HI LLC

An actuated magnetic field is generated at a plurality of distinct frequencies that at least partially cancels an outside magnetic field at the plurality of distinct frequencies, thereby yielding a total residual magnetic field. The total residual magnetic field is coarsely detected and a plurality of coarse error signals are respectively output. The total residual magnetic field is finely detected and a plurality of fine error signals are respectively output. The actuated magnetic field is controlled respectively at the plurality of distinct frequencies at least partially based on at least one of the plurality of coarse error signals, and finely controlled respectively at the plurality of distinct frequencies at least partially based on at least one of the plurality of fine error signals.

An illustrative system includes a sensor component and a controller conductively coupled by way of a first wire and a second wire in a twisted pair configuration. The controller includes a driver configured to drive the sensor component by way of the first and second wires with a drive current in accordance with a gain parameter and a control loop circuit. The control loop circuit is configured to receive a control signal representative of a target current value for the drive current, adjust the gain parameter based on a difference between the target current value and an actual current value of current that is actually being driven through the sensor component, and abstain from adjusting the gain parameter based on current capacitively coupled onto the first and second wires by an external electric field.

A wearable module for use in an optical measurement system includes a housing including a top surface, a light guide including a distal end portion adapted to protrude from the top surface of the housing, and a spring member configured to bias the distal end portion of the light guide away from the top surface of the housing. The light guide is configured to receive, at the distal end portion, photons from a light pulse scattered by a target within a body of a user and guide the received photons toward a photodetector.

An optical measurement system includes a first light source configured to emit a first light pulse toward a target, a second light source configured to emit a second light pulse toward the target, a first detector, a second detector, and a processing unit. The processing unit is configured to determine a plurality of temporal distributions of photons included in the first light pulse and the second light pulse and detected by the first detector and the second detector after the photons are scattered by the target. The processing unit is further configured to determine, based on the plurality of temporal distributions, a distance between the first light source and the second detector.

An illustrative optical measurement system includes a light source configured to emit light directed at a target, an array of photodetectors configured to detect photons of the light after the light is scattered by the target, and a processing unit configured to measure a noise level of a photodetector included in the array of photodetectors, the noise level comprising a dark count rate that measures a dark count divided by a time period, determine that the noise level meets a predetermined threshold comprising a dark count rate threshold, and prevent, based on the determining that the noise level meets the predetermined threshold, an output of the photodetector from being used in generating a histogram based on a temporal distribution of photons detected by the array of photodetectors, the preventing comprising switching the output to a monitoring circuit that monitors a characteristic of the optical measurement system separate from the photodetector.

An illustrative method includes accessing, by a computing device, a model simulating light scattered by a simulated target, the model comprising a plurality of parameters. The method further includes generating, by the computing device, a set of possible histogram data using the model with a plurality of values for the parameters. The method further includes determining, by the computing device, a set of components that represent the set of possible histogram data, the set of components having a reduced dimensionality from the set of possible histogram data.

An illustrative multimodal measurement system includes a wearable assembly configured to be worn by a user; and a module configured to be removably inserted into the wearable assembly and comprising: a housing, a printed circuit board (PCB) and a light guide assembly configured to emit light directed at a target within the user. The light guide assembly comprises: a lower light guide portion housed within the housing and having a proximal end attached to the PCB, a conductive spring member housed within the housing and comprising a coil positioned around an external surface of the lower light guide portion, and a conductive upper light guide portion connected to the lower light guide portion and configured to protrude from an upper surface of the housing and be in contact with a surface of a body of the user.

A mental state awareness system comprises a non-invasive brain interface assembly configured for detecting brain activity of a user, a processor configured for determining a mental state of a user based on the detected brain activity, and a biofeedback device configured for automatically providing biofeedback to the user indicative of the determined mental state of the user.

An illustrative optical measurement system includes a light source configured to emit light directed at a target, an array of photodetectors configured to detect photons of the light after the light is scattered by the target, and a processing unit. The processing unit is configured to measure a noise level of a photodetector included in the array of photodetectors and determine that the noise level meets a predetermined threshold. The processing unit is further configured to prevent, based on the determining that the noise level meets the predetermined threshold, an output of the photodetector from being used in generating a histogram based on a temporal distribution of photons detected by the array of photodetectors.

An illustrative 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.