Showing papers on "Electrode array published in 2002"

Fitting process for a neural stimulation system

Abstract: A programming system and method for use with an implantable tissue stimulator allows a clinician or patient to quickly determine a desired electrode stimulation pattern, including which electrodes of a multiplicity of electrodes in an electrode array should receive a stimulation current, including the amplitude, width and pulse repetition rate of such current. Movement of the selected group of electrodes is facilitated through the use of a directional pointing device, such as a joystick. As movement of the selected group of electrodes occurs, current redistribution amongst the various electrode contacts takes place. The redistribution of stimulus amplitudes utilizes re-normalization of amplitudes so that the perceptual level remains fairly constant. This prevents the resulting paresthesia from falling below the perceptual threshold or above the comfort threshold. A software wizard provides a software user interface, including the use of easy-to-understand instructional, data-gathering and/or parameter-setting screens, that walks a user step by step through the programming process.

Systems and methods for automatically optimizing stimulus parameters and electrode configurations for neuro-stimulators

Abstract: Methods and devices for automatically optimizing the stimulus parameters and/or the configuration of electrodes to provide neural stimulation to a patient. In one embodiment, a system includes an electrode array having an implantable support member configured to be implanted into a patient and a plurality of therapy electrodes carried by the support member. The system can also have a pulse system operatively coupled to the therapy electrodes to deliver a stimulus to the therapy electrodes, and a sensing device configured to be attached to a sensing location of the patient. The sensing device generates response signals in response to the stimulus. The system can also include a controller operatively coupled to the pulse system and to the sensing device. The controller includes a computer operable medium that generates command signals that define the stimulus delivered by the pulse system, evaluates the response signals from the sensing device, and determines a desired configuration for the therapy electrodes and/or a desired stimulus to be delivered to the therapy electrodes.

Threshold, comfortable level and impedance changes as a function of electrode-modiolar distance.

Abstract: Objective: The study investigated the hypothesis that threshold and comfortable levels recorded from cochlear implant patients would reduce, and dynamic range increase, as distance of the electrode from the modiolar wall (radial distance) decreases Two groups of cochlear implant patients participated; one group using the Nucleus ® 24 Contour™ electrode array, and one group using the Nucleus standard straight (banded) array The Nucleus 24 Contour array has been shown in temporal bone studies to lie closer to the modiolus than the banded array The relationship of electrode impedance and radial distance is also investigated Design: The study, conducted at three centers, evaluated 21 patients using the Contour array, and 36 patients using the banded array For each patient, threshold, comfortable levels and dynamic range were measured at four time points Common ground electrode impedance was recorded clinically from each patient, at time intervals up to 12 wk An estimate of the radial distance of the electrode from the modiolus was made by analysis of Cochlear view x-rays Results: Threshold and comfortable levels were significantly lower for the Nucleus 24 Contour array than for the banded array However, dynamic range measurements did not show the predicted increase In a majority of subjects, a significant correlation was found between the estimated radial distance of the electrode from the modiolus and the measured threshold and comfortable levels This trend was not observed for dynamic range The analysis indicates that other factors than radial distance are involved in the resultant psychophysical levels Clinical impedance measures (common ground) were found to be significantly higher for the Contour array However, the electrodes on the Contour array are half-rings, which are approximately only half the geometric size of the full rings as electrodes of the standard array When the geometric electrode area in the two array designs are normalized, the trends in the electrode impedance behavior are similar Conclusions: The results support the hypothesis that the relationship between the radial distance of the electrode and the psychophysical measures are influenced by patterns of fibrous tissue growth and individual patient differences, such as etiology and neural survival Impedance measures for the Nucleus 24 Contour electrode array were higher than the banded electrode array, but this is primarily due to the reduction in electrode surface area The different outcomes in impedance over time suggest differences in the relative contributions of the components of impedance with the two arrays (Ear & Hearing 2002;23;28S– 40S)

Flexible electrode array for artificial vision

Abstract: An image is captured or otherwise converted into a signal in an artificial vision system. The signal is transmitted to the retina utilizing an implant. The implant consists of a polymer substrate made of a compliant material such as poly(dimethylsiloxane) or PDMS. The polymer substrate is conformable to the shape of the retina. Electrodes and conductive leads are embedded in the polymer substrate. The conductive leads and the electrodes transmit the signal representing the image to the cells in the retina. The signal representing the image stimulates cells in the retina.

