According to some embodiments, a device for sensing neuromuscular signals is provided. The device may comprise a plurality of signal electrodes aligned along an interior portion of a wearable structure, each signal electrode being configured to detect neuromuscular signals. The device may comprise a plurality of amplifiers, wherein each amplifier includes (i) a first input operatively coupled to a corresponding signal electrode, (ii) an inverting input, and (iii) an output corresponding to a neuromuscular signal channel. The device may comprise one or more buffers configured to tap a voltage at the inverting input of a respective amplifier of the plurality of amplifiers. The device may comprise circuitry configured to operatively couple a plurality of outputs of the plurality of amplifiers to generate a common mode reference signal, wherein the common mode reference signal is provided to the inverting input of one or more amplifiers of the plurality of amplifiers.

A biopotential signal acquisition system, comprising: a first active electrode including an integrated pre-amplifier and an analogue to digital converter; a second active electrode including an integrated pre-amplifier and an analogue to digital converter, wherein the second active electrode has variable gain; a test signal generator for generating a test signal at a test frequency and coupling the test signal to the first and/or second active electrodes; and a digital signal processor configured to: process the digital outputs of the first and second active electrodes to derive a gain control signal based on a difference between the first and second active electrode outputs at the test frequency, and apply the gain control signal to the second active electrode. The disclosure also relates to an electronic circuit or device and a biopotential signal acquisition method.

A method for pre-processing electrical sensing signals for compensating for common mode to differential mode conversion caused by signal transfer function nonlinearities. Linearization functions are applied to the input signals to counter the nonlinearities. The method includes a calibration process in which a plurality of sets of standardized test signals are applied to the input channels of the measurement operation, and corresponding test outputs measured for each test signal set. The parameters of the linearization functions are set based on the obtained dataset of test outputs.

A method for pre-processing electrical sensing signals for compensating for common mode to differential mode conversion caused by signal transfer function nonlinearities. Linearization functions are applied to the input signals to counter the nonlinearities. The method includes a calibration process in which a plurality of sets of standardized test signals are applied to the input channels of the measurement operation, and corresponding test outputs measured for each test signal set. The parameters of the linearization functions are set based on the obtained dataset of test outputs.

The present invention relates to a physiological measurement device, system and method. The device (11) comprises multiple input channels (15) configured to obtain multiple measurement signals (s.sub.i) acquired from a subject; a recording unit (10) configured to filter the multiple measurement signals (s.sub.i) by use of a digital filter and calculate multiple vector signals (y.sub.j) from the multiple filtered measurement signals; a stimulation unit (20) configured to generate one or more stimulation signals (w.sub.k) for electrically stimulating tissue of the subject; multiple output channels (22, 32) configured to output the multiple vector signals (y.sub.i) and the one or more stimulation signals (w.sub.k); and a processing unit (27) configured to determine adjusted filter coefficients of the digital filter during or after the generation and output of the one or more stimulation signals (w.sub.k) based on the current filter coefficients, the one or more stimulation signals (w.sub.k) and the multiple measurement signal (s.sub.i) acquired while the one or more stimulation processing stimulation signals (w.sub.k) are outputted for stimulation.

A bioelectrical signal abnormality monitoring method comprises: generating a noise signal having a preset constant frequency; superposing the noise signal onto a right leg drive electrode; using a front-end circuit to preprocess analog signals from a reference electrode and a collecting electrode, and outputting the analog signals to an analog-to-digital converter; using the analog-to-digital converter to convert into digital signals, and transmitting the digital signals to an operation analysis unit; the operation analysis, unit performing band-stop filtering on the digital signals, performing a subtraction operation on the digital signals before and after the band-stop filtering processing to obtain a difference value, storing the difference value in a queue, periodically solving for the RMS of the data in the queue, and based on the RMS and a fitting formula, calculating the impedance of the human body; and judging an electrode connection state according to the impedance of the human body.

In general, this disclosure is directed to a mixer amplifier that can be utilized within a chopper stabilized instrumentation amplifier. The chopper stabilized instrumentation amplifier may be used for physiological signal sensing, impedance sensing, telemetry or other test and measurement applications. In some examples, the mixer amplifier may include a current source configured to generate a modulated current at a modulation frequency for application to a load to produce an input signal, an amplifier configured to amplify the input signal to produce an amplified signal, and a demodulator configured to demodulate the amplified signal at the modulation frequency to produce an output signal indicating an impedance of the load.

A biosignal apparatus is described including an amplifier and a sampler. The amplifier is configured to alternate between an operating state and a low power state based on a periodically changing control signal. The sampler is configured to sample a signal output from the amplifier in response to the amplifier being in the operating state and maintain the sampled signal in response to the amplifier being in the low power state.

A device for determining a physiological or psychological state of a mammal is disclosed. The device has at least one earpiece with a main body having a body of revolution with an axis of revolution, and an endpiece configured to be inserted into an ear canal. The endpiece has a cylindrical channel intended to receive a body of revolution for detachably mounting the endpiece on the main body, the endpiece being arranged to be movable in rotation about the axis of revolution in order to allow at least one electrode to be oriented toward a zone of the brain of the mammal, and the endpiece having a plurality of electrodes arranged on an outer surface of the endpiece, each electrode being configured to pick up an electrical signal in the ear canal of the mammal.

A device for determining a physiological or psychological state of a mammal is disclosed. The device has at least one earpiece with a main body having a body of revolution with an axis of revolution, and an endpiece configured to be inserted into an ear canal. The endpiece has a cylindrical channel intended to receive a body of revolution for detachably mounting the endpiece on the main body, the endpiece being arranged to be movable in rotation about the axis of revolution in order to allow at least one electrode to be oriented toward a zone of the brain of the mammal, and the endpiece having a plurality of electrodes arranged on an outer surface of the endpiece, each electrode being configured to pick up an electrical signal in the ear canal of the mammal.