thermally conductive capsule exterior material, and further wherein said heat absorption medium is configured to absorb heat from a power source through said fluidically sealing and thermally conductive capsule exterior to undergo a state change.

21. The device of claim 20, wherein said device further comprises:

a power source mounted in said housing.

22. The device of claim 21, wherein said power source comprises at least two batteries.

23. The device of claim 20, wherein said device is a medical implant.

24. The device of claim 23, wherein said medical implant is a tissue stimulating device.

25. The device of claim 24, wherein said medical implant is a prosthetic hearing device.

26. The device of claim 25, wherein said prosthetic hearing device is configured to be totally implantable.

27. The device of claim 20, wherein said heat absorption medium is configured to undergo a state change at a temperature of between approximately 36°

and 43°

Celsius.

28. The device of claim 20, wherein said absorption medium is configured to undergo a state change at a temperature of between approximately 39°

and 41°

Celsius.

29. The device of claim 20, wherein said heat absorption medium is configured to absorb at least 480 Joules before the temperature of said housing can reach said state change temperature.

30. The device of claim 20, wherein said heat absorption medium is configured to absorb at least 470 Joules before the temperature of said housing can reach said state change temperature.

31. The device of claim 20, wherein said heat absorption medium is electrically non-conductive and chemically inert.

32. The device of claim 20, wherein said heat absorption medium comprises n-heneicosane.

33. The device of claim 20, wherein said housing is biocompatible.

34. The device of claim 20, wherein said housing is a hermetically sealed titanium housing.

35. The device of claim 20, wherein said device is configured to be a totally implantable medical implant.

36. The device of claim 20, wherein said device is adapted to be at least partially implanted in an individual.

37. The device of claim 20, wherein said device is adapted to be entirely implanted in a recipient.

40. The implantable medical device of claim 20, wherein said biocompatible housing is configured so that said thermally conductive capsule exterior of said heat absorption capsule is in direct contact with an exterior surface of said heat generating electronic assembly.

41. The implantable medical device of claim 20, wherein said biocompatible housing further comprises:

a conductor configured to thermally conductively couple said heat generating electronic assembly to said thermally conductive capsule exterior of said heat absorption capsule.

43. The implantable medical device of claim 20, wherein said state change is from a substantially solid state to a substantially liquid state.

45. The implantable medical device of claim 20, wherein said heat absorption medium is configured to undergo said state change to prevent said electronic assembly from exceeding a maximum device temperature threshold.