Neural prosthetic micro system

Abstract: A neural prosthetic micro system (100) includes an electrode array (115) coupled to an integrated circuit (IC) (110) which IC may include signal conditioning and processing circuitry. The IC may include a high pass filter that passes signals representative of local field potential (LFP) activity in a subject's brain.

Microstructured arrays for cortex interaction and related methods of manufacture and use

Abstract: A brain implant system consistent with embodiments of the present invention includes an electrode array having a plurality of electrodes for sensing neuron signals. A method for manufacturing the electrode array includes machining a piece of an electrically conductive substance to create a plurality of electrodes extending from a base member. Each electrode also has a corresponding base section. A nonconductive layer is provided around at least a portion of the base section of each electrode to support the plurality of electrodes. The base section of the electrodes are then cut to separate the base member from the plurality of electrodes supported by the nonconductive support layer. The present invention also includes a complete brain implant system using the above electrode array.

Implantable devices having a liquid crystal polymer substrate

Abstract: An implantable medical device (IMD) is disclosed that is formed on a substrate composed of liquid crystal polymer (LCP). In one embodiment, the IMD can be an interconnection module for interconnecting an electrode array (102) to an equipment module (116). The interconnecting module (109) includes conductors (110A-110C) disposed on the LCP substrate and coupled to the electrode array, and wherein the conductors are encapsulated using a silicone or LCP encapsulant. In another embodiment, the IMD is an electrode array and interconnect module disposed on an integral LCP substrate. An equipment module can be coupled to the interconnect module. Alternatively, a hybrid electronic circuit can be coupled to the interconnect module for signal processing and conditioning signals received from the electrode array or for providing stimulus signals to the electrode array. In this embodiment, all of the conductors and at least a portion of the electrodes in the electrode array are encapsulated using a silicone or LCP encapsulant. In another embodiment, the IMD is an electrode disposed on an LCP substrate. The interconnecting module is used to provide signal paths to and from the electrodes in the electrode array to the hybrid circuit. In this embodiment, all of the conductors, the hybrid electronic circuit and at least a portion of the electrodes in the electrode array are encapsulated using a silicone or LCP encapsulant .

Electrode array for use in electrochemical cells

Abstract: The invention features an electrode array (7) in which pairs of electrodes (1) are geometrically arranged so that the broadest faces of the exposed electrodes are not directly opposing to each other. Rather, the broadest facing surfaces of the electrodes in the array are parallel, adjacent, or offset at an angle. The electrode geometry of an electrode array of the invention permits electrodes to be in close proximity, thereby lowering series resistance, while minimizing the possibility for short circuits that can cause electrical leakage. An electrode array of the invention can be used in an electrochemical cell, such as a battery, e.g., a lithium battery, a capacitor, a flow-through capacitor, or a fuel cell.

Multiplexed electrode array extension

Abstract: An apparatus and method for selectively interacting with electrically excitable tissue of a patient are provided. The apparatus includes an implantable pulse generator (220) having a number of output sources (222-224) that transmit pulse signals. An extension unit (226) couples the implantable pulse generator to an implantable electrode array (238-243). The implantable electrode array has a number of electrodes, wherein the number of electrodes is greater than the number of output sources. The extension unit is configured to electrically connect the output sources to a portion of the electrodes.

Neurophysiology of cochlear implant users I: effects of stimulus current level and electrode site on the electrical ABR, MLR, and N1-P2 response.

