An artificial retina will be a huge boon for many people with visual impairments, and the likelihood is growing closer to reality year after year. One of the latest developments is taking a different and more optimistic approach, using small dots that convert light into electricity. Virtual reality has helped show that this could be the way forward.
This photovoltaic retinal prosthesis É Cole Polytechnic comes from the Federal de lane, where Diego Guzzi has been working on the idea for many years.
Early retinal prosthetics developed decades ago, and the idea is as follows: A camera outside the body (for example, on a pair of glasses) sends a signal to a small microelectrode array on a wire, which contains a lot of All contain small electrodes that pierce the nonfunctioning retinal surface and stimulate the working cells directly.
The problems with this are mainly that the array needs to run a wire from outside the eye to power and send data – usually saying “don’t” when it comes to prosthetics and the body in general. . Arrays themselves are limited by the number of electrodes they can have, depending on the size of each one, meaning that for many years the optimal resolution at best conditions was a few dozen or a hundred “pixels.” (The concept does not translate directly because of the way the visual system works.)
Ghazi’s approach overcomes both of these problems using photovoltaic materials, which convert light into electricity. This is no different from what happens in a digital camera, except that instead of recording the charge as an image, it sends the current into the retina like a Patrick electrode. The implant does not need power or any wires to relay data, as both are provided by the light shining on it.
In EPFL prostheses, there are thousands of tiny photovoltaic dots, which a device should theoretically illuminate outside the eye that detects it from a camera. Of course, this is still a tough thing for engineering. The second part of the setup will be a pair of mirrors or glasses that capture an image and present it through the eye to the implant.
We first heard about this approach in 2018, and since then, something has changed, As documents for new documents.
“We’ve increased the number of pixels from about 2,300 to 10,500,” Gezi explained in an email to TechCrunch. “So now it’s hard to see them separately, and they look like a continuous movie.”
Of course, it’s a different story when those dots are pressed against the retina. After all, it’s only 100 × 100 pixels or so if it were a square – not a high definition at all. But the idea is not to repeat the human vision, which can be an impossible task, to begin with, let alone be realistic for one’s first shot.
“Technically, it’s possible to make pixels smaller and smaller,” Gezi said. “The problem is that the current pixel area decreases.”
The more you connect, the harder it is to make it work, and there is also the risk (which they tested) that two adjacent dots will stimulate the same network in the retina. But too little and created image may not be sensible to the user. 10,500 Sounds A lot, and this it can Enough is enough – but the simple fact is that there is no data to support it. To begin with, the team turned to what seems to be a viable medium: VR.
Because the team can’t install experimental retinal implants on people to see if it works, they needed another way to tell if there were some dimensions to the equipment for everyday tasks, such as identifying objects. And resolution sufficient will suffice. And letters.
To do so, they need to use VR. In addition to the slightly simulated “phosphorus” placed in the dark environment, the light bracelets that they expect to be created by implants stimulate the retina; Ghazi compared people to people who would compare themselves to bright, changing stars. They ask participants how well they can understand things like words or scenes, the number of phosphors, the area they appear, and the length of their light or “tail” when the image is illuminated.
Finding out their origin The most important factor was the perspective – the overall size of the area where the image appears. Even a clear image is difficult to understand if it only focuses on your vision. Even if the overall clarity suffers, it is better to improve the vast field of vision. Strong analysis of the brain’s visual system also derives from objects such as edges and rare objects less than speed.
This demonstration showed that the application criteria are theoretically correct, and the team can start working towards human trials. This is not something that can happen in a hurry, and while this approach is auspicious compared to previous, wired ones, it will still be many years before it is possible in the best of circumstances. Nevertheless, the prospect of a retina implant that works this way is fascinating, and we will follow it closely.