Showing papers on "Electrode array published in 1985"

Method and apparatus for enhancing liquid hydrocarbon production from a single borehole in a slowly producing formation by non-uniform heating through optimized electrode arrays surrounding the borehole

Abstract: Method and apparatus for enhancing liquid hydrocarbon production through a single traditional producing borehole recognizing traditional producing well spacing from a slowly producing formation by use of non-uniform heating through interrelated electrode arrays surrounding the borehole. Heating the formation around the borehole through an interrelated electrode array designed for the formations geometry and geophysics favorably redistributes the pressure gradient throughout the formation for a substantial distance beyond the borehole permitting net energy effective production. One optimum electrode array may consist of ring electrodes or electrode segments so disposed as to electrically approximate a ring. Electrically conductive well bore casing in the formation may be used as an electrode. A return electrode of low impedance disposed close to the surface of the earth may be utilized.

Implantable apparatus for localized heating of tissue

Abstract: With the object of repetitively treating deep-seated, inoperable tumors by hyperthermia as well as locally heating other internal tissue masses repetitively, a receiving antenna, transmission line, and electrode arrangment are implanted completely within the patient's body, with the receiving antenna just under the surface of the skin and with the electrode arrangement being located so as to most effectively heat the tissue to be treated. An external, transmitting antenna, driven by an external radio-frequency energy source, is closely coupled to the implanted receiving antenna so that the energy coupled across the air-skin interface provides electromagnetic energy suitable for heating the tissue in the vicinity of the implanted electrodes. The resulting increase in tissue temperature may be estimated by an indirect measurement of the decrease in tissue resistivity in the heated region. This change in resistivity appears as a change in the loading of the receiving antenna which can be measured by either determining the change in the phase relationship between the voltage and the current appearing on the transmitting antenna or by measuring the change in the magnitude of the impedance thereof. Optionally, multiple electrode arrays may be activated or inactivated by the application of magnetic fields to operate implanted magnetic reed switches.

Discharge excitation type short pulse laser device

Abstract: A discharge excitation type short pulse laser device which is constructed with first and second main electrodes disposed in confrontation with the direction of the laser beam axis as their longitudinal direction, an auxiliary electrode provided on the rear surface part of the second main electrode and opposed to the second main electrode through the dielectric member, a pulse circuit for applying a pulse voltage across the first and second main electrodes, and a circuit for applying a voltage across the auxiliary electrode and the second main electrode, the circuit forming a part of the pulse circuit, or being independent of the pulse circuit, wherein the second main electrode is made of an electrically conductive material having a plurality of apertures therein, the second main electrode and the dielectric member are disposed in tight adhesion each other, and the second main electrode is thinly formed to enable creeping discharge to be produced on the surface of the dielectric member, thereby distributing electrons to be the seed for the main discharge to be generated across the main electrode.

Electrode arrays for cellular displays

Abstract: An electric flat panel display has a matrix of flat panel display cells and a fault tolerant driver circuit and an electrode array. A folded field drive scheme applies a periodic voltage signal to a common electrode. Opposing electrodes are set to one of two voltage states by voltage setting circuits.

Optimal conditions for the measurement of muscle fibre conduction velocity using surface electrode arrays.

Abstract: Three factors influencing the accuracy of the muscle fibre conduction velocity estimates were studied. They were the recording position, the interelectrode distance and the misalignment of the electrode with respect to the muscle fibres. Experiments were performed on the biceps muscle of a normal subject. Bipolar recordings were made simultaneously from a linear electrode array consisting of 13 contacts. The accuracy of the conduction velocity was evaluated by the cross-correlation method. When the recording site was close to the innervation zone, the peak values of the cross-correlation function decreased and the estimates of the time delays became unreliable. High correlations were obtained when the interelectrode distance was small. Furthermore, the misalignment between electrode axis and muscle fibre axis led to overestimation of muscle fibre conduction velocity, but this effect was less if wider electrodes were used.

Simplified electrode array for impedance cardiography.

