Abstract: Methods and devices for obtaining a blood pressure measurement of a subject measure a transit time of a blood pulse of the subject. A method includes sensing, with a pulse ejection sensor of a wrist-worn device, ejection of blood from the left ventricle. Arrival of a resulting blood pressure pulse at the wrist is sensed via a pulse arrival sensor of the wrist-worn device. A transit time of the blood pressure pulse from the left ventricle to the wrist is determined. A relative blood pressure value of the subject is determined based on the transit time. A reference absolute blood pressure value associated with the relative blood pressure value is received. An absolute blood pressure value for the relative blood pressure value is determined based on the reference absolute blood pressure value and the relative blood pressure value.

Abstract: Methods and devices for obtaining a blood pressure measurement of a subject measure a transit time of a blood pulse of the subject. A method includes sensing, with a pulse ejection sensor of a wrist-worn device, ejection of blood from the left ventricle. Arrival of a resulting blood pressure pulse at the wrist is sensed via a pulse arrival sensor of the wrist-worn device. A transit time of the blood pressure pulse from the left ventricle to the wrist is determined. A relative blood pressure value of the subject is determined based on the transit time. A reference absolute blood pressure value associated with the relative blood pressure value is received. An absolute blood pressure value for the relative blood pressure value is determined based on the reference absolute blood pressure value and the relative blood pressure value.

Abstract: A camera attachment for measuring a temperature of a surface, and related methods of measuring the temperature of the surface, employ a temperature reactive material that is thermally coupled with the surface and imaged to provide image data of the temperature reactive material that is analyzed to measure the temperature. A camera attachment for measuring a temperature of a surface includes a distal surface configured to be thermally coupled with the surface, a frame configured to be coupled with a camera that has a field of view, and a temperature reactive material coupled with the frame and thermally coupled with the distal surface. The frame positions the temperature reactive material within the field of view of the camera so that an image captured by the camera includes at least a portion of the temperature reactive material.

Abstract: A sleep monitor includes a layered sensor that includes at least one substrate layer that includes multiple laterally adjacent substrates. The substrate layer may be formed by interdigitating fingers of a first sheet with fingers of a second sheet. Combining multiple substrates in a single layer of a layered sensor may allow multiple materials and/or sensing mechanisms to be combined together in a single layer.

Abstract: An impeller for a pump is disclosed herein. The impeller can include a hub having a fixed end and a free end. The impeller can also have a plurality of blades supported by the hub. Each blade can have a fixed end coupled to the hub and a free end. The impeller can have a stored configuration and a deployed configuration, the blades in the deployed configuration extending away from the hub, and the blades in the stored configuration being compressed against the hub.

Abstract: A pulse transit time is measured non-invasively and used to calculate a blood pressure value. A method of determining one or more blood pressure values includes propagating an alternating drive current through a thorax of a subject via electrodes located on a wrist-worn device. Resulting voltage levels of the subject are sensed by the wrist-worn device. The voltage levels are processed to detect when a volume of blood is ejected from the left ventricle. Output from a pulse arrival sensor coupled to the wrist-worn device is processed to detect when a blood pressure pulse generated by ejection of the volume of blood from the left ventricle arrives at the wrist. A pulse transit time (PTT) for transit of the blood pressure pulse from the left ventricle to the wrist is calculated. One or more blood pressure values for the subject are determined based on the PTT.

Abstract: An in-bed haptic device may include an array of actuation cells. Actuation cells of the array of actuation cells may be configured to actuate (e.g., expand, contract, or otherwise change shape) in a predetermined sequence to provide haptic outputs. The in-bed haptic device may be configured to be placed beneath a user during use, for example between a user and a mattress. The haptic outputs may be provided to help a user relax, to move and/or wake a user, to indicate outputs, alerts, or notifications at the in-bed haptic device or another electronic device, or the like.

Abstract: A camera attachment for measuring a temperature of a surface, and related methods of measuring the temperature of the surface, employ a temperature reactive material that is thermally coupled with the surface and imaged to provide image data of the temperature reactive material that is analyzed to measure the temperature. A camera attachment for measuring a temperature of a surface includes a distal surface configured to be thermally coupled with the surface, a frame configured to be coupled with a camera that has a field of view, and a temperature reactive material coupled with the frame and thermally coupled with the distal surface. The frame positions the temperature reactive material within the field of view of the camera so that an image captured by the camera includes at least a portion of the temperature reactive material.

Abstract: An impeller for a pump is disclosed herein. The impeller can include a hub having a fixed end and a free end. The impeller can also have a plurality of blades supported by the hub. Each blade can have a fixed end coupled to the hub and a free end. The impeller can have a stored configuration and a deployed configuration, the blades in the deployed configuration extending away from the hub, and the blades in the stored configuration being compressed against the hub.

