Abstract: The present invention is an improved method of electrically stimulating percepts in a patient with a visual prosthesis, to induce the perception of color. In particular, the present invention is a method of inducing the perception of color by determining experimentally which patterns induce which colors, storing that information and using the stored information to induce the perception of color according to video input data and the stored color information.

Abstract: It is critical in an inductively link medical implant, such as a visual prosthesis or other neural stimulator, to adjust the external coil to a location to maximize communication between the external coil and internal coil. Converting the signal strength between the coils to a signal easily discernible by a clinician, preferably an audible tone, facilitates the adjustment of the external coil to a preferred location.

Abstract: The invention is a retinal prosthesis with an improved configuration mounting necessary components within and surrounding the eye. The present invention better allows for the implantation of electronics within the delicate eye structure. The invention provides for less height of the part external to the eye by mounting a receiver coil around an electronics package.

Abstract: The present invention is a method of improving the persistence of electrical neural stimulation, and specifically a method of improving the persistence of an image supplied to a retina, or visual cortex, through a visual prosthesis. A continuously stimulated retina, or other neural tissue, will desensitize after a time period in the range of 20 to 150 seconds. However, an interruption of the stimulation on the order of a few milliseconds will restore the retinal sensitivity without the user perceiving the interruption, or with the user barely perceiving the interruption.

Abstract: Stimulation inputs are provided to a visual prosthesis implant. The images captured by a video decoder are received and digitized to provide a plurality of video frames; integrity of the video frames is checked, the checked video frames are filtered, and the filtered video frames are converted to stimulation inputs. A similar system is also disclosed.

Abstract: The invention is a method of making a flexible electrode array, comprising a silicone containing body, a metal trace layer and an electrode pad on the surface, including the steps of irradiating a surface area of a molded silicone containing layer yielding traces with the light beam from a pulsed ultraviolet laser source; immersing said irradiated molded silicone layer for inducing the deposit of metal ions to form metal traces; applying a silicone containing layer on the silicone containing layer and the metal traces; irradiating the surface for drilling holes in the molded silicone containing layer; and immersing the irradiated molded silicone layer for inducing the deposit of metal ions to form metal electrode pads.

Abstract: The invention is directed to a method of making an implantable insulated electrical circuit that utilizes polyparaxylylene, preferably as Parylene, a known polymer that has excellent living tissue implant characteristics, to provide for chronic implantation of conductive electrical devices, such as stimulators and sensors. The device is thin, flexible, electrically insulated, and stable after long exposure to living tissue. Layers of Parylene may be combined with layers of a polymer, such as polyimide, to yield greater design flexibility in the circuit. Multiple electrical conduction layers may be stacked in the circuit to increase packing density.

Abstract: The invention is directed to an implantable insulated electrical circuit that utilizes polyparaxylylene, preferably as Parylene, a known polymer that has excellent living tissue implant characteristics, to provide for chronic implantation of conductive electrical devices, such as stimulators and sensors. The device is thin, flexible, electrically insulated, and stable after long exposure to living tissue. Layers of Parylene may be combined with layers of a polymer, such as polyimide, to yield greater design flexibility in the circuit. Multiple electrical conduction layers may be stacked in the circuit to increase packing density.

Abstract: Polymer materials are useful as electrode array bodies for neural stimulation. They are particularly useful for retinal stimulation to create artificial vision, cochlear stimulation to create artificial hearing, or cortical stimulation many purposes. The pressure applied against the retina, or other neural tissue, by an electrode array is critical. Too little pressure causes increased electrical resistance, along with electric field dispersion. Too much pressure may block blood flow. Common flexible circuit fabrication techniques generally require that a flexible circuit electrode array be made flat. Since neural tissue is almost never flat, a flat array will necessarily apply uneven pressure. Further, the edges of a flexible circuit polymer array may be sharp and cut the delicate neural tissue. By applying the right amount of heat to a completed array, a curve can be induced.

Abstract: A video processing unit configured to convert a video image to stimulation patterns for stimulating neural tissue in a subject's eye and comprising a power button, wherein the video processing unit is configured to be powered on after a first time interval upon activation of a power button, wherein the video processing unit is configured to be powered off after a second time interval upon activation of a power button.

Abstract: A visor for retinal stimulation of visually impaired. The visor comprises a frame, an external coil, a camera and a mounting system. A connector allows the external coil to be positioned along a first direction. A sliding device allows the external coil to be positioned along a second direction. Positioning of the visor on a subject's nose allows the external coil to be positioned along a third direction. Positioning of the external coil along the first, second or third direction is useful to maximize coupling RF coupling between the external coil and an internal coil implanted on a subject wearing the visor.

