Showing papers on "Electrode array published in 1993"

Subcutaneous multi-electrode sensing system, method and pacer

Abstract: A method and apparatus for providing an enhanced capability of detecting and gathering electrical cardiac signals via an array of relatively closely spaced subcutaneous electrodes (located on the body of an implanted device) which may be employed with suitable switching circuits, signal processors, and memory to process the electrical cardiac signals between any selected pair or pairs of the electrode array in order to provide a leadless, orientation insensitive means for receiving the electrical signal from the heart. This far-field EGM may be used to provide storage and analysis of arrhythmic events and to provide control signals for the delivery of various therapies including pacing, cardioversion and defibrillation therapies as well as the delivery of antiarrhythmic drugs, and, in the pacing context, to effect capture detection and automatic stimulation threshold adaption, recording of PMT episodes, measurement of refractory periods in order to set timing windows for antitachy pacing therapies, and as a control signal for use in adjusting pacing rate to physiologic demand.

Methods and apparatus for advancing catheters through severely occluded body lumens

Abstract: A catheter system is provided that includes an electrode array near the distal end of the catheter. High frequency current is supplied between the electrodes of the array and a common electrode to cause heating of material lying between the electrodes. The catheter may include means for steering it through the lumen. In a preferred embodiment, the steering means includes a plurality of steering wires in contact with the catheter body. The steering wires may be formed of a shape-memory alloy. Wires of such an alloy may be made to contract when heated above a preselected transition temperature. The wires may be heated by the selective conduction of electrical current through them. Conduction of current through the steering wires is controlled based on the current flowing through the electrodes of the array. An inflatable balloon may be included proximal to the electrode array for dilating the vessel after the occlusion has been penetrated by the electrode array. The balloon may be shielded and protected behind a portion of the catheter having a diameter greater than the diameter of the uninflated balloon disposed about the catheter body. The catheter will include means for protecting the walls of the vessel from exposure to electrical current from the electrodes. This will commonly include switching means or other means for current control. The vessel wall may also be protected by setting the electrodes back some distance from the outer edge of the distal tip.

Telemetry system and apparatus

Abstract: A system is disclosed for enabling telemetry from an audio prosthesis, preferably a cochlear prosthesis. An electrode array (10) is used for both delivering stimuli and for seeking evoked potentials. Preferably a delay is provided between stimulus and measurement. The sensing electrodes (14, 31) are distinct from the stimulus electrodes (12, 13).

Capacitive proximity sensors

Abstract: Capacitive proximity sensors (10) are disclosed that can be fabricated in different shapes, sizes and materials used in a wide variety of applications. Each such sensor includes a sensing electrode (11) and a guard electrode (12). The sensor electrode and guard electrode can be parallel conductors separated by an insulating layer (13), such as a double-sided circuit board shaped to suit the application. One such sensor is transparent for use in conjunction with an optical bar-code scanner. Another sensor is annular in shape for use in conjunction with a telephone transmitter. The sensing electrode and the guard electrode are driven in unison by an RF signal (21). The proximity of an object to the sensor is observed by detecting (in 24) changes in the RF current flowing through the sensing electrode caused by the proximity of an object to the sensing electrode.

Using compound electrodes in electrical impedance tomography

Abstract: A compound electrode composed of a large outer electrode to inject current and a small inner electrode to sense voltage was developed and used to measure voltages from a physical phantom. The measured voltages were smaller in amplitude than those from conventional electrodes, demonstrating that the compound electrode can minimize contact impedance voltage drop from the measured data. A finite-element model was used for the compound electrode and incorporated into the regularized Newton-Raphson reconstruction algorithm. A sensitivity study showed that the reconstructed resistivity distributions are less dependent on the unknown contact resistance values for a compound electrode than a conventional electrode and that the use of a compound electrode results in improved images for the reconstruction algorithm. >

Method for manufacturing a semiconductor memory device having a capacitor with increased effective area

Abstract: A storage electrode of a capacitor of a semiconductor memory device and a method for manufacturing the same are disclosed. A first electrode of the capacitor comprises a main electrode having a plurality of microtrenches and micropillars formed therein, an outer wall surrounding the microtrenches and micropillars, a granular silicon layer formed on an outer sidewall of the outer wall, and a column electrode supporting the main electrode and electrically connecting the main electrode to a source region of a transistor of the semiconductor device. The first electrode preferably has a horizontally fin-structured auxiliary electrode formed underneath the main electrode and electrically connected to the column electrode of the first electrode. The capacitor may be formed by using an etching end-point detection layer and an HSG polysilicon layer. The effective surface area of the storage electrode of a capacitor is increased to thereby obtain adequate cell capacitance. Also, uniform shapes of the storage electrodes are preferably obtained to thereby attain uniform cell capacitance.