Abstract: Objective As the need for objective measures with cochlear implant users increases, it is critical to understand how electrical potentials behave when stimulus parameters are systematically varied. The purpose of this study was to record and evaluate the effects of implanted electrode site and stimulus current level on latency, amplitude, and threshold measures of electrically evoked auditory potentials, representing brainstem and cortical levels of the auditory system. Design The electrical auditory brainstem response (EABR), electrical auditory middle latency response (EAMLR), and the electrical late auditory response (ELAR) were recorded from the same experimental subjects, 11 adult Clarion cochlear implant users. The Waves II, III, and V of the EABR, the Na-Pa complex of the EAMLR and the N1-P2 complex of the ELAR were investigated relative to electrode site (along the intra-cochlear electrode array) and stimulus current level. Evoked potential measures were examined for statistical significance using analysis of variance (ANOVA) for repeated measures. Results For the EABR, Wave V latency was significantly longer for the basal electrode (7) compared with the mid (4) and apical (1) electrodes. For the EAMLR and ELAR, there were no significant differences in latency by electrode site. For all subjects and each of the evoked potentials, the apical electrodes tended to have the largest amplitude and the basal electrodes the smallest amplitude, although amplitude differences did not reach statistical significance. In general, decreases in stimulus current level resulted in statistically significant decreases in the amplitude of Wave V, Na-Pa and N1-P2. The evoked potential thresholds for Wave V, Na-Pa, and N1-P2 were significantly higher for the basal Electrode 7 than for Electrodes 4 and 1. Conclusions Electrophysiologic responses of Waves II, III, and V of the EABR, Na-Pa of the EAMLR, and N1-P2 of the ELAR were characterized as functions of current level and electrode site. Data from this study may serve as a normative reference for expected latency, amplitude and threshold values for the recording of electrically evoked auditory brainstem and cortical potentials. Responses recorded from cochlear implant users show many similar patterns, yet important distinctions, compared with auditory potentials elicited with acoustic signals.

A novel electrode power profiler for dimmable ballasts using DC link voltage and switching frequency controls

Abstract: A novel electrode power profiler for dimmable ballasts using a series-resonant parallel-loaded inverter is presented. Dimming of fluorescent lamps and control of the electrode power are achieved by simultaneously adjusting the DC link voltage and the switching frequency of the inverter. The current gradient along the electrode, which is due to the distributed lamp current property on the electrode, is deliberated in formulating the power and voltage models of the electrode. As the electrode heating relies on two near-orthogonal current components including the lamp current and the resonant tank circuit current, a simple feedback control is developed to derive the electrode power. Reduction of the electrode power (due to the decrease in the lamp current) during dimming is compensated by increasing the switching frequency of the inverter, in order to increase the resonant tank circuit current. Experimental results of a T8 36 W prototype are verified with theoretical predictions.

Mri-safe cardiac stimulation device

Abstract: An MRI-safe cardiac stimulation device includes a voltage discharge unit (14 of Figure 1) adapted to generate voltage pulses, a pair of implantable electrodes (22 and 24 of Figure 1) connected to deliver voltage pulses from the voltage discharge unit (14 of Figure 1) to implanted cardiac tissue, and an electrode isolation system (15 of Figure 1) adapted to electrically isolate the electrodes (22 and 24 of Figure 1) from the voltage discharge unit (14 of Figure 1) during time intervals between the voltage pulses, the electrode isolation system (15 of Figure 1) being responsive to the voltage pulses to connect the voltage discharge unit (14 of Figure 1) to the electrodes (22 and 24 of Figure 1) during the voltage pulses.

Method and apparatus for selecting an optimal electrode configuration of a medical electrical lead having a multiple electrode array

Abstract: An electrical medical lead is provided having two or more electrodes, electrically insulated from each other and electrically coupled to individually insulated filars in a multi-filar coiled conductor. When the lead is used with a medical device equipped with a switch matrix, electrodes are selected individually or simultaneously to serve as an anode or cathode in any unipolar, bipolar or multi-polar configuration for delivering stimulation and/or sensing signals in excitable tissue. In one embodiment, a tip electrode array is expandable for improving electrode contact with targeted tissue and stabilizing lead position.

