Sensing temperature within medical devices

Patent metadata

Field	Value
Publication number	US-9653935-B2
Application number	US-201313783761-A
Country	US
Kind code	B2
Filing date	Mar 4, 2013
Priority date	Apr 20, 2012
Publication date	May 16, 2017
Grant date	May 16, 2017

Abstract

Devices, systems, and techniques for monitoring the temperature of a device used to charge a rechargeable power source are disclosed. Implantable medical devices may include a rechargeable power source that can be transcutaneously charged. The temperature of an external charging device and/or an implantable medical device may be monitored to control the temperature exposure to patient tissue. In one example, a temperature sensor may sense a temperature of a portion of a device, wherein the portion is non-thermally coupled to the temperature sensor. A processor may then control charging of the rechargeable power source based on the sensed temperature.

First claim

What is claimed is:

1. A method comprising:
sensing a temperature of a portion of a housing of a medical device by a temperature sensor disposed within the housing of the medical device; and
controlling charging of a rechargeable power source based on the sensed temperature;
wherein the temperature sensor is configured to sense the temperature of the portion of the housing without being thermally-coupled to the portion of the housing.

2. The method of claim 1 , wherein sensing the temperature comprises sensing a level of infrared radiation emitted from the portion of the housing of the medical device, and sensing the temperature based on the sensed level.

3. The method of claim 1 , wherein sensing the temperature comprises:
exciting a phosphor material disposed on the portion of the housing with electromagnetic radiation;
detecting a phase shift in a luminescence of the phosphor material in response to the excitation; and
determining the temperature of the portion of the housing based on the phase shift.

4. The method of claim 1 , wherein the temperature sensor is mounted to a printed circuit board within the housing of the medical device.

5. The method of claim 1 , wherein the temperature sensor is a first temperature sensor and the portion of the housing is a first portion of the housing, and wherein the method further comprises sensing, by a second temperature sensor, a temperature of a second portion of the housing of the device, and controlling charging of the rechargeable power source based on the sensed temperatures from the first and second temperature sensors.

6. The method of claim 5 , wherein:
the first portion of the housing comprises a first housing surface of the medical device;
the second portion of the housing comprises a second housing surface of the medical device; and
the first housing surface opposes the second housing surface.

7. The method of claim 5 , further comprising:
selecting to sense the temperature of the first portion of the housing with the first temperature sensor;
responsive to the selection, controlling a first shutter of the first temperature sensor to open; and
responsive to the selection, controlling a second shutter of the second temperature sensor to close.

8. The method of claim 1 , further comprising:
comparing the sensed temperature to a threshold temperature; and
determining when the sensed temperature exceeds the threshold temperature, wherein controlling charging of the rechargeable power source comprises adjusting a power level used to charge the rechargeable power source.

9. The method of claim 1 , further comprising:
calculating a temperature change rate from the sensed temperature when the rechargeable power source is charging;
determining when the temperature change rate increases subsequent to the temperature change rate decreasing during the charging; and
responsive to the determination, presenting a notification that instructs a user to replace a phase change material cartridge thermally coupled to the device.

10. The method of claim 1 , further comprising:
calculating a temperature change rate from the sensed temperature when the rechargeable power source is charging;
determining a temperature change rate; and
calibrating a sensor based on the determined temperature change rate.

11. The method of claim 1 , wherein the portion of the housing comprises a phase change material thermally coupled to at least one of the portion of the housing of the device and a coil that transfers energy to the rechargeable power source during charging.

12. The method of claim 1 , wherein:
the medical device comprises an external charging device and the at least one processor; and
the rechargeable power source is housed by an implantable medical device.

13. The method of claim 1 , wherein the medical device comprises an implantable medical device that houses the rechargeable power source.

14. The method of claim 1 , further comprising:
comparing the sensed temperature to a fault condition threshold; and
disconnecting the rechargeable power source from at least one electrical circuit when the sensed temperature exceeds the fault condition threshold.

15. The method of claim 1 , wherein the temperature sensor is not attached to the portion of the housing.

16. A system comprising:
a medical device comprising a housing;
a temperature sensor disposed within the housing and configured to sense a temperature of a portion of the housing of the medical device without being thermally coupled to the portion of the housing; and
at least one processor configured to control charging of a rechargeable power source based on the sensed temperature.

17. The system of claim 16 , wherein the temperature sensor is configured to sense a level of infrared radiation emitted from the portion of the housing of the medical device, and sense the temperature based on the sensed level.

18. The system of claim 16 , further comprising a phosphor material disposed on the portion of the housing, wherein:
the temperature sensor is configured to:
excite the phosphor material with electromagnetic radiation; and
detect a phase shift in a luminescence of the phosphor material in response to the excitation; and

the at least one processor is configured to determine the temperature of the portion of the housing based on the phase shift.

19. The system of claim 16 , further comprising a printed circuit board within the housing of the device, wherein the temperature sensor is mounted to the printed circuit board.

20. The system of claim 16 , wherein the temperature sensor is a first temperature sensor and the portion of the housing is a first portion of the housing, and wherein the system further comprises a second temperature sensor disposed within the housing and configured to sense a temperature of a second portion of the housing of the medical device, and the at least one processor is configured to control charging of the rechargeable power source based on the sensed temperatures from the first and second temperature sensors.

21. The system of claim 20 , wherein:
the first portion of the housing comprises a first surface of the housing;
the second portion of the housing comprises a second surface of the housing; and
the first surface opposes the second surface.

22. The system of claim 20 , wherein the at least one processor is configured to:
select the first temperature sensor to sense the temperature of the first portion of the housing instead of the second temperature sensor to sense the temperature of the second portion of the housing;
responsive to the selection, control a first shutter of the first temperature sensor to open; and
responsive to the selection, control a second shutter of the second temperature sensor to close.

23. The system of claim 16 , wherein the at least one processor is configured to:
compare the sensed temperature to a threshold temperature;
determine when the sensed temperature exceeds the threshold temperature; and
adjust a power level used to charge the rechargeable power source.

24. The system of claim 16 , wherein the at least one processor is configured to:
calculate a temperature change rate from the sensed temperature when the rechargeable power source is charging;
determine when the temperature change rate falls one of below or above a threshold during the charging; and
responsive to the determination, issue a notification that instruct

Assignees

• Medtronic Inc

Inventors

• Cong Peng
• Gaddam Venkat R
• Olson David P
• Scott Erik R
• Smith Todd V
• Perz Leroy L

Classifications

• H02J7/975

  in response to temperature · CPC title

• G01K11/20

  using thermoluminescent materials (G01K11/32 takes precedence) · CPC title

• G01J5/0887

  Integrating cavities mimicking black bodies, wherein the heat propagation between the black body and the measuring element does not occur within a solid; Use of bodies placed inside the fluid stream for measurement of the temperature of gases; Use of the reemission from a surface, e.g. reflective surface; Emissivity enhancement by multiple reflections · CPC title

• G01K11/006

  using measurement of the effect of a material on microwaves or longer electromagnetic waves, e.g. measuring temperature via microwaves emitted by the object (G01K17/003, G01J5/00 take precedence; measuring the effect of a material on X-, gamma- or particle radiation G01K11/30) · CPC title

• A61N1/3787 Primary

  from an external energy source · CPC title