Abstract: Impedance cardiography has enjoyed widespread interest owing to the promise of noninvasive monitoring of cardiac function. In clinical practice, one factor limiting its use has been the need to use circumferential electrodes. These electrodes can be inconvenient to apply, may interfere with chest tubes or intravenous lines, and can cause additional apprehension in critically ill patients. The paper describes a more convenient electrode array. It uses four disposable electrocardiographic electrodes, two on the base of the neck and two on the lower left, anterolateral surface of the thorax. Simultaneous impedance derivative recordings were made with this ‘spot’ electrode array and with the conventional ‘band’ electrode array, at rest and after exercise on ten normal volunteers. On a given individual, the two signals had shapes which were remarkably similar and relative heights which correlated well, exhibiting correlation coefficients (r′) between 0·77 and 0·98. This new array should facilitate impedance cardiographic measurements in the clinical setting.

Nonuniformity of fringe field correction for electro-optic devices

Abstract: Additional control in a differentially-encoded printer utilizing an electro-optic element is achieved by normalizing or equalizing the strength of the fringe fields Such normalization is provided by applying analog voltages to the adjacent electrodes in addition to the encoded data sample voltages Specifically, normalization of the strength of the fringe fields is achieved by characterizing the interaction between each adjacent pair of electrodes by measuring the efficiency amplitude of the fringe field caused by each adjacent pair of electrodes when a test voltage is applied to alternate electrodes and converting efficiency amplitude to an analog voltage for each electrode by a transfer function plotting efficiency amplitude versus voltage, storing the analog voltage for each electrode and adding the analog voltage for each electrode to the data sample voltage for that electrode to provide at the electrodes a full set of voltage differences that will provide normalization of the strength of the fringe fields associated with one complete data scan line

Metering system for measuring parameters of high ac electric energy flowing in an electric conductor

Abstract: Fig 5 (21,22,23); with by separate current sensor means (27,29,31,49,51,53) for generating separate polarized light outputs [Fig. 6 (69)] representative of voltage and current passing through the conductor, electronic means [35,37,39)] for receiving and transforming the voltage and current outputs into power, voltage, and current signals.

Arrangement for detecting spatial inhomogeneities in a dielectric

Abstract: The arrangement includes a capacitive probe comprising pairs of sensor electrodes, arranged in a pseudo-random sequence, with which a common transmitting electrode is associated. The transmitting electrode is fed by an electrical voltage source and to the sensor electrodes of each pair an electrode circuit is connected which generates an output signal which corresponds to the difference of the displacement currents induced in the sensor electrodes. The electronic circuit is constructed such that it maintains the sensor electrodes at any time at a virtual ground potential. For this purpose each sensor electrode may be connected to the inverting input of an operational amplifier whose non-inverting input lies at the potential at which the sensor electrodes are to be held with respect to the supply voltage. The sensed signal is used in a correlative measurement of speed or travel time.

Electrical memory equipment

Abstract: PURPOSE:To realize an easily manufacturable electrical memory equipment by forming a film which contains an organic charge mobile complex compound between electrodes facing each other. CONSTITUTION:After the first electrode 11 is formed by depositing copper on a glass substrate, the electrode is dipped in an acetonitrile solution of TCNQ (tetracyanoquinodimethane complex) and a film 13 made of a complex of TCNQ and copper is formed on the surface of the copper electrode 11. Then, the second electrode 12 is formed by applying an aluminum paste on the film 13. In an electric element obtained in this way, if the electric potential of the first electrode 11 is made higher than that of the second electrode 12, the film 13 is maintained a high resistance state to threshold intensity of electric field and is suddenly switched to a low resistance state at higher intensity. In such a state, no change at the normal temperature and the element can be used for a memory equipment. Further, in order to return to the original high resistance state, heating and slow cooling or applying a current bias is required.

