Research On Math Modeling And Synthesis Scheme Of Stimulating Pulse For Artificial Retina

Vision is an ancient research task, with the development of modern information technologies and micro-electronics technologies, new contents are involved in it, such as artificial retina;especially the research about its model and theory has been one of the hotspots.There are several primary problems in the research of artificial retina: requiring a kind of parallel and correct spatial sequence to stimulate mass feeling nerves in order to convert the optical signals which the light-sensitive cells receive into stimulating pulse electrical signals which the brain's visual cortex can deal with, thereby the target objects are precisely coded;making sure the electric parameters which electrodes stimulate nerve cells and designing reactive circuit to adapt to the changes of high luminance and contrast;synthesizing separate pictures into a whole and so on. This paper will focus on solving the problems of math modeling and synthesis scheme of stimulating pulse for artificial retina, and therefore establishes foundations for the subsequent work.It has been revealed by the preceding related research that the distinct channels with discrete frequency exist in human vision system, which have different sensibility for different ranges of both spatial and frequency respectively. The visual image is the result coming from the synthesizing of the information snatched by these channels. And wavelet transform takes on the features of multi-resolution and variable scales, which can deal with the signal at different scales and resolutions, so there are same characteristics between wavelet transform and the system of human imaging. In this paper related human vision characters are introduced;features of vision information abstraction and the wavelet transform theory are analyzed;a math modeling of artificial retina based on wavelet transform is presented;and also on these bases, the synthesis scheme of stimulating pulse for artificial retina is given. We can conclude from this scheme that because of the existence of timing-sharing repeat-using and time-coding mechanisms, human eyes can complete the reception andtransformation functions easily;and the frequency of electrode stimulation for artificial retina should be around 30Hz, which provide data for the implement of its hardware simulation and emulation.