Showing papers on "Electrode array published in 1994"

Methods and apparatus for surgical cutting

Abstract: An electrosurgical probe comprises a shaft having an electrode array (12) at its distal end and a connector at its proximal end. The array (12) includes a plurality of isolated electrode terminals, and an electrosurgical power supply (28) is provided with a multiplicity of independently limited or controlled current sources and a connector. The electrosurgical probe and the power supply may be connected through their respective connectors so that the independent current sources are connected to individual electrode terminals. By applying very high frequency electrical energy to the electrode array, target tissue may be cut or ablated while heat dissipation through low impedance paths, such as blood and normal saline, will be minimized.

Systems and methods for positioning multiple electrode structures in electrical contact with the myocardium

Abstract: Systems and methods evaluate electrical contact between the myocardium and one or more electrodes inside the heart. The systems and methods electrically sense electrical contact between the myocardium and electrodes and generate unitary contact-indicating outputs indicating the presence or absence of electrical contact between the myocardium and each particular electrode. The systems and methods also correlate the electrode-specific unitary outputs to generate a compound contact-indicating output. The compound output represents the aggregate of the electrical contact between the myocardium and multiple electrodes on a multiple electrode array.

Electrode array catheter

Abstract: An electrode array catheter, typically used for mapping, pacing and ablation, includes a flexible delivery sheath (36, 64) and an electrode assembly (2, 62) slidably mounted within the delivery sheath for movement between retracted and deployed positions. The electrode assembly includes an ablation electrode (10, 90) and a plurality of mapping electrodes (26, 114) which are grouped in pairs and naturally assume a three-dimensional array when deployed. The electrodes are distributed to contact a portion of the chamber wall (130) surrounding the target site. The electrode assembly tip has a coiled conical shape (24) in one embodiment and has a number of axially extending, radially outwardly curved arms (118) in another embodiment. A flat flexible circuit (110), having axially extending electrode traces (112) connecting proximal terminals (108) to distal electrode pads (114), is slit (116) axially and is preformed and to create the curved arms.

Implantable multichannel stimulator

Abstract: A multichannel stimulation system includes a plurality of implantable microminiature stimulators (microstimulators), each being connected to a respective implanted electrode or electrode array. Each microstimulator is selectively operable as controlled by an external (non-implanted) control unit. The electrode or electrode array is implanted so as to contact nerves and/or tissue that is to be stimulated. Operating power is inductively coupled from the control unit to the microstimulators. An information signal is also coupled to the microstimulators to control which of the microstimulators is to be activated to provide a stimulation pulse to its respective electrode. In one embodiment, the invention provides a cochlear prosthesis with an intracochlear electrode array being implanted within the human cochlea, and with selected electrodes of the array being connected to individual ones of the plurality of microstimulators. The control unit of such cochlear prosthesis includes a small external transmitter coil that is worn next to the skin where the microstimulators are implanted. The control unit generates a power signal and an information signal for powering and controlling the cochlear prosthesis.

Segmented electrode assemblies for ablation of tissue

Abstract: This invention is a multiple electrode array for ablating tissue that carries at least two electrode segments (26, 27, 28, 29) that are circumferentially spaced form each other. Insulation (30) electrically isolates the separated electrode segments from each other. Signal wires (19) attached to the separated electrode segments convey ablating energy independently to the separated electrode segments. Because of its segmented structure, the array can place only one of the electrode segments in contact with tissue at one time. Because each segment is electrically isolated, and because each segment is independently served by its own signal wire, a physician can operate an ablation energy generator to selectively channel the ablation energy only to the segment actually contacting the tissue.

Determination of the position of nucleus cochlear implant electrodes in the inner ear.

Abstract: Accurate determination of intracochlear electrode position in patients with cochlear implants could provide a basis for detecting migration of the implant and could aid in the selection of stimulation parameters for sound processor programming. New computer algorithms for submillimeter resolution and 3-D reconstruction from spiral computed tomographic (CT) scans now make it possible to accurately determine the position of implanted electrodes within the cochlear canal. The accuracy of these algorithms was tested using an electrode array placed in a phantom model. Measurements of electrode length and interelectrode distance from spiral CT scan reconstructions were in close agreement with those from stereo microscopy. Although apparent electrode width was increased on CT scans due to partial volume averaging, a correction factor was developed for measurements from conventional radiographs and an expanded CT absorption value scale added to detect the presence of platinum electrodes and wires. The length of the cochlear canal was calculated from preoperative spiral CT scans for one patient, and the length of insertion of the electrode array was calculated from her postoperative spiral CT scans. The cross-sectional position of electrodes in relation to the outer bony wall and modiolus was measured and plotted as a function of distance with the electrode width correction applied.

