Abstract: A method of editing a video configuration file downloadable to or from a video processing unit of a fitting system for a visual prosthesis is shown. The visual prosthesis has a plurality of electrodes and the video configuration file defines mapping of a video signal captured from a camera of the visual prosthesis to an electrical signal for the electrodes. The editing controls a brightness map for an individual electrode or electrode groups, together with a temporal stimulation pattern to which an individual electrode or electrode groups are assigned. A related computer-operated system is also disclosed.

Abstract: An apparatus and method for retinal stimulation are shown. The method comprises varied parameters, including frequency, pulse width, and pattern of pulse trains to determine a stimulation pattern and visual perception threshold.

Abstract: A retinal stimulation system. The retinal stimulation system comprises an electronics package; and at least a first and a second electrode, each associated with the electronics package and configured to apply current to a subject's retina; wherein current to be applied by the first electrode and the second electrode is configured to be higher for the first electrode when the first electrode has an impedance lower than a second electrode's impedance.

Abstract: The invention is a method of identifying a preferred location for an electrode array to the neural characteristics of an individual subject. The response to electrical neural stimulation varies from subject to subject and array location to array location. Measure of impedance may be used to predict the electrode height from the neural tissue and, thereby, predict the preferred location. Alternatively, electrode height may be measured directly to predict the preferred location.

Abstract: A method to provide visual current feedback of a retinal stimulation system. The method comprising: providing a retinal stimulation system configured to stimulate neural tissue in a subject's eye, the retinal stimulation system comprising: an electronics package; and at least a first and a second electrode, each associated with the electronics package and configured to apply current to a subject's retina; wherein current to be applied by the first electrode and the second electrode is configured to be higher for the first electrode when the first electrode has an impedance lower than a second electrode's impedance; and providing a visual interface configured to show impedance of at least one of the electrodes.

Abstract: A method for stimulating a subject's retina. The method comprising selecting at least a first and a second electrode each configured to apply current to a subject's retina, determining impedance for the at least first electrode and second electrode, and applying current to the subject's retina through the at least first and second electrode, wherein current to be applied by the first electrode and the second electrode is configured to be higher for the first electrode when the first electrode has an impedance lower than a second electrode's impedance.

Abstract: A method, device and system for stimulating visual tissue, typically in the retina or visual cortex, to achieve an artificial percept of light or image. The method includes providing stimulating electrodes suitable for placement in proximity to the visual tissue and generating a series of short-duration stimulation signals having a duration of less than about 0.5 milliseconds each. The short-duration stimulation signals are applied through the stimulating electrodes with varying frequencies that are substantially matched to a spiking range of frequencies of at least one ganglion cell for perceiving brightness or image.

Abstract: A method of editing a video configuration file downloadable to or from a video processing unit of a fitting system for a visual prosthesis is shown. The visual prosthesis has a plurality of electrodes and the video configuration file defines mapping of a video signal captured from a camera of the visual prosthesis to an electrical signal for the electrodes. The editing controls a brightness map for an individual electrode or electrode groups, together with a temporal stimulation pattern to which an individual electrode or electrode groups are assigned. A related computer-operated system is also disclosed.

Abstract: The invention is a method of automatically adjusting an electrode array to the neural characteristics of an individual subject. The response to electrical neural stimulation varies from subject to subject. Measure of impedance may be used to predict the electrode height from the neural tissue and, thereby, predict the threshold of perception. Alternatively, electrode height may be measured directly to predict the threshold of perception. Also, impedance measurement may be used to quickly identify defective electrodes and proper electrode placement.

Abstract: The invention is a method of automatically adjusting an electrode array to the neural characteristics of an individual subject. The response to electrical neural stimulation varies from subject to subject. Measure of impedance may be used to predict the electrode height from the neural tissue and, thereby, predict the threshold of perception. Alternatively, electrode height may be measured directly to predict the threshold of perception. Also, impedance measurement may be used to quickly identify defective electrodes and proper electrode placement.

Abstract: A method, device and system for stimulating visual tissue, typically in the retina or visual cortex, to achieve an artificial percept of light or image. The method includes providing stimulating electrodes suitable for placement in proximity to the visual tissue and generating a series of short-duration stimulation signals having a duration of less than about 0.5 milliseconds each. The short-duration stimulation signals are applied through the stimulating electrodes with varying frequencies that are substantially matched to a spiking range of frequencies of at least one ganglion cell for perceiving brightness or image.

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, and cortical stimulation, and many related 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 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.

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 pixels of the acquired image 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.

Abstract: Methods and devices for fitting a visual prosthesis are described. In one of the methods, threshold levels and maximum levels for the electrodes of the prosthesis are determined and a map of brightness to electrode stimulation levels is later formed. A fitting system for a visual prosthesis is also discussed, together with a computer-operated system having a graphical user interface showing visual prosthesis diagnostic screens and visual prosthesis configuration screens.

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 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 fitting and training system for a visual prosthesis. A patient, using the visual prosthesis observes a display and indicates location, movement, shape or other properties of the display image to provide for improved fitting and training. In one embodiment, the patient uses a touch screen monitory which displays an image. The patient touches the monitor at the location where the patient perceives the image. The system then corrects the image to the location indicated by the patient. In another embodiment a patient observes an image moving across the touch screen monitor and indicates by moving their hand across the monitor which direction the believe the image is moving. The system can then rotate the image to match the image perceived by the patient.

Abstract: Existing epiretinal implants for the blind are designed to electrically stimulate large groups of surviving retinal neurons using a small number of electrodes with diameters of several hundred ?m. To increase the spatial resolution of artificial sight, electrodes much smaller than those currently in use are desirable. In this study we stimulated and recorded ganglion cells in isolated pieces of rat, guinea pig, and monkey retina. We utilized micro-fabricated hexagonal arrays of 61 platinum disk electrodes with diameters between 6 and 25 ?m, spaced 60 ?m apart. Charge-balanced current pulses evoked one or two spikes at latencies as short as 0.2 ms, and typically only one or a few recorded ganglion cells were stimulated. Application of several synaptic blockers did not abolish the evoked responses, implying direct activation of ganglion cells. Threshold charge densities were typically below 0.1 mC/cm2 for a pulse duration of 100 ?s, corresponding to charge thresholds of less than 100 pC.

Abstract: To accurately represent a visual scene a visual prosthesis must convey luminance information across a range of brightness levels. To do this, the brightness of phosphenes produced by an individual electrode should scale appropriately with luminance, and the same luminance should produce equivalently bright phosphenes across the entire electrode array. Given that the function relating current to brightness varies across electrodes, it is necessary to develop a fitting procedure that will permit brightness to be equated across an entire array. The current invention describes a method of performing a brightness fitting that normalizes brightness across electrodes. The method determines a set of parameters that are stored in the subjects Video Configuration File—the look-up table that converts the video camera input to stimulation profiles for each electrode. One electrode would be specified as the standard.