Object imaging with a piezoelectric robotic tactile sensor

Abstract: A two-dimensional, electrically-multiplexed robotic tactile sensor was realized by coupling a piezoelectric polyvinylidene fluoride (PVDF) polymer film to a monolithic silicon integrated circuit (IC). The IC incorporates 64 sensor electrodes arranged in a symmetrical 8*8 matrix. Each electrode occupies a 400*400 mu m square area, and they are separated from each other by 300 mu m. A 40- mu m thick piezoelectric PVDF polymer film was attached to the electrode array with an electrically non-conductive urethane adhesive. The response of the tactile sensor is linear for loads spanning 0.8 to 135 grams of force (gmf). The response bandwidth is 25 Hz, the hysteresis level is tolerable, and, for operation in the sensor's linear range, taxel crosstalk is negligible. The historically persistent stability and response reproducibility limitation associated with piezoelectric-based tactile sensors has been solved by implementing a novel pre-charge voltage bias technique to initialize the pre- and post-load sensor responses. A rudimentary tactile object image measurement procedure for applied loads has been devised to recognize the silhouette of a sharp edge, square, trapezoid, isosceles triangle, circle, toroid, slotted screw, and cross-slotted screw. >

In vivo estimation of cardiac transmembrane current.

Abstract: The ionic currents that cross the myocardial membrane during cardiac activation have a corresponding return path in the extracellular space. The transmembrane current (Im) during activation of cardiac cells in situ has previously been envisioned only in mathematical models. We have developed a remarkably simple in vivo technique that incorporates an electrode array with cellular dimensions to continuously estimate the extracellular counterparts of cardiac Ims. Mathematical modeling was performed for uniform plane wave propagation to clarify the biophysical basis and underlying assumptions inherent in this approach. Five-element electrode arrays incorporating 75-microns-diameter silver electrodes with center-to-center distances of 210 microns were experimentally verified to provide spatially sufficient samples for voltage gradient determinations of myocardial activation. Similar results were obtained with 25-microns-diameter electrodes at a center-to-center spacing of 65 microns. An estimate of Im was obtained from the derivative of the magnitude of the voltage gradient of the measured interstitial potentials. The inward component of Im generated by normal Na+ channel activation at 37 degrees C was measured in vivo to be less than 1 msec in duration, consistent with previously known voltage-clamp and simulation results. Intravenous KCl bolus injection was used to demonstrate the voltage-dependent depression of Na(+)-mediated Im in vivo, culminating in either severely depressed Na(+)-mediated or Ca(2+)-mediated activations. Normal Na(+)-, depressed Na(+)-, and possibly Ca(2+)-mediated currents can be recorded in vivo using this technique.

Display device and display system using the same

Abstract: Pixel electrodes and thin film transistors are arranged in a matrix in a display device, while polymer dispersion liquid crystals are interposed between an opposite electrode and the pixel electrodes on an electrode substrate. A signal is written into each pixel electrode by a pair of drive ICs for outputting signals in positive and negative polarities respectively with respect to an electrical potential at the opposite electrode. Two transistors are provided at each pixel electrode or an analog switch is provided at a signal output terminal of each drive IC so that signals of positive and negative polarities are not simultaneously written into an identical pixel electrode. When no voltage is applied to the pixel electrode, the incident light is reflected so as to be dispersed by the liquid crystal, and when a voltage is applied to the pixel electrode, the state of the liquid crystal is made light-permeable. The display device is used as a display panel to construct a viewfinder having a low electrical power consumption. The display device is also used as a light valve to construct a projection type television capable of displaying a magnified video picture on a screen with a high luminance.

