Bio-engineers are hailing new tech as a ‘paradigm shift’. The new implant can transmit video images directly to the visual cortex, bypassing the eye and optic nerve.
Trials have shown the new technique has successfully restored partial sight to six blind people.
The implant – named Orion – by the team Baylor Medical College in Texas and the University of California Los Angeles consists of a brain implant with 60 electrodes that can deliver patterns of stimulation to the visual part of the brain.
The team worked in collaboration with the University of California, Los Angeles and Second Sight.
How was does Orion Work?
Most patients with acquired blindness have an undamaged ‘visual brain’. It is just relatively unused because no information is being transmitted from the eyes.
What Orion does is use a camera mounted on a pair of eyeglasses to capture images, and then delivers a pattern of stimulation directly to the brain. The pattern is designed to produce a percept of a corresponding visual image.
The team tested it by asking participants in the study who had been blind for years to look at a blacked-out computer screen and point to a white square that appears at intervals on different locations on the monitor.
Amazingly the majority of the time they can successfully point to the square.
The tech works because our brains contain distinct maps of the visual field; every spot in the visual world has a corresponding spot in the brain that represents that spatial location.
It has been known for years that if you are able to stimulate someone’s brain at a certain location, a point of light can be produced in a specific visual spot. This is how the image can be produced in those who are blind as well as those who are sighted.
However, the visual cortical prosthetic device is only useful for those who were born sighted and who later lost their sight. This is because if a person is born blind, the parts of the brain that support sight are never fully developed. Visual information cannot be effectively transmitted to the brain.
Eventually, if the technology allowed bio-engineers to add hundreds of thousands of electrodes to the brain they could produce a rich visual image.
The best way to think about the technique is to imagine a painting that uses pointillism, where thousands of tiny spots come together to create a full image.
Vincent van Gogh, Self Portrait, 1887, using pointillist technique.
Pointillism is a technique of painting in which small, distinct dots of color are applied in patterns to form an image.
While the technology to do this does not exist yet the team are hoping their research is the first to step to map out each visual spot in the brain. This will allow them to understand more about how it could be implemented in future.
What next for the technology
“For many years, we have been studying how the brain encodes visual information. When you think of vision, you think of the eyes, but most of the work is being done in the brain. The impulses of light that are projected onto the retina are converted into neural signals that are transmitted along the optic nerve to parts of the brain,” said Dr. Daniel Yoshor, chair and professor of neurosurgery at Baylor.
“In the future, we hope to use our understanding of how the brain processes visual information to develop a visual prosthetic that will restore useful vision to the blind.”
The next step for Yoshor and his team will be testing the Orion in the first-ever FDA-approved clinical trial of a visual cortical prosthesis. This will be the first time that a visual cortical prosthetic has advanced enough to make a clinical trial a reality.
While this initial research is only an early feasibility study it allows the team to evaluate the device design concept. This means they can now move onto clinical safety trials and look to improve the device functionality. While the technology is still in its infancy these initial results are an amazing first step.
