Feasibility Assessment of an Optically Powered Digital Retinal Prosthesis Architecture for Retinal Ganglion Cell...

Area of Science:

• Biomedical Engineering
• Neuroscience
• Ophthalmology

Background:

• Electrical stimulation of retinal neurons can elicit visual percepts in blind patients.
• Existing retinal implants have limited visual acuity and surgical complications due to transcutaneous cables.

Purpose of the Study:

• To introduce a novel wireless retinal implant architecture powered and controlled by near-infrared (NIR) light.
• To overcome the limitations of wired implants, such as reduced reliability and surgical risks.

Main Methods:

• Developed a retinal implant using a multi-junction photovoltaic cell and a CMOS stimulator with a diamond microelectrode array.
• Utilized NIR illumination (850 nm at 4 mW/mm²) for power and data transmission.
• Demonstrated neural response elicitation in a degenerate rat retina using fluorescence imaging with a calcium indicator.

Main Results:

• The NIR-powered system successfully powered the stimulator and elicited responses in retinal ganglion cells (RGCs).
• Achieved high stimulation rates of up to 35,000 pulses per second at the average stimulation threshold.
• Confirmed the feasibility of wireless, high-repetition-rate stimulation for RGCs.

Conclusions:

• The presented infrared-powered digital retinal implant architecture is feasible for eliciting neural responses.
• This wireless approach offers a potential solution for more reliable and less invasive visual prosthetics.
• Further research is needed to address limitations and optimize visual acuity restoration.