Facebook Technologies, LLC

Meta Platforms Technologies, LLC

Jonathan Reid

Ning Guo

Alexandre Barachant

Daniel Z Wetmore

Curtis Barbre

Brandon Pool

Akshay Yembarwar

The disclosed computer-implemented method may include (1) sampling an output signal of an amplifier that amplifies a voltage difference between two electrodes, (2) calculating, based on a power spectral density of the output signal, a noise power of the output signal over a predetermined frequency band, (3) estimating an interface impedance of at least one of the two electrodes based on the noise power and a predetermined intrinsic current noise of the amplifier, and (4) performing an operation based at least in part on the estimated interface impedance. Various other methods, systems, and devices are also disclosed.

Systems and methods for utilizing intrinsic current noise to measure interface impedances

Methods and systems for reducing electromagnetic interference in analog circuit of a control device for an augmented reality (AR) or virtual reality (VR) system are described. An analog circuit associated with the control device may include at least one amplifier and an analog-to-digital converter coupled to an amplifier by one or more electrical conductors. Electromagnetic interference induced in the one or more electrical conductors by an external AC magnetic field may be reduced using at least one component of the control device configured to reduce the electromagnetic interference.

Electromagnetic interference reduction in extended reality environments

Techniques for shielding wearable surface electromyography (sEMG) devices are described. According to some aspects, an sEMG device may comprise amplification circuitry comprising at least a first differential amplifier and at least two sEMG electrodes electrically connected to the amplification circuitry. The device may further comprise at least one auxiliary conductor not electrically connected to the amplification circuitry, wherein the at least one auxiliary conductor is configured to be electrically coupled to a wearer of the wearable device, and an electromagnetic shield surrounding the wearable device at least in part and electrically connected to the at least one auxiliary conductor.

Shielding techniques for noise reduction in surface electromyography signal measurement and related systems and methods

Arrangements for improving neuromuscular recording electrode contact with a body surface are described. According to some aspects, a sensor assembly may include a housing and one or more electrodes that are moveable relative to the housing. The electrodes may rotate and/or translate relative to the housing and/or have at least two degrees of freedom relative to the housing. The sensor may include a spring element that stores potential energy and biases the electrodes toward a starting position in which the electrodes extend at least partially out of the sensor housing. In some embodiments, application of a contact force to one or more of the electrodes of the sensor compresses the spring element, causing the spring element to store potential energy.

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Brooklyn, NY, United States of America

Jonathan Reid