A hermetic wireless subretinal neurostimulator for vision prostheses

Area of Science:

• Biomedical Engineering
• Neuroscience
• Ophthalmology

Background:

• The development of effective visual prosthetics is crucial for restoring sight to individuals with retinal degenerative diseases.
• Previous retinal implant designs have faced challenges with longevity, biocompatibility, and surgical implantation.
• Miniaturization and wireless operation are key goals for next-generation retinal prostheses.

Purpose of the Study:

• To develop and evaluate a miniaturized, wirelessly operated retinal prosthesis for preclinical studies.
• To assess the long-term in vitro and in vivo performance of the novel retinal implant.
• To validate a customized surgical technique for subretinal implantation.

Main Methods:

• A miniaturized, hermetically encased retinal prosthesis with a 15-channel stimulator chip was designed.
• The prosthesis utilizes a polyimide electrode array with sputtered iridium oxide film electrodes implanted subretinally.
• Wireless operation was tested in vitro and in vivo (Yucatan minipig) using a custom RF transmitter and PXI computer control.

Main Results:

• Long-term in vitro pulse testing indicated electrode lifetimes consistent with industry standards.
• Wireless system operation was successfully verified in physiological saline.
• The retinal implant demonstrated functional operation in two pigs for up to five and a half months, confirmed by stimulus artifact detection.

Conclusions:

• The developed wirelessly operated retinal prosthesis demonstrates feasibility for preclinical evaluation.
• The device incorporates design improvements for conformal attachment and subretinal implantation.
• This research represents a significant step towards advanced visual prosthetic devices for restoring vision.