Method for non-impact printing utilizing a multiplexed matrix of controlled electrode units and device to perform method

Abstract: Method and device for high quality printing with substantially reduced cross-coupling while reducing the manufacturing cost of printers that use a matrix of individual control electrode units (7) by connecting individual control electrode segments (11) in series to reduce the number of electronic drive circuits. An information carrier (8) such as paper is placed between a back electrode (9) and an electrode matrix (3) both of which are connected to voltage sources (17). Voltage sources connected to the control electrode unit matrix (3) at least partially open and close passages (10) through the electrode matrix (3); charged pigment particles attracted from a particle carrier (4) through the open passages (10) are deposited on the information carrier (8) to form visible images.

Deflectable loop electrode array and method.

Abstract: A cardiac arrhythmia mapping and ablation catheter has a main catheter (18) that is provided with a mapping and ablation system attached to its distal end which includes an adjustable loop (20) carrying an electrode array including a plurality of parallel-connected, separately operable mapping/ablation electrodes (36) in conductive relation to the external environment and arranged in spaced serial relation along the loop. Insulated conductors (38, 40) connect the electrodes (36) 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 (24, 26) are used to control the size, shape and deflection or posture of the loop (20). A distal extension (22) may optionally be provided to adapt the loop specifically to addressing the tricuspid annulus. A fixed version is also disclosed.

Improvements to apparatus and method for electroporation

Abstract: A new quickly replaceable electrode assembly for electroporation that also provides the functions of a pipette, capable of sucking up samples; applying extremely high electric field strength to samples at lower, safer voltages due to close spacing of the electrode plates; and expelling samples quickly and completely; along with a quick-connect receptacle for the electrode assembly. New methods are detailed for construction of electrode assemblies, providing electric current, monitoring characteristics of electric pulses delivered to samples, and space saving hand held units using low voltage D.C., A.C. line, and piezoelectric power supplies, with peak current delivered indicators are disclosed.

A common electrode driving circuit for use in a display apparatus

Abstract: A common electrode driving circuit for use in a display apparatus including a first substrate; a second substrate opposed to the first substrate with a display medium interposed therebetween; a plurality of pixel electrodes, a plurality of common electrode driving terminals provided on a surface of the first substrate opposed to the second substrate; and at least one common electrode provided on a surface of the second substrate opposed to the first substrate. The common electrode is opposed to the plurality of pixel electrodes and is connected to the plurality of common electrode driving terminals respectively through a plurality of common electrode transfer resistances. The common electrode driving circuit includes a detection device for detecting a resultant voltage applied to the common electrode through at least one of the plurality of common electrode transfer resistances; and a driving voltage generating circuit for generating a driving voltage based on a reference signal and a resultant voltage applied to the common electrode which is detected by the detection device and outputting the driving voltage to the plurality of common electrode driving terminals.

Electrode array microchip

Abstract: An electrode array microchip, fabricated preferrably using CMOS technology, comprising electrodes made with overglass cuts over metal2 regions is disclosed. Overglass cuts of dimensions approximately an order of magnitude smaller than dimensions quoted in current design rules for CMOS technology are successfully employed to make exposed electrodes of dimensions on the order of microns. Thus, the electrode array chip can be produced cheaply on commercial fabrication lines. The invention finds many uses in biology and medicine, particularly when applied to the measurement of neural electrical activity.

Flat panel display screens and systems

Abstract: A high brightness presentation display system includes: a transparent display panel having a viewing side and a non-viewing side, furcated row electrode array, furcated column electrode array defining matrix crosspoints and an electro-responsive display producing medium at said matrix crosspoints. Row electrode drive circuitry is connected to selectively drive electrodes in the row electrode array and column electrode drive circuitry is connected to selectively drive electrodes in the column electrode array such that conjoint voltages on selected row and column electrodes operate the display. The furcated electrode spacing and interelectrode spacings are such as to enhance discrimination, and the multiple sub-pixels due to the furcations of electrodes enhance brightness. Optical sensor positioned on the non-viewing side for viewing through the transparent display panel at a predetermined position from the viewing side of the transparent display panel is activated by a remote source producing a control beam of optical energy through the transparent display panel. Optionally, electrically generated icons displayed on the panel can be used to locate the sensors. Color displays and displays having high visibility in sunlight are disclosed.

