Showing papers on "Electrode array published in 1979"

Device for passing an electric current between an electrode workpiece and an electrode tool

Abstract: A device for applying electrical current and voltage pulses between an electrode workpiece and an electrode tool, in the form of a wire or ribbon, in a travelling wire EDM apparatus, wherein a pulse generator providing such current and voltage pulses is connected across the electrodes. The travelling wire electrode is supported and guided by a pair of support and guide members and the pulse generator is connected across one of the support and guide members of the travelling wire electrode and the workpiece. A capacitor is connected across two contact members one engaged with the travelling wire electrode and the other with the workpiece, and is supported by one of the travelling wire support and guide members. The effect of the capacitor connected directly across the machining gap is to reduce considerably to a negligible value the inductance of the electrical circuit applying the current and voltage pulses across the electrodes.

Sequential motor unit stimulation through peripheral motor nerves in the cat.

Abstract: An electrode array is described that can be used to stimulate skeletal muscle through the peripheral motor nerves. This electrode array differs from the sleeve electrode that is used conventionally in that the motor units are stimulated sequentially, a mode of stimulation which closely mimics the normal asynchronous firing pattern of motor units that occurs during voluntary activity. Using this stimulation technique, tetanic contractions can be developed by muscle at low stimulation voltages and within physiological stimulation frequencies. Furthermore, unlike synchronous electrical stimulation, during sequential stimulation, submaximal tensions can be maintained for sustained periods of time. The applications of this electrode array to rehabilitation medicine are discussed

ac induced corrosion. The effect of an alternating voltage on electrodes under charge-transfer control

Abstract: The equation relating current to voltage for an electrode under charge-transfer control has been solved for a sinusoidal modulation of the electrode potential. The rectified Faradaic component has been obtained, so as to derive its value as a function of the Tafel parameter and of the amplitude of the modulating voltage, as well as of average electrode potential. The case where one electrode reaction is under diffusion control also has been treated. The amplitude and phase characteristics of the harmonic components have been derived, and their use for determining the kinetic properties of the electrode have been discussed. The capacitative current generated by the alternating voltage also has been investigated, and the conditions under which it can be separated from the Faradaic current have been given. The implications of these results on the corrosion due to AC leakage have been examined.

Electric supply for ion therapy

Abstract: A power supply provides direct current to electrodes attached to a patient. The positive electrode is at least partially silver and releases silver ions as a result of the electric current. Silver ions have known bactericidal properties and may be used to treat infected living tissue. Tissue may, however, be damaged by voltages in excess of 1.1 volts. Accordingly, the power supply has two modes. Under normal conditions the power supply has a constant current output. If the voltage between the electrodes reaches a reference voltage of not more than 1.1 volt, the output is changed to a constant voltage mode, abruptly limiting the output voltage. A mode indicator may be incorporated in the supply.

Spatial Resolution of Four Electrode Array

Abstract: The in vivo measurement of specific impedance in brain tissue involves several technical aspects. The most stringent difficulties relate to electrode polarization and spatial resolution of the measuring system. The polarization is solved by usinga four electrode arrangement with a very high impedance preamplifier on the potential electrodes. This paper discusses the relative effectiveness of the various possible linear configurations of four electrodes in terms of spatial resolution. The accuracy of computed spatial resolution with respect to corresponding experimental ones is specified.

Evaluation of Electrode Array Material for Neural Prostheses

Abstract: Matrix support materials for brain surface electrodes used in neuroprosthetic applications were evaluated after chronic subdural implantation over the parietal cortex of the cat. Four types of array fabricated with Silastic, Dacron mesh, or platinum wire annuli were implanted for periods ranging from 5 weeks to 1 year. We evaluated the arrays by access resistance measurements and gross and histological observations of the tissue beneath both nonstimulated and stimulated electrodes. A porous type matrix constructed of Dacron mesh proved to be the superior design because of its minimal compression of the cortical surface, facility of handling during implantation and autopsy, and satisfactory electrical characteristics provided by a good electrode-brain interface. (Neurosurgery, 5: 681--686, 1979).

Improved electrode array and method of making the same

Abstract: An electrode array 10 specifically for implantation into the human cochlea comprising a biologically inert tube 20 about which is formed a number of electrodes 13 each of which is associated with an insulated conducting wire 14 which passes through a slot 16 in the tube 20 and at one end thereof; the electrodes each being formed of a strip of thin foil and lie substantially within the diameter of the tube 20, the inner end 12 of which is tapered for easy insertion into the cochlea and to minimise trauma during the insertion procedure.

