If Your Blind Can You See Again
"Allí," says Bernardeta Gómez in her native Spanish, pointing to a large black line running beyond a white sheet of paper-thin propped at arm's length in front of her. "There."
It isn't exactly an impressive feat for a 57-yr-old woman—except that Gómez is blind. And she'southward been that way for over a decade. When she was 42, toxic optic neuropathy destroyed the bundles of nerves that connect Gómez'southward eyes to her brain, rendering her totally without sight. She's unable even to observe light.
But later 16 years of darkness, Gómez was given a half-dozen-month window during which she could see a very depression-resolution semblance of the globe represented by glowing white-yellow dots and shapes. This was possible thanks to a modified pair of glasses, blacked out and fitted with a tiny camera. The contraption is hooked upwardly to a computer that processes a live video feed, turning it into electronic signals. A cable suspended from the ceiling links the organization to a port embedded in the back of Gómez's skull that is wired to a 100-electrode implant in the visual cortex in the rear of her brain.
Russ Juskalian
Using this, Gómez identified ceiling lights, messages, basic shapes printed on paper, and people. She even played a simple Pac-Man–like calculator game piped direct into her brain. Four days a calendar week for the duration of the experiment, Gómez was led to a lab by her sighted hubby and hooked into the system.
Gómez's first moment of sight, at the end of 2018, was the culmination of decades of research by Eduardo Fernandez, director of neuroengineering at the Academy of Miguel Hernandez, in Elche, Spain. His goal: to render sight to equally many equally possible of the 36 million blind people worldwide who wish to see again. Fernandez'south arroyo is particularly heady because information technology bypasses the middle and optical fretfulness.
Much earlier inquiry attempted to restore vision by creating an artificial middle or retina. It worked, but the vast majority of blind people, like Gómez, have damage to the nerve arrangement connecting the retina to the back of the brain. An bogus eye won't solve their incomprehension. That's why in 2015, the visitor 2nd Sight, which received approval to sell an artificial retina in Europe in 2011—and in the US in 2013—for a rare affliction called retinitis pigmentosa, switched two decades of work away from the retina to the cortex. (2nd Sight says slightly more than 350 people are using its Argus II retinal implant.)
During a contempo visit I made to palm-studded Elche, Fernandez told me that advances in implant applied science, and a more refined agreement of the human visual system, accept given him the conviction to go direct to the brain. "The data in the nervous system is the same information that's in an electrical device," he says
Restoring sight by feeding signals directly to the encephalon is ambitious. But the underlying principles take been used in human-electronic implants in mainstream medicine for decades. "Right at present," Fernandez explains, "we have many electric devices interacting with the human trunk. One of them is the pacemaker. And in the sensory system nosotros take the cochlear implant."
Russ Juskalian
This latter device is the hearing version of the prosthesis Fernandez built for Gómez: an external microphone and processing system that transmits a digital signal to an implant in the inner ear. The implant's electrodes send pulses of current into nearby nerves that the brain interprets as sound. The cochlear implant, which was first installed in a patient in 1961, lets over half a million people around the globe have conversations equally a normal office of everyday life.
"Berna was our first patient, but over the side by side couple of years we will install implants in five more blind people," says Fernandez, who calls Gómez past her first proper name. "We had done similar experiments in animals, only a cat or a monkey can't explicate what it'southward seeing."
Berna could.
Her experiment took courage. It required brain surgery on an otherwise healthy body—always a risky process—to install the implant. And so once again to remove it six months later, since the prosthesis isn't approved for longer-term utilise.
Seizures and phosphenes
I hear Gómez before I run across her. Hers is the vocalisation of a adult female about a decade younger than her historic period. Her words are measured, her cadence is perfectly smoothen, and her tone is warm, confident, and steady.
When I finally meet her in the lab, I discover Gómez knows the layout of the space so well she barely needs aid navigating the small hallway and its fastened rooms. When I walk over to greet her, Gómez's face is initially pointing in the incorrect direction until I say hi. When I achieve out to shake her manus, her husband guides her hand into mine.
Gómez is here for a brain MRI to run across how things look one-half a year after having her implant removed (they look good). She's likewise here to see a potential second patient who is in town, and in the room during my visit. At ane point during this meeting, as Fernandez explains how the hardware connects to the skull, Gómez interrupts the discussion, tilts frontwards, and places the prospect's mitt on the back of her head, where a metal outlet used to be. Today at that place'due south virtually no evidence of the port. The implant surgery was so uneventful, she says, that she came to the lab the very adjacent day to get plugged in and start the experiments. She'south had no issues or pain since.
Gómez was lucky. The long history of experiments leading to her successful implant has a checkered past. In 1929, a German neurologist named Otfrid Foerster discovered that he could elicit a white dot in the vision of a patient if he stuck an electrode into the visual cortex of the encephalon while doing surgery. He dubbed the phenomenon a phosphene. Scientists and sci-fi authors have since imagined the potential for a photographic camera-to-computer-to-brain visual prosthesis. Some researchers even built rudimentary systems.
In the early on 2000s, the hypothetical became a reality when an eccentric biomedical researcher named William Dobelle installed such a prosthesis in the head of an experimental patient.
In 2002, the writer Steven Kotler recalled with horror watching Dobelle crank upward the electricity and a patient fall to the floor writhing in a seizure. The cause was as well much stimulation with as well much current—something, it turns out, brains don't like. Dobelle's patients also had problems with infections. Yet Dobelle marketed his beefy device as nigh ready for twenty-four hours-to-day use, complete with a promotional video of a bullheaded man driving slowly and unsteadily in a closed parking lot. When Dobelle died in 2004, so did his prosthesis.
