Portable Biomimetic Retina for Learning, Perception-based Image Acquisition

Abstract

We developed a portable biomimetic retina for blind subjects with retinal defects. 1-To simplify the visual prosthetic function, image segmentation of input patterns PI was provided by a set of line elements with specific lengths and orientations. 2-The segmented images were mapped by a filter module (FM: array of tunable spatio-temporal (ST) filters) onto a data stream as future stimulation signals for the human central visual system. 3-The foveal region of the central visual system was simulated by an inverter module (IM) to test the generation of a visual percept P2 of a given PI before the entire system will be applied to blind humans. 4-The parameter vector (PV) of FM could be modified interactively by the human user with evolutionary algorithms (EA) based on a perceptual comparison. 5-Two small displays for separate presentation of PI and the simulated percept P2 were integrated in a lightweight head mount and were combined with a 3-D acceleration sensor (AS) for head movement detection. 6-Subjects with normal vision were able to tune FM in a perception-based dialog exclusively by means of specific small head movements and to iteratively select the best three out of six possible percepts P2 until the output of IM, P2 became identical to a given PI.