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: 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 electronic device can include a housing that includes an optically transparent component. First and second light emitters can be positioned in the internal volume defined by the housing. A light detector can be positioned in the internal volume and can be optically isolated from the first and second light emitters within the internal volume. An opaque material can be disposed on the optically transparent component and can be positioned to inhibit light emitted from the second light emitter from reaching the light detector and to allow light emitted from the first light emitter to reach the light detector.

Abstract: An electronic device can include a housing defining an aperture, and an electromagnetic radiation emitter and an electromagnetic radiation detector disposed in the housing. An optical component can be disposed in the aperture and can include a first region of a first material having a first index of refraction, the first region aligned with the electromagnetic radiation emitter, a second region of the first material, the second region aligned with the electromagnetic radiation detector, and a bulk region surrounding a periphery of the first region and a periphery of the second region, the bulk region including a second material having a second index of refraction that is lower than the first index of refraction.

Abstract: An electronic device can include a housing that includes an optically transparent component. First and second light emitters can be positioned in the internal volume defined by the housing. A light detector can be positioned in the internal volume and can be optically isolated from the first and second light emitters within the internal volume. An opaque material can be disposed on the optically transparent component and can be positioned to inhibit light emitted from the second light emitter from reaching the light detector and to allow light emitted from the first light emitter to reach the light detector.

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: The present disclosure generally relates to wearable devices and methods for measuring a photoplethysmographic signal. The wearable devices and methods may include a force sensor that provides input used for motion-noise filtering to obtain improved PPG signals. Feedback from the force sensor may also be used to indicate whether the amount of pressure exerted by the device should be adjusted, or whether the device should be switched to a locked state.

Abstract: This relates to systems and methods for determining one or more of a user's physiological signals. The one or more of the user's physiological signals can be determined by measuring pulsatile blood volume changes. Motion artifacts included in the signals can be canceled or reduced by measuring non-pulsatile blood volume changes and adjusting the signal to account for the non-pulsatile blood information. Non-pulsatile blood volume changes can be measured using at least one set of light emitter-light sensor. The light emitter can be located in close proximity (e.g., less than or equal to 1 mm away) to the light sensor, thereby limiting light emitted by the light emitter to blood volume without interacting with one or more blood vessels and/or arterioles. In some examples, the systems can further include an accelerometer configured to measure the user's acceleration, and the acceleration signal can be additionally be used for compensating for motion artifacts.

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: This relates to systems and methods for determining one or more of a user's physiological signals. The one or more of the user's physiological signals can be determined by measuring pulsatile blood volume changes. Motion artifacts included in the signals can be canceled or reduced by measuring non-pulsatile blood volume changes and adjusting the signal to account for the non-pulsatile blood information. Non-pulsatile blood volume changes can be measured using at least one set of light emitter-light sensor. The light emitter can be located in close proximity (e.g., less than or equal to 1 mm away) to the light sensor, thereby limiting light emitted by the light emitter to blood volume without interacting with one or more blood vessels and/or arterioles. In some examples, the systems can further include an accelerometer configured to measure the user's acceleration, and the acceleration signal can be additionally be used for compensating for motion artifacts.

Abstract: A system for monitoring health of a rotor is presented. The system includes a processing subsystem that generates a measurement matrix based upon a plurality of resonant-frequency first delta times of arrival vectors corresponding to a blade and a first sensing device, and a plurality of resonant-frequency second delta times of arrival vectors corresponding to the blade and a second sensing device, generates a resonant matrix based upon the measurement matrix such that entries in the resonant matrix are substantially linearly uncorrelated and linearly independent, and generates a resonance signal using a first subset of the entries of the resonant matrix, wherein the resonance signal substantially comprises common observations and components of the plurality of resonant-frequency first delta times of arrival vectors and the plurality of resonant-frequency second delta times of arrival vectors.

Abstract: A creep life management system includes at least one sensor apparatus coupled to a first component. The at least one sensor apparatus is configured with a unique identifier. The creep life management system also includes at least one reader unit coupled to a second component. The at least one reader unit is configured to transmit an interrogation request signal to the at least one sensor apparatus and receive a measurement response signal transmitted from the at least one sensor apparatus. The creep life management system further includes at least one processor programmed to determine a real-time creep profile of the first component as a function of the measurement response signal transmitted from the at least one sensor apparatus.

Abstract: Various embodiments include systems and apparatuses adapted for detecting two-dimensional turbomachine exhaust temperature. In some embodiments, a system includes a two-dimensional grid sized to mount within an exhaust path of a gas turbomachine, a radiation detection device for detecting radiation emitted from the two-dimensional grid at a plurality of points on the two-dimensional grid, the radiation detection device being mountable proximate the exhaust path and the two-dimensional grid and at least one computing device connected with the radiation detection device, the at least one computing device configured to generate a planar map of the temperature of the exhaust from the gas turbomachine based upon the intensity of the radiation emitted from two-dimensional grid detected at the plurality of points on the two-dimensional grid.

Abstract: A system is disclosed. The system includes a processing subsystem that determines preliminary voltages corresponding to a plurality of blades based upon blade passing signals (BPS), and generates a plurality of clearance values by normalizing the preliminary voltages for effects of one or more operational parameters, wherein the plurality of clearance values are representative of clearance of the plurality of blades.

Abstract: A pyrometry imaging system for monitoring a high-temperature asset which includes at least one component is provided. The system includes a lens element in optical communication with the at least one component. The lens element is configured to receive at least a portion of thermal radiation emitted from the at least one component. The system also includes a view limiting device positioned between the lens element and a dispersive element. The dispersive element is configured to split the at least a portion of thermal radiation emitted into a plurality of wavelengths. The system further includes at least one camera device in optical communication with the dispersive element. The at least one camera device is configured to receive at least one wavelength from the dispersive element.

Abstract: A method is presented. The method includes the steps of generating rotation signals corresponding to a plurality of rotations of a rotor physically coupled to a plurality of blades, and determining peak voltages corresponding to the plurality of blades by applying time synchronous averaging technique to blade passing signals using the rotation signals, wherein the peak voltages are representative of clearances of the plurality of blades.

Abstract: Various embodiments of the invention include a system having: at least one computing device connected with an array of ultrasonic probes on a gas turbomachine component, the at least one computing device configured to: instruct a first probe in the array of ultrasonic probes to transmit an ultrasonic beam to at least one additional probe in the array of ultrasonic probes; and determine a property of a medium between the first probe and the at least one additional probe based upon a time between transmission of the ultrasonic beam from the first probe and reception of the ultrasonic beam at the at least one additional probe.

Abstract: Systems and methods of estimating an efficiency of a section of a steam turbine are disclosed. The systems and methods include determining a set of measurement data obtained directly from a set of sensors on the steam turbine, determining a set of derived data relating to measurements that cannot be obtained directly from the set of sensors, and estimating the efficiency of the section using the set of measurement data and the set of derived data. The systems and methods disclosed use physics-based models combined with nonlinear filtering techniques to estimate steam turbines' efficiencies when physical sensors are not available. These models capture the behavior of different components of the power plant, including all steam turbine sections, admission and crossover pipes, flow junctions, admission and control valves.

Abstract: A system for monitoring equipment and transmitting data and/or signals from one or more satellite nodes to a base node for transmission to a monitor or controller for the equipment. The system may transmit high frequency acoustic signals from one or more satellite nodes embedded in the equipment through a structural component of the equipment to the base node, eliminating the need to hardwire the satellite nodes in harsh environments.