European scientists introduce new type of optic nerve stimulation for the blind
The sensation of seeing light in the form of white patterns, without actually looking at light, is thought to help overcome blindness. As an alternative to retinal implants or nerve electrodes that stimulate the visual cortex to “see” light, scientists from the Swiss Federal Institute of Technology in Lausanne (EPFL) and the Sant’Anna School of Advanced Studies in Italy are currently working on a device for the blind – one that bypasses the eyeball entirely and sends messages to the brain.
Previous attempts to stimulate the optic nerve were risky because the electrodes would move around and provided unstable electrical stimulation of the nerve fibers within. The patients also had a difficult time interpreting the jarring stimulation. Fortunately, optic stimulation with the new intraneural electrodes provides rich visual information to the patients while keeping the optic nerve and the pathway to the brain intact.
In the lab, the scientists engineered an electrode array of 12 electrodes that pierce through instead of around a rabbit’s optic nerve – each stimulating electrode was observed to induce a specific pattern of cortical activation, suggesting that intraneural stimulation of the optic nerve is more informative than existing measures.
Professor Silvestro Micera, whose expertise includes intraneural electrode-hand prosthetics for amputees, said that intraneural stimulation is a valuable solution for several neuroprosthetic devices for sensory and motor function restoration and thinks greatly of the translational potentials of this approach to provide a visual aid for daily living.
EPFL’s Diego Ghezzi assures, “As intraneural stimulation has the potential to provide informative visual patterns, human clinical trials to fine-tune these patterns should begin soon.”