Unlike Dobelle, who proclaimed a cure for the blind, Fernandez almost constantly says things like, "I don't want to get whatsoever hopes up," and "We hope to take a organization people can use, only right at present we're merely conducting early experiments."
But Gómez did in fact encounter.
Bed of nails
If the basic thought behind Gómez'southward sight—plug a camera into a video cable into the brain—is simple, the details are not. Fernandez and his team offset had to figure out the camera part. What kind of signal does a human retina produce? To try to answer this question, Fernandez takes man retinas from people who have recently died, hooks the retinas up to electrodes, exposes them to light, and measures what hits the electrodes. (His lab has a close relationship with the local hospital, which sometimes calls in the middle of the night when an organ donor dies. A human retina can be kept alive for merely about seven hours.) His team also uses machine learning to match the retina'due south electrical output to simple visual inputs, which helps them write software to mimic the process automatically.
The next step is taking this signal and delivering it to the brain. In the prosthesis Fernandez congenital for Gómez, a cabled connection runs to a common neuro-implant known as a Utah array, which is just smaller than the raised tip on the positive stop of a AAA battery. Protruding from the implant are 100 tiny electrode spikes, each well-nigh a millimeter tall—together they look like a miniature bed of nails. Each electrode can deliver a electric current to between one and iv neurons. When the implant is inserted, the electrodes pierce the surface of the brain; when it's removed, 100 tiny droplets of blood grade in the holes.
Fernandez
Fernandez had to calibrate i electrode at a time, sending it increasingly strong currents until Gómez noted when and where she saw a phosphene. Getting all 100 electrodes dialed in took more than a month.
"The advantage to our arroyo is that the assortment's electrodes beetle into the brain and sit close to the neurons," Fernandez says. This lets the implant produce sight with a much lower electric current than was needed in Dobelle'southward system, which sharply reduces the chance of seizures.
The big downside to the prosthesis—and the master reason Gómez couldn't keep hers beyond half-dozen months—is that nobody knows how long the electrodes tin can last without degrading either the implant or the user'south encephalon. "The body's immune arrangement starts to break down the electrodes and surround them with scar tissue, which eventually weakens the signal," Fernandez says. In that location's also the problem of the electrodes flexing as someone moves around. Judging from research in animals and an early look at the array Gómez used, he supposes the current setup could last two to three years, and perhaps upwardly to 10 before it fails. Fernandez hopes a few modest tweaks will extend that to a few decades—a critical prerequisite for a piece of medical hardware that requires invasive encephalon surgery.
Eventually, the prosthesis, like a cochlear implant, will demand to transmit its signal and power wirelessly through the skull to accomplish the electrodes. But for now, his squad has and then far left the prosthesis cabled for experiments—providing the almost flexibility to keep updating the hardware earlier settling on a blueprint.
At ten pixels by ten pixels, which is roughly the maximum potential resolution Gómez's implant could render, ane may perceive basic shapes like letters, a door frame, or a sidewalk. But the contours of a face, let alone a person, are far more complicated. That's why Fernandez augmented his arrangement with paradigm recognition software to identify a person in a room and beam a design of phosphenes to Gómez's brain that she learned to recognize.
At 25 past 25 pixels, Fernandez writes in a slide he likes to nowadays, "vision is possible." And because the Utah array in its electric current form is so small and requires then little power to run, Fernandez says there's no technical reason his team couldn't install 4 to 6 on each side of the encephalon, offering vision at 60 ten sixty pixels or higher. Still, nobody knows how much input the human being encephalon can take from such devices without being overwhelmed and displaying the equivalent of Telly snow.
What it looks like
Russ Juskalian
Gómez told me she would have kept the implant installed if she had been given the option and that she'll be kickoff in line if an updated version is bachelor. When Fernandez is done analyzing her array, Gómez plans to have it framed and hang information technology on her living room wall.
Back in Fernandez's lab, he offers to claw me up to a noninvasive device he uses to screen patients.
Sitting in the same leather chair Gómez occupied during last year's quantum experiment, I wait as a neurologist holds a wand with two rings against the side of my head. The device, called a butterfly coil, is connected to a box that excites neurons in the encephalon with a powerful electromagnetic pulse—a phenomenon chosen transcranial magnetic stimulation. The first blast feels equally if someone is shocking my scalp. My fingers involuntarily scroll into my palms. "Look, it worked!" Fernandez says, chuckling. "That was your motor cortex. Now nosotros will try to give you some phosphenes."
The neurologist repositions the wand and sets the machine for a rapid series of pulses. This time when she fires, I feel an intense zzp-zzp-zzp, equally if someone were using the back of my skull as a door knocker. Then, fifty-fifty though my eyes are wide open up, I see something: a bright horizontal line flashes beyond the center of my field of vision, along with two shimmering triangles filled with what looks similar TV snow. The vision fades as quickly equally it arrived, leaving a brief afterglow.
"This is like what Berna could see," Fernandez says. Except her "sight" of the world was stable as long every bit the signal was existence transmitted to her brain. She could also plough her head and, with her spectacles on, look effectually the room. What I had seen were merely internal phantoms of an electrically excited brain. Gómez could actually attain out and bear upon the world she was looking at for the first time in sixteen years.
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Source: https://www.technologyreview.com/2020/02/06/844908/a-new-implant-for-blind-people-jacks-directly-into-the-brain/
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