Recognition Of Objects Formed By Irregular Phosphene Maps Based On Simulated Artificial Vision

Visual prosthesis as a new neural prostheses, electrical stimulate different part of the pathway (retina, optic nerve or primary visual cortex) and elite phosphenes with different sizes, brightness and shapes. The organization of phosphenes constitutes a rich and complex patterns "visual prosthesis" to repair the visual experience. Its feasibility has already been confirmed by some Euramerican scientists. However, how to understanding the view of phosphenes composition depends on the psychology of perception and cognition of implant wearer. Furthermore, how to use a limited number of stimulation points, formed by low-resolution vision to present understandable visual experience becomes the focus of prosthesis designers and physicists. It is necessary to determine minimum requirements for daily visual tasks. The purpose of this study is to investigate the recognition of common objects in daily life based on the simulated prosthetic vision.we assessed the effect of five parameters (resolution, distortion, dropout percentage, gray scale and luminance)and two image processing methods on objects recognition.The study consisted of three parts including the design of the e psychophysical experiment platform for pixelized objects, the choice and processing methods of materials using in the experiments, and Design of Experiments as well as results analysis and discussion.The results showed that distortion and dropout percentage had significant impact on the objects recognition. With the increase of distortion level and dropout percentage the recognition decreased considerably; the accuracy decreased significantly only at gray level 2 while the other three gray levels showed no obvious difference. The two image processing methods had significant difference when the degree of irregularity increased to a high level (at distortion level 0.6 and 0.8, dropout percentage of 70%).