CMOS output driver which can tolerate an output voltage greater than the supply voltage without latchup or increased leakage current

Abstract: A mixed mode buffer circuit 11 including a first input (12), a second input (13), and an output (14). A voltage exceeding a supply voltage of mixed mode buffer circuit 11 can be applied to the output (14) without latchup or an increase in leakage current. The mixed mode buffer includes an output transistor (24) of a first conductivity type having a first electrode coupled to the output (14), a control electrode coupled to the first input (12), a second electrode coupled for receiving the supply voltage, and a bulk electrode. A first transistor (19) biases the bulk electrode when the voltage at the output is within a first predetermined range. A first bulk bias circuit (28) biases the bulk electrode when the output voltage is within a second predetermined range. A second bulk bias circuit (27) and a second transistor (18) couples the voltage at the output to the bulk electrode and the control electrode respectively, when the output voltage exceeds the second predetermined range.

Photodetector, a photodector array comprising photodetectors, an object detector comprising the photodetecter array and an object detecting procedure

Abstract: A photodetector has a semiconductor substrate which produces light-induced charge upon the absorption of incident light. A first electrode and a second electrode are attached to the surface of the semiconductor substrate so as to form metal-semiconductor junctions. When control voltage VB, which is variable in a positive range through a negative range, is applied to the first electrode, a photocurrent flows through the second electrode and depletion layers are formed in the surface of the semiconductor substrate. The control voltage VB applied to the first electrode increases the expanse of one of the depletion layers relative to that of the other to cause the light-induced charge to drift toward one of the depletion layers or the other. Consequently, a positive or negative current is delivered through the second electrode. Thus, the photosensitivity of the photodetector can be controlled by the control voltage VB.

Vertical transistor having an underlying gate electrode contact

Abstract: A method for forming a vertical transistor (10) begins by providing a substrate (12). A conductive layer (16) is formed overlying the substrate (12). A first current electrode (26), a second current electrode (30), and a channel region (28) are each formed via one of either selective growth, epitaxial growth, in-situ doping, and/or ion implantation. A gate electrode or control electrode (34) is formed laterally adjacent the channel region (28). A selective/epitaxial growth step is used to connect the conductive layer (16) to the control electrode (34) and forms a control electrode interconnect which is reliable and free from electrical short circuits to the current electrodes (26 and 30). The transistor (10) may be vertically stacked to form compact inverter circuits.

Four-Channel cochlear system with a passive, non-hermetically sealed implant

Abstract: A low-cost, multichannel cochlear stimulation system utilizes a passive, non-hermetically sealed, implantable receiver/electrode array and an external wearable processor. At one end of the receiver/electrode array, positioned subcutaneously near the surface of skin above the ear, multiple receiving coils are arranged in an appropriate pattern. At the other end, which is adapted for insertion into the spiral-shaped cochlea, electrodes are spaced apart along the spiral. Each electrode is electrically connected to a respective receiving coil in a monopolar or bipolar fashion. The wearable processor senses audible sounds, converts the sensed sounds to corresponding electrical signals, and divides the electrical signals into multiple frequency bands or channels. A continuous interleaved sampling (CIS) speech processing strategy applies the processed signals of each channel to each of multiple external coils, one coil for each channel, as a series of narrow, rapid, biphasic current pulses. The external coils are aligned, using a suitable headpiece, with corresponding coils of the receiver/electrode array. The narrow CIS pulses contain sufficiently high frequency components to inductively couple the biphasic current pulses directly to the aligned implanted coils without having to modulate a high frequency carrier signal with the biphasic pulses. The induced voltage at the implanted coils causes the biphasic current pulse to appear at a respective electrode of the implanted electrode array, thereby providing electrical stimulation at the cochlea as a function of sensed audible sounds.

