Patent ID: 8457752
Filing Date: 2013-06-04
Classification: A61N

Abstract:
1. A method of visual neural stimulation comprising: applying a stimulation current to retinal cells of a patient with an electrode array that is electrically connected with a retinal prosthesis; determining an off cell threshold of the retinal cells by increasing the stimulation current from zero until a spot is perceived by the patient such that, by further increasing the stimulation current, the spot grows darker; determining an on cell threshold of the retinal cells by further increasing the stimulation current such that, at the on cell threshold, the spot grows lighter; determining a transition point of the retinal cells where on cells overwhelm off cells; developing a stimulation map based on said off cell threshold, said on cell threshold and said transition point; and stimulating the retinal cells with said electrode array according to said stimulation map to create a perception of light for the patient and to increase contrast between background and foreground phosphenes, where stimulation current between said off cell threshold and said transition point is used to darken a point in an image perceived by the patient.