Showing papers on "Electrode array published in 1990"

Variable rate cardiac pacer

Abstract: An endocardial lead having first and second spaced apart electrodes resides in a patient's heart. The first electrode is a sensing electrode and the second electrode is a carrier signal driving electrode. The lead has a conductor coupling a source of alternating current carrier signals of a predetermined frequency to the second electrode. A third electrode is in electrical contact with body tissues. A cardiac pacer apparatus includes a pacer can which functions as a fourth electrode and has a plastic top wherein the third electrode is located. Said third electrode acts in cooperation with the first electrode to form a pair of sensing electrodes. The sensing electrode pair is further coupled to a sense amplifier for receiving an amplifying modulated electrical signals developed across the sensing electrode pair. A demodulator and filters circuit for demodulating the modulated carrier signal and recovering the modulating signal therefrom is connected to the output of the sense amplifier. The modulating signal is proportional to instantaneous stroke volume of the patient's heart and the demodulator and filters circuit develops a control signal therefrom called a stroke volume signal. The control signal is applied to the pulse generator so as to control the rate of stimulating pulses.

Unitary multiple electrode sensor

Abstract: A unitary multiple electrode sensor for detecting analytes in blood or blood component samples and devices for using them. The unitary multiple electrode sensor includes a sensor support member and at least one electrode array being deposited on the sensor support member, the electrode array having sensor-activating chemical(s) attached to an embodiment thereof. A test sample is applied to the electrode array to begin the test; and a sensor apparatus measures the test reaction which is occurring on the electrode array.

Plural Stage Voltage Booster Circuit With Efficient Electric Charge Transfer Between Successive Stages

Abstract: Electric charge transmit elements (QD) transmit electric charge from a terminal side (NA) to a control electrode side (NB) of the circuit. The voltage at the control electrode side (NB) is raised by a capacitor configuration (CB). Voltage stabilizing elements (QC) are connected in parallel to the electric charge transmit elements between the terminal side and the control electrode side. In transferring the electric charge from the control electrode side (NB) to the other terminal side (NC), the voltage at the control electrode side (NB) is kept higher than the other terminal side (NC). Therefore, because loss of voltage by the electric charge transfer elements (QB) in transferring the electric charge is eliminated, a predetermined voltage is obtained efficiently in a short time, and a highly reliable booster circuit is provided.

Method and apparatus for conducting electrochemiluminescent measurements

Abstract: A method and apparatus for triggering and measuring electrochemiluminescent phenomena using a voltage waveform applied at the voltammetric working electrode which improves the precision and accuracy of measurements. This waveform has a decreasing scan rate in the range of voltages for which electrochemiluminescence is triggered and is substantially sinusoidal in shape in this range. The waveform results from locating the reference electrode (20) of a potentiostat in close potential proximity to its counter electrode (16), and applying a uniform scanning voltage waveform at the reference electrode (20). The waveform also can be synthesized digitally, converted to analog form, and applied directly to the working electrode (18) with the reference electrode (20) in close potential proximity to the working electrode (18).

Electron emitting element and image display device and drawing device using the same

Abstract: PURPOSE: To ensure such a low resistance that voltage reduction in a surface electrode can be ignored and improve electron emitting efficiency by providing a pair of an electrode and a surface electrode and an insulating layer supported between these electrodes on a base, and further providing an opening part on the surface electrode. CONSTITUTION: An electron emitting element 31 has a pair of an electrode 1 and a surface electrode 3 and an insulating layer 2 supported between these electrodes on a base 5, and the surface electrode 3 has an opening part 4. The width of the opening part 4 is less than 100μm, and the opening part is formed in plural number. Therefore, in the element 31, it is unnecessary to particularly thin the surface electrode, and the film formation in the surface electrode is facilitated. Further, as the resistance of the surface electrode can be maintained low, voltage reduction in the surface electrode can be ignored, allowing the addition of an effective electric filed to the element and the prevention of failure by exothermic. The electrons leading through the insulating layer 2 to the exposed part of the layer 2 are emitted without loosing energy. COPYRIGHT: (C)1991,JPO&Japio

