Can Someone See Again Without Original Eyeballs
"Allí," says Bernardeta Gómez in her native Spanish, pointing to a big black line running across a white canvas of cardboard propped at arm's length in front of her. "In that location."
It isn't exactly an impressive feat for a 57-year-onetime 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'due south eyes to her encephalon, rendering her totally without sight. She's unable even to detect light.
But subsequently 16 years of darkness, Gómez was given a 6-month window during which she could see a very depression-resolution semblance of the world represented by glowing white-yellowish dots and shapes. This was possible thanks to a modified pair of spectacles, blacked out and fitted with a tiny photographic camera. The contraption is hooked up to a figurer that processes a alive video feed, turning information technology into electronic signals. A cablevision suspended from the ceiling links the organisation 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, bones shapes printed on paper, and people. She even played a simple Pac-Man–similar computer game piped directly into her brain. 4 days a week for the duration of the experiment, Gómez was led to a lab by her sighted hubby and hooked into the system.
Gómez'due south first moment of sight, at the end of 2018, was the culmination of decades of research by Eduardo Fernandez, manager of neuroengineering at the University of Miguel Hernandez, in Elche, Spain. His goal: to render sight to as many as possible of the 36 one thousand thousand blind people worldwide who wish to encounter again. Fernandez'southward approach is particularly heady because it bypasses the center and optical nerves.
Much earlier research attempted to restore vision by creating an artificial eye or retina. Information technology worked, but the vast majority of blind people, like Gómez, take damage to the nervus system connecting the retina to the back of the brain. An artificial eye won't solve their incomprehension. That'due south why in 2015, the company 2nd Sight, which received approval to sell an artificial retina in Europe in 2011—and in the The states in 2013—for a rare affliction called retinitis pigmentosa, switched ii decades of piece of work away from the retina to the cortex. (Second Sight says slightly more than 350 people are using its Argus 2 retinal implant.)
During a contempo visit I made to palm-studded Elche, Fernandez told me that advances in implant engineering, and a more refined understanding of the human visual system, take given him the conviction to get straight to the encephalon. "The information in the nervous system is the aforementioned information that's in an electric device," he says
Restoring sight by feeding signals directly to the brain is ambitious. Just the underlying principles have been used in human-electronic implants in mainstream medicine for decades. "Right now," Fernandez explains, "we accept many electric devices interacting with the man body. Ane 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 indicate to an implant in the inner ear. The implant's electrodes send pulses of current into nearby fretfulness that the brain interprets as sound. The cochlear implant, which was first installed in a patient in 1961, lets over half a meg people around the globe have conversations as a normal part of everyday life.
"Berna was our first patient, but over the next couple of years nosotros will install implants in five more blind people," says Fernandez, who calls Gómez past her first name. "Nosotros had done similar experiments in animals, only a true cat or a monkey can't explain what it's seeing."
Berna could.
Her experiment took courage. It required encephalon surgery on an otherwise healthy body—ever a risky procedure—to install the implant. And and so once again to remove it six months afterwards, since the prosthesis isn't approved for longer-term use.
Seizures and phosphenes
I hear Gómez before I come across her. Hers is the voice of a adult female about a decade younger than her age. Her words are measured, her cadency is perfectly smooth, and her tone is warm, confident, and steady.
When I finally run across her in the lab, I notice Gómez knows the layout of the infinite so well she barely needs help navigating the pocket-sized hallway and its attached rooms. When I walk over to greet her, Gómez's face is initially pointing in the wrong management until I say how-do-you-do. When I reach out to milkshake her hand, her hubby guides her hand into mine.
Gómez is here for a brain MRI to see how things look half a twelvemonth after having her implant removed (they look skillful). She's too hither to see a potential second patient who is in town, and in the room during my visit. At one bespeak during this meeting, as Fernandez explains how the hardware connects to the skull, Gómez interrupts the discussion, tilts forward, and places the prospect's mitt on the back of her head, where a metallic outlet used to be. Today there's well-nigh no testify of the port. The implant surgery was and then uneventful, she says, that she came to the lab the very adjacent solar day to get plugged in and showtime the experiments. She's had no problems or hurting since.
Gómez was lucky. The long history of experiments leading to her successful implant has a checkered by. 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 brain while doing surgery. He dubbed the miracle 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 up the electricity and a patient fall to the flooring writhing in a seizure. The cause was besides much stimulation with also much current—something, it turns out, brains don't similar. Dobelle's patients also had issues with infections. All the same Dobelle marketed his bulky device as nearly fix for mean solar day-to-day utilise, complete with a promotional video of a bullheaded human being driving slowly and unsteadily in a airtight parking lot. When Dobelle died in 2004, so did his prosthesis.
Unlike Dobelle, who proclaimed a cure for the bullheaded, Fernandez almost constantly says things like, "I don't want to get whatsoever hopes up," and "Nosotros promise to have a system people tin can employ, but right at present we're merely conducting early experiments."
