Study Of Simulated Phosphene Characteristics Based On Tactile Perception

As the rapid development of visual prosthesis, the study about the evaluation of the effect after prosthesis implantation becomes an active area of artificial vision research in these years. Phosphenes which are generated by the stimulation of implanted visual prosthesis are elements of the image which the patient will see after implantation, so the study of the phosphene's characteristics becomes more and more important. The first question is that how we could help the blind to describe the phosphene's characteristics precisely, so dependable data could be provided to the researcher. The focus of this paper is that a study on an evaluation system of phosphene's characteristics based on tactile perception which is a kind of important function for the blind, taking simulated phophene as the research object.This paper includes two parts: the first part is the study of simulated phosphene positioning based on tactile perception. In this part, a tactile board based on rectangular coordinate is used as the tactile guidance. The whole positioning system and a series of psychophysical experiments are designed. The results of the accuracy, dispersion and response time are analyzed to evaluate the performance of the system. It is concluded that the simulated phosphene positioning system with tactile board is accurate and reproducible in evaluating simulated phosphene. Then a new tactile guidance based on polar coordinate which conform the human physiological requirement better is used in the following research. All of the tactile guidance system and designation of the psychophysical experiments is improved. The second part is a study of the evaluation of simulated phosphene's based on tactile perception,. At the first stage of the study, the effect of different tactile boards, distributions of simulated phosphene and distances on the evaluation of the phosphene size is studied. The conclusion is that the method of the evaluation of simulated phosphene size based on tactile perception is available. The error of size evaluation of simulated phosphene decreases in the near distance using tactile board with round holes.