MEDICAL SENSOR WITH TEMPERATURE CONTROL

• US 20120248985A1
• Filed: 03/31/2011
• Published: 10/04/2012
• Est. Priority Date: 03/31/2011
• Status: Active Grant

• Current Assignee: Covidien LP (Medtronic Plc)
• Original Assignee: Nellcor Puritan Bennett LLC (Medtronic Plc)
• Inventors: Lin, Andy S., Li, Youzhi, Chen, Bo, Lisogurski, Daniel, Schlottau, Friso
• Granted Patent: US 9,282,924 B2
• Time in Patent Office: Days
• US Class Current: 315/117
• CPC Class Codes: A61B 2560/0252 using ambient temperature
• CPC Class Codes: A61B 2560/0266 for monitoring or limiting apparatus function
• CPC Class Codes: A61B 5/14551 for measuring blood gases
• CPC Class Codes: A61B 5/6826 Finger

Abstract

Embodiments of the present disclosure relate to techniques for controlling the temperature of light sources within physiological sensors in order to regulate the wavelengths emitted by the light sources. The sensors may include a temperature control element that is designed to provide heating and/or cooling to the light sources. The sensors also may include a temperature sensor designed to detect the temperature of the light sources. Based on the detected temperature, a controller can vary the amount of heating and/or cooling provided by the temperature control element to maintain the temperature of the light sources at a desired temperature or within a desired temperature range.

Claims

1. A physiological sensor comprising:

one or more light sources capable of emitting wavelengths of light;

a detector configured to detect light at the emitted wavelengths; and

a temperature control element configured to provide cooling or heating, or a combination thereof, to the one or more light sources to regulate the wavelengths of light emitted by the one or more light sources.

2. The sensor of claim 1, wherein the one or more light sources comprises a red light emitting diode and an infrared light emitting diode.

3. The sensor of claim 1, further comprising a temperature sensor configured to detect a temperature of the one or more light sources.

4. The sensor of claim 3, wherein the one or more light sources are mounted on a substrate coupled to the temperature control element.

5. The sensor of claim 1, wherein the temperature control element comprises a thermoelectric cooler.

6. The sensor of claim 1, wherein the temperature control element comprises a resistive heater.

7. The sensor of claim 1, wherein the temperature control element comprises a thermoelectric element switchable between a cooling mode and a heating mode.

8. The sensor of claim 1, comprising an encoder configured to store peak wavelength data for the one or more light sources.

9. A system comprising:

one or more light sources capable of emitting wavelengths of light corresponding to physiological parameters of a patient;

a thermoelectric element configured to provide cooling or heating, or a combination thereof, to the one or more light sources to regulate the wavelengths of light emitted by the one or more light sources; and

a controller configured to adjust an amount of cooling or heating, or a combination thereof, provided by the thermoelectric element to maintain the one or more light sources at a target temperature.

10. The system of claim 9, wherein the controller is configured to set the target temperature at a temperature that enables the one or more light sources to emit wavelengths of light corresponding to an isosbestic point.

11. The system of claim 9, further comprising a temperature sensor configured to detect a temperature of the one or more light sources, wherein the controller is configured to switch the thermoelectric element between a heating mode and a cooling mode based on the detected temperature.

12. The system of claim 11, wherein the controller is disposed within a physiological sensor comprising the one or more light sources, the temperature sensor, and the thermoelectric element.

13. The system of claim 9, comprising a patient monitor configured to receive a signal generated based on the emitted wavelengths and to calculate the physiological parameters, wherein the controller is disposed within the patient monitor.

14. The system of claim 9, wherein the target temperature comprises a temperature range.

15. A method comprising:

determining a temperature adjustment for aligning a temperature of one or more light sources configured to emit wavelengths of light with a target temperature; and

adjusting operation of a temperature control element that provides cooling or heating, or a combination thereof to the one or more light sources to achieve the target temperature.

16. The method of claim 15, wherein determining a temperature adjustment comprises comparing a detected temperature of the light sources to the target temperature.

17. The method of claim 15, wherein adjusting operation of a temperature control element comprises adjusting a level of power provided to the temperature control element.

18. The method of claim 15, wherein adjusting operation of a temperature control element comprises switching a direction of current flowing through a thermoelectric element.

19. The method of claim 15, comprising setting the target temperature by comparing a peak wavelength of the one or more light sources to a calibration wavelength, determining a temperature that enables the one or more light sources to emit the calibration wavelength, and setting the determined temperature as the target temperature.

20. The method of claim 15, comprising setting the target temperature by comparing an emitted wavelength of the one or more light sources that corresponds to a first physiological parameter to an adjusted wavelength for obtaining a second physiological parameter different from the first physiological parameter, determining a temperature that enables the one or more light sources to emit the adjusted wavelength, and setting the determined temperature as the target temperature.