Abstract: A method and apparatus for protecting an electronic implantable medical device prior to it being implanted in a patient's body. The apparatus affords protection against electronic component damage due to electrostatic discharge and/or physical damage due to improper handling. The apparatus is comprised of a circuit board having a conductive surface for receiving and releasably grasping the electrodes of the medical device to support the device's housing proximate to the surface of the circuit board. Two conductive paths are formed on the circuit board extending between two conductive surfaces for shunting electrostatic discharge currents to prevent such currents from passing through the device's electronic circuitry. The conductive paths include oppositely oriented diodes, preferably comprising diodes which emit light (i.e., LEDs) when current passes therethrough. Additionally, an external monitor/generator is provided to enable functional testing of the medical device.

Abstract: A full-body charger for charging one or more battery-powered devices wherein such devices are configured for implanting beneath a patient's skin for the purpose of tissue, e.g., nerve or muscle, stimulation and/or parameter monitoring and/or data communication. Devices in accordance with the invention include a support structure, typically chair-shaped or bed-shaped, capable of supporting a patient's body while providing a magnetic field to one or more of the implanted devices using one or more coils mounted within for providing power to the implanted devices. Consequently, in a preferred embodiment, a single, generally sequential, charging cycle can charge all of the implanted devices and thus minimize the charge time requirements for a patient and accordingly improve the patient's life style.

Abstract: The objective of the current invention is to restore color vision, in whole or in part, by electrically stimulating undamaged retinal cells, which remain in patients with, lost or degraded visual function. The invention is a retinal color prosthesis. Functionally, There are three main parts to this invention. One is external to the eye. The second part is internal to the eye. The third part is means for communication between those two parts. The external part has subsystems. These include an external imaging means, an eye-tracker, a head-motion tracker, a data processor, a patient's controller, a physician's local controller, a physician's remote controller, and a telemetry means. The imaging means may include a CCD or CMOS video camera. It gathers an image of what the eyes would be seeing if they were functional. Color information is acquired by the imaging means. The color data is processed in the video data processing unit.

Abstract: An implantable substrate sensor has electronic circuitry and electrodes formed on opposite sides of a substrate. A protective coating covers the substrate, effectively hermetically sealing the electronic circuitry under the coating. Exposed areas of the electrodes are selectively left uncovered by the protective coating, thereby allowing such electrodes to be exposed to body tissue and fluids when the sensor is implanted in living tissue. The substrate on which the electronic circuitry and electrodes are formed is the same substrate or “chip” on which an integrated circuit (IC) is formed, which integrated circuit contains the desired electronic circuitry. Such approach eliminates the need for an hermetically sealed lid or cover to cover hybrid electronic circuitry, and allows the sensor to be made much thinner than would otherwise be possible. In one embodiment, two such substrate sensors may be placed back-to-back, with the electrodes facing outward.

Abstract: A magnetic control system for selectively enabling/disabling an implantable device's operation using externally applied pulsed magnetic means, e.g., a controlled electromagnet or the like. Typically, such implantable devices stimulate a neural pathway or muscle and/or block pain or muscle stimulation according to programmable settings. Preferably, once programmed from an external programmer, such implantable devices can operate “independently” using the externally provided programmed information. However, in certain circumstances, it may be desired to stop/pause the operation of such selected implanted device while not affecting other such devices. Accordingly, embodiments of the present invention include a magnetic sensor, preferably a magnetoresistive, Hall effect, saturated core reactors, or the like, to sense an externally provided magnetic field. By externally applying pulsed magnetic fields in sequences of controlled polarities, durations, intensities, etc.

Abstract: An automatic tuning system for a magnetic field generating tuned circuit includes a processor configured to maintain the resonant frequency of a tuned circuit equal to a reference frequency. The tuned circuit is driven by a power amplifier whose output provides an amplified signal at the reference frequency. The tuned circuit includes a magnetic field generating inductor and a bank of individually switchable capacitors controlled by the processor capable of adding and removing the respective capacitances to and from the tuned circuit. The inductor includes a Faraday shield to shield the tuned circuit from the influence of electric fields. A power sense circuit monitors the power delivered by the power amplifier to the tuned circuit and the processor sequentially switches the capacitors in a binary progression format to achieve maximum power delivery indicative of conforming the resonant frequency of the tuned circuit to the reference frequency.

