At Australia’s Swinburne University of Technology research is underway to develop a method of activating optic nerves by laser stimulation. The idea is to embed gold nanoparticles within the eye that can then be excited by lasers from within a pair of glasses. If successful, this technology will help people suffering from eye diseases like retinitis pigmentosa and macular degeneration.
The researchers are looking for a non-contact method of stimulating nerves and are exploring the use of laser light, rather than the direct electrical stimulation techniques that have become the conventional approach.
Using a very low intensity laser source they are trying to generate the right amount of heat required to elicit a response from nerve cells without damaging them.
According to researcher PhD student Chiara Paviolo, the new concept explores the potential for light to deliver far more precise nerve cell stimulation than electrodes.
“Electrodes need an electrical current and so they consequently stimulate a group of nerves,” Paviolo said.
“Light, however, allows us to target individual nerves and this should mean more accurate communication of optical signals – an essential outcome if the information delivered to the brain via a prosthesis is to mean anything useful in terms of shapes, colours, dimensions. You don’t just want optical ‘noise’.”
The initial goal is to successfully bond the nanoparticles to the nerve and then achieve a response to light heat.
Gold nanoparticles are being used because gold is inert, biocompatible and has plasmonic or light-responsive properties. The gold nanoparticles can also be fabricated to respond to different wavelengths, making the interface controllable.
“One of the challenges is to develop nanoparticles that are thermally stable,” said Professor of Biointerface Engineering Sally McArthur . “While on one hand heat is necessary, it also has to be limited to avoid damaging cells. Laser heat has long been used in medicine to deliberately kill tissue, but in this instance the opposite result is sought.”
To measure and control the heat, the Swinburne team is building a molecular thermal sensor to measure how much heat is produced, so they can then work out how to control it.
Press release: Bionic eye hope blends lasers and gold…
