A three-month study of a bionic eye being developed by a team of biomedical researchers at the University of Sydney and UNSW has shown to be safe and stable for long-term implantation, paving the way towards human trials.
The device, known as the Phoenix99 Bionic Eye, has two main components which need to be implanted: a stimulator attached to the eye and a communication module positioned under the skin behind the ear.
According to its developers, a very small camera attached to glasses captures the visual scene in front of the wearer. The images are processed into a set of stimulation instructions, which are sent wirelessly through the skin to the communication module of the prosthesis.
The implant decodes the wireless signal and transfers the instructions to the stimulation module, which delivers electrical impulses to the neurons of the retina. The electrical impulses, delivered in patterns matching the images recorded by the camera, trigger neurons which forward the messages to the brain, where the signals are interpreted as a vision of the scene.
Published in Biomaterials, the researchers used a sheep model to observe how the body responds and heals when implanted with the device, with the results allowing for further refinement of the surgical procedure. The biomedical research team is now confident the device could be trialled in human patients.
Professor Gregg Suaning, head of the School of Biomedical Engineering, said the positive results were a significant milestone for the Phoenix99 Bionic Eye.
“This breakthrough comes from combining decades of experience and technological breakthroughs in the field of implantable electronics,” Suaning said.
Mr Samuel Eggenberger, a biomedical engineer who is completing his doctorate with Suaning, said the system bypasses malfunctioning cells by stimulating the remaining healthy cells directly, effectively tricking the brain into believing that light was sensed.
“Importantly, we found the device has a very low impact on the neurons required to ‘trick’ the brain. There were no unexpected reactions from the tissue around the device and we expect it could safely remain in place for many years.”
“Our team is thrilled by this extraordinary result, which gives us confidence to push on towards human trials of the device. We hope that through this technology, people living with profound vision loss from degenerative retinal disorders may be able to regain a useful sense of vision,” Eggenberger said.
The team will now apply for ethics approval to perform clinical trials in human patients, as they continue to develop and test advanced stimulation techniques.