Method for dynamically positioning a control electrode array in a direct electrostatic printing device

Abstract: A method and device to enhance the printing quality of direct electrostatic printers which utilize an electrode array and electrical signals to generate an electrical field to cause toner particles to be deposited directly onto plain paper to form visible images. The invention relates to an improvement to dynamically position and maintain a desired distance between the electrode array and the surface of the charged particles on the particle carrier.

Thin-film transistor and display device using the same

Abstract: In a thin-film transistor 171, in order to sufficiently suppress an optical leakage current Ioff, thereby achieving a high ON/OFF current ratio, at least one of shortest distances between an arbitrary intersection of an outline of a gate electrode 131 and an outline of a drain electrode 141 and an intersection of the outline of the gate electrode 131 and an outline of a source electrode 151 is formed to be larger than the shortest distance between a portion of the outline of the gate electrode 131 overlapping the drain electrode 141 and another portion thereof overlapping the source electrode 151.

Sensor for detecting presence of person in vehicle seat etc.

Abstract: At least one measurement electrode (2,3) connected to a voltage source (1) generates an electric field in the region of the monitored location (4) and changes in the capacitance of the measurement electrodes are measured. At least one further reference electrode (5,6) connected to the voltage source generates an electric field outside the immediate vicinity of the monitored position. Relative changes in the capacitances of the reference and measurement electrodes can be measured. The capacitance changes can be measured via associated voltage changes.

Method and device for monitoring electrodes of electrical heart stimulators

Abstract: In a method for continuous, electrical monitoring of the electrodes of an electrical heart stimulator, having at least one stimulation electrode and an indifferent electrode, the inter-electrode voltage is kept constant by regulation of a very low compensating current, and the magnitude of this current is measured and monitored. A device for such electrode monitoring includes control electronics and an output stage for delivery to the stimulation electrode of stimulation pulses. The output stage is devised to supply the electrodes with a weak, continuous current, or a repeated, pulsed current, producing a net direct current, in addition to stimulation pulses. A monitoring unit senses the inter-electrode voltage and, on the basis thereof, deliver an output signal to the control electronics for the purpose of controlling the weak current so the inter-electrode voltage is kept constant at a given value. This output signal is monitored, with significant deviations thereof, or an inability to maintain the inter-electrode voltage constant indicating the presence of a fault in the electrode system.

Plasma display panel and its drive method

Abstract: PURPOSE: To provide a plasma display panel capable of performing a sure priming discharge at low voltage further with high contrast, by providing a priming electrode between cells in parallel to a plurality of scanning electrodes or maintaining electrodes. CONSTITUTION: A phosphor 7 is arranged to face a discharge gas space 5 sealed between glass insulating substrates 1, 2. Further, a plurality of parallel scanning electrodes 11 and discharge maintaining parallel maintaining electrodes 12 are provided with a power supplying bus electrode 3 on the same plane to a display cell (not shown in the drawing) through a protective film 9. A plurality of parallel data electrodes 4, supplying a display data, are provided orthogonal to these electrodes. A priming electrode 15 performing a priming discharge is provided between the cells in this scanning electrode 11 or the like, to supply a priming particulate. In the AC surface discharging plasma display panel, the priming electrode 15 is provided in parallel to the scanning electrode 11 or maintaining electrode 12, to make a low voltage discharge capable, further to generate low brightness while obtaining high contrast. COPYRIGHT: (C)1996,JPO

Controllable-birefringence, acousto-optic tunable filter and a laser tuned by the same

Abstract: An acousto-optic tunable filter ("AOTF") with a pair of electrodes on opposite sides of the waveguide. A voltage source applies a potential across the electrodes, thereby creating an electric field through the waveguide. The electric field controls an optical property of the waveguide by altering the birefringence of the waveguide. Suitably adjusting the potential applied by the voltage source results in suppression of sidelobes, correction of asymmetric sidelobes, and compensation for physical variations in the waveguide. The AOTF can be tuned very rapidly by a tuning voltage applied to the electrodes. In combination with a thermistor, the control voltage can compensate for changes in temperature. A spatially-varying electric field is generated by using a set of electrodes at different potentials, or by using a resistive element as an electrode, or by shaping the electrodes according to the desired field. A rapidly-varying control voltage can modulate a light beam in the filter. The AOTF finds an application as the tuning element of an external-cavity tunable laser.