Voltage controlled power supply for electrostatic coating apparatus

Abstract: A power supply for generating a high unidirectional voltage at a charging electrode of an electrostatic spray coating apparatus has circuitry for sensing the magnitude of current flow to the electrode and for controlling application of an input voltage to the power supply in accordance therewith to control the magnitude of the high voltage. The arrangement is such that whenever the current flow is less than a predetermined value all cycles of the input voltage are applied to the power supply, but whenever the current exceeds the predetermined value only a limited number of the cycles are applied to the power supply. In this manner, the danger of arcing between the electrode and an article being coated is eliminated or at least significantly reduced.

Devices for detecting the rupture of an electrical circuit element

Abstract: The device comprises means for applying a DC voltage U as a function of the voltage taken from the terminals of a fuse between a fixed electrode and a movable electrode forming together a capacitor. The movable electrode is urged towards the fixed electrode by an electret fast to the latter and in the opposite direction by a magnet and by the voltage U. As soon as this voltage exceeds a threshold corresponding to the rupture of the fuse, the movable electrode swings over and closes a switch for warning purposes.

Spatially distributed electrostatic perforation of moving webs

Abstract: A method and apparatus for controlling the perforation of webs being moved in a longitudinal direction, by an array of electrodes spatially distributed in a transverse direction, wherein selected control electrodes are added to or removed from the electrode array to provide a transverse, or spatial, degree of control over web porosity. Synchronized sensing of multiple point transverse web porosity, combined with logic circuitry provides the controls for selection and actuation of the appropriate control electrodes. A combined temporal and spatial porosity control embodiment is disclosed. The combined and alternate embodiments described are particularly useful for perforating paper, film, and like materials, where a high degree of area-balanced porosity control is desired.

Deep and/or shallow electrical resistivity investigation suitable for dual resistivity-induction logging

Abstract: A dual resistivity and induction apparatus for the investigation of earth formations traversed by a borehole, comprises an electrode system, supported on a support member, comprising a central electrode and five pairs of electrodes respectively short-circuited and aligned symmetrically about the central electrode at increasing distances therefrom; the central electrode and the electrodes of the fourth and fifth pairs are called current electrodes, the electrodes of the first, second and third pairs are called voltage electrodes; a source of alternating current at a first frequency, f 1 , is coupled between the electrodes of the fifth and fourth pairs; a source of alternating current at a second frequency, f 2 , is coupled between the electrodes of the fifth pair and an electrode at electrical infinity with respect to the electrode system; a circuit arrangement coupled to the electrodes of the fourth pair for generating current at f 1 from the central electrode for maintaining the potential difference between the first and second pairs of electrodes at substantially zero and for generating current at f 2 from the central electrode for maintaining the potential difference between the first and third pairs of electrodes at substantially zero; first and second impedances, respectively interposed between each of the source of alternating current and the current generating circuit and the fourth pair of current electrodes; and transmitter and receiver coils supported on the support member, for inducing at a third frequency, f 3 , electromagnetic energy; the length, along the axis of the support member, of each of the electrodes of the fifth pair is several orders of magnitude smaller than the relative spacing along the support member of that fifth pair of electrodes to reduce the interference between the electrode system and the coil system

IR Corrected electrochemical cell test instrument

Abstract: A test instrument for an electrochemical cell generates a current which counteracts the cell current so that it is briefly reduced to zero thereby allowing the electrode potential or cell potential to be measured free from the IR or ohmic polarization loss. A sample and hold circuit is enabled shortly after the current is interrupted to sense the voltage level of the electrode or electrochemical cell which has only experienced the voltage change due to the IR polarization losses. When cell current is restored, the IR corrected potential stored in the sample and hold circuit is compared to the control potential, and the difference between the two causes automatic adjustment of the average cell current such that the IR corrected potential of the cell is maintained despite any changes in IR polarization.

Electrode assembly for use in electric field therapy apparatus

Abstract: An electrode assembly for use in electric field therapy apparatus comprises arranging between a pair of opposed electrodes an appropriate number of auxiliary electrodes with a certain distance interposed therebetween and containing all of these electrodes thus arranged in an insulating material, and enables electric field to be applied to a desired sick part of human body to be treated by selectively using pairs of these electrodes and effective electric field therapy to be attained due to the presence of the auxiliary electrodes which serve to prevent the electric field from being diffused.

