A Prototype Retinal Prosthesis for Visual Stimulation

Vision loss has severe impacts on its victims, carrying with it physiological, psychological, social, and economic consequences thereby degrading the quality of life and depriving the individual from performing many of the daily living activities. This article describes the design and development of a prototype retinal prosthesis for visual stimulation. The system consists of a webcam, a notebook computer, and a prototype excitatory circuit. The system is driven by a MATLAB^reg-based custom-built software. Live webcam images are converted to an 8 x 8 mosaic of 256 grayscale shades. Subsequently, electrical impulses are generated by the excitatory circuit in real-time to topographically stimulate the corresponding epiretinal cells. Following their conversion to grayscale, recorded data from the central pixel of the mosaic yielded: 36.24 nC for black, 48.48 nC for red, 55.68 nC for green, 67.68 nC for blue, and 91.92 nC for white. These results correlate well with data reported in the literature. The hallmark of this work is in the potential of partial restoration of sight that would add quality to the life of individuals with vision loss.