Abstract: An implantable micro-miniature device is disclosed. The device comprises a thin hermetic insulating coating and at least one thin polymer or metal secondary coating over the hermetic insulating layer in order to protect the insulating layer from the erosive action of body fluids or the like. In one embodiment the insulating layer is ion beam assisted deposited (IBAD) alumina and the secondary coating is a parylene polymer. The device may be a small electronic device such as a silicon integrated circuit chip. The thickness of the insulating layer may be ten microns or less and the thickness of the secondary layer may be between about 0.1 and about 15 microns.

Abstract: The present invention is a visual prosthesis for stimulating visual neurons to create the perception of light. The visual prosthesis electrically stimulating the retina with implanted electrodes exhibits interaction between electrodes stimulated closely together in both space and time. The visual prosthesis of the present invention includes means for determining a minimum distance at which spatiotemporal interactions occur, determining a minimum time at which spatiotemporal interactions occur, and avoiding stimulation of electrodes within the minimum distance during the minimum time. The minimum are ideally established for each individual patient. Alternatively, approximate minimums have been established by the applicants at 2 mm and 1.8 milliseconds.

Abstract: The present invention is an implantable electrode array having electrodes with variable pitch and variable size. Electrode arrays of the prior art provide electrodes with a common spacing and size. However, this is not how the human body is arranged. As an example, the retina has closely spaced retinal receptors near the fovea. Those receptors are spaced farther apart, farther away from the fovea. Further, the amount of electrical current required to stimulate the perception of light increases with distance from the fovea. Hence, larger electrodes are required to transfer the necessary current farther away from the fovea.

Abstract: The present invention is an improved fitting and training system for a visual prosthesis. Fitting a visual prosthesis through automated means is challenging and fitting a visual prosthesis manually is tedious for clinician and patent, and provides great opportunity for error. A hybrid of computer controlled and manual fitting provides effective, efficient and controlled fitting process. The process includes testing a group of electrodes in random order by providing a prompt followed by stimulation and the patient responding if they saw a percept. After each set, a maximum likelihood algorithm is used to determine the next stimulation level, or if further stimulation is needed for each electrode.

Abstract: Techniques and functional electrical stimulation to eliminate discomfort during electrical stimulation of the retina are provided. According to a first technique, discomfort is eliminated through control of timing group assignment. According to a second technique, discomfort is eliminated through an edge detection method. According to a third technique, brightness clipping is used to eliminate discomfort. According to a fourth technique, direct reduction of current is obtained by scaling it down by a factor which is dependent on the sum of current in all electrodes. According to a fifth technique, the current being fed to each electrode is adjusted, by dividing it by a weighted sum of currents fed to the surrounding electrodes. According to a sixth technique, a method based on the current summation effect is used. According to a seventh technique, a large return electrode is used. According to an eighth technique, the return electrode is used for a pseudo-multi-polar stimulation.

Abstract: The invention is a method of automatically adjusting an electrode array to the neural characteristics of an individual patient. By recording neural response to a predetermined input stimulus, one can alter that input stimulus to the needs of an individual patient. A minimum input stimulus is applied to a patient, followed by recording neural response in the vicinity of the input stimulus. By alternating stimulation and recording at gradually increasing levels, one can determine the minimum input that creates a neural response, thereby identifying the threshold stimulation level. One can further determine a maximum level by increasing stimulus until a predetermined maximum neural response is obtained.

Abstract: The invention is a method of automatically adjusting an electrode array to the neural characteristics of an individual patient. The perceptual response to electrical neural stimulation varies from patient to patient and The response to electrical neural stimulation varies from patient to patient and the relationship between current and perceived brightness is often non-linear. It is necessary to determine this relationship to fit the prosthesis settings for each patient. It is advantageous to map the perceptual responses to stimuli. The method of mapping of the present invention is to provide a plurality of stimuli that vary in current, voltage, pulse duration, frequency, or some other dimension; measuring and recording the response to those stimuli; deriving a formula or equation describing the map from the individual points; storing the formula; and using that formula to map future stimulation.

Abstract: The present invention is an improved method of electrically stimulating percepts in a patient with a visual prosthesis, to induce a more controlled perception of light. In particular, the present invention is an improved electrode array to maximize retinal response. The array of the present invention is an array with a center section with no electrode, surrounded by a ring of small high density electrodes. Electrodes beyond to ring are gradually larger and more widely spaced.

Abstract: A visual prosthesis and a method of operating a visual prosthesis are disclosed. Neural stimulation through electrodes is controlled by spatial maps, where a grouped or random association is established between the data points of the acquired data and the electrodes. In this way distortions from the foveal pit and wiring mistakes in the implant can be corrected. Moreover, broken electrodes can be bypassed and a resolution limit can be tested, together with testing the benefit the patient receives from correct spatial mapping.