AC plasma address liquid crystal display

Abstract: A drive system for a matrix cross point addressing system comprises a first substrate having a transparent first linear electrode array thereon. A second substrate having a second linear electrode array thereon, oriented transverse of the first linear electrode array defines therewith a matrix of cross-points. An array of insulating ribs on the second linear electrode array defines an array of channels and an ionizable gas medium fills the array of channels, each channel of the array being aligned with a transparent electrode of the first linear electrode array, respectively. A layer of electric field responsive material, such as a liquid crystal, is sandwiched between the transparent first linear electrode array and a dielectric layer. First circuit means applies a first pulse operating voltage to the first linear electrode array and second circuit means for applying second pulse operating voltage to said second linear electrode array so that the conjoint voltages at selected matrix cross-points (1) causes a discharge in the gas therebetween and forms a charge on the dielectric layer and change the state properties of said electric field responsive material, and (2) remove said charge to cause said material to revert to its initial state, the conjoint voltage applied to the electrodes at a selected site is varied to vary the size charge at selected discharge sites and vary the area of said electric field responsive material at said site which is effected by the charge stored on said dielectric layer.

Cochlear implant devices.

Abstract: A cochlear prosthesis comprising an electrode array of individually addressable electrodes and a stimulator device to provide electrical stimuli to selected groupings of electrodes in response to sound signals. The stimuli and the electrode groupings being determined by reference to a predefined instruction set. The cochlear prosthesis is characterized in that in response to different sound signals at least two distinct current distribution geometries are induced in the auditory structures of a user. This may be achieved by using different electrode geometries, different stimulation modes, combinations of stimulation modes and/or electrode geometries.

Low breakdown voltage gas discharge device and methods of manufacture and operation

Abstract: A low breakdown voltage gas discharge device includes an envelope filled with an appropriately selected working substance. Two main electrodes are sealed in a vacuum-tight manner inside the envelope, and are separated by a predetermined distance. A supplemental electrode extends between the main electrodes along the direction of the electrical discharge, and has its geometrical and electrical parameters satisfy the following equation: S=Id /C, where S is the surface area of the supplemental electrode and depends on the distance between the main electrodes, Id is the current flowing in the supplemental electrode during normal glow discharge, and C is a constant characterizing the current Id, the composition of the supplemental electrode, and the type and pressure of the working substance. The supplemental electrode is connected to an AC or DC power source via a switch, so that the supplemental electrode always acts as a preparatory glow discharge cathode.

Identification of pin-open faults by measuring current or voltage change resulting from temperature change

Abstract: A method and apparatus for determining whether semiconductor components are electrically connected to a printed circuit board. A voltage (or current) is connected to two traces leading to connections to a semiconductor component to be tested. The initial current (or voltage) is measured at an initial temperature. Then, the temperature of the semiconductor is changed. Current (or voltage) is measured again after the temperature change. A change in current (or voltage) indicates that the semiconductor component is electrically connected to the trace.

Capacitor for semiconductor integrated circuit

Abstract: A first electrode, first ferroelectric thin-film, second electrode, second ferroelectric thin-film and third electrode are laid in this order on a source region of a field-effect transistor. The first and third electrodes are connected by a metal lead. The second electrode is connected to a ground line or a drive line.

Programmable non-volatile memory cell

Abstract: A non-volatile memory cell having a structure having improved integration and simplified electrode wiring structure. The programmable non-volatile memory cell of the present invention adopts a mono-layer gate scheme to simplify the electrode wiring structure and to eliminate a current leakage problem of an insulating film between electrodes. A side and bottom of a semiconductor region, which is disposed directly below a capacity electrode section with a gate insulating film interposed therebetween that compose a control electrode, are isolated from another semiconductor region and semiconductor substrate by insulating films. Thus, a high programming control voltage which is not limited by a junction yield voltage between the semiconductor regions and semiconductor substrate may be applied. Due to that, an area of the capacity electrode section of a floating electrode may be considerably reduced.

