Abstract: An exemplary optical measurement system includes a signal generator configured to generate a signal and a processing unit configured to direct the signal generator to apply the signal to a component within the optical measurement system, generate, based on a response of the component to the signal, characterization data representative of a timing uncertainty associated with the component, and perform, based on the characterization data, an action associated with the component.

Abstract: In a non-invasive optical detection system and method, sample light is delivered into a scattering medium. A first portion of the sample light passing through a volume of interest exits the scattering medium as signal light, and a second portion of the sample light passing through a volume of non-interest exits the scattering medium as background light that is combined with the signal light to create a sample light pattern. Reference light is combined with the sample light pattern to create an interference light pattern having a holographic beat component. Ultrasound is emitted into the volume of non-interest in a manner that decorrelates the background light of the sample light pattern from the holographic beat component. The holographic beat component is detected during the measurement period. An optical parameter of the volume of interest is determined based on the detected holographic beat component.

Abstract: A neural phantom device configured and arranged to produce a magnetic field to simulate a neural signal. The neural phantom device includes a driver having a signal source configured to produce a simulated neural signal, and either i) a carrier wave source configured to produce a carrier wave having a frequency of at least 250 Hz or ii) an optical carrier wave source configured to produce an optical carrier wave, wherein the driver is configured to modulate the simulated neural signal using the carrier wave or optical carrier wave to generate a modulated signal. The neural phantom device also includes a phantom configured to receive the modulated signal, demodulate the modulated signal to recover the simulated neural signal, and generate the magnetic field in response to the simulated neural signal.

Abstract: An exemplary optical measurement system includes a light source configured to emit light directed at a target. The optical measurement system further includes a photodetector configured to detect a photon of the light after the light is scattered by the target. The optical measurement system further includes a control circuit configured to receive a first input voltage that is a temperature-dependent voltage. The control circuit is further configured to receive a second input voltage that is a temperature-invariant voltage. The control circuit is further configured to output, based on a combination of the first input voltage and the second input voltage, a bias voltage for the photodetector, wherein the combination of the first and second input voltages is configured to cause the bias voltage to vary based on temperature.

Abstract: An exemplary photodetector system includes a plurality of photodetectors connected in parallel and a processor communicatively coupled to the plurality of photodetectors. The processor is configured to receive an accumulated output from the plurality of photodetectors. The accumulated output represents an accumulation of respective outputs from each of the plurality of photodetectors detecting photons during a predetermined measurement time period that occurs in response to a light pulse being directed toward a target within a body. The processor is further configured to determine, based on the accumulated output, a temporal distribution of photons detected by the plurality of photodetectors, and generate, based on the temporal distribution of photons, a histogram representing a light pulse response of the target within the body.

Abstract: A wearable module assembly for an optical measurement system includes a first wearable module, a second wearable module, and a connector. The first and second wearable modules each include a light source configured to emit a light pulse toward a target within a body of a user, a housing that houses the light source and the plurality of detectors and includes a substantially hexagonal surface that faces a surface of the body of the user when the wearable module assembly is worn by the user, and a plurality of detectors each positioned at a fixed distance from the first light source and each configured to detect a set of photons included in the light pulse after the set of photons are scattered by the target. The connector directly connects the first wearable module and the second wearable module at mutually-facing side surfaces of the respective housings.

Abstract: A light intensity modulator includes an input optical fiber; an output optical fiber; an optical arrangement having a lens, where the optical arrangement is configured to receive light from the input optical fiber, pass the light through the lens, and direct the light to the output optical fiber; and a piezoelectric device coupled to the lens, where the piezoelectric device is configured for moving the lens to alter overlap of the output optical fiber and the light directed to the output optical fiber to modulate intensity of light in the output optical fiber.

Abstract: At least one magnetic field actuator is configured for generating an actuated magnetic field that at least partially cancels an outside magnetic field, thereby yielding a total residual magnetic field. A plurality of magnetometers are configured for taking measurements of the total residual magnetic field. The magnetometers include a plurality of coarse magnetometers and a plurality of fine magnetometers. A processor is configured for acquiring the total residual magnetic field measurements from the coarse magnetometers, estimating the total residual magnetic field at the fine magnetometers based on total residual magnetic field measurements acquired from the plurality of coarse magnetometers, and controlling the actuated magnetic field at least partially based on the total residual magnetic field estimates at the fine magnetometers in a manner that suppresses the total residual magnetic field at the fine magnetometers to a baseline level, such that at least one of the fine magnetometers is in-range.

Abstract: Source light having a range of optical wavelengths is generated. The source light is split into sample light and reference light. The sample light is delivered into a sample, such that it is scattered by the sample, resulting in signal light that exits the sample. The signal light and reference light are combined into an interference light pattern having optical modes. Different subsets of the optical modes of the interference light pattern are respectively detected, and high-bandwidth analog signals respectively corresponding to the different subsets of optical modes of the interference light pattern are output. At least one characteristic is extracted from each of the plurality of high-bandwidth analog signals, and low-bandwidth digital signals respectively comprising the extracted characteristics are output. The sample is analyzed based on the low-bandwidth digital signals.

Abstract: An illustrative system includes an extended reality system and a brain interface system configured to be concurrently worn by a user. The extended reality system is configured to provide the user with an extended reality experience and output a timing signal while the extended reality experience is being provided to the user, the timing signal representing a plurality of timing events that occur during the extended reality experience. The brain interface system is configured to receive the timing signal from the extended reality system while the extended reality experience is being provided to the user, acquire brain activity measurements while the extended reality experience is being provided to the user, and output measurement timestamp data representative of a temporal association of the brain activity measurements with the timing events.

