Thermal management for implantable wireless power transfer systems
Thermal management solutions for wireless power transfer systems are provided, which may include any number of features. In one embodiment, an implantable wireless power receiver includes at least one thermal layer disposed on an interior surface of the receiver configured to conduct heat from a central portion of the receiver towards edges of the receiver. The thermal layer can comprise, for example, a copper layer or a ceramic layer embedded in an acrylic polymer matrix. In some embodiments, a plurality of thermal channels can be formed within the receiver to transport heat from central regions of the receiver towards edges of the receiver via free convection. In yet another embodiment, a fluid pipe can be connected to the receiver and be configured to carry heat from the receiver to a location remote from the receiver. Methods of use are also provided.
1. A power receiver of a wireless power transfer system, comprising:
an implantable housing;
a receiver coil supported by the implantable housing;
electronics disposed within the implantable housing and coupled to the receiver coil, the electronics configured to control wireless power transfer from an external power transmitter to the receiver coil; and
only one insulating layer disposed on an interior surface of the implantable housing and comprising a thermal layer formed of a first material and a central portion formed of a second material, the thermal layer and central portion being positioned in the same plane, the only one insulating layer configured to dissipate heat generated by the electronics and distribute the heat across the only one insulating layer.
2. The power receiver of claim 1 , wherein the thermal layer comprises a copper layer.
3. The power receiver of claim 1 wherein the only one insulating layer comprises a thickness of less than 0.5 mm copper.
4. The power receiver of claim 1 wherein the only one insulating layer comprises a thickness of less than 1 mm aluminum.
5. The power receiver of claim 1 wherein the central portion of the only one insulating layer comprises a silicon rubber material.
6. The power receiver of claim 1 wherein the thermal layer comprises a copper layer and the central portion comprises a silicon rubber material.
7. The power receiver of claim 1 , wherein the only one insulating layer comprises a ceramic layer embedded in an acrylic polymer matrix.
8. The power receiver of claim 1 , wherein the only one insulating layer has a thickness of less than 0.5 mm.
9. The power receiver of claim 1 further comprising an interior layer positioned adjacent to the only one insulating layer.
10. The power receiver of claim 1 further comprising an inner housing disposed within the implantable housing.
11. The power receiver of claim 10 wherein the second material forming the central portion has a higher thermal conductivity along an axis connecting the central portion to the thermal layer than along an axis connecting the central portion to the inner housing, to promote heat spreading toward one or more edges of the implantable housing.
12. The power receiver of claim 1 wherein the second material has a lower thermal conductivity than the first material.
13. The power receiver of claim 1 wherein the first material has a different thermal conductivity than the second material such that the only one insulating layer can direct heat toward one or more edges of the implantable housing.
14. A method of reducing heat transferred to tissue by an implanted wireless power receiver, comprising the steps of:
implanting a wireless power receiver in a patient, the wireless power receiver comprising an implantable housing, a receiver coil supported by the implantable housing, and electronics disposed within the implantable housing and coupled to the receiver coil, the electronics configured to control wireless power transfer from an external power transmitter to the receiver;
receiving wireless power with the wireless power receiver; and
conducting heat generated by the electronics from a central portion of the wireless power receiver towards edges of the wireless power receiver with only one insulating layer disposed on an interior surface of the implantable housing and comprising a thermal layer formed of a first material and a central portion formed of a second material, the thermal layer and central portion being positioned in the same plane.
15. The method of claim 14 , wherein the thermal layer comprises at least one copper layer.
16. The method of claim 14 , wherein the only one insulating layer comprises a thickness of less than 0.5 mm copper.
17. The method of claim 14 , wherein the only one insulating layer comprises a thickness of less than 1 mm aluminum.
18. The method of claim 14 , wherein the central portion of the only one insulating layer comprises a silicon rubber material.
19. The method of claim 14 , wherein the thermal layer comprises a copper layer and the central portion comprises a silicon rubber material.
20. The method of claim 14 further comprising an interior layer positioned adjacent to the only one insulating layer.
21. The method of claim 14 further comprising an inner housing disposed within the wireless power receiver.
22. The method of claim 21 wherein the second material forming the central portion has a higher thermal conductivity along an axis connecting the central portion to the thermal layer than along an axis connecting the central portion to the inner housing, to promote heat spreading toward one or more edges of the wireless power receiver.
23. The method of claim 14 wherein the second material has a lower thermal conductivity than the first material.
24. The method of claim 14 wherein the first material has a different thermal conductivity than the second material such that the only one insulating layer can direct heat toward one or more edges of the wireless power receiver.
25. A power receiver of a wireless power transfer system, comprising:
an implantable housing;
a receiver coil supported by the implantable housing;
electronics disposed within the implantable housing and couple to the receiver coil, the electronics configured to control wireless power transfer from an external power transmitter to the receiver coil; and
only one insulating layer disposed on an interior surface of the implantable housing and comprising a thermal layer formed of a first material and a central portion formed of a second material, the thermal layer and central portion being positioned in the same plane, the only one insulating layer configured to dissipate heat generated by the electronics to promote heat spreading across the only one insulating layer.
26. The power receiver of claim 25 wherein the central portion of the only one insulating layer comprises a silicon rubber material.
27. The power receiver of claim 25 wherein the thermal layer comprises a copper layer and the central portion comprises a silicon rubber material.
28. The power receiver of claim 25 wherein the only one insulating layer comprises a ceramic layer embedded in an acrylic polymer matrix.
29. The power receiver of claim 25 further comprising an interior layer positioned adjacent to the only one insulating layer.
30. The power receiver of claim 25 further comprising an inner housing disposed within the implantable housing.
31. The power receiver of claim 30 wherein the second material forming the central portion has a higher thermal conductivity along an axis connecting the central portion to the thermal layer than along an axis connecting the central portion to the inner housing, to promote heat spreading toward one or more edges of the implantable housing.
32. The power receiver of claim 25 wherein the second material has a lower thermal conductivity than the first material.
33. The power receiver of claim 25 wherein the first material has a different thermal conductivity than the second material such that the only one insulating layer can direct heat toward one or more edges of the implantable housing.