Electro-kinetic air transporter-conditioner with a multiple pin-ring configuration

Abstract: A system massages a user's feet and generates an electro-kinetic airflow that contains safe amounts of ozone that can deodorize the user's feet or socks. The system includes an ion generator comprising a high voltage pulse generator whose output pulses are coupled between left and right first and second electrode arrays. Preferably the first electrode array includes first and second pointed electrodes, and the second electrode array includes annular-like electrodes having a central opening coaxial with the associated pointed electrode. Preferably the annular-like electrodes are formed from a single sheet of metal by extrusion or punching such that the surface of the annular-like electrodes is smooth and continuous through the opening and into a collar region through which the air flows. Particulate matter in the ambient air electrostatically adheres to the smooth continuous surface of the annular-like electrodes.

Providing a reference voltage to a cross point memory array

Abstract: Providing a reference voltage to a cross point memory array. The invention is a cross point memory array and some peripheral circuitry that, when activated, provides a reference voltage to a cross point array. The peripheral circuitry can be activated before, after or during selection of a specific memory plug. If the peripheral circuitry is activated during selection, only the unselected conductive array lines should be brought to the reference voltage. Otherwise, all the conductive array lines can be brought to the reference voltage.

Non-contact voltage measurement method and device, and detection probe

Abstract: It is possible to avoid the effects of floating capacitance, and to measure a voltage with a simple operation and in a non-contact manner, without measuring the floating capacitance. A measurement method for measuring an AC voltage applied to a conductor, without contacting the conductor, using a detection probe, provided with a detection electrode capable of covering part of a surface of insulation for insulating the conductor and a shield electrode for covering the detection electrode, and an oscillator for outputting a signal having a certain frequency, wherein one end of each of a core wire and a sheath wire of a shield cable are connected to the detection electrode and the shield electrode, and a floating capacitance effect is substantially made zero by establishing an imaginary short-circuit state between each of the other ends, the measurement method comprising the steps of measuring impedance between the detection electrode and the conductor by applying the signal from an oscillator to the detection electrode via the shield cable, measuring a current discharged from the detection electrode attributable to the voltage applied to the conductor, and obtaining the applied voltage based on the measured impedance and current.

Insertion tool system for an electrode array

Abstract: A device (10) used for inserting an electrode array (15) into a cochlea of a subject. Particularly, the device (10) is adapted for insertion of electrode arrays (15) having an elongate carrier member (21) and a removable means (22) extending through the carrier member (21). The device includes a handle (11), an elongate positioning member (12) mounted to the handle (11), an actuator member (17) movable relative to the elongate positioning member (12), and at least one anchor member (16) connected to the actuator member (17) and engageable with the removable means (22). On insertion of the electrode array (15) into a subject's cochlea, the actuator member (17) can be moved relative to the elongate positioning member (12) to withdraw the removable means (22) from the carrier member.

Design strategies for multielectrode arrays applicable for high-throughput impedance spectroscopy on novel gas sensor materials.

Abstract: This paper reports the first design and fabrication of a 64 multielectrode array for high-throughput impedance spectroscopy. The purpose of this work is the development of a measurement system for the discovery and improvement of sensor materials using combinatorial methods. An array of interdigital capacitors (IDC) screen-printed onto a high-temperature-resistant Al2O3 substrate is determined to be the optimal test plate. The electrode layout, and therefore also the idle capacity, is determined by specific requirements. Calculation of the idle capacity of the IDC as a function of the electrode width and distance allows adjustment and thus optimization of the array. Parasitic effects caused by the leads and contacts are compensated by a software-aided calibration. Apart from the use of the substrates for discovery of new sensor materials, the presented electrode array is also suitable for electrocatalytic applications as well as impedance spectroscopic studies of semiconductors and dielectrics.

Method of making composite electrode and current collectors

Abstract: Composite electrode/current collectors for capacitors, e.g., a flow-through capacitor or electric double layer capacitor are disclosed. Also disclosed are methods for making a composite electrode/current collectors and capacitors having at least one composite electrode/current collector.