Device for detecting two levels of a liquid having high and low electrodes of metals of different electrode potentials which are connected by conductors so as to form an electrical primary cell

Abstract: A two-level detector for an electrically conductive liquid having a common electrode serving as a potential reference and situated at a low level, a high electrode situated at a high level, and a low electrode situated at the low level, the electrodes being connected by conductors to electronic apparatus for detecting the liquid at said two levels by means of currents flowing through the liquid. The high and low electrodes are made of metals that have different electrode potentials. A first conductor and a second conductor interconnect the electrodes to constitute an electrical primary cell that is short-circuited when both electrodes are simultaneously in contact with the liquid. The second conductor is extended to connect the electrode assembly to a signal terminal of the electronic apparatus. The common electrode is made of a metal whose electrode potential is different by about 0.4 volts from that taken by the first and second conductors of the equipotential link between the high and low electrodes when all three electrodes are in the liquid; the common electrode is connected to a common terminal of the electronic apparatus. The electronic apparatus constitutes a self-latching electronic relay which latches when a voltage above a voltage threshold of about 0.4 volts appears across the signal and common terminals because of the high electrode making contact with the liquid, and which automatically applies a voltage to said signal and common terminals that replaces the voltage from the high electrode when the liquid level drops.

Surface shape sensor, and individual verification device and started-type system using the same

Abstract: PURPOSE:To shorten the time required for the whole signal processing and reduce the size by using the change in electric properties caused by the touch of the skin. CONSTITUTION:Plural linear contact electrodes 2 (linear electrodes) are provided on the surface of a substrate 3 in a one-dimensional array form. The respective linear contact electrodes 2 are connected to electrode take-out pads. When a finger 1 whose fingerprint is to be detected is pressed on the linear contact electrodes 2 in the direction of a right angle to the direction of electrode array, resistance values between the linear contact electrodes 2 change in accordance with the amount of the touched projecting parts of the fingerprint in the adjacent linear contact electrodes 2, and therefore one-dimensional resistance distribution is generated. Then, the resistance values of the surface of the finger between the adjacent linear contact electrodes 2 are sequentially read from the respective electrode take-out pads in the longitudinal direction of the finger 1. A pressure sensitive sheet 4 where the resistance values change in accordance with the strength of pressing force can be provided on the whole surfaces of the linear contact electrodes 2.

Telecommunications instrument with capacitive controller

Abstract: of EP0564164Capacitive proximity sensors (10) are disclosed that can be fabricated in different shapes, sizes and materials used in a wide variety of applications. Each such sensor includes a sensing electrode (11) and a guard electrode (12). The sensor electrode and guard electrode can be parallel conductors separated by an insulating layer (13), such as a double-sided circuit board shaped to suit the application. One such sensor is transparent for use in conjunction with an optical bar-code scanner. Another sensor is annular in shape for use in conjunction with a telephone transmitter. The sensing electrode and the guard electrode are driven in unison by an RF signal (21). The proximity of an object to the sensor is observed by detecting (in 24) changes in the RF current flowing through the sensing electrode caused by the proximity of an object to the sensing electrode.

Recording and reproducing apparatus and method for applying a pulse voltage and an electromagnetic wave

Abstract: A recording-reproducing apparatus includes an electrode, a material that changes its intramolecular electron distribution upon the application of electromagnetic wave irradiation and an electric field provided on the electrode, and an electrically conductive probe having a pointed tip. The apparatus projects an electromagnetic wave onto the material, and applies a pulse voltage between the electrode and the conductive probe.