Symposium: Cochlear implant, 1978—fact or supposition. Traumatic intracochlear electrode implantation†‡

Abstract: The success of intracochlear electrode implantation hinges on the ability of peripheral auditory neurons to survive long-term interface with an electrode array and prolonged electrical stimulation. Histopathological studies have been conducted on a series of neomycin sulphate otointoxicated cats to assess the long-term effects of electrode implantation on an impaired cochlea (analogous to potential human sensory deaf implant candidates). The results of these studies may be summarized as follows: 1. Long-term electrode implantation can be achieved without significant loss of primary auditory neurons using an electrode array embedded in Silastic which is molded to conform to the basal scala tympani if surgical implantation has not disrupted the basilar membrane or osseous spiral lamina. 2. A fibrous tissue matrix forms around the Silastic, displacing perilymph and effectively sealing the electrode at the round window preventing perilymph fistula. 3. While osteoneogenesis will occur whenever the periosteum of the bony labyrinth is disrupted, the molded Silastic sheathing prevents electrode displacement by small areas of new bone formations. 4. Traumatic electrode insertion, with fracture of the osseous spiral lamina or rupture of the basilar membrane, produces severe loss of neural elements in the region of injury and extensive new bone formation preventing satisfactory electrical stimulation. The findings suggest that long-term cochlear implantation is feasible in sensory deafened animals using Silastic sheathed electrode arrays which have been molded to conform to the basal scala tympani provided the integrity of the scala tympani, osseous spiral lamina and basilar membrane is maintained.

Multistage depressed collector for dual mode operation

Abstract: The object of the invention is to provide a depressed collector which captures the spent electrons of a microwave transmitting tube at high efficiency in both high and low power modes of operation. The collector comprises entrance and end electrodes (14 and 18, respectively), electrode (18) having a spike extending toward entrance electrode (14). Intermediate electrodes (15, 16 and 17) and the entrance electrode (14) each have a central aperture and, together, these electrodes capture most high power mode spent electrons. The apertures of the electrodes (14-17) increase in size in a downstream direction. To capture low power mode spent electrons a low power mode electrode (19) is positioned between the last intermediate electrode (17) and the end electrode (18). This electrode (19) has a central aperture preferably smaller but no larger than that of electrode (17). An auxiliary low power mode electrode 20 may be disposed between electrodes 19 and 18 and has a central aperture larger than that of the low power mode electrode (20). All of the electrodes 14-20 are at voltages provided by a voltage divider 21 connected between a potential as at a negative terminal (21) and a common ground return 23.

Characteristics of a corona system under negative direct and pulsed voltage

Abstract: The characteristics of a clean electrode system energised in clean atmospheric air are studied when the applied voltage is negative direct and negative pulsed respectively. The discharge patterns along the wire electrode are measured by means of an optical system which includes a photomultiplier. A linear relationship is found to exist between the average photon current and the corona current. When the photon currents are the same, the discharge patterns are similar for both types of applied voltage. The Trichel current waveshapes are also similar at low voltage levels. However, at high pulsed voltage values, the Trichel current amplitude and frequency are affected by the space charge conditions.

Backup electrode for an electrostatic recorder

Abstract: A backup electrode arrangement comprises a resilient insulating member across one surface of which are a plurality of electrode segments separated from one another and comprising an electrically resistive material forming a shoe. The electrode shoes provide pressure engagement against an array of recording electrodes in an electrostatic recorder with a recording medium disposed therebetween. The electrical resistivity of the shoes is sufficiently high to protect the recording electrodes from pinhole shorts in the dielectric layer of the recording medium. With the backup electrode positioned directly opposite to the recording electrode array, the charging path impedance is reduced permitting reduction in writing speed and a corresponding increase in overall recording time.

Method of forming electrostatic image

Abstract: A control electrode assembly is provided between a corona discharger and an electrostatic recording medium. The control electrode assembly has a pair of conductive electrodes interposing therebetween a insulating layer having a through hole extending from the upper conductive electrode to the lower conductive electrode. Selected one of the conductive electrodes is grounded through a change-over switch, which connects the selected electrode to the ground and disconnects the other non-selected electrode from the ground to electrically open it. Corona ions from the corona discharger charge the electrically opened conductive electrode to establish an electric field within the through hole. The corona ion current passing through the through hole can be modulated by operating the change-over switch to control the direction of the electric field established within the through hole in accordance with an image signal to form an electrostatic image on a recording medium.

