Abstract: Systems and devices for a conformable wearable device are described. The wearable device may include a sensor module comprising one or more sensors configured to acquire physiological data from a user. In some cases, the wearable device may include a deformable material coupled with the sensor module and configured to transition between a planar orientation in an unworn state and a non-planar orientation in a worn state and a flexible material that at least partially encases the sensor module and the deformable material. The deformable material may be configured to at least partially conform to a body part of the user to bring the sensor module into contact with the body part of the user when the deformable material is in the worn state. In some cases, the deformable material is further configured to retain the non-planar orientation after being conformed to the body part of the user.

Abstract: Methods, systems, and devices for adjusting a power output level of a light source on a wearable device are described. A photodetector on the wearable device may measure a first photoplethysmography (PPG) signal derived from an ambient light source that is powered externally to the wearable device. The wearable device may calculate a quality metric of the first PPG signal based on measuring the first PPG signal. The wearable device may adjust the power output level of the light source powered by the wearable device based on the quality metric of the first PPG signal.

Abstract: Methods, systems, and devices for contact detection for a wearable device are described. The system may measure, by the one or more optical components, a photoplethysmogram (PPG) signal for a user of the wearable device and detect a change in the PPG signal or a change in morphology between cardiac pulse waveforms that are based on the PPG signal and reference cardiac pulse waveforms. In some cases, the system may determine, based on the change in the PPG signal or the change in morphology coinciding with a change in a metric measured by the wearable device, that the change in the PPG signal or the change in morphology is based on a change in contact between the wearable device and the skin of the user of the wearable device. The system may output the PPG signal and an indication of the change in contact.

Abstract: Methods, systems, and devices for analyzing fluid using a wearable device are described. The method may include collecting a bodily fluid of a user using a fluid collection component that includes one or more measurement channels configured to change color when exposed to the bodily fluid. Further, the method may include transmitting light associated with one or more wavelengths and generating one or more signals based on the light reflected off the one or more measurement channels of the fluid collection component and received by a wearable device. Moreover, the method may include determining a color of the one or more measurement channels based on the one or more signals and determining a presence or concentration of one or more substances within the bodily fluid based on the color.

Abstract: Methods, systems, and devices for measurement multiplexing for a wearable device are described. The method may include transmitting light using a light-emitting component of a wearable device via a set of transmission angles and receiving the light using a photodetector of the wearable device via a set of reception angles. Further, the method may include selecting a transmission angle from the set of transmission angles and a reception angle from the set of reception angles based on a comparison of a set of signal quality metrics associated with the set of transmission angles and the set of reception angles. The method may further include acquiring physiological data associated with the user using the transmission angle and the reception angle.

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.

Abstract: Methods, systems, and devices for wearing detection are described. A method may include directing light from a first light emitting element to a first light detecting element via an optical interface, at least one of the first light emitting element or the first light detecting element dedicated to detecting a level of surface contact at the optical interface. The method may include measuring, via the first light detecting element, an amount of escaped light which escaped the optical interface, where the amount of escaped light is indicative of the level of surface contact. The method may further include controlling an activation of a second light emitting element and a second light detecting element based on the level of surface contact, at least one of the second light emitting element or the second light detecting element dedicated to measuring a physiological phenomenon at a user of the wearable device.