It’s the ultimate high-tech fantasy: a wacky invention that could be placed over our eyes—or inside our ears—to help the blind see or the deaf hear.
Turns out, that tech may not be so far away. Researchers have been plugging away at such a task for a decade—no more so than at the University of Stanford, which has its own dedicated artificial retina team.
An artificial retina works like a very small computer chip with a camera. Hundreds of metal electrodes come out of the retina to both measure the activity of the neurons and transmit images to the brain.
The problem is that the process is very data intensive. And when computer chips work hard—as anyone with a laptop can tell you—they get very hot. Too hot to be stuck onto your eyeballs.
“The chips required to build a high-quality artificial retina would essentially fry the human tissue they are trying to interface with,” EJ Chichilnisky, a professor in neurosurgery at Stanford, and one of the members of this artificial retina team, bluntly puts it.
Nonetheless, Chichilnisky and his team have announced that they have created a way to solve the heat problem by compressing the amount of data created.
Artificial retina explainer
Stanford University explains that to convey visual information to the brain, neurons in normal retina send a series of electrical impulses— known as “spikes.”
It’s more complicated for an artificial retina to do this, as it has to take the image, digitise it, compress it and send it to the brain.
The team has developed new tech that helps better understand “which signal samples matter and which can be ignored.”
“It’s a bit like being at a party trying to extract a single coherent conversation amid the din of a crowded room—a few voices matter a lot, but most are noise and can be ignored,” the university says.
These newer retina prototypes can compress data whilst digitising it, retaining the most useful information and making it easier to implement in hardware.
Each spike is analysed, with unique signals recorded for further processing. This process misses just five percent of cells, but it reduces acquired data by 40 times.
There’s a long way to go before the artificial retinas are ready. This is just a first step. But, the researchers think this is the first stop towards cool-running implantable chips that could work in the eye or in brain-controlled machines to revive motion to the paralysed, restore hearing to the deaf, or help improve memory.
Robert Scott Lazar