Numerical Design of a Micro-LED Based Optogenetic Stimulator for Visual Cortical Prosthesis

Visual impairment represents a critical public health and safety issue, and visual prostheses provide a promising solution to addressing it. Here we present a design strategy for a micro-LED based optogenetic stimulator as visual prosthesis on cortex, and numerically evaluate its performance. First, we provide an introductory overview of visual prostheses, and categorize visual prostheses into four distinct groups based on the stimulation location (retina or visual cortex) and stimulation modality (electrical or optical). Specifically, we focus on the design involving a micro-LED array implanted on the dura mater for visual cortex prosthesis. The study evaluates two optogenetic approaches based on different photosensitive proteins (C1V1 and ChrimsonR) and determines the method of utilizing green light for C1V1 activation. Through comprehensive optical simulations, we optimize the design parameters, and thermal simulations are employed to ensure efficient heat dissipation and tissue safety. The resulting stimulation effects and potential for vision recovery are thoroughly discussed. While challenges associated with tissue scattering and the elucidation of biological visual signal mechanisms impede the efficacy of optical stimulation, further research is warranted to fully harness the potential of visual cortex prostheses and surmount these obstacles.