Plasma processing apparatus and method for confining an RF plasma under very high gas flow and RF power Density conditions

Abstract: The present invention includes a system and method for confining plasma within a plasma processing chamber. The plasma processing apparatus comprises a first electrode, a power generator, a second electrode, at least one confinement ring, and a ground extension surrounding the first electrode. The first electrode is configured to receive a workpiece and has an associated first electrode area. The power generator is operatively coupled to the first electrode, and the power generator is configured to generate RF power that is communicated to the first electrode. The second electrode is disposed at a distance from the first electrode. The second electrode is configured to provide a complete electrical circuit for RF power communicated from the first electrode. Additionally, the second electrode has a second electrode area that is greater than the first electrode area. At least one confinement ring is configured to assist confine the plasma. The plasma is generated with the RF power being communicated between the first electrode and the gas residing inside the confinement rings. The ground extension drains charge from the plasma boundaries with a grounded conductive surface.

Electro-kinetic air transporter and conditioner device with enhanced housing configuration and enhanced anti-microorganism capability

Abstract: An electro-kinetic air conditioner for removing particulates from the air creates an airflow using no moving parts. The airflow is subjected to UV radiation from a germicidal lamp within the device. The conditioner includes an ion generator that has an electrode assembly including a first array of emitter electrodes, a second array of collector electrodes, and a high voltage generator. The device can also include a third or leading or focus electrode located upstream of the first array of emitter electrodes, and/or a trailing electrode located downstream of the second array of collector electrodes, and/or an interstitial electrode located between collector electrodes, and/or an enhanced emitter electrode with an enhanced length in order to increase emissivity.

Insertion needle for use with implantable, expandable, multicontact electrodes

Abstract: An insertion needle facilitates the implantation of an electrode array carried on a flexible, foldable or compressible, subcarrier or substrate. Such subcarrier or substrate folds or compresses during implantation, thereby facilitating its insertion using the insertion needle. Once implanted, such subcarrier or substrate expands, thereby placing the electrodes in a desired spaced-apart positional relationship, and thus achieving a desired electrode array configuration. The insertion needle has a lumen with a non-circular cross-sectional shape, e.g., having a width greater than its height, to facilitate sliding the folded or compressed paddle-type electrode array therein, and further includes a longitudinal slit.

Miniaturized high-density multichannel electrode array for long-term neuronal recordings

Abstract: A high-density multichannel microwire electrode array is disclosed. The array can comprise a variable number of electrodes. A method of assembling the array is further disclosed. Additionally, a plurality of devices employing the array are disclosed, including an intelligent brain pacemaker and a closed loop brain machine interface.

Design and fabrication of a novel two-dimension MEMS-based tunable capacitor

Abstract: In this paper, a novel bulk micromachined two-dimension tunable capacitor is proposed with the techniques of silicon-glass wafer bonding and deep reactive ion etch. The micromechanical tunable capacitor comprises a suspended plate array, a bottom electrode array corresponding with it that is fixed on the glass substrate, and side-interdigitated comb structures. When the suspended plate array is laterally driven by the electrostatic comb actuator, the capacitance (the first dimension) between the suspended plate array and bottom array, together with the interdigitated comb capacitance (the second dimension) tune linearly with applied voltage. Thus it increases tuning ratio and unbiased base capacitance. The finite element method simulation with ANSYS 5.5 is used to analyze the varying behavior of the capacitor. Meanwhile, the fabrication process is very simple in that only three masks are used, and very efficient to achieve high-Q values, because it employs glass instead of silicon as substrate.

An electrochemical redox couple activitated by microelectrodes for confined chemical patterning of surfaces.

Abstract: Microelectrodes, printed as an array on the surface of a silicon chip, generate chemically active species in a solution of electrolyte held between the electrode array and a glass plate The active species induce chemical change in molecules coupled to the surface of the glass plate, which is separated from the electrode array by a gap of several micrometers This paper explores the nature and pattern of the induced chemical change The patterning is discussed with respect to the electrolyte composition and the magnitude and duration of current applied to the microelectrodes We show that under suitable conditions the active species is confined to micrometer-sized features and diffusion does not obscure the surface pattern produced