Devices, systems, and methods herein relate to electromyography (EMG) that may be used in diagnostic and/or therapeutic applications, including but not limited to electrophysiological study of muscles in the body relating to neuromuscular function and/or disorders. Sensor assemblies and methods are described herein for non-invasively generating an EMG signal corresponding to muscle tissue where the sensor may be positioned directly on a surface of the muscle tissue including any associated membrane (e.g., mucosal, endothelial, synovial) overlying the muscle tissue. A sensor assembly may include one or more pairs of closely spaced, atraumatic electrodes in a bipolar or multipolar configuration. The first and second electrodes may be applied against a surface of muscle tissue (that may include a membrane overlying the muscle) and receive electrical activity signal data corresponding to an electrical potential difference of the portion of muscle between the electrodes.

Devices, systems, and methods herein relate to electromyography (EMG) that may be used in diagnostic and/or therapeutic applications, including but not limited to electrophysiological study of muscles in the body relating to neuromuscular function and/or disorders. Sensor assemblies and methods are described herein for non-invasively generating an EMG signal corresponding to muscle tissue where the sensor may be positioned directly on a surface of the muscle tissue including any associated membrane (e.g., mucosal, endothelial, synovial) overlying the muscle tissue. A sensor assembly may include one or more pairs of closely spaced, atraumatic electrodes in a bipolar or multipolar configuration. The first and second electrodes may be applied against a surface of muscle tissue (that may include a membrane overlying the muscle) and receive electrical activity signal data corresponding to an electrical potential difference of the portion of muscle between the electrodes.

The present disclosure facilitates capture (e.g., bipolar capture) of differentially-acquired wide-band phase gradient signals (e.g., wide-band cardiac phase gradient signals, wide-band cerebral phase gradient signals) that are simultaneously sampled. Notably, the exemplified system minimizes non-linear distortions (e.g., those that can be introduced via certain filters such as phase distortions) in the acquired wide-band phase gradient signals so as to not affect the information therein that can non-deterministically affect analysis of the wide-band phase gradient signal in the phase space domain. Further, a shield drive circuit and shield-drive voltage plane may be used to facilitate low noise and low interference operation of the acquisition system.

An electrocardiogram (ECG) extension cable includes a first connector configured to be electrically coupled to a physiological monitoring device; a second connector configured to be electrically coupled to an ECG lead set including a processor; an input/output (I/O) wire configured to transmit data between the physiological monitoring device and the processor; a ground wire that establishes a ground path between the first connector and the second connector; a series protection element coupled in series along the ground wire; a bypass path coupled to the ground wire in parallel to the series protection element; and a switching element arranged along the bypass path and configured to redirect the ground path along the bypass path, thereby bypassing the series protection element.

An electrocardiogram (ECG) extension cable includes a first connector configured to be electrically coupled to a physiological monitoring device; a second connector configured to be electrically coupled to an ECG lead set including a processor; an input/output (I/O) wire configured to transmit data between the physiological monitoring device and the processor; a ground wire that establishes a ground path between the first connector and the second connector; a series protection element coupled in series along the ground wire; a bypass path coupled to the ground wire in parallel to the series protection element; and a switching element arranged along the bypass path and configured to redirect the ground path along the bypass path, thereby bypassing the series protection element.

A system includes a signal generator, configured to pass a generated signal, which has two different generated frequencies, through a circuit including a bidirectional semiconductor device. The system further includes a processor, configured to identify, while the generated signal is passed through the circuit, a derived frequency, which derives from the generated frequencies, on the circuit, and to generate, in response to identifying the derived frequency, an output indicating that a property of the bidirectional semiconductor device is asymmetric. Other embodiments are also described.

Multiple wireless sensor assemblies are individually attached to standard biopotential electrodes, which are placeable on a subject's body at locations for biopotential signal recording. The sensor assemblies, which are electrically isolated, simultaneously measure potential voltages from the body sites in accordance with a synchronization. The measured signals are amplified, digitized, and filtered, and then sent wirelessly to a monitoring system. The monitoring system receives multiple sensor signals and constructs biopotential vectors depending on the placement and number of the sensors. The sensor signals are referenced to a common virtual center bias to synthesize a common mode rejection.

Disclosed herein are various embodiments of an interface control subsystem that may be used between an electrode terminal and a recording terminal of a neurostimulation and neurorecording system. The interface control subsystem may operate in three modes. In a disable mode, a first transistor and a second transistor disposed between the electrode terminal and the recording terminal may operate in a cutoff region and generate a high impedance. In an active mode, the first transistor and the second transistor may operate in a saturation region and generate a low impedance. In a stimulation mode, the first transistor and the second transistor operate in a triode region and generate an impedance between the high impedance of the disable mode and the low impedance of the active mode. The interface control subsystem may further limit voltage at the recording terminal in response to a detected overvoltage condition.

An apparatus includes two or more medical systems and a low impedance path. The two or more medical systems have respective electrical outputs and respective separate isolation grounds each isolated from power lines and from earth ground, wherein the two or more medical systems are electrically coupled one with the other via the patient. The low impedance path connects the separate isolation grounds of the medical systems to one another, causing one or more leakage currents to flow via the low impedance path instead of via the patient.

An apparatus includes two or more medical systems and a low impedance path. The two or more medical systems have respective electrical outputs and respective separate isolation grounds each isolated from power lines and from earth ground, wherein the two or more medical systems are electrically coupled one with the other via the patient. The low impedance path connects the separate isolation grounds of the medical systems to one another, causing one or more leakage currents to flow via the low impedance path instead of via the patient.