Abstract: Estimation of a characteristic of a user's physiological signals can be improved using one or more calibration relationships that may be dependent on a characteristic of the optical sensor. For example, different calibration relationships can be used that are dependent on a spatial characteristic and/or that are dependent on a wavelength characteristic of the light emitting component(s) of the respective emitter of a channel. In some examples, a unique calibration relationship can be used for each channel. In some examples, a common calibration relationship can be used for multiple channels with shared distance and/or wavelength characteristics. Utilizing distance-dependent and/or wavelength-dependent calibration relationships can improve robustness of pulse oximetry measurements.

Abstract: Robust estimation of a characteristic of a user's physiological signals can be achieved by filtering or classifying samples. Rather than estimating the characteristic of the user's physiological signals based on each sample at a first wavelength and a second wavelength, a robust system and method can, in some examples, estimate the characteristic using samples at the first wavelength and the second wavelength that meet one or more criteria and filter out samples that fail to meet the one or more criteria. In some examples, the system and method can weight samples based on the one or more criteria, and estimate the characteristic using the weighted samples. Samples failing to meet the one or more criteria can be given less weight or no weight in the estimation. The one or more criteria can include a criterion based on at least the physiological signal at a third wavelength.

Abstract: A measurement engine of a wearable electronic device may compensate for wavelength variations of light emitted as part of blood-oxygen saturation measurements. In some cases, determining an estimated blood-oxygen saturation value is based at least partially on temperature data that may be used to compensate for temperature-based wavelength variations of the emitted light, drive current data that may be used to compensate for drive-current-based wavelength variations of the emitted light, and/or calibration information that may be used to compensate for manufacturing variability across different light emitters. In various embodiments, the measurement engine may use temperature data, the drive current data, and/or calibration information in a variety of ways to determine estimated blood-oxygen saturation values, including using lookup tables or calibration curves, applying functions, and the like.

Abstract: A wearable device is described. The wearable device includes a housing having a back cover, and an optical mask on first portions of the back cover. The back cover includes a set of windows, with a first subset of windows in the set of windows being defined by an absence of the optical mask on second portions of the back cover, and a second subset of windows in the set of windows being inset in a set of openings in the back cover. An optical barrier surrounds each window in the second subset of windows. A set of light emitters is configured to emit light through at least some of the windows in the set of windows. A set of light detectors is configured to receive light through at least some of the windows in the set of windows.

Abstract: Estimation of a characteristic of a user's physiological signals can be improved using one or more calibration relationships that may be dependent on a characteristic of the optical sensor. For example, different calibration relationships can be used that are dependent on a spatial characteristic and/or that are dependent on a wavelength characteristic of the light emitting component(s) of the respective emitter of a channel. In some examples, a unique calibration relationship can be used for each channel. In some examples, a common calibration relationship can be used for multiple channels with shared distance and/or wavelength characteristics. Utilizing distance-dependent and/or wavelength-dependent calibration relationships can improve robustness of pulse oximetry measurements.

Abstract: A measurement engine of a wearable electronic device may compensate for wavelength variations of light emitted as part of blood-oxygen saturation measurements. In some cases, determining an estimated blood-oxygen saturation value is based at least partially on temperature data that may be used to compensate for temperature-based wavelength variations of the emitted light, drive current data that may be used to compensate for drive-current-based wavelength variations of the emitted light, and/or calibration information that may be used to compensate for manufacturing variability across different light emitters. In various embodiments, the measurement engine may use temperature data, the drive current data, and/or calibration information in a variety of ways to determine estimated blood-oxygen saturation values, including using lookup tables or calibration curves, applying functions, and the like.

Abstract: A wearable device is described. The wearable device includes a housing having a back cover, and an optical mask on first portions of the back cover. The back cover includes a set of windows, with a first subset of windows in the set of windows being defined by an absence of the optical mask on second portions of the back cover, and a second subset of windows in the set of windows being inset in a set of openings in the back cover. An optical barrier surrounds each window in the second subset of windows. A set of light emitters is configured to emit light through at least some of the windows in the set of windows. A set of light detectors is configured to receive light through at least some of the windows in the set of windows.

Abstract: An integrated window for a photosensor for use in an electronic device has first and second transparent regions separated by an opaque region. The first transparent region allows a transmitter to emit light out of the housing of the electronic device and the second transparent region allows a receiver to receive light through the housing. The opaque region is disposed between the first and second transparent regions to isolate them from one another such that the transmitted light is isolated from the received light.

Abstract: Robust estimation of a characteristic of a user's physiological signals can be achieved by filtering or classifying samples. Rather than estimating the characteristic of the user's physiological signals based on each sample at a first wavelength and a second wavelength, a robust system and method can, in some examples, estimate the characteristic using samples at the first wavelength and the second wavelength that meet one or more criteria and filter out samples that fail to meet the one or more criteria. In some examples, the system and method can weight samples based on the one or more criteria, and estimate the characteristic using the weighted samples. Samples failing to meet the one or more criteria can be given less weight or no weight in the estimation. The one or more criteria can include a criterion based on at least the physiological signal at a third wavelength.