Abstract: The invention is a method of qualifying an implantable ceramic component made of high-purity dense yttria tetragonal zirconium oxide polycrystal (Y-TZP) by application of non-destructive tests. Specifically, a qualified Y-TZP ceramic component or witness sample is examined by X-ray diffraction to determine the initial monoclinic phase content. The component or witness sample is exposed to steam at 127° C. for a predetermined period of time, preferably six hours. The monoclinic phase content is determined for the post-exposure sample. The absolute difference between the initial monoclinic phase content and the post-exposure monoclinic phase content is calculated by difference. If the difference is less than 2.1% the sample is accepted. In an alternate embodiment, the components that pass the screening test are examined by ultrasonic testing to evaluate soundness of the ceramic component. Any component that presents a flaw of greater than three microns is rejected.

Abstract: A programmable signal analysis device for detecting and counting neurological and muscular events in living tissue that incorporates one or more signal threshold levels to identify an event, a counter to count events, and a timer to determine event frequency as events per unit time. The threshold levels and counter/timer operating modes/parameters are digitally programmable to identify and count events, i.e., electrical signals having defined parameters. Such a circuit is of particular use in a microstimulator/sensor which is capable of being injected into living tissue at the site of interest. The microstimulator/sensor is used to stimulate a neural pathway or muscle and/or to block a neural pathway to alleviate pain or block stimulation of a muscle.

Abstract: An implantable, integrated apparatus that contacts the brain with a plurality of metal needles to detect electrical signals or to transmit signals to the brain. The needles are connected by wires that pass along a flex connector to a ceramic case that contains electrodes to carry the signals to the electrical processing components that are hermetically contained in the ceramic case. The processed signals are received by or are transmitted by an antenna to a remote central processor.

Abstract: The invention discloses apparatus for connecting electrically conductive wire to a miniature, implantable sensor or stimulator device for detecting electrical signals or stimulating living tissue. The implantable device has an electrically conductive end on its case which is intimately connected to a doorknob electrode for communicating electrical signals between the living tissue and the device by a biocompatible wire. A spring clip removably attaches to the doorknob electrode so that the wire may be easily attached to the doorknob electrode during surgery. An insulating rubber boot, which may be silicone, surrounds the case end, doorknob electrode, and spring clip to isolate the living tissue from the conductive components. The components are all biocompatible materials.

Abstract: An implantable enzyme-based monitoring system suitable for long term in vivo use to measure the concentration of prescribed substances such as glucose is provided. In one embodiment, the implantable enzyme-based monitoring system includes at least one sensor assembly, an outer membrane surrounding the sensor assembly and having a window therein, and a polymeric window cover affixed to the outer membrane and covering the window. Preferably, the outer membrane of the monitoring system is silicone and the window cover is a polymer of 2-hydroxyethyl methacrylate (HEMA), N,N,-dimethylaminoethyl methacrylate (DMAEMA) and methacrylic acid (MA). Also provided herein is an implantable enzyme-based monitoring system having at least one sensor assembly, an outer membrane surrounding the sensor assembly and a coating affixed to the exterior surface of the outer membrane, wherein the coating resists blood coagulation and protein binding to the exterior surface of the outer membrane.

Abstract: A method and apparatus for improving visual acuity when providing a visual image from a “high” resolution input device to a “low” resolution output device. The described invention is of particular use when the output device is an array of electrodes as part of a retinal prosthesis used to restore vision to a visually-impaired patient. In that various limitations may, within the foreseeable future, limit the density of such an electrode array (and thus the resolution of the output image), the present invention teaches techniques to assign processed pixel subsets of a higher resolution image to a single electrode. By varying the pixel subsets, e.g., by jittering, and/or altering the processing criteria, the perceived visual acuity may be further improved. Alternatively and additionally, such processing may be further extended to drive neighboring electrodes in combination to thus stimulate virtual electrode sites and thus further enhance visual acuity.

Abstract: The invention is a method for increasing the airflow to a zinc-air battery such that the energy density is 500 mwh/cc to 1000 mwh/cc. This allows 8 to 16 hours use as a primary (throw-away) battery, with, for example, high-duty cycle, high-drain cochlear implants, and neuromuscular stimulators for nerves, muscles, and both nerves and muscles together. The systems incorporating the high energy density source are also part of the invention, as well as the resulting apparatus of the method. The uses of this inexpensive, i.e., a $1.00 per day, throw-away primary battery are new uses of the modified zinc-air battery and are directed toward helping people hear again, walk again, and regain body functionality which they have otherwise lost permanently.