Abstract: A magnetocardiography (MCG) system includes a passively shielded enclosure having walls defining the passively shielded enclosure, each of the walls including passive magnetic shielding material to reduce an ambient background magnetic field within the passively shielded enclosure; an MCG measurement device including optically pumped magnetometers (OPMs); and active shield coils within the passively shielded enclosure and stationary relative to the passively shielded enclosure and the MCG measurement device, wherein the active shield coils are configured to further reduce the ambient background magnetic field within a user area of the passively shielded enclosure.

Abstract: A shielding arrangement for a magnetoencephalography (MEG) system includes a passively shielded enclosure having a plurality of walls defining the passively shielded enclosure, each of the plurality of walls including passive magnetic shielding material to reduce an ambient background magnetic field within the passively shielded enclosure; a vestibular wall extending from a first vertical wall to define, and at least partially separate, a vestibular area of the passively shielded enclosure adjacent the doorway and a user area of the passively shielded enclosure; and active shield coils distributed within the passively shielded enclosure and configured to further reduce the ambient background magnetic field within the user area of the passively shielded enclosure.

Abstract: An optical measurement system includes a wearable module having at least one time-resolved single photon photodetector configured to detect photons from at least one light pulse after the at least one light pulse is scattered by a target within a body of a user; at least one light guide configured to receive the photons and guide the photons to the at least one photodetector; and a housing that houses both the at least one photodetector and at least a portion of the at least one light guide. The optical measurement system further includes a signal processing circuit configured to determine a temporal distribution of the photons detected by the at least one photodetector and generate a histogram based on the temporal distribution of the photons.

Abstract: An optical measurement system comprising an optical source configured for delivering sample light in an anatomical structure, such that the sample light is scattered by the anatomical structure, resulting in physiological-encoded signal light that exits the anatomical structure, an optical detector configured for detecting the physiological-encoded signal light, and a processor configured for acquiring a TOF profile derived from the physiological-encoded signal light, the initial TOF profile having an initial contrast-to-noise ratio (CNR) between a plurality of states of a physiological activity in the anatomical structure. The processor is further configured for applying one or more weighting functions to the initial TOF profile to generate a weighted TOF profile having a subsequent CNR greater than the initial CNR between the plurality of states of the physiological activity.

Abstract: A magnetic field recording system includes a headgear to be placed on a user; optically pumped magnetometers (OPMs) disposed in or on the headgear to detect magnetic fields; at least two sensing modalities selected from the following: i) a magnetic sensing modality, ii) an optical sensing modality, or iii) an inertial sensing modality; and a tracking unit configured to receive, from each of the at least two sensing modalities, a corresponding magnetic data stream, optical data stream, or inertial data stream and to track a position or orientation of the headgear or user; and a system controller configured to control operation of the OPMs and to receive, from the tracking unit, the position or orientation of the headgear or user.

Abstract: A method of operating an optically pumped magnetometer (OPM) includes directing a light beam through a vapor cell of the OPM including a vapor of atoms; applying RF excitation to cause spins of the atoms to precess; measuring a frequency of the precession; for each of a plurality of different axes relative to the vapor cell, directing a light beam through the vapor cell, applying a magnetic field through the vapor cell along the axis, applying RF excitation to cause spins of the atoms to precess, and measuring a frequency of the precession in the applied magnetic field; determining magnitude and components of an ambient background magnetic field along the axes using the measured frequencies; and applying a magnetic field based on the components around the vapor cell to counteract the ambient background magnetic field to facilitate operation of the OPM in a spin exchange relaxation free (SERF) mode.

Abstract: An exemplary controller may include a single clock source configured to generate a single clock signal used to drive one or more components within a plurality of magnetometers and a plurality of differential signal measurement circuits configured to measure current output by a photodetector of each of the plurality of magnetometers.

Abstract: An illustrative system may include a component configured to be worn on a body of a user, the component comprising a time-to-digital converter (TDC) configured to: receive, during a predetermined event detection time window that commences in response to an application of a light pulse to a target within the body, a signal triggered by an event in which a photodetector detects a photon of the light pulse after the light pulse reflects from the target; and measure, based on the receiving the signal, a time interval between when the event occurred and an end of the predetermined event detection time window. The system may further include a processor configured to determine, based on the time interval and the predetermined event detection time window, an arrival time of the photon at the photodetector.

Abstract: A physiological activity detection system comprises a signal acquisition module configured for non-invasively acquiring a signal from an anatomical structure of a user, the acquired signal having a physiological-encoded component and a periodic artifact component that dominates the physiological-encoded component. The physiological activity detection system further comprises a phase-locked loop (PLL) component configured for estimating a phase of the periodic artifact component of the acquired signal, and generating a periodic reference signal having a phase representative of the estimated phase of the periodic artifact component of the acquired signal.

Abstract: An exemplary wearable sensor unit includes 1) a magnetometer comprising a vapor cell comprising an input window and containing an alkali metal, and a light source configured to output light that passes through the input window and into the vapor cell along a transit path, and 2) a temperature control circuit external to the vapor cell and configured to create a temperature gradient within the vapor cell, the temperature gradient configured to concentrate the alkali metal within the vapor cell away from the transit path of the light.