Ferroelectric memory with non-destructive readout including grid electrode between top and bottom electrodes

Abstract: A ferroelectric memory has a top electrode (12) a bottom electrode (14) and a grid electrode (18) having spaced conducting members located between the top electrode (12) and the bottom electrode (14). A ferroelectric material (16) is positioned between the top electrode and the bottom electrode. A dielectric material (20) is located immediately between the spaced coducting members of the grid electrode (18) and the top electrode (20). This forms ferroelectric fingers (22) which can be selectively polarized by applying a voltage between the top electrode and the grid electrode during reading of the memory cell (10). When the read operation is complete, the ferroelectric fingers (22) will spontaneously repolarize to the state of the rest of the continuous ferroelectric bulk (16). This results in a ferroelectric memory with nondestructive readout.

Non-volatile memory with hot carriers transmitted to floating gate through control gate

Abstract: A non-volatile memory includes a charge injecting electrode, a control electrode, and a floating electrode The charge injecting electrode generates hot carriers by a tunnel effect The control electrode is formed on the charge injecting electrode to set a tunnel voltage The floating electrode is formed on the control electrode via an insulating film The hot carriers generated by the charge injecting electrode are injected over an energy barrier of the insulating film into the floating electrode

Errors due to measuring voltage on current-carrying electrodes in electric current computed tomography

Abstract: It is shown that when a multiplicity of electrodes are attached to a body's surface, the voltage data are most sensitive to changes in resistivity in the body's interior when voltages are measured from all electrodes, including those carrying current. This assertion, which is true despite the presence of significant levels of skin impedance at the electrodes, is supported both theoretically and by experiment. Data were first taken for current and voltage at all electrodes. Then current was applied only at a pair of electrodes, with voltages measured on all other electrodes. Targets could be detected with better signal-to-noise ratio by using the reconstructed data than by using the directly measured voltages on noncurrent-carrying electrodes. Images made from voltage data using only non-current-carrying electrodes had higher noise levels. It is concluded that in multiple electrode systems for electric-current-computed tomography, current should be applied and voltage should be measured from all available electrodes. >

Current patterns for impedance tomography

Abstract: In an electrical impedance imaging system that is capable of forming images based on internal resistivity of a body, an array of electrodes is applied to the surface of the body and energized by a plurality of current generators. Each current generator is controlled to produce current patterns containing single fixed magnitudes. The current generators are also controlled to apply current to the respective electrode only when the current generator is at peak current value to minimize transient conditions and maximize the rate at which images can be produced.

Impulse patterns of auditory nerve fibres to extra- and intracochlear electrical stimulation.

Abstract: The impulse patterns of single auditory nerve fibres in cats with normal hearing and in deafened cats were studied during electrical stimulation of the cochlea at different locations. In the case of extracochlear round-window membrane stimulation, cats with normal hearing showed lowest thresholds (32 dB re 1 μA rms) for sinusoidal stimulation in the frequency range 50-300 Hz. These thresholds were independent of the acoustically determined characteristic frequencies of the fibres. The fibres of acutely deafened cats (by Neomycin) showed no spontaneous activity and could be activated only electrically with similar current values as in normal hearing cats. The action potentials were highly synchronized with the electrical signal up to 12.8 kHz. Intracochlear electrical stimulation was performed using a human multichannel cochlear implant electrode array. The excitation thresholds of the fibres for current stimulation showed poor place dependency when using different electrodes (monopolar) in the first turn of the cochlea with a remote indifferent electrode inside the middle ear. Better localization could be obtained when using bipolar stimulation with electrode pairs (electrode distance 0.75 mm) in the scala tympani. With parallel bipolar stimulation at two different locations (distance 1.5 mm) using two independent current sources a clear interaction could be observed in the firing pattern of single fibres. The measured gain and phase relations between current signal and neuronal response allowed the calculation of a model describing the summation of current density vectors acting on an excitable nerve membrane model. On the basis of these measurements, input networks were calculated to improve the channel separation of multichannel cochlear implants.

