An optically powered single-channel stimulation implant as test system for chronic biocompatibility and biostability of miniaturized retinal vision prostheses.

A microsystem based microimplant with an optically powered single-channel stimulator was designed and developed as test system for an epi-retinal vision implant. Biostability of the hybrid assembly and the encapsulation materials were evaluated in pilot experiments in chronic implantations in a cat animal model. The implant was fabricated on a flexible polyimide substrate with integrated platinum electrode, interconnection lines, and contact pads for hybrid integration of electronic components.

Subretinal implantation and testing of polyimide film electrodes in cats.

Background: Progress in the field of microelectronics has led to the development of visual prostheses for the treatment of blinding diseases. One concept under investigation is an electronic subretinal prosthesis to replace the function of lost photoreceptors in degenerative diseases, such as retinitis pigmentosa.

Methods: In the subretinal prosthesis design concept, an array of stimulation electrodes is placed in the subretinal space.