Resonator and chip-type filter using it

Abstract: A resonator comprises two dielectric substrates. A ground electrode and a U-shaped pattern electrode are formed respectively on the two surfaces of the first dielectric substrate. A take-out electrode is drawn out at a certain distance from one end of the pattern electrode, and is connected to the take-out terminal electrode. A guard electrode is formed opposite to the other end of the pattern electrode. A shield electrode is formed on a second dielectric substrate. The pattern electrode, the ground electrode and the shield electrode are connected by a terminal electrode. In addition, the guard electrode, the ground electrode and the shield electrode are connected by a terminal electrode. A chip-type filter can be obtained by forming a plurality of pattern electrodes on an dielectric substrate, and coupling them electromagnetically.

System and method for control of a Pockel's cell

Abstract: A two-step solid state optical switch system includes an electro-optical material positioned between a first electrode and a grounded second electrode. A voltage source is electrically connectable to the first electrode by an ON switch. When the ON switch is closed, a plurality of field effect transistors establish electrical contact between the voltage source and the first electrode to charge the first electrode and change the optical characteristics of the electro-optical material. An OFF switch, which is also electrically connectable to the first electrode, includes a plurality of field effect transistors, which establish electrical contact between ground and the first electrode when the OFF switch is closed. With the closing of the OFF switch, any voltage on the first electrode is removed to restore the optical characteristics of the electro-optical material. Electronic components of the system selectively activate the ON switch and the OFF switch in a sequence so that both switches are never simultaneously closed.

Electrostatic fibrous filter

Abstract: The particle collection efficiency of a fibrous filter is significantly increased by imposing a high voltage potential on electrodes placed on either side of the filter. This creates a strong electrostatic field across the filter which electrically enhances the fiber's particle collection ability. The electrostatic field strength, and particle collection efficiency, increase with the voltage employed to establish the electrostatic field. An insulated electrode as the front electrode in combination with a conductive electrode as the rear electrode enables a very high electrical potential to be imposed on the electrodes without resulting in arcing between electrodes. Pre-charging of dust particulates with the same polarity as the insulated electrodes further increase collection efficiency without resulting in a charge buildup in front of the electrodes or a blocking of airflow by particles collecting on the electrodes.

The use of averaged electrode voltages to assess the function of nucleus internal cochlear implant devices in children.

Abstract: Averaged electrode voltages (AEVs) provide an objective measure of the output of the Nucleus multichannel cochlear implant device. AEVs are the peak-to-peak voltages of each electrode in the internal array and are recorded from electrodes placed on the scalp. This article summarizes average voltage data for 25 children with complete insertions of the electrode array. Data are compared with previously published adult data and are evaluated based on the location of the recordings (clinic versus operating room). AEV data can be applied clinically to identify implant problems. AEV recordings for this purpose are particularly important with children who may not be able to provide accurate reports of implant function. Case studies are presented to illustrate the application of the AEV procedure to examine implant malfunction in six children.

Three electrode type saw longitudinal coupling filter

Abstract: A three electrode type SAW longitudinal coupling filter includes a piezoelectric substrate having an electromechanical coupling factor (K 2 ) higher than 10% and, three sets in total of input electrodes and output electrodes. Each of the electrodes includes a plurality of a electrode fingers of comb shape and are formed on the piezoelectric substrate. Reflectors are disposed at opposite sides of the input electrodes and output electrodes. The number of pairs of electrode fingers of the input electrodes is differentiated from the number of pairs of electrode fingers of the output electrodes. By the above arrangement, a large pass-band width can be obtained with small ripples and with an increase of the attenuation amount outside the band region.

Identifying electrode failures with cochlear implant generated surface potentials.

Abstract: A procedure for measuring surface potentials called electrode-by-electrode (E-E) mapping is described that can detect the nonintermittent malfunctioning of the implanted receiver and electrode array of multichannel cochlear implants, such as the Cochlear (Nucleus) device. E-E mapping is based on the sequential stimulation of all paired combinations of electrodes. The recorded waveforms were averaged and all peak-to-peak amplitudes were combined into one graph for a comprehensive check on open circuit or short-circuited electrodes. Normative data from 21 patients are given. E-E mapping detected electrode failure in three patients whose behavioral thresholds were in agreement with hardware problems, including one case of overstimulation at high stimulus levels. In one patient who was suffering from overstimulation without any deviant thresholds, no failure could be detected. The procedure takes about a quarter of an hour and the stimulus amplitude needed is below threshold for most patients, which makes it especially useful in children. An informative partial E-E map can be made during implantation and requires virtually no extra theater time.