Energy-efficient split-electrode TFEL panel

Abstract: A driving architecture for a matrix addressed TFEL display includes upper and lower data electrode arrays divided by a narrow gap and scanning electrodes arranged in complementary pairs one for each array of data electrodes The data electrodes are charged at a rate which minimizes the power loss in the resistive component of the data electrode circuitry The top and bottom data electrode arrays may be driven simultaneously, thereby decreasing the time needed to scan the panel, thus permitting more electrodes and larger screens The split-screen array provides shorter data electrodes which take less time to charge, thus permitting use of energy-saving techniques which require a slower charging rate

Blood-sugar measuring device

Abstract: PURPOSE: To simplify operation by perfectly removing the substance adhered to the surface of an electrode, by detecting an oxidizing current by the use of a measuring electrode, an opposed electrode and a reference electrode and subsequently applying voltage capable of electrolyzing water between the measur ing electrode and the opposed electrode and washing the surface of the electrodes with generated gas. CONSTITUTION: Blood is added to a sensor part 8 to perform the reaction of enzyme with glucose and sweep voltage is applied to the non-reversal input terminal 9 of an operational amplifier 10. Hereupon, an oxidizing current flows to a measuring electrode. Said oxidizing current is converted to voltage through an operational amplifier 11 and a resistor 12 to be outputted to an output termi nal 14. The concn. of glucose in blood is obtained from the peak value of the output at said terminal 14. In washing the sensor part 8, the input voltage of the input terminal 9 is brought to 0V and a switch 13 is subsequently closed to apply voltage capable of electrolyzing water between an opposed electrode 3 and the measuring electrode 2 to generate oxygen from the opposed electrode 3 hydrogen gas from the measuring electrode 2 and to detach the substances adhered to the electrodes. COPYRIGHT: (C)1987,JPO&Japio

Methd of logging an earth formation penetrated by a borehole to provide an estimate of impedance distribution with depth using end emitting current electrodes sequentially activated and a multiplicity of potential electrodes of a moving logging array

Abstract: The response characteristics of a combination of hole-centered electric logging tools in a variety of borehole conditions can be obtained by means of impedance values as entries of a matrix resulting from measurements over a series of depth increments, utilizing an array of 2M-1 electrode assemblies of equal incremental spacing positioned on a rigid mandrel. While the array moves continuously along the borehole, current is continuously emitted from the centrally located current electrode allowing the impedance matrix to be formed by the principle of linear superposition in terms of voltage and voltage difference measurements between adjacent electrodes.

Electrical charging apparatus for electrophotography

Abstract: An electrical charging apparatus which includes a confronting electrode formed by a metallic plate, a heat-resistant electrically insulative member for covering a surface of the confronting electrode, an exciting electrode in the form of a thin wire fixed to a surface of the heat-resistant electrically insulative member so as to face the confronting electrode through the heat-resistant electrically insulative member, a power source for applying a high voltage AC current between the confronting electrode and the exciting electrode, and a control electrode in the form of a mesh provided to confront the exciting electrode.

Display electrode array

Abstract: PURPOSE:To form a display electrode array with stable performance by providing a light shield electrode which covers at least the channel part of a thin-film TR and fixed at a specific voltage, and allowing the shield electrode to form electric capacity with no variation between channels across an insulating layer CONSTITUTION:A gate line for exciting an FET1 is shown by 13 and a drain line are shown by 14 The light shield electrode is divided into 15-a and 15-b, and overlap parts with a picture-element electrode 2 are 16-a and 16-b Even if there is mask matching deviation between the light shield electrodes 15-a and 15-b and picture-element electrode 2 and capacity 16-a decreases, capacity 16-b increases and the total amount of stored electricity is unchanged Further, the area of the transparent picture-element electrode 2 covered with the light shield electrodes 15-a and 15-b is unchanged and the transmissivity of external illumination light is fixed Consequently, electric characteristics have no unevenness and the display electrode array which has high manufacture yield and suits to a large-capacity display device is obtained