Capacitive path sensor with oscillator - has screening electrode between capacitor active and earthing electrodes, at same potential as active electrode

Abstract: The path sensor system has an oscillator, a transmit and reception capacitance, a demodulator and a switching amplifier, with the oscillator comprising an externally influence capacitor (5) with an active electrode (6) and an earthing electrode (7). Between the two capacitor electrodes is fitted a screening electrode (11) at the same potential as the active electrode. Pref. a compensation electrode is provided for the effect of water on the sensor. The three above-mentioned electrodes, and possibly the compensation electrode are plate-shaped. All the electrodes may be flexible, e.g., of foils. The earthing electrode may be larger than the active electrode, and the screening electrode smaller than the earthing electrode. ADVANTAGE - Flat configuration for electromagnetic field with unidirectional stray effect.

Water analyzer with multiple electrodes

Abstract: A water analyzer having several electrodes of the type which normally interfere with one another. These electrodes include a first electrode which is an active measurement electrode which perturbs the solution in which it is used and a second electrode whose reading is affected by the operation of the first electrode. Accurate readings are provided by sequencing the operation of the electrodes so that they are not always operating at the same time. In addition, further correction of the readings is provided to compensate for the known error resulting from the operation of the active electrode or electrodes. Such electrodes read conditions such as pH, dissolved oxygen and conductivity.

Apparatus and method for making surface photovoltage measurements of a semiconductor

Abstract: An apparatus for making ac surface photovoltage (SPV) measurements of a specimen of semiconductor material under variable dc bias voltage conditions includes a light source whose output beam is intensity modulated, a reference electrode, a guard electrode, a back electrode, a first voltage for biasing the reference electrode with a variable dc voltage and a second voltage separate from the first voltage for biasing the guard electrode such that an accumulation layer is established in the area on the specimen controlled by the guard electrode to prevent flow of carriers between the area controlled by the reference electrode and the rest of the specimen.

Low-power electromagnetic digitizer tablet

Abstract: A low-power electromagnetic digitizer table employing triangular-shaped electrodes (10) arrayed in a single plane. A pointing device coil (20) when energized induces signal voltages in the electrodes underneath. The electrodes are scanned in timed relation, and the induced voltages digitized and compared to determine the X/Y coordinates of the pointing device with respect to the electrode array.

Switched capacitance meter reading device using variable width electrodes

Abstract: A humidity and temperature resistant apparatus for determining the orientation of a rotatable meter hand relative to a dial spaced apart from a meter hand that creates and depletes a charge between a center electrode, a meter hand, and an outer variable width electrode array very rapidly to transport electrons through a resistor capacitor combination attached to a positive power supply whereby the average current drawn through the resistor capacitor combination creates a voltage that corresponds proportionally to the magnitude of the capacitance being measured. The variable width electrode array is disposed on a surface of a substrate delimiting a center portion containing an aperture for receiving a rotatable member, and includes a center electrode located in the center portion on the surface of the substrate at least partially circumscribing the aperture and a calibration ring that circumscribes and is spaced apart from the center electrode.

Field emitter array memory device

Abstract: A field emitter array memory device having two or more collector electrod an extraction electrode, at least one deflector electrode, and at least one electron field emitter is disclosed. The field emitter array memory circuit has bias voltages for collector electrodes, for the at least one deflector electrode and for the extraction electrode. In a preferred embodiment of the invention, first and second input signal voltages selectively applied to first and second deflector electrodes selectively switch the flow of electrons emitted from an electron field emitter from a first collector electrode to a second collector electrode and vice versa. A latched memory output is also included. Electron flow from the electron field emitter to one of the first and second collector electrodes is maintained until a signal voltage is applied to a deflector electrode to cause the electron flow to deflect from one collector electrode to the other collector electrode.

