Abstract: Methods, systems, and devices for optical signal measurement are described. A wearable electronic device may activate a first combination of optical sensors, the first combination of optical sensors including a set of transmitter sensors and a set of receiver sensors. In some cases, one or more optical sensor of the first combination of optical sensors may be positioned under a protrusion on an inner surface of the wearable electronic device. The device may measure, at the set of receiver sensors at a first time, one or more signals from the set of transmitter sensors, determine a signal quality metric associated with the one or more signals, and select a second combination of optical sensors for use at a second time based on the signal quality metric.

Abstract: Methods, systems, and devices for optical signal measurement are described. A wearable electronic device may activate a first combination of optical sensors, the first combination of optical sensors including a set of transmitter sensors and a set of receiver sensors. In some cases, one or more optical sensor of the first combination of optical sensors may be positioned under a protrusion on an inner surface of the wearable electronic device. The device may measure, at the set of receiver sensors at a first time, one or more signals from the set of transmitter sensors, determine a signal quality metric associated with the one or more signals, and select a second combination of optical sensors for use at a second time based on the signal quality metric.

Abstract: Disclosed is an apparatus for measuring photoplethysmogram. The apparatus includes a ring structure with at least one photon source and at least one photon detector positioned on an inner surface of the ring structure. The apparatus further includes a controller configured to measure a preliminary photoplethysmogram during a first time period by taking a first number of samples, determine a form factor from said preliminary photoplethysmogram, determine an inter beat interval from said preliminary photoplethysmogram, and use the form factor and the inter beat interval to determine a second number of samples to be taken during a second time period of measurement of the photoplethysmogram and the distribution of the samples to be taken in function of time.

Abstract: Methods, systems, and devices for optical signal measurement are described. A wearable electronic device may activate a first combination of optical sensors, the first combination of optical sensors including a set of transmitter sensors and a set of receiver sensors. In some cases, one or more optical sensor of the first combination of optical sensors may be positioned under a protrusion on an inner surface of the wearable electronic device. The device may measure, at the set of receiver sensors at a first time, one or more signals from the set of transmitter sensors, determine a signal quality metric associated with the one or more signals, and select a second combination of optical sensors for use at a second time based on the signal quality metric.

Abstract: Disclosed is an apparatus for measuring photoplethysmogram. The apparatus includes a ring structure with at least one photon source and at least one photon detector positioned on an inner surface of the ring structure. The apparatus further includes a controller configured to measure a preliminary photoplethysmogram during a first time period by taking a first number of samples, determine a form factor from said preliminary photoplethysmogram, determine an inter beat interval from said preliminary photoplethysmogram, and use the form factor and the inter beat interval to determine a second number of samples to be taken during a second time period of measurement of the photoplethysmogram and the distribution of the samples to be taken in function of time.

Abstract: An apparatus for measuring photoplethysmogram includes a ring structure with at least one photon source and at least one photon detector positioned on an inner surface of the ring structure. The apparatus further includes a controller configured to measure a preliminary photoplethysmogram during a first time period by taking a first number of samples, determine a form factor from the preliminary photoplethysmogram, determine an inter beat interval from the preliminary photoplethysmogram, and use the form factor and the inter beat interval to determine a second number of samples to be taken during a second time period of measurement of the photoplethysmogram and the distribution of the samples to be taken in function of time.

Abstract: A method for measuring stress based on the heart rate (HR), the heart rate variability (HRV), and the activity level of a user includes recording the HR, the HRV, and the activity level of a user at various times during the day. Thereafter, the three values are correlated to arrive at a stress level of the user. The stress level is estimated based on a predetermined set of algorithms and analysis methods. The physical disposition and the activity levels of the user are automatically detected and the vital parameters, i.e., the HR and the HRV recorded at times that are deemed fit for conducting orthostatic tests.

Abstract: Disclosed is an apparatus for measuring photoplethysmogram. The apparatus includes a ring structure with at least one photon source and at least one photon detector positioned on an inner surface of the ring structure. The apparatus further includes a controller configured to measure a preliminary photoplethysmogram during a first time period by taking a first number of samples, determine a form factor from said preliminary photoplethysmogram, determine an inter beat interval from said preliminary photoplethysmogram, and use the form factor and the inter beat interval to determine a second number of samples to be taken during a second time period of measurement of the photoplethysmogram and the distribution of the samples to be taken in function of time.

Abstract: A method for measuring stress based on the heart rate (HR), the heart rate variability (HRV), and the activity level of a user includes recording the HR, the HRV, and the activity level of a user at various times during the day. Thereafter, the three values are correlated to arrive at a stress level of the user. The stress level is estimated based on a predetermined set of algorithms and analysis methods. The physical disposition and the activity levels of the user are automatically detected and the vital parameters, i.e., the HR and the HRV recorded at times that are deemed fit for conducting orthostatic tests.