Multielectrode probe and circuitry and process pertaining thereto

Abstract: A system, method and probe for monitoring the corrosion rate of different metals in identical corrosive fluids and under identical conditions, such metals being employed as electrodes other than reference electrodes in a probe having also a reference electrode. The preferred probe comprises a probe body holding at least four electrodes, where one is placed in the center and the others around it in a circle. The center electrode is preferably used as a permanent reference electrode. Each electrode on the circle can then be connected in turn to a channel on a multistation PAIR meter as test and auxiliary electrodes, whereby the corrosion rate on each of them can be monitored in turn. This arrangement greatly enhances the utility of the multistation PAIR meter and with only two entry ports in a system, all channels can serve to answer specific questions on specific electrodes or metals. The novel probe can also be used with a one channel PAIR meter employed with a multi-station manual switch. In an alternative electrode arrangement, the center electrode is used as a permanent auxiliary electrode while the system itself is used as a reference electrode and a plurality of test electrodes are employed.

Electric arc furnace

Abstract: In an electric arc furnace having a fluid-cooled electrode support arm which is provided with an electrode holding means, the outside of the electrode support arm is plated with cooper and the electrode holding means is electrically insulated with respect to the support arm, by way of which the electrode current is carried to a contact jaw that bears against the electrode. In an electric arc furnace with for example three parallel electrode support arms the electrode current is taken partly by way of a heavy-current tube and partly by way of the electrode support arm in order to balance the different reactance in relation to the two other electrode support arms. In order to eliminate reactance asymmetry, a reactance loop is provided in at least one heavy-current conductor between the transformer of the electric arc furnace and the associated electrode support arm.

Determination of the SI Volt at the PTB

Abstract: Work on an electrostatic measuring system for the determination of the SI volt and the conversion factor KV at the PTB is reported. The system consists of a so-called voltage balance and a generator for the dc measuring voltage. There is a need for the development of such a device with an uncertainty below 1 part in 106 because measurements with existing voltage balances, and results obtained by other methods show discrepancies of several parts in 106. In order to reduce the uncertainty and to simplify the apparatus a special measuring method was developed. The voltage/force transducer of the PTB voltage balance is formed from two coaxial cylindrical electrodes and the generated force is substituted for the force of gravity on a weight of 2 g. The electrode voltage is composed of a constant part of 10186 V, derived in a 1000-fold stepup from 10 standard cells, and a much smaller variable part used for balancing the scale beam by means of a control loop. Taking the root sum of squares the total relative uncertainty of the SI volt and of KV is expected to be less than 4 parts in 107.

Electrolyzing method and apparatus

Abstract: PURPOSE: To attain stable conditions under which electrodes are not dissolved, by placing graphite electrodes and an auxiliary electrode in the same treating vessel and supplying part of electric current in each of forward and backward periods to the auxiliary electrode so that the electrode always acts as anode. CONSTITUTION: An apparatus for continuously treating a metallic web 1 is composed of an electrolytic cell 4 provided with graphite electrodes 7, 8 and an auxiliary electrode 30 and of a power supply unit provided with a power source 14 for supplying AC to the electrodes 7, 8, 30. Part of AC in each of forward and backward periods is supplied to the auxiliary electrode 30 so that the electrode 30 always acts as anode. COPYRIGHT: (C)1987,JPO&Japio

Arrangement for the measurement of the electric voltage parameters of a high voltage conductor

Abstract: For the measurement of the voltage parameters, such as instantaneous value, phase position, absolute value or sign of the high voltage of a high voltage conductor (1), a sensor (15) is conductively connected with a reference electrode and a non-earthed electrode (10) arranged along an equipotential surface in the proximity of the high voltage conductor (1), which electrodes both lie at a defined potential. The reference electrode can be the high voltage conductor (1), a second electrode (50) arranged on an equipotential surface or an auxiliary conductor (57) conductively connected with the high voltage conductor (1). The sensor, which can be a one-sidedly clamped mechanical piezo-oscillator, modulates the brightness of a radiated-in light bundle (32), which is reflected to the measuring device, converted by a receiver (40) into an electrical signal and evaluated. For the testing of the functional capability, an excitation signal, which is independent of the energy of the high voltage conductor, can be transmitted to the sensor (15) for the short-term modulation of the light bundle radiated in. For recognition of the zero position in the presence of a direct voltage at the high voltage conductor, the sensor can be switched free of voltage or reversed in polarity by means of a circuit arrangement which is testable in respect of functional capability.

