Electrode array

About: Electrode array is a research topic. Over the lifetime, 7061 publications have been published within this topic receiving 137433 citations.

An Integrated-Circuit Approach to Extracellular Microelectrodes

Abstract: This paper describes a new multielectrode microprobe which utilizes integrated-circuit fabrication techniques to overcome many of the problems associated with conventional microelectrodes. The probe structure consists of an array of gold electrodes which are supported on a silicon carrier and which project beyond the carrier for a distance of about 50 ? to allow a close approach to active neurons. These electrodes are covered with a thin (0.4-?) layer of silicon dioxide which is selectively removed at the electrode tips using high-resolution photoengraving techniques to define the recording areas precisely. The processing sequence described permits any two-dimensional electrode array to be realized. Interelectrode spacings can be accurately controlled in the range from 10 to 20 ? or larger, and electrode-tip diameters can be as small as 2 ?.

Fitting process for a neural stimulation system

Abstract: A programming system and method for use with an implantable tissue stimulator allows a clinician or patient to quickly determine a desired electrode stimulation pattern, including which electrodes of a multiplicity of electrodes in an electrode array should receive a stimulation current, including the amplitude, width and pulse repetition rate of such current. Movement of the selected group of electrodes is facilitated through the use of a directional pointing device, such as a joystick. As movement of the selected group of electrodes occurs, current redistribution amongst the various electrode contacts takes place. The redistribution of stimulus amplitudes utilizes re-normalization of amplitudes so that the perceptual level remains fairly constant. This prevents the resulting paresthesia from falling below the perceptual threshold or above the comfort threshold. A software wizard provides a software user interface, including the use of easy-to-understand instructional, data-gathering and/or parameter-setting screens, that walks a user step by step through the programming process.

Graphene-based carbon-layered electrode array technology for neural imaging and optogenetic applications

Abstract: Neural micro-electrode arrays that are transparent over a broad wavelength spectrum from ultraviolet to infrared could allow for simultaneous electrophysiology and optical imaging, as well as optogenetic modulation of the underlying brain tissue. The long-term biocompatibility and reliability of neural micro-electrodes also require their mechanical flexibility and compliance with soft tissues. Here we present a graphene-based, carbon-layered electrode array (CLEAR) device, which can be implanted on the brain surface in rodents for high-resolution neurophysiological recording. We characterize optical transparency of the device at >90% transmission over the ultraviolet to infrared spectrum and demonstrate its utility through optical interface experiments that use this broad spectrum transparency. These include optogenetic activation of focal cortical areas directly beneath electrodes, in vivo imaging of the cortical vasculature via fluorescence microscopy and 3D optical coherence tomography. This study demonstrates an array of interfacing abilities of the CLEAR device and its utility for neural applications.

Differential touch sensor and control circuit therefor

Abstract: A differential touch sensor apparatus for detecting the presence of an object such as a human appendage, the apparatus having a first electrode, a second electrode positioned proximate to the first electrode, a differential circuit connected to the first and second electrodes, and a pulse or other signal source connected to provide electrical signals that generate an electric field between the first and second electrodes. Introduction of an object near the first electrode affects the electric field between the first and second electrodes, thereby affecting the voltage difference between them. A differential circuit provides an output signal responsive to the difference in voltage between the first and second electrodes. In an alternative embodiment, a strobe electrode is provided proximate to both said first and second electrodes and the pulses or other signals are provided to the strobe electrode to induce an electric field between the strobe electrode and each of the first and second electrodes.

Deflectable loop electrode array mapping and ablation catheter for cardiac chambers

Abstract: A cardiac arrhythmia mapping and ablation catheter has a main catheter that is provided with a mapping and ablation system attached to its distal end which includes an adjustable loop carrying an electrode array including a plurality of parallel-connected, separately operable mapping/ablation electrodes in conductive relation to the external environment and arranged in spaced serial relation along the loop. Insulated conductors connect the electrodes electrically with an input/output device outside the catheter for mapping the electrical activity of the chamber wall contacted and ablating tissue as indicated. Drawstring control wires are used to control the size, shape and deflection or posture of the loop. A distal extension may optionally be provided to adapt the loop specifically to addressing the tricuspid annulus. A fixed version is also disclosed.