3D-stacked retinal prosthesis chip with binary image capture and edge detection functions for human visual restoration

Abstract

Retinal prosthesis is a promising treatment for vision degeneration. However, clinical experiments show that the patients can only recognize several grayscales at low resolution with electrical stimulation. This paper proposes a retinal prosthesis chip with binarization and edge detection functions to maximize the brightness difference and reduce redundant information. The binarization operation is designed as a column-parallel processing element for saving space. Moreover, the fill factor achieves 50.79% by separating the sensor and stimulator into different chips. Finally, the SPICE simulator verified the effectiveness of the proposed circuit, which achieves an FoM of 110nW/(frame·pixel).