Experimental investigations into the arc properties of vacuum interrupters with horseshoe electrode, four pole electrode, and their applications

Abstract: By using ferromagnetic material around electrodes to generate strong nonuniform magnetic fields, vacuum arcs can be kept in well-defined diffuse mode or multiple arc mode. As a result, the arc voltage is low and stable, the current is confined in certain areas, and high interrupting ability and small size are achieved. The different arc modes for different electrodes, the arc voltage versus arc current for flat electrodes, horseshoe, and four-pole electrode, and the vacuum arc distribution are measured. The criteria of choice of electrode diameter and electrode distance are given. >

Capacitive position sensor including a scale with integral topographical features which effect the mutual capacitance between cursor electrodes

Abstract: A capacitive position sensor has a scale (10), having hollow or raised topographical features, and a cursor (20) having an electrode array comprising at least two transmitting electrodes (21a, 21b) and at least one receiving electrode (21c) separated by shielding electrodes (21g) The coupling capacitances (Cac, Cbc) between transmitting and receiving cursor (20) electrodes are modified as a function of the position (x) of the scale topographic feature (11) relative to the cursor, the evaluation of the variation of the signals picked up by the receiving electrode permitting a precise measurement of the relative displacement between scale and cursor

Flexible transducer array support

Abstract: Electrodes 12 with associated connecting strips 13 are embedded in or on a flexible support 11 of plastics material. The connecting strips 13 couple the electrodes 12 with a plug/socket connector 17. The electrodes 12 are provided with a surface layer of polymeric piezo electric material. The electrode array can be positioned in contact with a surface of any shape and ultrasonic signals generated by supplying electrical pulses to the electrodes 12.

Method for manufacturing capacitor and bipolar transistor

Abstract: A lower electrode of a capacitor is manufactured simultaneously with an electrode such as a collector electrode and a base electrode of a bipolar transistor, and an upper electrode of the capacitor is manufactured simultaneously with another electrode such as an emitter electrode of the bipolar transistor. A dielectric layer between the lower and upper electrodes is manufactured simultaneously with other insulating layers of the bipolar transistor.

Dielectric detecting system

Abstract: A dielectric detecting system comprises: an earth electrode; a sensor electrode opposed to the earth electrode for constituting a first condenser therebetween whose electric capacitance varies in dependence on an existence of the dielectric; a medium electrode positioned between the earth electrode and the sensor electrode for constituting a second condenser between the medium electrode and the earth electrode and a third condenser between the medium electrode and the sensor electrode in such a manner that one of an electric capacitance of the second condenser and an electric capacitance of the third condenser serves for detecting an other dielectric; and an operational amplifier for equalizing electric potential of the medium electrode to that of the sensor electrode.

Unified complex electrode

Abstract: PURPOSE:To make it possible to cultivate neurocytes and to realize simultaneous multipoints measurement of electric activity of the neurocytes by forming the unified complex electrode to have the specific area of electrode and the specific surface resistance of electrode part. CONSTITUTION:This unified complex electrode has the plural number of electrodes 1 that have mutually the same interval between the nearest electrodes on the insulated board 3, and the wiring part is formed by wiring lead line 2 from electrode 1 nearly radially. The insulating layer 4 covering the lead line 2 is formed, the electrode area is set as >=3X mum and mum, and the surface resistance of the electrode part is set as . In the unified complex electrode, distance between the nearest electrodes is set as >=10mum and <=1000mum. In addition, the insulating layer 4 covering the lead line 2 has a dent n each electrode, and is formed on almost all the surface of the insulating board 3 except the region near to the contact point of lead line 2 with their outer circuit. In addition, the plural number of electrode centers are set at each crossing point of the grid that is composed of 8X8.

Insulation defect detection by high voltage electrode means

Abstract: In an apparatus for testing cable (comprising a metallic core jacketed by insulation) to detect localized defects on the insulation caused by its carbonization, the cable is moved in an axial path through an array of five ring electrodes radially spaced from that path and spaced from each other along the path by axial gaps. The first and fifth electrodes from left to right are grounded while high voltage circuits supply current to the middle three electrodes at DC voltages which causes (a) the second and fourth electrode, and (b) the third electrode to be positive and negative, respectively, relative to ground, and which voltages are high enough to produce flow of charge through the atmosphere adjacent the electrodes, and between the electrodes and the moving cable. Means are provided to monitor the current drain by the electrode array and to be responsive to an increase in such current caused by the coming into proximity with the electrode of a defect on the moving cable to produce a warning signal actuating a marker device to produce an ink spot on the cable. Signals caused by increases in such current resulting from traversal at different times by such a defect of separate axial gaps between the electrodes are subject to time delays and are then compared for time coincidence, and their failure to be appropriately time coincident results in non-actuation of the marker device.