Physiological monitoring devices and methods using optical sensors
A monitoring device configured to be attached to a subject includes a photoplethysmography (PPG) sensor configured to measure physiological information from the subject, a blood flow stimulator, and a processor configured to process signals from the PPG sensor to determine a signal-to-noise level of the signals. In response to a signal-to-noise level determination, the processor is configured to instruct the blood flow stimulator to increase blood perfusion at a location where the PPG sensor is attached to the subject. The signal-to-noise level determination may be a determination that the signal-to-noise level is below a threshold level. The blood flow stimulator may be a heating element or light source configured to heat the location of the subject.
1. A monitoring device configured to be attached to a subject, the monitoring device comprising:
a photoplethysmography (PPG) sensor configured to measure physiological information from the subject, the PPG sensor comprising at least one optical emitter and at least one optical detector;
a blood flow stimulator; and
at least one processor configured to process signals from the PPG sensor to determine a signal-to-noise level of the signals, and wherein, in response to a signal-to-noise level determination, the at least one processor is configured to instruct the blood flow stimulator to increase blood perfusion at a location where the PPG sensor is attached to the subject.
2. The monitoring device of claim 1 , wherein the signal-to-noise level determination is a determination that the signal-to-noise level is below a threshold level.
3. The monitoring device of claim 1 , wherein the blood flow stimulator comprises a heating element configured to heat the location of the subject.
4. The monitoring device of claim 1 , wherein the blood flow stimulator comprises a light source configured to heat the location of the subject.
5. The monitoring device of claim 4 , wherein the light source comprises at least one LED.
6. The monitoring device of claim 1 , wherein, subsequent to instructing the blood flow stimulator to increase blood perfusion, the at least one processor is configured to process further signals from the PPG sensor to determine a signal-to-noise level of the further signals, and wherein, if the signal-to-noise level of the further signals is at or above a threshold level, the at least one processor is configured to instruct the blood flow stimulator to stop increasing blood perfusion.
7. The monitoring device of claim 1 , wherein the monitoring device is configured to be positioned at or within an ear of the subject.
8. The monitoring device of claim 1 , wherein the monitoring device is configured to be secured to an appendage of the subject.
9. A method of monitoring a subject via a monitoring device attached to the subject, wherein the monitoring device comprises a photoplethysmography (PPG) sensor comprising at least one optical emitter and at least one optical detector, a blood flow stimulator, and at least one processor, the method comprising:
processing signals from the PPG sensor to determine a signal-to-noise level of the signals; and
instructing the blood flow stimulator to increase blood perfusion at a location where the PPG sensor is attached to the subject in response to the signal-to-noise level determination.
10. The method of claim 9 , wherein the signal-to-noise level determination is a determination that the signal-to-noise level is below a threshold level.
11. The method of claim 9 , wherein the blood flow stimulator comprises a heating element, and wherein instructing the blood flow stimulator to increase blood perfusion at the location comprises instructing the heating element to heat the location.
12. The method of claim 9 , wherein the blood flow stimulator comprises a light source, and wherein instructing the blood flow stimulator to increase blood perfusion at the location comprises instructing the light source to heat the location.
13. The method of claim 12 , wherein the light source comprises at least one LED.
14. The method of claim 9 , further comprising:
processing further signals from the PPG sensor to determine a signal-to-noise level of the further signals; and
instructing the blood flow stimulator to stop increasing blood perfusion when the signal-to-noise level of the further signals is at or above a threshold level.
15. The method of claim 9 , wherein the monitoring device is configured to be positioned at or within an ear of the subject.
16. The method of claim 9 , wherein the monitoring device is configured to be secured to an appendage of the subject.
17. A monitoring device configured to be attached to a subject, the monitoring device comprising:
a photoplethysmography (PPG) sensor configured to measure physiological information from the subject, the PPG sensor comprising at least one optical emitter and at least one optical detector;
a blood flow stimulator; and
at least one processor configured to process signals from the PPG sensor to determine a confidence score of the signals, and wherein, in response to a confidence score determination, the at least one processor is configured to instruct the blood flow stimulator to increase blood perfusion at a location where the PPG sensor is attached to the subject.
18. The monitoring device of claim 17 , wherein the confidence score is an indication of how strongly the signals can be trusted.
19. The monitoring device of claim 17 , wherein the confidence score of the signals comprises a signal-to-noise level of the signals.