Abstract: A DC to DC transmission system includes at least three conductors between a source and a sink, a first switch which alternately connects each conductor to the source, a second switch which alternately connects each conductor to the sink. The switches are synchronized such that one conductor is alternately coupled between the same polarity side of the source and sink and another conductor is alternately coupled between the other polarity side of the source and sink. The alternating connection between the conductors and source and sink may be undertaken at a wide range of frequencies.

Abstract: The present invention is an electrode array for neural stimulation. In particular, the present invention provides electrode shapes and electrode coating advantageous in maximizing the charge dissipation without harming neural tissue. Neurotophic factors are used to further improve electrode performance.

Abstract: System and apparatus for measuring pressure comprising a microelectronic device, an interface member attached to the microelectronic device, a pressure sensor having a diaphragm responsive to external pressure exerted upon the diaphragm, wherein the interface member is positioned between the microelectronic device and the pressure sensor and is attached to the pressure sensor providing a first cavity between the pressure sensor diaphragm and the interface member and wherein the pressure in the first cavity is set at an initial predetermined pressure.

Abstract: An object locator system utilizes a microtransponder (12) that is used in association with an object to be located. A remote locator (10) transmits an encoded signal in which is embedded an identification code associated with the object to be located. The microtransponder (12) receives the encoded transmitted signal and processes such signal utilizing fast fourier transform techniques. The microtransponder (12) correlates the transformed received signal with a fast fourier transformed version of an identification code associated with the microtransponder (12) and upon detection of a correlation, transmits an acknowledgement signal to the remote locator (10). The remote locator (10) determines the distance to the microtransponder (12) based upon the round trip time from transmission of the coded signal to the microtransponder (12) to the receipt of the acknowledgement signal.

Abstract: An electrode having a plurality of electrically conductive segments, each segment being electrically isolated from adjacent segments. The segments are adapted to control living tissue, typically a neuromuscular pathway for delivery of stimulation signals to a desired pathway. The segments may be selectively chosen for the delivery of the stimulation signals, so as to avoid delivery of stimulation signals to tissue in contact with segments not chosen.

Abstract: A medical instrument, particularly a surgical instrument with a displaceable push/pull activation tube arranged on the proximal end of a hand manipulator, that also contains an inner tube for retaining a fixed jaw, for activating remote tool parts on the distal end, in which a force-limiting device limits the transmission of force to the remote tool parts from the hand manipulator via an extendable coil spring. The medical instrument optionally features a fiber scope to enable optical viewing to locate the implanted device for removal as well as a saline flush capability. The instrument has jaws that are cylindrical in shape to facilitate grasping an implanted cylindrical device.

Abstract: A system for monitoring temperature in a body, the system comprising at least one implantable device, wherein the implantable device(s) is operable to sense temperature in the body and to generate status signals based on the sensed temperature in the body. The system further comprising a system control unit for wirelessly communicating with the implantable device(s), and the system control unit comprising a signal receiver for receiving the status signals, and also a programmable controller for producing notification signals based on the received status signals. A notification unit can alternatively communicate with the system control unit or the implantable device(s) for disclosing the sensed body temperature based on the notification signals.

Abstract: Apparatus connect 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 biocompatible materials.

Abstract: This invention is a method and apparatus for implanting retinal tacks and retinal electrode element with spiked electrodes. In one aspect of the invention, a tack suitable for insertion into the retina is driven into the retina by the repeated minute blows from the rapid contractions and expansions of the piezoelectric crystal. In a different aspect of the invention, a retinal electrode element with spiked electrodes suitable for insertion into the retina is driven into the retina by the repeated minute blows from the rapid contractions and expansions of the piezoelectric crystal. In another aspect of the invention, a single, short impulse is used to drive the tack home. In a different aspect of the invention, a single, short impulse is used to drive the retinal electrode element with spiked electrodes home. With this mode of tack and electrode element implanting, a remotely placed driver couples its motion to the tack using a thin, elongated tube filled with a suitable hydraulic fluid.

Abstract: Methods are utilized 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 electronics filter circuit includes an electromechanical resonator that is mounted directly to the surface of a silicon integrated circuit, rather than being a surface mounted or leaded filter can on a circuit board. This filter circuit allows the integrated circuit electronic package to be significantly smaller than a conventional electromechanical resonator package. 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 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 present invention is an implantable electronic device formed within a biocompatible hermetic package. Preferably the implantable electronic device is used for a visual prosthesis for the restoration of sight in patients with lost or degraded visual function. The package may include a hard hermetic box, a thin film hermetic coating, or both.

Abstract: System and apparatus for measuring pressure including a microelectronic device, an interface member attached to the microelectronic device, a pressure sensor having a diaphragm responsive to external pressure exerted upon the diaphragm, wherein the interface member is positioned between the microelectronic device and the pressure sensor and is attached to the pressure sensor providing a first cavity between the pressure sensor diaphragm and the interface member and wherein the pressure in the first cavity is set at an initial predetermined pressure.

Abstract: An implantable device comprising a sensing unit, wherein the sensing unit is adapted to rectify biological/neurological signals in the form of sensed electrical signals from body tissue adjacent to the location of the implantable device. The sensing unit of the implantable device comprises at least one amplifier, wherein the supply current to the at least one amplifier is responsive to the magnitude of the sensed electrical signals provided to the at least one amplifier. The implantable device is further capable of integrating the rectified sensed electrical signals and generating output signals, wherein the output signals contain indicia of biopotential parameters of the body tissue.

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 a 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 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, zerconia, 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: 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: This invention is for directly modulating a beam of photons onto the retinas of patients who have extreme vision impairment or blindness. Its purpose is to supply enough imaging energy to retinal prosthetics implanted in the eye which operate essentially by having light (external to the eye) activating photoreceptors, or photo-electrical material. The invention provides sufficient light amplification and does it logarithmically. While it has sufficient output light power, the output light level still remains at a safe level. Most preferred embodiments of this invention provide balanced biphasic stimulation with no net charge injection into the eye. Both optical and electronic magnification for the image, as for example, using an optical zoom lens, is incorporated. Otherwise, it would not be feasible to zoom in on items of particular interest or necessity. Without proper adjustment, improper threshold amplitudes would obtain, as well as uncomfortable maximum thresholds.

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.