Physiological monitoring devices and methods using optical sensors
A monitoring device configured to be attached to a subject includes a sensor configured to detect and/or measure physiological information and a processor coupled to the sensor. The sensor includes at least one optical emitter and at least one optical detector. The processor receives and analyzes signals produced by the sensor, and the processor changes wavelength of light emitted by the at least one optical emitter in response to detecting a change in subject activity. For example, the processor instructs the at least one optical emitter to emit shorter wavelength light in response to detecting an increase in subject activity, and the processor instructs the at least one optical emitter to emit longer wavelength light in response to detecting an decrease in subject activity. Detecting a change in subject activity may include detecting a change in at least one subject vital sign and/or subject motion.
1. A monitoring device configured to be attached to a subject, the monitoring device comprising:
a sensor configured to detect and/or measure physiological information from the subject, wherein the sensor comprises at least one optical emitter and at least one optical detector; and
a processor coupled to the sensor, wherein the processor is configured to receive and analyze signals produced by the sensor, and wherein the processor is configured to change a wavelength of light emitted by the at least one optical emitter in response to determining that the subject has changed locations.
2. The monitoring device of claim 1 , wherein determining that the subject has changed locations comprises determining that the subject has moved from indoors to outdoors.
3. The monitoring device of claim 2 , wherein the processor is configured to change the wavelength of light emitted by the at least one optical emitter from at least one visible wavelength to at least one infrared (IR) wavelength in response to determining that the subject has moved from indoors to outdoors.
4. The monitoring device of claim 2 , wherein the at least one optical emitter comprises at least one visible light emitter and at least one IR emitter, and wherein the processor is configured to change the wavelength of light emitted by the at least one optical emitter from at least one visible wavelength to at least one infrared (IR) wavelength by directing only the at least one IR emitter to emit IR light.
5. The monitoring device of claim 3 , wherein the processor is configured to monitor blood oxygenation or tissue oxygenation.
6. The monitoring device of claim 1 , wherein the sensor comprises a photoplethysmography (PPG) sensor.
7. The monitoring device of claim 2 , wherein the sensor comprises a PPG sensor, and wherein the processor is configured to receive and analyze signals produced by the PPG sensor to determine that the subject has moved from indoors to outdoors.
8. The monitoring device of claim 1 , wherein the monitoring device is configured to be positioned at or within an ear of the subject.
9. The monitoring device of claim 1 , wherein the monitoring device is configured to be secured to an appendage of the subject.
10. A monitoring device configured to be attached to a subject, the monitoring device comprising:
a photoplethysmography (PPG) sensor; and
at least one processor, wherein the at least one processor is configured to process PPG sensor signals and determine if the subject is located indoors or outdoors, and wherein the at least one processor is configured to select a PPG sensor polling routine utilizing different wavelengths associated with indoor or outdoor conditions depending on whether the subject is located indoors or outdoors, respectively.
11. The monitoring device of claim 10 , wherein, if the subject is located indoors, the PPG sensor polling routine is configured to direct the PPG sensor to utilize light with at least one visible wavelength and at least one infrared (IR) wavelength, and wherein, if the subject is located outdoors, the PPG sensor polling routine is configured to direct the PPG sensor to utilize light with at least two distinct IR wavelengths or two different IR wavelength bands.
12. The monitoring device of claim 11 , wherein the at least one processor is further configured to determine blood and/or tissue oxygenation of the subject via the PPG sensor.
13. The monitoring device of claim 10 , wherein the monitoring device is configured to be positioned at or within an ear of the subject.
14. The monitoring device of claim 10 , wherein the monitoring device is configured to be secured to an appendage of the subject.
15. A method of monitoring a subject wearing a sensor configured to detect and/or measure physiological information from the subject, the sensor comprising at least one optical emitter, at least one optical detector, and at least one processor, the method comprising the following performed by the at least one processor:
analyzing signals produced by the sensor to determine if the subject has changed locations; and
changing a wavelength of light emitted by the at least one optical emitter in response to determining that the subject has changed locations.
16. The method of claim 15 , wherein analyzing signals produced by the sensor to determine if the subject has changed locations comprises determining that the subject has moved from indoors to outdoors.
17. The method of claim 16 , comprising changing the wavelength of light emitted by the at least one optical emitter from at least one visible wavelength to at least one infrared (IR) wavelength in response to determining that the subject has moved from indoors to outdoors.
18. The method of claim 16 , wherein the at least one optical emitter comprises at least one visible light emitter and at least one IR emitter, and wherein the method comprises changing the wavelength of light emitted by the at least one optical emitter from at least one visible wavelength to at least one infrared (IR) wavelength by directing only the at least one IR emitter to emit IR light.
19. A method of monitoring a subject wearing a PPG sensor device having at least one processor, the method comprising:
processing PPG sensor signals via the at least one processor to determine if the subject is located indoors or outdoors; and
selecting a PPG sensor polling routine utilizing different wavelengths associated with indoor or outdoor conditions depending on whether the subject is located indoors or outdoors, respectively.
20. The method of claim 19 ,
wherein, if the subject is located indoors, the PPG sensor polling routine is configured to direct the PPG sensor to utilize light with at least one visible wavelength and at least one infrared (IR) wavelength; and
wherein, if the subject is located outdoors, the PPG sensor polling routine is configured to direct the PPG sensor to utilize light with at least two distinct IR wavelengths or two different IR wavelength bands.
21. The method of claim 20 , further comprising determining blood and/or tissue oxygenation of the subject via the PPG sensor.
22. The method of claim 19 , wherein the monitoring device is configured to be positioned at or within an ear of the subject.
23. The method of claim 19 , wherein the monitoring device is configured to be secured to an appendage of the subject.