Abstract: An integrated window for a photosensor for use in an electronic device has first and second transparent regions separated by an opaque region. The first transparent region allows a transmitter to emit light out of the housing of the electronic device and the second transparent region allows a receiver to receive light through the housing. The opaque region is disposed between the first and second transparent regions to isolate them from one another such that the transmitted light is isolated from the received light.

Abstract: Robust estimation of a characteristic of a user's physiological signals can be achieved by filtering or classifying samples. Rather than estimating the characteristic of the user's physiological signals based on each sample at a first wavelength and a second wavelength, a robust system and method can, in some examples, estimate the characteristic using samples at the first wavelength and the second wavelength that meet one or more criteria and filter out samples that fail to meet the one or more criteria. In some examples, the system and method can weight samples based on the one or more criteria, and estimate the characteristic using the weighted samples. Samples failing to meet the one or more criteria can be given less weight or no weight in the estimation. The one or more criteria can include a criterion based on at least the physiological signal at a third wavelength.

Abstract: A wearable device is described. The wearable device includes a housing having a back cover, and an optical mask on first portions of the back cover. The back cover includes a set of windows, with a first subset of windows in the set of windows being defined by an absence of the optical mask on second portions of the back cover, and a second subset of windows in the set of windows being inset in a set of openings in the back cover. An optical barrier surrounds each window in the second subset of windows. A set of light emitters is configured to emit light through at least some of the windows in the set of windows. A set of light detectors is configured to receive light through at least some of the windows in the set of windows.

Abstract: Embodiments of the present invention include systems and methods that relate to pulse oximetry. Specifically, one embodiment includes an oximeter sensor comprising a light emitting element configured to emit light, a light detector configured to detect the light, and a memory chip having a built-in trimmed resistor, the trimmed resistor having a resistance value that is detectable by a monitor.

Abstract: An integrated window for a photosensor for use in an electronic device has first and second transparent regions separated by an opaque region. The first transparent region allows a transmitter to emit light out of the housing of the electronic device and the second transparent region allows a receiver to receive light through the housing. The opaque region is disposed between the first and second transparent regions to isolate them from one another such that the transmitted light is isolated from the received light.

Abstract: An integrated window for a photosensor for use in an electronic device has first and second transparent regions separated by an opaque region. The first transparent region allows a transmitter to emit light out of the housing of the electronic device and the second transparent region allows a receiver to receive light through the housing. The opaque region is disposed between the first and second transparent regions to isolate them from one another such that the transmitted light is isolated from the received light.

Abstract: Embodiments of the present invention include systems and methods that relate to pulse oximetry. Specifically, one embodiment includes an oximeter sensor comprising a light emitting element configured to emit light, a light detector configured to detect the light, and a memory chip having a built-in trimmed resistor, the trimmed resistor having a resistance value that is detectable by a monitor.

Abstract: An integrated window for a photosensor for use in an electronic device has first and second transparent regions separated by an opaque region. The first transparent region allows a transmitter to emit light out of the housing of the electronic device and the second transparent region allows a receiver to receive light through the housing. The opaque region is disposed between the first and second transparent regions to isolate them from one another such that the transmitted light is isolated from the received light.

Abstract: Embodiments of the present invention include systems and methods that relate to pulse oximetry. Specifically, one embodiment includes an oximeter sensor comprising a light emitting element configured to emit light, a light detector configured to detect the light, and a memory chip having a built-in trimmed resistor, the trimmed resistor having a resistance value that is detectable by a monitor.

Abstract: The relates to a back surface of the device including one or more protrusions configured to create the localized pressure. In some examples, the protrusion(s) can be located between the optical components and one or more edges of the back plate. In some examples, the protrusion(s) can include a surface that can be raised relative to the back plate of the device. In some examples, one or more protrusions can include one or more recessed regions. In some examples, the cover structure disposed over each of the openings may itself be a protrusion that can apply local regions of higher pressure. The protrusion(s) can be capable of applying localized pressure to multiple spatially separated regions of the skin. Additionally or alternatively, the protrusion(s) can be capable of applying different amounts of localized pressure. Examples of the disclosure can include the Fresnel lens(es) and/or optical isolation optically coupled to the protrusion.

Abstract: Described herein are methods for determining a target musculoskeletal activity cycle (MSKC) to cardiac cycle (CC) timing relationship. The method may include detecting a first characteristic of a signal responsive to a CC timing of a user that repeats at a frequency that corresponds to a heart rate of the user; detecting a second characteristic of a signal responsive to a rhythmic musculoskeletal cycle activity (MSKC) timing of the user that repeats at a frequency that corresponds to the MSKC rate of the user; determining a value representative of an actual timing relationship between the first characteristic and the second characteristic; detecting a third characteristic of a signal corresponding to a physiological metric that varies with the actual timing relationship between the first and second characteristics; and determining a target value representative of a preferred timing relationship between the first and second characteristics.