A low input current amplifier has a voltage spectral density curve to operate at 50 Hz or less and is connected to dielectric materials to receive a signal irrespective of ground reference. The amplifier outputs a first output. A multi-stage amplifier includes a stage connected in series with the low input current amplifier to amplify the first signal to distinguish the incidence, traverse and physiological condition of a living human. The resulting signal is then processed by an algorithm and displayed as human specific motion, heart rate and respiratory rate.

Integrated electronic circuit (10,12) for an implantable probe module, including a number of pixel circuits each having: an electrode for contacting a biological tissue; a biasing stage (M.sub.1,C) with a capacitor and a first transistor, which is coupled to the capacitor and injects in an input node (N.sub.IN) a biasing current (I.sub.bias) that depends upon the charge of the capacitor; a second transistor coupled to the electrode and to the input node (N.sub.IN); an amplifier coupled to a reference voltage (V.sub.ref1) and to the input node (N.sub.IN). The integrated electronic circuit (10,12) furthermore includes a feedback stage electrically controllable so as to be alternatively coupled or decoupled from each pixel circuit. The feedback stage forms, when coupled to a pixel circuit, an autozeroing loop that charges the corresponding capacitor so that the biasing current (I.sub.bias) is such that on the input node (N.sub.IN) a voltage substantially equal to the reference voltage is present.

Integrated electronic circuit (10,12) for an implantable probe module, including a number of pixel circuits each having: an electrode for contacting a biological tissue; a biasing stage (M.sub.1,C) with a capacitor and a first transistor, which is coupled to the capacitor and injects in an input node (N.sub.IN) a biasing current (I.sub.bias) that depends upon the charge of the capacitor; a second transistor coupled to the electrode and to the input node (N.sub.IN); an amplifier coupled to a reference voltage (V.sub.ref1) and to the input node (N.sub.IN). The integrated electronic circuit (10,12) furthermore includes a feedback stage electrically controllable so as to be alternatively coupled or decoupled from each pixel circuit. The feedback stage forms, when coupled to a pixel circuit, an autozeroing loop that charges the corresponding capacitor so that the biasing current (I.sub.bias) is such that on the input node (N.sub.IN) a voltage substantially equal to the reference voltage is present.

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.

Hat, helmet, and other headgear apparatus includes dry electrophysiological electrodes and, optionally, other physiological and/or environmental sensors to measure signals such as ECG from the head of a subject. Methods of use of such apparatus to provide fitness, health, or other measured or derived, estimated, or predicted metrics are also disclosed.

Hat, helmet, and other headgear apparatus includes dry electrophysiological electrodes and, optionally, other physiological and/or environmental sensors to measure signals such as ECG from the head of a subject. Methods of use of such apparatus to provide fitness, health, or other measured or derived, estimated, or predicted metrics are also disclosed.

A process of capturing a biopotential signal at a surface of a body includes using a sensor receiver which forms a first signal connection with the body wherein one or more parameters of impedance of the first signal connection are unknown. The biopotential signal is received at an output of a first signal channel having a first transfer function dependent on the one or more unknown first impedance parameters. The biopotential signal is received at an output of a second signal channel having a second transfer function dependent on the one or more unknown first impedance parameters. The process also comprises deriving a set of relations for the biopotential signal based on the transfer function of the first signal channel, the transfer function of the second signal channel, and outputs of the first and second signal channels. The set of relations is solved to determine the captured biopotential signal.

A process of capturing a biopotential signal at a surface of a body includes using a sensor receiver which forms a first signal connection with the body wherein one or more parameters of impedance of the first signal connection are unknown. The biopotential signal is received at an output of a first signal channel having a first transfer function dependent on the one or more unknown first impedance parameters. The biopotential signal is received at an output of a second signal channel having a second transfer function dependent on the one or more unknown first impedance parameters. The process also comprises deriving a set of relations for the biopotential signal based on the transfer function of the first signal channel, the transfer function of the second signal channel, and outputs of the first and second signal channels. The set of relations is solved to determine the captured biopotential signal.

Provided are implantable and bioresorbable medical devices comprising a bioresorbable substrate and an electronic circuit supported by the bioresorbable substrate. The electronic circuit comprises a membrane of silicon having a thickness less than or equal to 5 m and an array of dissolvable electrodes, wherein the dissolvable electrodes are formed from the membrane of silicon. The electronic circuit is configured to conformally contact a biological tissue and electrically interface with biological tissue during use. The silicon may be highly doped to provide the requisite characteristics for electrically interfacing with biological tissue, and may be further used to form other components of the electronic circuit, including back-plane transistors electrically connected to the electrode array.

An apparatus and method (4,5,6,7,2) for capacitive measurement of electrophysiological signals (1) suppresses or reduces motion artifacts by providing a feedback mechanism. An average voltage between a capacitive sensor electrode (1) and the body (3) is controlled so as to reduce or minimize motion-induced signals.