TEMPERATURE SENSOR FOR BODY TEMPERATURE MEASUREMENT

• US 20120024833A1
• Filed: 04/01/2010
• Published: 02/02/2012
• Est. Priority Date: 04/06/2009
• Status: Active Grant

• Current Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Klewer, Jasper, Cheung, Amy, Van Pieterson, Liesbeth, Bakkers, Erik
• Granted Patent: US 8,716,629 B2
• Time in Patent Office: Days
• US Class Current: 219/211
• CPC Class Codes: A41D 13/1281 with incorporated means for medical monitoring
• CPC Class Codes: A61B 5/0008 Temperature signals
• CPC Class Codes: A61B 5/01 Measuring temperature of body parts ; Diagnostic temperature sensing, e.g. for malignant or inflamed tissue clinical contact thermometers G01K13/20
• CPC Class Codes: A61B 5/6804 Garments; Clothes
• CPC Class Codes: G01K 1/14 Supports; Fastening devices; Arrangements for mounting thermometers in particular locations
• CPC Class Codes: G01K 1/16 Special arrangements for conducting heat from the object to the sensitive element
• CPC Class Codes: G01K 1/165 for application in zero heat flux sensors
• CPC Class Codes: G01K 13/20 Clinical contact thermometers for use with humans or animals
• CPC Class Codes: G01K 2217/00 Temperature measurement using electric or magnetic components already present in the system to be measured

Abstract

This invention relates to a temperature sensor for body temperature measurements. The temperature sensor is made of several layers, where a first layer has a central heater embedded therein, a second layer which is attached to the first layer has at least one first thermistor embedded therein for measuring a first temperature value, a third layer has at one ore second thermistor embedded therein separated from the first thermistor for measuring at least one second temperature value, but this third layer is adapted to be in contact to the skin of the surface of the body for conducting the heat escaping from the body through the layers. The difference between the first and the second temperature values indicates the heat flux from the body. The heat emitted from central heater is tuned oppositely to the heat flux until a zero heat flux is reached, where the temperature at the at least one second thermistor at zero heat flux indicates the body temperature. These layers are fabric layers.

Claims

1. A temperature sensor for body temperature measurements, comprising:

a first layer having a central heater embedded therein,

a second layer attached to the first layer having at least one first thermistor embedded therein for measuring a first temperature value,

at least one third layer having at least one second thermistor embedded therein separated from the first thermistor for measuring at least one second temperature value, the at least one third layer being adapted to be in contact to the skin of the surface of the body for conducting the heat escaping from the body through the layers, the difference between the first and the second temperature values indicating the heat flux from the body, where the heat emitted from central heater is tuned oppositely to the heat flux until a zero heat flux is reached, where the temperature at the at least one second thermistor at zero heat flux indicates the body temperature, wherein the first, second and at least the third layer are fabric layers.

2. A temperature sensor according to claim 1, wherein the layers are stitched or laminated together, interwoven, or combination thereof.

3. A temperature sensor according to claim 1, wherein the first and the second layers are made of the same fabric and form a single functional layer having the central heater and the at least one first thermistor embedded therein such that they are separated from each other.

4. A temperature sensor according to claim 1, wherein the central heater is stitched, or embroidered, or woven, or laminated into the first layer using conductive yarn.

5. A temperature sensor according to claim 1, wherein the dimension of the central heater is adapted to the depth of measurement such that the larger the depth is to be measured the larger becomes the dimension of the central heater.

6. A temperature sensor according to claim 1, wherein the central heater is printed onto the first layer using conductive ink or conductive paste.

7. A temperature sensor according to claim 1, wherein the central heater is made of a conductive material with a resistance between 5-150 ohm/meter.

8. A temperature sensor according to claim 1, wherein the thermistors are attached to a woven, stitched or knitted conductive circuit.

9. A temperature sensor according to claim 8, wherein the conductive circuit is made of conductive material having a resistance lower 20 ohm/meter.

10. A temperature sensor according to claim 1, wherein the fabric layers are made of woven or non-woven fabrics.

11. A temperature sensor according to claim 1, wherein the second and the at least the third layers are separated by a flexible heat insulating layer.

12. A temperature sensor according to claim 1, further comprising an insulating layer applied on top of the first layer.

13. A temperature sensor according to claim 1, further comprising a transmitter for transmitting the temperature measured at the at least one second thermistor at zero heat flux to an external monitoring device comprising a receiver.

14. A temperature sensor according to claim 1, wherein the temperature sensor is integrated into patch.

15. A temperature sensor according to claim 1, wherein the patch further comprises a processing unit for converting the output from the at least one second thermistor at zero heat flux into the measured body temperature, a battery, and an indicator means for indicating the measured body temperature.

16. A temperature sensor according to claim 1, further comprising a side thermistor (Tside) arranged at the periphery of the third layer and adapted to measure a third temperature value at the periphery of the third layer, where the difference between the second and the third temperature values indicates the horizontal heat flux within the third layer.

17. A temperature sensor according to claim 16, further comprising a side heater is arranged at the periphery of the third layer adapted to be tuned oppositely to the heat flux until a zero horizontal heat flux is reached in the third layer.

18. A temperature sensor according to claim 17, wherein the side heater is adapted to the geometrical shape of the third layer.

19. A garment comprising the temperature sensor as claimed in claim 1 integrated therein such that when the garment is placed onto the body or is being worn by the body the at least one third layer becomes in contact to the skin of the surface of the body.