Method of logging an earth formation penetrated by a borehole to provide an improved estimate of impedance distribution with depth using a single continuously emitting current electrode and a multiplicity of potential electrodes of a moving logging array

Abstract: The response characteristics of a combination of hole-centered electric logging tools in a variety of borehole conditions can be obtained by means of impedance values as entries of a matrix resulting from measurements over a series of depth increments, utilizing an array of 2M-1 electrode assemblies of equal incremental spacing positioned on a rigid mandrel. While the array moves continuously along the borehole, current is continuously emitted from the centrally located current electrode allowing the impedance matrix to be formed by the principle of linear superposition in terms of voltage and voltage difference measurements between adjacent electrodes.

The velocity filter, a system for recording and on line decomposition of complex extracellular spike trains by analog computing

Abstract: The velocity filter system consists of an electrode array (n electrodes), a set of analog delay circuits and a linear adder. When properly adjusted, the delays shift the recording signals of each electrode channel such that spikes of the same propagation direction and velocity are enhanced up ton-fold over the remaining signals. The influence of electrode parameters on the system's performance is investigated experimentally, and key design considerations are given. A working model (n=4) is described featuring a new type of en passant extracellular electrode array with low noise and good reproducibility. Recordings on the thoracal connectives of the stick insectAcrophylla wulfingii are presented demonstrating the expected performance of the system. A velocity resolution ofΔV/V=15% was achieved. An experimental example of the automatic decomposition of overlapping spike complexes is presented. The system is capable to work on line in real time without the need of templates and computers. Once adjusted, the system can select spikes of specified conduction velocities from overlapping complexes continuously in real time without intervention of an operator, and thus decompose overlapping complexes automatically. Already in the present state of development, applications in invertebrate and vertebrate electrophysiology are possible.

Construction of a periodic electrode array

Abstract: A design for an electrode array for use in nonlinear optics experiments is presented. The array applies a spatially periodic transverse electric field (amplitude ∼ 3 kV/mm and period 4 mm) to a gas sample through which a laser beam is focused.

Monolithic integrated planar semi-semiconductor arrangement and process for its production

Abstract: A monolithic integrated semi-conductor arrangement in which the breakdown voltage is adjusted by a cover electrode (7) in the pn junction region. A suitable voltage is applied to this cover electrode (7) via a voltage divider (1) in order to adjust the breakdown voltage. To obtain a breakdown voltage which is essentially independent of temperature it is envisaged that the voltage divider(1) consists of diffused zones, which have differentiated dopings. The different temperature coefficients thus produced for the resistances (R1, R2) of the voltage divider (1) cause a temperature-dependent voltage change in the cover electrode , with the result that the breakdown voltage temperature is stabilized.

Electric field forming apparatus

Abstract: An electric field forming unit that has a long surface life, high reliability, and provides a uniform surface corona discharge along the entire length of the discharge electrode The electric field forming unit includes a dielectric substrate made of a fine ceramic having a discharge electrode and an inductive electrode formed on opposite sides thereof The discharge electrode has peripheral edges which are provided with a better linearity than a discharge electrode formed from an electroconductive paste by screen printing The discharge electrode may be formed of a metalized tape in a thin line form

Method and apparatus for applying electrical stimulus pulses to a subject

Abstract: A method and apparatus for stimulating evoked potentials in a human subject maintains the common mode voltage at the stimulation electrodes substantially constant both before and during application of a stimulus pulse of constant current. A pair of resistors are connected between the stimulation electrodes and are joined at a reference node. One stimulation electrode (e.g., the anode) is connected through a field effect transistor to the power supply voltage and the other electrode (e.g., the cathode) is connected to the supply common return through a transistor which, when turned on, is controlled to conduct a constant current. The voltage at the reference node is supplied to the gate of a second field effect transistor which has its source clamped to a reference voltage. The voltage at the drain of the second field effect transistor is suppled back to the gate of the first field effect transistor. The two field effect transistors cooperate to supply a voltage to the anode electrode which is controlled such that the voltage at the reference node remains substantially constant before, during and after the switching transistor switches to provide a stimulation pulse. The common mode voltage at the anode and cathode is thus maintained substantially constant during stimulation pulses to minimize stimulus artifacts at the sensing electrodes.

