One aspect of the present disclosure relates to a system that can prevent unintended signal components (noise) in an electric waveform that can be used for at least one of neural stimulation, block, and/or sensing. The system can include a signal generator to generate a waveform that includes an intended electric waveform and unintended noise. The system can also include a signal transformer device (e.g., a very long wire) comprising a first coil and a second coil. The first coil can be coupled to the signal generator to receive the waveform and remove the unintended noise from the electric waveform. The second coil can pass the electric waveform to an electrode. The second coil can be coupled to a capacitor that can prevent the waveform from developing noise at an electrode/electrolyte interface between an electrode and a nerve.

The double layer capacitance of a working electrode of a sensor may be measured with minimal disruption to the sensor equilibrium by open circuiting the working electrode and measuring the voltage drift on a periodic, or as-needed, basis. The values of the double layer capacitance may be monitored over time to determine, e.g., sensor age and condition.

An electrocardiography (ECG) physiological monitoring system that includes an ECG sensor assembly having first and second capacitive electrodes that are configured to electrically couple to a subject's skin and detect ECG signals, a reference electrode that is configured to average the capacitance potential of the first and second electrodes, an electronics module that is in direct communication with the ECG sensor assembly and programmed to control the ECG sensor assembly, process ECG signals therefrom, and wirelessly transmit the processed ECG signals, and transmission conductors that are configured to provide a signal communication path between the electronics module and the ECG sensor assembly.

A bioelectrode including a plate, a first electrode disposed on a first side of the plate, and a second electrode disposed on the first side of the plate and separate from the first electrode. The bioelectrode further includes a first guard portion disposed on a second side of the plate, a second guard portion disposed on the second side of the plate and separate from the first guard portion, and a preamplifier configured to output a voltage signal based on a biosignal measured between the first electrode and the second electrode.

A handheld, conforming capacitive sensing apparatus configured to measure Sub-Epidermal Moisture (SEM) as a mean to detect and monitor the formation of pressure ulcers. The device incorporates an array of electrodes which are excited to measure and scan SEM in a programmable and multiplexed manner by a battery-less RF-powered chip. The scanning operation is initiated by an interrogator which excites a coil embedded in the apparatus and provides the needed energy burst to support the scanning/reading operation. Each electrode measures the equivalent sub-epidermal capacitance corresponding and representing the moisture content.

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 catheter includes an elongated body having a longitudinal axis, a distal assembly distal the elongated body, the distal assembly having a tapered helical form comprising a larger, electrode-carrying proximal loop and a smaller, softer distal loop, and a shape-memory support member extending through at least the proximal loop. For example, the helical loop subtends at least about 720 radial degrees, with the proximal loop subtending about 360 radial degrees, and the distal loop subtending about 360 radial degrees. The softer distal loop with a straight distal end atraumatically guides the distal assembly into a tubular region so that the larger proximal loop can sit on the ostium of the tubular region with improved electrode and tissue contact.

A sleeping mask includes a signal processor for processing sensor data, an infrared light source coupled to the signal processor and configured to emit infrared light toward an eyelid of a user, and an array of infrared sensors coupled to the signal processor and configured to receive infrared light reflected from the eyelid of the user.

A method for use in analyzing impedance measurements performed on a subject, the subject being arranged such that body fluid levels in at least one leg segment of the subject changed between a first time and a second time, the method including, in a processing system, at the first time, determining at least one first impedance value indicative of the impedance of the at least one leg segment of the subject; at the second time, determining at least one second impedance value indicative of the impedance of the at least one leg segment of the subject; and determining an indicator based on the at least one first and at least one second impedance values, the indicator being indicative of changes in the body fluid levels.

Diagnostic apparatus (24) includes a sealed case (40), including a biocompatible material and configured for implantation within a body of a human subject (22). At least one antenna (42) is configured to be implanted in the body in proximity to a target tissue (28) and to receive radio frequency (RF) electromagnetic waves propagated through the target tissue and to output a signal in response to the received waves. Processing circuitry (44,46), which is contained within the case, us coupled to receive and process the signal from the antenna so as to derive and output an indication of a characteristic of the target tissue.