Abstract: Systems and methods are described for providing a 3D display, such as a light-field display. In some embodiments, a display device includes a light-emitting layer comprising an addressable array of light-emitting elements. An optical layer overlays the light-emitting layer. The optical layer includes a plurality of distributed lenses. In some embodiments, the distributed lenses include non-contiguous lens regions. In some embodiments, distributed lens regions with different optical centers are interlaced with one another. A spatial light modulator is operative to provide control over which lens regions transmit light from the light-emitting layer outside the display device. In some embodiments, the use of interlaced and/or non-contiguous distributed lenses provides improved display resolution with a reduction in diffraction effects.

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: Systems and methods are described for providing a 3D display, such as a light-field display. In some embodiments, a display device includes a light-emitting layer that includes a plurality of separately-controllable pixels. A lens structure overlays the light-emitting layer. The lens structure includes an array of collimating optical elements. A phase-modifying layer is positioned between the light emitting layer and the lens structure. The pixels of the light emitting layer are used in generating spatial emission patterns that work in unison with the phase-modifying layer in order to generate beams of light through the collimating optical elements with extended focus depths. Multiple beams are used to generate voxels at various distances from the display surface with the correct eye convergence for the viewer. Beams with extended focus depths may be used to generate the correct eye retinal focus cues.

Abstract: Methods, systems, and devices for determining blood pressure based on morphological features of pulses are described. A system may include a wearable device that uses one or more light emitting components configured to emit light, one or more photodetectors configured to receive light, and a controller that couples the one or more light emitting components to the one or more photodetectors. The wearable device may transmit lights associated with multiple wavelengths, and acquire photoplethysmogram (PPG) data that includes one or more PPG waveforms associated with the respective wavelengths. The system may determine respective sets of morphological features associated with each of the PPG waveforms based on systolic and diastolic peaks corresponding to the heartbeat of the user. The system may determine one or more blood pressure metrics for the user based at least in part on a comparison of the respective sets of morphological features.

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 manufacturing a wearable device are described. A method for manufacturing a wearable device may include coupling a printed circuit board (PCB) to an inner ring-shaped housing that contains a plurality of apertures by aligning a plurality of sensors of the PCB with the plurality of apertures. The method may also include coupling an outer ring-shaped housing to the inner ring-shaped housing by surrounding the inner ring-shaped housing with the outer ring-shaped housing. Additionally, the method may include injecting a filler material through an additional aperture of the outer ring-shaped housing to fill a cavity defined by the inner ring-shaped housing and the outer ring-shaped housing, filling at least a portion of the plurality of the inner ring-shaped housing with the filler material.

Abstract: A wearable device is described. The wearable device may be constructed of one or more flexible materials, and may be referred to as a flexible wearable device. The flexible wearable device may include a flexible housing that is made of a material that is elastically deformable, where the flexible housing at least partially surrounds components of the flexible wearable device. The flexible housing may include apertures disposed within the surface of the flexible housing to enable light to be transmitted and received through the flexible housing. The flexible wearable device may also include a printed circuit board (PCB) disposed within the flexible housing (e.g., within a cavity formed by the flexible housing). The PCB may include sensors configured to acquire physiological data from a user by transmitting light and receiving light through the apertures. The PCB may be constructed of flexible regions that are elastically deformable.

Abstract: Some embodiments of an example apparatus may include a display, a first controllable diffuser overlaying the display, the first controllable diffuser being selectively operable to diffuse light in a first diffusion direction, and a second controllable diffuser overlaying the display, the second controllable diffuser being selectively operable to diffuse light in a second diffusion direction substantially perpendicular to the first diffusion direction. In some embodiments, an example method may include emitting a light beam from a light emitting device; linearly polarizing the light beam; passing the light beam through LC and birefringent materials; and applying a voltage to alter polarization of the LC material, from a first state causing the light to diffuse in a first direction upon passing through the birefringent material, to a second state causing the light beam to diffuse in a second direction upon passing through the birefringent material.

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: A light-emitting layer of an apparatus includes an addressable array of light-emitting elements including a first light-emitting element and a periodic optical layer overlaying the light-emitting layer. The periodic optical layer includes at least a first periodic optical feature having a first optical power and a second periodic optical feature having a different optical power. A first controllable light-steering layer is disposed between the light-emitting layer and the periodic optical layer. The first controllable light-steering layer is switchable between directing light from the first light-emitting element through the first periodic optical feature and directing light from the first light-emitting element through the second periodic optical feature.

Abstract: Systems and devices for optimized structures for optical measurement are described. A wearable device may include a housing configured to house one or more sensors to acquire physiological data from a user. The wearable device may further include one or more light sources disposed on a surface of the housing and positioned to direct light into a tissue surface of the user and one or more detectors disposed on the surface of the housing and positioned to receive light from the one or more light sources along a plurality of optical paths where a first optical path may be through the tissue surface and a second optical path may be directly from the one or more light sources. The wearable device may include one or more light blocking components disposed on a surface of the housing that are configured to block stray light along the second optical path.

