Phosphene Positioning System Based On Tactile Perception

In recent years, as the stimulated electrodes have been implanted in retina, optic nerve and visual cortex to generate visual perceptions (phosphenes), the research of prosthetic vision becomes a hot topic in the world. A novel and completely implantable visual prosthesis based on optic nerve stimulation with penetrating electrode array is proposed by C-Sight group in China. After electrode array's implantation, it is crucial to evaluate the characteristics of the stimulated phosphene. As the first stage of phosphene perception, the paper focuses on simulated phosphene positioning.The paper includes three parts: to design a tactile based simulated phosphene positioning system; to study the characteristic of simulated phosphene positioning based on the system; to consider experimental related psychophysical problems in order to set up a scientific training procedure. First of all, we set up a simulated phosphene position system. And then, an experiment is designed to evaluate the performance of the system, including accuracy, dispersion and response time. After improving the system and training procedure based on the previous experimental result, another experiment is designed as a new cycle. According to three compared experiments, which are using simple tactile guide, with visual guide and with tactile board, we conclude that the simulated phosphene positioning system with tactile board is accurate (the mean error is less than 10mm) and reproducible (the standard deviation is less than 6mm) in evaluating simulated phosphene.