Liquid crystal display device for reducing unevenness of display

Abstract: A liquid crystal display device applying a scanning voltage wave to a plurality of scanning electrodes and a signal voltage wave to a plurality of signal electrodes to selectively render visible display elements defined at the intersection of scanning electrodes and signal electrodes, and superimposing a correcting voltage upon at least one of the scanning voltage wave and/or the signal voltage wave in order to eliminate unevenness of display. The correcting voltage to be superimposed upon the signal voltage wave and/or the scanning voltage wave is determined and weighed in accordance with the positions from the end portion of the scanning electrode group applied with the scanning voltage wave and/or the positions from the end portion of the signal electrode applied with the signal voltage waveform, of display elements to be rendered visible.

Liquid crystal electro-optical deflector having electrode array and comb shaped electrode formed on resistive layer

Abstract: The disclosed deflector includes a thin film of liquid crystal on either side of which there is positioned at least one plane of electrodes, the assembly forming an array of elementary, quadripolar phase-shifters placed side by side, their electrodes being taken to different control potentials, generating a spatial modulation of the phase of the beam going through the deflector.

System for sensing and/or controlling the level of current in a transistor

Abstract: A transistor sense electrode (20) is coupled to the input branch (24) of a current mirror (22). The current mirror's branch (26) carries a current substantially equal to the current in the input branch to indicate the current flowing in the transistor. A preferred embodiment includes an amplifier (30) which senses the difference between the voltage at the sense electrode (20) and a reference voltage (Vx). The sensed difference in voltage causes the amplifier to apply a control signal to the current mirror to vary the current in the input branch so as to hold the sense electrode's voltage at the level of the reference voltage (Vx). A preferred package for the system's circuitry is also disclosed.

Voltage regulator with power boost system

Abstract: An improved voltage regulator system is provided which includes a differential amplifier, an output transistor having a control electrode coupled to an output of the differential amplifier and a current carrying electrode fed back to an input of the amplifier, an input control transistor having a first current carrying electrode connected to the control electrode of the output transistor and a second current carrying electrode connected to a point of fixed potential and means for selectively applying a control signal to a control electrode of the input control transistor.

Thyristor with first and second independent control electrodes

Abstract: A thyristor of the present invention turns on by applying a specified voltage to a first control electrode and turns off by applying a specified voltage to a second control electrode. These first and second control electrodes are independent of each other, so that the turning-on and turning-off conditions can be determined independently. When a transistor having the second control electrode is turned on by applying the specified voltage to the second control electrode until just before the turning-on, a first main electrode and a first semiconductor region can be electrically connected, so that the back gate potential of the transistor having the first control electrode can be fixed at the potential of the first main electrode.

A System For Impact Insertion Of A 100 Electrode Array Into Cortical Tissue

Abstract: ABSTRACI Complex silicon microelectrode arrays capable of having up to 100 electrodes per device are now a reality. By directly interfacing to the central nervous system, these devices could allow for restoration of sensory or motor functions at a level previously unobtainable. However, the structural complexity of these devices has mandated the development of a new insertion technology not necessary for simpler electrode designs. To meet this demand, a pneumatic momentum-transfer system has been developed. This portable system uses a sliding mass mechanism to achieve an impact insertion of a silicon structure consisting of 100 sharpened needles into cortical tissue. The system has successfully implanted these silicon electrode arrays in over 30 feline preparations. Preliminary histological evidence shows an expected inflammatory response with a small amount of bleeding, yet no significant long-term neural tissue damage due to the insertion procedure. These results suggest that impact insertion is a viable way to introduce complicated electrode structures into the central nervous system.

Apparatus for measuring a winding temperature of electric machines

Abstract: An apparatus for measuring the winding temperature of electric machines uses an a.c. reference voltage source generating an a.c. reference voltage with a predetermined, non-line frequency, preferably below 10 Hz., a current detector detecting the current generated from the a.c. reference voltage and/or the a.c. reference voltage directly, and a measuring and evaluating device measuring the current to determine the winding temperature. The a.c. reference voltage is added geometrically to the line voltage and generates a current proportional to the winding conductance which is temperature dependent.