Abstract: A protective, biocompatible coating or encapsulation material protects and insulates a component or device intended to be implanted in living tissue. The coating or encapsulation material comprises a thin layer or layers of alumina, zirconia or other ceramic, less than 25 microns thick, e.g., 5-10 microns thick. The alumina layer(s) may be applied at relatively low temperature. Once applied, the layer provides excellent hermeticity, and prevents electrical leakage. Even though very thin, the alumina layer retains excellent insulating characteristics. In one embodiment, an alumina layer less than about 6 microns thick provides an insulative coating that exhibits less than 10 pA of leakage current over an area 75 mils by 25 mils area while soaking in a saline solution at temperatures up to 80° C. over a three month period.

Abstract: A programming system for controlling and/or altering an implantable device's operation using externally applied magnetic means, e.g., a permanent magnet or the like. Typically, such devices stimulate a neural pathway or muscle and/or block pain or muscle stimulation according to programmable settings, e.g., the amplitude, duration, frequency/repetition rates, etc., of stimulation pulses applied to the neural pathways/muscles. Preferably, once programmed from an external programmer, such implantable devices can operate “independently” using the externally provided programmed information. However, external programmers may be unavailable due to cost, size, or other constraints. Accordingly, embodiments of the present invention include a magnetic sensor, preferably a magnetoresistive, Hall effect, saturated core reactors, or the like, to sense an externally provided magnetic field. By externally applying magnetic fields in sequences of controlled polarities, durations, intensities, etc.

Abstract: An electrically sensing and stimulating outer sheath for ensuring accurate surgical placement of a microsensor or a microstimulator near a nerve in living tissue is disclosed. The electrically sensing outer sheath may also be used to verify the function of the microstimulator or microsensor during surgical placement but before the outer sheath is removed. In the event that the microstimulator is not optimally placed near the nerve, or if the microstimulator is malfunctioning, this can be determined prior to removal of the outer sheath, thus reducing the possibility of nerve or tissue damage that might be incurred during a separate operation to remove the microstimulator.

Abstract: An oxygen monitoring system measures the oxygen concentration in a patient's blood for use as a physiological control parameter in rate responsive pacing. The oxygen monitoring system includes an oxygen monitoring circuit embedded in a cardiac stimulation lead and monitors the blood oxygen in a patient's venous system that passes through and into the lead. The oxygen monitoring circuit includes a working electrode, a counter electrode, a reference electrode and an IC chip electrically interconnected between the electrodes and programmed to carry out an oxygen concentration measuring process. Oxygen surrounding the electrodes causes current to flow between the electrodes and the IC chip varies the value of current generated by a current source coupled between the working electrode and counter electrode in a manner to maintain the voltage between the working electrode and reference electrode at a preselected value. The variation of the current source value is a direct measure of the blood oxygen concentration.

Abstract: Battery driven voltage control circuitry charges an output capacitor, which periodically supplies a current pulse. The circuitry converts battery voltage VBAT to a charging voltage VUPC based upon programmed parameters and the voltage VCOMPL at the capacitor. The circuitry includes a voltage converter for multiplying VBAT to produce VUPC. VCOMPL is sampled to determine its “droop” at the end of an output current pulse. If the droop is lower than a threshold, then the voltage converter increases the charging voltage. If the droop is above a threshold, then the voltage converter reduces the charging voltage. This feedback maintains the output voltage within an acceptable operating range to produce an efficacious output current pulse for stimulation without causing unproductive energy loss. In order to avoid premature depletion of battery energy, VUPC is compared with VCOMPL to determine the optimum clock rate to be used to convert VBAT to VUPC.

Abstract: The invention is a filter circuit that includes an electromechanical resonator that is mounted directly to the surface of a silicon integrated circuit, rather than being mounted as a surface mounted or leaded filter can on a circuit board. This filter system allows the integrated circuit electronic package to be significantly smaller than when a conventional electromechanical resonator package is used. The electromechanical resonator may be protected during processing and during use with a protective cover that is made of a material such as titanium. The protective cover is attached to the integrated circuit chip.

Abstract: A device configured for implanting beneath a patient's skin for the purpose of tissue, e.g., nerve or muscle, stimulation and/or parameter monitoring and/or data communication. Devices in accordance with the invention are comprised of a sealed housing, typically having an axial dimension of less than 60 mm and a lateral dimension of less than 6 mm, having a non-circular, e.g., an oval or polygon shaped, cross-section containing a power source for powering electronic circuitry within including a controller, an address storage means, a data signal receiver and an input/output transducer. When used as a stimulator, such a device is useful in a wide variety of applications to stimulate nerves and associated neural pathways. Alternatively, devices of the present invention are configurable to monitor a biological parameter. Furthermore, a placement structure is shown for facilitating placement of the implantable device proximate to neural/muscular tissue.