Current interrupter electrode configuration

Abstract: A vacuum type current interrupter is provided having a low mass movable electrode which can be moved into electrical contact with a stationary electrode for carrying large currents associated with power lines. A third electrode is positioned in the vacuum envelope in opposing relation to the stationary electrode and adjacent the movable electrode. When the stationary and movable electrodes are separated an arc will appear between their contact surfaces. The third electrode is conductively connected to the movable electrode so that the arc will spread from the latter to the relatively larger surface of the third electrode, to reduce local overheating of the electrodes during arcing.

Reduction of sparkle noise and mottling in CCD imagers

Abstract: In a CCD imager of the single-layer electrode type wherein the gate electrodes are of one conductivity and the "gaps" between electrodes are of opposite conductivity type, sparkle and mottling are reduced by controlling the conductivity of the gaps. Such control is achieved by employing an overlying control electrode which is insulated from the gaps and gate electrodes, to which an adjustable control voltage is applied. The latter can be derived in open-loop fashion; however, in a preferred form of the invention, the leakage current between a pair of adjacent electrodes is sensed and employed to control a voltage which is fed back to the control electrode.

Counter electrode arrangement of an electrochromic display device

Abstract: An electrochromic display device comprises a single counter electrode and a plurality of display electrodes. The counter electrode is charged and is maintained at a given potential by a donor electrode which transfers charge to the counter electrode in response to the action of a reference electrode. A potentiostat operates to supply current to the donor electrode in accordance with the potential of the counter electrode as sensed by the reference electrode. Both the donor electrode and the counter electrode are preferably of platinum black. The donor electrode is preferably arranged in the manner of a frame about the display area. The counter electrode is preferably grid-shaped.

Structure of membrane transistor

Abstract: PURPOSE:To reduce a drain current and make it suitable for such an application as a liquid crystal indication device, by detouring a channel region located between a soruce electrode and a drain electrode so that its total passage becomes longer a distance between the electrodes. CONSTITUTION:A gate electrode 26 is formed on an insulating substrate 25 such as a glass, the gate insulating electrode is surrounded by a gate insulation membrane 27, and a source electrode 29 and a drain electrode 30 are attached onto the end section of the membrane 27 and the substrate 25, respectively. And then, by forming a semiconductor membrane 28 of CdSe and CdSTe, etc. on the surface of the mem- brane 27 which is exposed by being surrounded by these electrodes, a membrane transistor is prepared. In this constitution, a channel region located between the electrodes 29 and 30 is provided with notches which cross these electrodes perpendicularly and are in mutually opposite direction, so that the channel length becomes substantially long. Or, it may be possible to form between these two electrodes a channel consisting of a spiral circuit. It is possible, by doing so, to reduce drain current and also to obtain a satisfactory characteristic.

Electrode assembly for inner ear

Abstract: A B S T R A C T An electrode array specifically for implantation into the human cochlea comprising a biologically inert tube about which is formed a number of electrodes each of which is associated with an insulated conducting wire which passes through a slot in the tube and at one end thereof; the electrodes each being formed of a strip of thin foil and lie substantially within the diameter of the tube, the inner end of which is tapered for easy insertion into the cochlea and to minimise trauma during the insertion procedure.

Method of control for an electrolytic display cell and especially a cell of the metal halide type and a circuit for the application of said method

Abstract: The electrolytic display cell comprises a plurality of electrodes having suitable shapes for character display, a counter-electrode and an electrolyte. A negative voltage is applied to one of the electrodes for writing on said electrode and a positive voltage is applied for erasure. On completion of erasure, the voltage between electrode and counter-electrode has a tendency to rise to a threshold value corresponding to a parasitic reaction. The end of the erasure pulses is determined by the instant at which the electrode--counter-electrode voltage rises to the threshold voltage corresponding to the production of a parasitic reaction.

Voltage protection circuit for binary data-storage device

Abstract: A voltage protection circuit for controlling an input data signal on a signal-carrying line to a binary data-storage device having an input line for receiving the input data signal comprises two transistors in series having current-control electrodes coupled to an input control terminal and a third transistor having its current-control electrode coupled to the input line with one current-conducting electrode coupled to a voltage source and another current-conducting electrode coupled to current-conducting electrodes of the first two transistors.