Histopathology following electrode insertion and chronic electrical stimulation

Abstract: We have examined a number of safety issues associated with cochlear implants. This work has been primarily designed to evaluate the histopathological effects of intracochlear electrode implantation and chronic electrical stimUlation. The results of these studies may be summarized as follows: 1) The insertion of the banded free-fit scala tympani array into human cadaver temporal bones produces minimal damage, occurring primarily to a localized region of the spiral ligament. This damage would not result in significant neural degeneration and thus, would not compromise the efficacy of the multiple channel device; 2) chronic intracochlear electrical stimUlation for continuous periods of 500 to 2000 hours, lIsing charge balanced biphasic current pulses developing charge densities of 18-32 }AC/cmz. geom./phase, does not adversely affect the spiral ganglion cell popUlation; 3) labyrinthine infection severely reduces the viable spiral ganglion cell population; 4) the formation of new bone ­ present in approximately half of the animals we have implanted -is not associated with electrical stimulation ~ se; 5) scanning electron microscope studies of electrodes subjected to long periods of intracochlear electrical stimulation reveals minimal platinum dissolution when compared with unstimulated control electrodes, and electrodes that have been stimUlated for similar periods in inorganic saline.

Apparatus for continuously measuring the thickness

Abstract: In an apparatus for continuously measuring the thickness of a material deposition produced by means of a coating unit on a carrier material, the sedimentation thickness is electrically determined on the measuring electrode (9) of a reference probe (50) by detecting an alternating current signal on the measuring electrode (9). The measuring electrode (9) is provided between two field generating electrodes (17, 23) arranged within a metal casing (1) provided with inlet openings (4, 5), which electrodes are subjected to the action of alternating voltages which are out of phase by 180o between each other and of which the amplitudes are set at the beginning of the measurement so that no signal can occur at the measurement electrode (9). The material deposition produced during the coating operation of a carrier material on the neighbouring measurement electrode (9) causes an out-of-tune of the field flow in the reference probe (50) and, consequently, a measuring current in the measurement electrode (9) connected to an evaluation circuit.

Driving circuit for an electrostatic recording head

Abstract: The instant invention relates to a method and apparatus for driving an electrostatic recording head for recording images on a medium comprising a plurality of pin electrodes, the pin electrode arrays are separated into alternate even and odd arrays positioned on said recording head (A1, B1, A2, B2 . . . Ak, Bk . . . where Ak are odd arrays and Bk are even arrays), a plurality of control electrodes, each positioned adjacent one or more associated pin electrodes, each pin electrode array and associated control electrodes, when energized, producing the images, the pin and control electrodes are controlled by separate order control circuits which control the pin electrostatic arrays and the control electrode arrays for producing the images in the following order alternating between odd and even arrays: AN+1, B1 . . . A2N, BN, A1, BN+1, . . . AN, B2N, A3N+1, B2N+1 . . . A4N, B3N, A2N+1, B3N+1 . . . A3N, B4N wherein N is an integer greater than or equal to 2.

Light valve display device having integrated driving circuits

Abstract: A display device and operational method wherein driving and controlling electronic circuits (53) are provided along with a liquid crystal layer (21) as part of a unitary structure. An array of independent pixel reflective electrodes (13, 15, and 17) are provided behind the liquid crystal layer (21) and are individually driven by the electronic circuit (53) provided as part of the device. A light and electrostatic shield (33) is provided between the electrode array and the integrated electronic circuit (53). The shield (33) can also be utilized as a third electrode to bias the liquid crystal (21) for faster response when voltages are applied to the individual electrodes.