Image sensor with load capacitors formed from common and individual electrodes

Abstract: An image sensor comprises a light-receiving element array, switching elements for transferring electric charges from the light-receiving element array, multilayer interconnection, load capacitors for storing the transferred electric charges, which includes one electrode which is an individual electrode and the other electrode which is a common electrode, the electrodes interposing an insulating layer therebetween, a drive IC for sequentially applying the electric charges, and common signal lines guiding the electric charges form capacitors to the drive IC. The image sensor is characterized in that, the individual electrode of the load capacitor constitutes an upper electrode, the common electrode of the load capacitor constitutes a lower electrode; and the insulating layer is formed of a high dielectric constant material. Therefore, the lower common electrode can be formed free from irregularities and the respective upper individual electrodes are also formed consistently. Further, the load capacitors can be formed small in size with a large capacitance.

An improved electrode structure for capacitive position sensors

Abstract: A capacitance-type measuring apparatus includes first and second support members which are movable with respect to one another along a measurement axis; a first electrode array and a second electrode disposed on the first support member; and a third electrode array disposed on the second support member and capacitively coupling the first electrode array and second electrode for transmission of a signal between the first electrode array and second electrode through the third electrode array. One of the first electrode array or the second electrode is formed to have end portions configured such that the degree of coupling between the first electrode array and second electrode through the third electrode array decreases along the extent of each end portion relative to the measurement axis. This configuration permits improved measurement accuracies by reducing the effects of tilt between the first and second support members which changes the spacing between such members along the axis of measurement.

Method of restoring a wire electrode broken during an electric discharge machining operation

Abstract: A method of restoring a wire electrode which has been broken during an electric discharge machining operation. A new wire electrode, which replaces the broken wire electrode, moves from an initial machining point to an electrode breaking point with the application of a voltage between a workpiece and the wire electrode to generate an electric discharge therebetween resulting in smooth movement of the electrode.

Electrode line protective device.

Abstract: of EP0360109A converter station (1) in a high voltage direct current power transmission is provided with an electrode line protective device for detection of ground faults on the electrode line (7) of the station. An alternating voltage generator (19) injects an alternating signal with a predetermined frequency in the electrode line. The two ends of the electrode line are provided with suppression filters (9, 10) tuned to the measuring frequency. The suppression filter (10) arranged at the remote end of the electrode line, in relation to the feeding point, is matched, by means of a resistor (14), to the wave impedance of the electrode line. An impedance measuring device (21) senses the impedance of the electrode line at the feeding point in relation to ground at the measuring frequency. An indicating signal (f) is delivered from the measuring device if the impedance measured deviates from the impedance of the electrode line when in a faultless state.

Streak camera operable with low deflection voltage

Abstract: A streak camera for detecting a light signal representing optical events occurring in ultra-short time intervals, comprising a photocathode, an accelerating electrode, a focusing electrode, an anode, a traveling wave deflector having a deflecting electrode for deflecting photoelectrons emitted from the photocathode with a deflection voltage having a phase velocity, a deflection circuit for controlling the deflection voltage to be applied to the deflecting electrode of the deflector, an electron stream detector having for detecting the electron stream deflected by said deflector, and a voltage control unit for controlling voltages to be applied to the photocathode, the accelerating electrode, the focusing electrode, the anode and the electron stream detector, thereby controlling a potential distribution in a photoelectron transit path. The voltage control unit carrys out a voltage supply operation such that the anode is supplied with a positive voltage below 5 KV with respect to a voltage to be applied to the photocathode, and the focusing electrode is kept at the highest positive potential among the photocathode, the accelerating electrode, the focusing electrode and the anode.

Method and circuit arrangement for intermittent application of a voltage to an electrode

Abstract: A method and a circuit arrangement for intermittent application of an electrical DC or AC voltage by a switch to an electrode in contact with a material, in particular for cleaning the electrode. The method is suitable in particular for use in electromagnetic flow measuring technology. The objective is to protect the electrode from parasitic capacitances present in the switch and interference voltages occurring therein. This is achieved in that at least in the period in which no voltage is applied to the electrode, the electrical potential of the electrode is coupled to the terminal of the switch which is not allocated to the electrode. Impedance converters are suitable as coupling elements.