A Two-Dimensional Multielectrode Microprobe for the Visual Cortex.

Abstract: : The pattern recognition research effort being conducted at the AFIT Bioengineering Laboratory motivated the design of an electrode array microprobe capable of simultaneously recording the bioelectrical signals existing over a large surface area of the cortex of the mammalian brain. Data recorded from this device should increase the present level of knowledge of the interconnections of the various areas of the cerebral cortex and thus be instrumental in the development of theories on the pattern recognition capabilities of the human brain. An implanted system has been designed around this microprobe to detect the cortico-electrical signals, multiplex and modulate these data, and then transmit them across the intact scalp to external recording equipment. The electrode array microprobe, itself, makes use of junction field-effect transistors integrated directly onto the array substrate in order to multiplex the probe's output leads. The first example of a four by four version of the electrode array has been fabricated. It did not function as designed because of technical problems and a revised process schedule was produced. (Author)

High voltage generating vibrator

Abstract: PURPOSE:To obtain the high voltage generating vibrator which has no apprehension of an accident in winding by forming a common electrode at one end surface of a ceramic polarized in thicknesswise direction and forming a driving electrode on the periphery and a voltage rising electrode at the center of the other end surface. CONSTITUTION:A silver electrode 2 is baked to one end surface of the ceramic of a barium titanium zirconate 1, a circular voltage rising electrode 3 is formed on the other end surface thereof, a gap 4 is formed on the periphery thereof, the coaxial driving electrode 5 is baked thereto, and polarization is treated sequentially in the thickness-wise direction of the ceramic. The vibrator is nipped with a U-shaped insulating supports 6-8, clamps 8', 7' and lead wires 9, 9' are attached to upper inside surface of the support 7 and the lower inside surface of the support 8, and a lead wire 11 is attached to the electrode 3. When high frequency voltage is applied to the electrodes 2 and 5, the vibrator is resonated. When the vibrator resonates in maximum amplitude, a high voltage is produced from the electrode 5. This device can be simple, and has no apprehension of an accident during the use of a transformer in winding.

Ultrasonic converting element

Abstract: PURPOSE:To vary greatly the output voltage with the temperature change of the high molecular piezoelectric film, by providing the 1st flat plate type electrode opposing to the 1st reed-screen type electrode plus the 2nd flat plate type electrode opposing to the 2nd reed-screen type electrode each on the back of the film. CONSTITUTION:The 1st reed-screen type electrode 2 plus the 2nd reed-screen type electrode 3 are provided with some distance between on the surface of the high molecular piezoelectric film made of the polyvinylidene fluoride. On the other hand, the 1st and 2nd flat plate type electrodes 4 and 5 opposing to electrodes 2 and 3 are provided on the back of the film. As a result, the output voltage can be varied greatly by the temperature change of the polyvinylidene fluoride film.

High potential discharge control circuit including a resistive material coated electrode for induction-charging electrostatic spraying system

Abstract: HIGH POTENTIAL DISCHARGE CONTROL CIRCUIT INCLUDING A RESISTIVE MATERIAL COATED ELECTRODE FOR INDUCTION CHARGING ELECTROSTATIC SPRAYING SYSTEM Abstract of the Disclosure A high voltage discharge control circuit is provided for an induction-charging spraying system. The circuit comprises a first re-sistance means comprising an induction-charging electrode coated with a resistive material that retards transport of electric charge across the electrode surface to electrode edges or surface discontinuities which are most susceptible to arcing to an electrical ground point. A current limiting resistor may be in series with the resistive coating and a high voltage source to inhibit current surge to the electrode surface from other circuit elements. The circuit may also contain additional current limiting series resistors in the high voltage cable and in the power supply to further inhibit current surges. Shunt resistors are provided between high potential circuit elements and electrical ground to drain accumulated charge from the circuit.

Battery with positive and negative main electrodes - has extra electrode between separators to indicate charge state

Abstract: The battery has positive and negative main electrodes separated by two separators and immersed in an electrolyte. An additional electrode is located between the separators and is connected via an electrical impedance to the negative main electrode. The additional electrode is used to monitor the battery's charge state. The additional electrode (9) is completely immersed in the electrolyte (2) and against the separator (8) on the positive main electrode (5). The charging current is made to follow a specified inequality involving the additional electrode's signal current.