Evaluation of a High-Frequency Stimulation Platform for Retinal Experiments

Abstract

Cell-type-selective activation of retinal ganglion cells (RGCs) is a key challenge for epiretinal prostheses. Highfrequency stimulation has enabled preferential activation of functional RGC types. Existing commercial and custom nonapplication- specific integrated circuit stimulators often restrict temporal resolution (~ 16 us) and lack output logging capability. This paper presents and evaluates an open-hardware1 stimulation platform that overcomes these limitations, generates arbitrary current waveforms and provides dedicated outputs for the simultaneous logging of stimulation current and electrode voltage. Electrical characterization demonstrated accurate static behavior across channels and sinusoidal waveform generation up to 10 kHz with a 2.5 us practical temporal resolution (0.8 us theoretical limit). Successful integration with a commercial micro-electrode array setup was demonstrated with accurate stimulus delivery. The platform provides a basis for future impedance-aware, adaptive, and closed-loop stimulation strategies targeting RGC-selectivity.