Retinal Prosthesis Using Thin-Film Devices on a Transparent Substrate and Wireless Power Transfer

Retinal prostheses are promising techniques to restore eyesight sense for visually impaired people. However, some conventional retinal prostheses require external cameras, and the eyeball direction is different from the view direction. Moreover, some also require a wired connection between inside and outside of the body, and the quality of life (QOL) is seriously impaired. In this article, we have developed a retinal prosthesis using thin-film devices on a transparent substrate and wireless power transfer. The outstanding advantages are: thin-film photo-transistors are integrated to make the eyeball and view directions the same, a transparent substrate is employed to achieve epiretinal implantation, and wireless power transfer is adopted to ensure the QOL. Particularly in this article, a pig eyeball experiment is executed. It is found that the stimulating current is an appropriate value, and the oscillating frequency is dependent on the light illumination. From these results, it is concluded that the correct operation necessary for a retinal prosthesis as an implanted organ is confirmed.