Real-Time Simulation of Phosphene Images Evoked by Electrical Stimulation of the Visual Cortex

Applying electrical stimulation to the visual cortex has been shown to produce clot-like visual perceptions called phosphenes. Artificial prosthetic vision is based on the concept that patterns of phosphenes can be used to convey visual information to blind patients. We designed a system that performs real-time simulation of phosphene perceptions evoked by cortical electrical stimulation. Phosphenes are displayed as Gaussian circular and ellipsoid spots on a randomised grid based on existing neurophysiological models of cortical retinotopy and magnification factor. The system consists of a silicon retina camera (analogue integrated vision sensor), desktop computer and head-mounted display.