Kunstmatig zicht voor blinden: ontwikkeling van een intracorticale visuele prothese met hoge resolutie

Blindness affects over 43 million people worldwide, severely impacting their daily life. Current solutions remain limited, with medical treatments often unavailable. While retinal implants have restored partial vision in some cases, their effectiveness is restricted to individuals with residual retinal function. For those with complete vision loss due to optic nerve or retinal degeneration, direct electrical stimulation of the visual cortex offers an alternative. However, existing cortical implants suffer from a low resolution due to limited brain coverage, a small number of stimulation sites and inadequate electrode technology. To address these limitations, we developed high-density, flexible intracortical electrode arrays using ultra-thin, biocompatible polyimide with biodegradable coatings to enable safe insertion into both superficial and deeper regions of the primary visual cortex. These arrays, featuring low-impedance iridium oxide microelectrodes, allowed for stable, long-term and safe stimulation and recording over a large area. The system demonstrated excellent performance during chronic implantation in non-human primates, with high levels of neural activity recorded even after a year. The integration with custom-designed electronics for electrical stimulation and wireless transcutaneous power transfer marked two important steps towards a fully implantable visual prosthesis. Finally, to further improve resolution, advanced stimulation strategies such as intracortical bipolar current steering were employed. This technique selectively activated distinct neural populations based on current direction, reducing overlap and increasing the number of independently addressable sites by up to ninefold. These innovations represent a major advancement toward scalable, high-resolution visual prostheses capable of restoring meaningful vision.