Abstract: Methods, systems, and devices for adaptive sensors are described. A system may acquire physiological data from a user via multiple optical channels of a wearable device, where each optical channel includes a light-emitting component and a photodetector. The system may determine respective measurement quality metrics and respective power consumption metrics associated with each optical channel based on the physiological data. Additionally, the system may select one or more optical channels of the multiple optical channels of the wearable device based on a comparison of the respective measurement quality metrics and the respective power consumption metrics associated with each optical channel. The system may acquire additional physiological data using the one or more optical channels based on the selecting.

Abstract: Methods, systems, and devices for hardware noise filtering are described. A wearable device may emit light from a set of light emitting elements (e.g., light emitting diodes (LEDs)) based on a known input signal. The wearable device may measure an output signal at a set of photodetectors. The output signal may be generated by passing the light emitted from the set of light emitting elements into a material in contact with the wearable device. The wearable device may compare the known input signal to the output signal and may determine a hardware noise component of the output signal based on a known environmental noise component of the output signal and the comparison. The wearable device may store the hardware noise component for filtering hardware noise from sensor measurements.

Abstract: Methods, systems, and devices for wearable device are described. A wearable device may include a first light-emitting component positioned within an inner circumferential surface of the wearable device at a first radial position and a second light-emitting component positioned within the inner circumferential surface of the wearable device at a second radial position, where the first radial position and the second radial position define a segment of the inner circumferential surface between the first radial position and the second radial position. Additionally, the wearable device may include a photodetector configured to receive light emitted by the first light-emitting component and the second light-emitting component. In some cases, the photodetector may be positioned at a third radial position within the segment of the inner circumferential surface between the first radial position and the second radial position, where the third radial position is offset from a radial midpoint of the segment.