Abstract: An interface pressure sensor includes a fluid pressure sensor disposed in a volume defined by a shear wall. The volume is enclosed, and the fluid pressure sensor is encapsulated by, an infill material. The infill material defines a sensing surface that, when pressed, can impart a force that is detectable by the fluid pressure sensor.

Abstract: An interface pressure sensor includes a fluid pressure sensor disposed in a volume defined by a shear wall. The volume is enclosed, and the fluid pressure sensor is encapsulated by, an infill material. The infill material defines a sensing surface that, when pressed, can impart a force that is detectable by the fluid pressure sensor. The interface pressure sensor can be used for applanation tonometry.

Abstract: Embodiments are directed to systems and techniques for tracking menstrual cycles, which can include receiving temperature measurements from an array of temperature sensors positioned on a bed. A use period for the array can be determined when temperature measurements from at least one temperature sensor of the one or more temperature sensors exceed a first temperature threshold. In some embodiments, for each use period in a set of two or more use periods, a temperature of the user using the set of temperatures from the respective use period can be determined. After determining the temperature of the user for each use period in the set of two or more use periods, at least one change in the temperature of the user between different use periods can be identified. An ovulation day of the user based on the at least one change in the temperature of the user can be estimated.

Abstract: Embodiments are directed to systems and techniques for tracking menstrual cycles, which can include receiving temperature measurements from an array of temperature sensors positioned on a bed. A use period for the array can be determined when temperature measurements from at least one temperature sensor of the one or more temperature sensors exceed a first temperature threshold. In some embodiments, for each use period in a set of two or more use periods, a temperature of the user using the set of temperatures from the respective use period can be determined. After determining the temperature of the user for each use period in the set of two or more use periods, at least one change in the temperature of the user between different use periods can be identified. An ovulation day of the user based on the at least one change in the temperature of the user can be estimated.

Abstract: A camera attachment for measuring a temperature of a surface, and related methods of measuring the temperature of the surface, employ a temperature reactive material that is thermally coupled with the surface and imaged to provide image data of the temperature reactive material that is analyzed to measure the temperature. A camera attachment for measuring a temperature of a surface includes a distal surface configured to be thermally coupled with the surface, a frame configured to be coupled with a camera that has a field of view, and a temperature reactive material coupled with the frame and thermally coupled with the distal surface. The frame positions the temperature reactive material within the field of view of the camera so that an image captured by the camera includes at least a portion of the temperature reactive material.

Abstract: Embodiments described herein are directed to a temperature measurement device that includes a sensor body configured to be placed on a skin of a user. The temperature measurement device can include a first section defining a first lower surface and having a first thickness, a second section defining a second lower surface and having a second thickness, and a channel separating the first lower surface from the second lower surface. The temperature measurement device can also include a first set of temperature sensors positioned across the first thickness, a second set of temperature sensors positioned across the second thickness, and a processor configured to estimate a tissue temperature of the user based on comparing temperature signals from the first set of temperature sensors with temperature signals from the second set of temperature sensors.

Abstract: A sensor system may have a force sensor formed from a piezoelectric film. The piezoelectric film may comprise a number of tuned microstructures that are configured to resonate at a particular frequency. In accordance with the tuning of the microstructures, frequency signals corresponding to the microstructure resonance may be mechanically amplified before being processed by associated processing electronics. The processing electronics may be configured to identify a type of biological vibration detected by the force sensor.

Abstract: An impeller for a pump is disclosed herein. The impeller can include a hub having a fixed end and a free end. The impeller can also have a plurality of blades supported by the hub. Each blade can have a fixed end coupled to the hub and a free end. The impeller can have a stored configuration and a deployed configuration, the blades in the deployed configuration extending away from the hub, and the blades in the stored configuration being compressed against the hub.

Abstract: An impeller for a pump is disclosed herein. The impeller can include a hub having a fixed end and a free end. The impeller can also have a plurality of blades supported by the hub. Each blade can have a fixed end coupled to the hub and a free end. The impeller can have a stored configuration and a deployed configuration, the blades in the deployed configuration extending away from the hub, and the blades in the stored configuration being compressed against the hub.

Abstract: An impeller for a pump is disclosed herein. The impeller can include a hub having a fixed end and a free end. The impeller can also have a plurality of blades supported by the hub. Each blade can have a fixed end coupled to the hub and a free end. The impeller can have a stored configuration and a deployed configuration, the blades in the deployed configuration extending away from the hub, and the blades in the stored configuration being compressed against the hub.

Abstract: An interface pressure sensor includes a fluid pressure sensor disposed in a volume defined by a shear wall. The volume is enclosed, and the fluid pressure sensor is encapsulated by, an infill material. The infill material defines a sensing surface that, when pressed, can impart a force that is detectable by the fluid pressure sensor.