Just Gómez did in fact see.
Bed of nails
If the basic idea backside Gómez's sight—plug a photographic camera into a video cable into the brain—is uncomplicated, the details are non. Fernandez and his squad starting time had to figure out the camera part. What kind of indicate does a human retina produce? To endeavour to answer this question, Fernandez takes human being 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 shut relationship with the local infirmary, which sometimes calls in the center of the night when an organ donor dies. A human retina can exist kept live for only virtually seven hours.) His squad likewise uses automobile learning to match the retina'southward electric output to simple visual inputs, which helps them write software to mimic the procedure automatically.
The side by side step is taking this indicate and delivering it to the brain. In the prosthesis Fernandez built for Gómez, a cabled connectedness runs to a common neuro-implant known every bit a Utah assortment, which is just smaller than the raised tip on the positive end of a AAA battery. Protruding from the implant are 100 tiny electrode spikes, each about a millimeter tall—together they look similar a miniature bed of nails. Each electrode tin can deliver a electric current to betwixt one and iv neurons. When the implant is inserted, the electrodes pierce the surface of the brain; when it'southward removed, 100 tiny droplets of blood form in the holes.
Fernandez
Fernandez had to calibrate one electrode at a time, sending information technology increasingly strong currents until Gómez noted when and where she saw a phosphene. Getting all 100 electrodes dialed in took more a month.
"The advantage to our approach is that the assortment's electrodes protrude into the brain and sit down close to the neurons," Fernandez says. This lets the implant produce sight with a much lower electrical current than was needed in Dobelle'southward organisation, which sharply reduces the risk of seizures.
The large downside to the prosthesis—and the main reason Gómez couldn't keep hers beyond six months—is that nobody knows how long the electrodes tin can last without degrading either the implant or the user's brain. "The body's allowed system starts to break down the electrodes and surround them with scar tissue, which eventually weakens the signal," Fernandez says. There's also the problem of the electrodes flexing equally someone moves around. Judging from inquiry in animals and an early look at the array Gómez used, he supposes the current setup could last two to three years, and perhaps up to ten earlier it fails. Fernandez hopes a few minor tweaks will extend that to a few decades—a critical prerequisite for a piece of medical hardware that requires invasive brain surgery.
Eventually, the prosthesis, like a cochlear implant, will need to transmit its indicate and ability wirelessly through the skull to attain the electrodes. But for now, his team has then far left the prosthesis cabled for experiments—providing the most flexibility to proceed updating the hardware before settling on a design.
At 10 pixels past x pixels, which is roughly the maximum potential resolution Gómez's implant could render, one may perceive bones shapes like letters, a door frame, or a sidewalk. Simply the contours of a confront, permit alone a person, are far more than complicated. That's why Fernandez augmented his system with image recognition software to place a person in a room and axle a design of phosphenes to Gómez'southward brain that she learned to recognize.
At 25 by 25 pixels, Fernandez writes in a slide he likes to nowadays, "vision is possible." And because the Utah array in its current form is so small and requires and then little ability to run, Fernandez says at that place's no technical reason his team couldn't install four to 6 on each side of the brain, offering vision at lx x 60 pixels or college. Still, nobody knows how much input the human brain can take from such devices without being overwhelmed and displaying the equivalent of TV snow.
What it looks similar
Russ Juskalian
Gómez told me she would have kept the implant installed if she had been given the choice and that she'll be showtime in line if an updated version is available. When Fernandez is washed analyzing her array, Gómez plans to accept it framed and hang information technology on her living room wall.
Back in Fernandez's lab, he offers to hook me upward to a noninvasive device he uses to screen patients.
Sitting in the same leather chair Gómez occupied during last year's breakthrough experiment, I wait as a neurologist holds a wand with ii 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 called transcranial magnetic stimulation. The first smash feels as if someone is shocking my scalp. My fingers involuntarily curl into my palms. "Await, it worked!" Fernandez says, chuckling. "That was your motor cortex. Now we volition try to give you some phosphenes."
The neurologist repositions the wand and sets the machine for a rapid series of pulses. This fourth dimension when she fires, I experience an intense zzp-zzp-zzp, as if someone were using the back of my skull as a door knocker. And so, even though my eyes are wide open, I see something: a bright horizontal line flashes across the centre of my field of vision, forth with two shimmering triangles filled with what looks like Tv snow. The vision fades as speedily every bit it arrived, leaving a cursory afterglow.
"This is similar what Berna could encounter," Fernandez says. Except her "sight" of the world was stable as long as the signal was being transmitted to her brain. She could as well turn her head and, with her glasses on, look effectually the room. What I had seen were merely internal phantoms of an electrically excited brain. Gómez could actually reach out and touch the globe she was looking at for the first time in xvi years.
Source: https://www.technologyreview.com/2020/02/06/844908/a-new-implant-for-blind-people-jacks-directly-into-the-brain/
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