Abstract: Methods, systems, and devices for implementing an artificial artery to calibrate a wearable device are described. An artificial digit may be formed from a material configured with optical properties, thermal properties, or mechanical properties representative of human tissue (e.g., a human finger). The artificial digit may include one or more channels representative of human arteries, capillaries, or both. Additionally, or alternatively, the artificial digit may include electrochromic sheets that may adjust to light absorption properties of the material. A wearable device may be placed on the artificial digit, and one or more sensors of the wearable device may be activated to collect measurements when there is simulated fluid flow through the artificial digit (e.g., via a pump system). The wearable device sensors may be configured, or calibrated, according to the measurements.

Abstract: Display methods and apparatus are described. In some embodiments, to generate an image, light is selectively emitted from one or more light-emitting elements (such as a ?LEDs) in a light-emitting layer. The emitted light from each element is collimated using, for example, an array of microlenses having small apertures. Each beam of collimated light is split by a first diffractive grating into a first generation of child beams, and the first generation of child beams is split by a second diffractive grating into a second generation of child beams. Beams in the second generation of child beams that are not parallel to the original beam of collimated light may be blocked by a spatial light modulator (e.g. an LCD panel). The un-blocked beams operate in some respects as if they had been generated using optics with an aperture larger than the apertures of the microlenses.

Abstract: Methods, systems, and devices for wearing detection are described. A method may include directing light from a light source to a detector using an optical light guide of the wearable device, where the optical light guide includes an optical interface configured to allow at least a portion of the directed light to escape the optical light guide based on a refractive property of a material contacting the optical interface. The method may include measuring, via the detector, an amount of escaped light which escaped the optical light guide, where the amount of escaped light is indicative of a level of surface contact at the optical interface of the optical light guide. The method may further include controlling an activation of one or more sensors of the wearable device based on the amount of escaped light.

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.

Abstract: Systems and methods are described for providing a display. In some embodiments, a display device includes a light-emitting layer with an addressable array of light-emitting elements such as OLEDs. A flexible optical layer overlays the light-emitting layer. The flexible optical layer has a plurality of lens regions, where optical powers of the lens regions change in response to changing levels of tensile or compressive force on the flexible optical layer. When no force is applied, the lens regions may have no optical power, and the display may operate as a 2D display. When force is applied (e.g. by bending the display), the lens regions may operate as cylindrical lenses in a lenticular array, and the display may be operated as a 3D multiview display.

Abstract: Some embodiments of an apparatus may include: a tracking module configured to track viewer movement adjustments; and a light field image display structure configured to display a light field image using the viewer movement adjustments. Some embodiments of a method may include: projecting a beam spot on a viewer of a light field display; determining an estimated location of the beam spot reflected off the viewer; detecting an actual location of the beam spot reflected off the viewer; and determining image correction parameters based on a comparison of the estimated location and the actual location of the beam spot reflected off the viewer.

Abstract: Embodiments include 3D display devices and methods of operation. In an example device, a light-emitting layer is provided with an addressable array of light-emitting elements. An optical layer overlays the light-emitting layer. The optical layer includes an array of lenses operative to substantially collimate light from the light-emitting layer. To suppress stay light, an angular filter layer is provided along an optical path from the light-emitting layer to an exterior of the display. The angular filter is operative to substantially block light having an incident angle greater than a threshold angle and to substantially transmit light having an incident angle less than a threshold angle. The angular filter may be a thin-film interference bandpass filter. Different regions of the angular filter may be tuned for different wavelengths of light.

Abstract: Systems and methods are described for providing a 3D display, such as a light-field display. In some embodiments, a display device includes a light-emitting layer comprising an addressable array of light-emitting elements. An optical layer overlays the light-emitting layer. The optical layer includes a plurality of distributed lenses. In some embodiments, the distributed lenses include non-contiguous lens regions. In some embodiments, distributed lens regions with different optical centers are interlaced with one another. A spatial light modulator is operative to provide control over which lens regions transmit light from the light-emitting layer outside the display device. In some embodiments, the use of interlaced and/or non-contiguous distributed lenses provides improved display resolution with a reduction in diffraction effects.

Abstract: Some embodiments of an example apparatus may include a display, a first controllable diffuser overlaying the display, the first controllable diffuser being selectively operable to diffuse light in a first diffusion direction, and a second controllable diffuser overlaying the display, the second controllable diffuser being selectively operable to diffuse light in a second diffusion direction substantially perpendicular to the first diffusion direction. In some embodiments, an example method may include emitting a light beam from a light emitting device; linearly polarizing the light beam; passing the light beam through LC and birefringent materials; and applying a voltage to alter polarization of the LC material, from a first state causing the light to diffuse in a first direction upon passing through the birefringent material, to a second state causing the light beam to diffuse in a second direction upon passing through the birefringent material.