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 outer ferrite housing;
an inner titanium housing disposed within the outer ferrite housing;
a receiver coil supported by the outer ferrite housing;
a plurality of electronics disposed within the inner titanium housing and coupled to the receiver coil, the electronics configured to control wireless power transfer from an external power transmitter to the receiver coil;
a thermal medium disposed in the inner titanium housing, the thermal medium having a boiling point at a temperature greater than 38° C. but less than 45° C.; and
a pipe having a first end and a second end, the first end in flow communication with the thermal medium, the second end positioned at a location exterior to the outer ferrite housing, the pipe extending from the first end to the second end through the inner titanium housing and the outer ferrite housing, the pipe configured to carry a fluid or vapor generated by the thermal medium to the location exterior to the outer ferrite housing when the thermal medium surpasses its boiling point in response to heat generated in the outer ferrite housing.
2. The power receiver of claim 1 wherein the second end of the pipe is coupled to an implantable medical device.
3. The power receiver of claim 2 wherein the medical device comprises a blood pump.
4. The power receiver of claim 1 wherein heat from the fluid or vapor is rejected into a blood stream of a patient.
5. The power receiver of claim 1 wherein the vapor is allowed to condense at the location exterior to the outer ferrite housing to form droplets which can be pulled back towards the power receiver to absorb heat.
6. The power receiver of claim 1 wherein the pipe comprises a flexible tube.