this could happen only because she lost her brain in her midlife. On 10/28/21, Saurav Hegde <[email protected]> wrote: > Very informative case study. > > On Thu, Oct 28, 2021 at 4:34 PM Minar Singh <[email protected]> wrote: > >> Brain Implant Gives Blind Woman Artificial Vision in Scientific First >> >> https://www.sciencealert.com/a-brain-implant-has-allowed-a-blind-woman-to-see-simple-2d-shapes-and-letters?fbclid=IwAR0IZiWFG71-S2tiyLl4x3SC379iq9yV6f3-XojdCL_169RwgB6Xowkm-vI >> CARLY CASSELLA >> 28 OCTOBER 2021 >> A 'visual prosthesis' implanted directly into the brain has allowed a >> blind woman to perceive two-dimensional shapes and letters for the >> first time in 16 years. >> The US researchers behind this phenomenal advance in optical >> prostheses have recently published the results of their experiments, >> presenting findings that could help revolutionize the way we help >> those without sight see again. >> At age 42, Berna Gomez developed toxic optic neuropathy, a deleterious >> medical condition that rapidly destroyed the optic nerves connecting >> her eyes to her brain. >> In just a few days, the faces of Gomez' two children and her husband >> had faded into darkness, and her career as a science teacher had come >> to an unexpected end. >> Then, in 2018, at age 57, Gomez made a brave decision. She volunteered >> to be the very first person to have a tiny electrode with a hundred >> microneedles implanted into the visual region of her brain. The >> prototype would be no larger than a penny, roughly 4 mm by 4 mm, and >> it would be taken out again after six months. >> Unlike retinal implants, which are being explored as means of >> artificially using light to stimulate the nerves leaving the retina, >> this particular device, known as the Moran|Cortivis Prosthesis, >> bypasses the eye and optic nerve completely and goes straight to the >> source of visual perception. >> After undergoing neurosurgery to implant the device in Spain, Gomez >> spent the next six months going into the lab every day for four hours >> to undergo tests and training with the new prosthesis. >> The first two months were largely spent getting Gomez to differentiate >> between the spontaneous pinpricks of light she still occasionally sees >> in her mind, and the spots of light that were induced by direct >> stimulation of her prosthesis. >> Once she could do this, researchers could start presenting her with >> actual visual challenges. >> When an electrode in her prosthesis was stimulated, Gomez reported >> 'seeing' a prick of light, known as a phosphene. Depending on the >> strength of the stimulation, the spot of light could be brighter or >> more faded, a white color or more of a sepia tone. >> When more than two electrodes were simultaneously stimulated, Gomez >> found it easier to perceive the spots of light. Some stimulation >> patterns looked like closely spaced dots, while others were more like >> horizontal lines. >> "I can see something!" Gomez exclaimed upon glimpsing a white line in >> her brain in 2018. >> Vertical lines were the hardest for researchers to induce, but by the >> end of training Gomez was able to correctly discriminate between >> horizontal and vertical patterns with an accuracy of 100 percent. >> The Utah Electrode Array in actionThe Utah Electrode Array in action. >> (John A. Moran Eye Center at the University of Utah) >> "Furthermore, the subject reported that the percepts had more >> elongated shapes when we increased the distance between the >> stimulating electrodes," the authors write in their paper. >> "This suggests that the phosphene's size and appearance is not only a >> function of the number of electrodes being stimulated, but also of >> their spatial distribution… " >> Given these promising results, the very last month of the experiment >> was used to investigate whether Gomez could 'see' letters with her >> prosthesis. >> When up to 16 electrodes were simultaneously stimulated in different >> patterns, Gomez could reliably identify some letters like I, L, C, V >> and O. She could even differentiate between an uppercase O and a >> lowercase o. >> The patterns of stimulation needed for the rest of the alphabet are >> still unknown, but the findings suggest the way we stimulate neurons >> with electrodes in the brain can create two-dimensional images. >> The last part of the experiment involved Gomez wearing special glasses >> that were embedded with a miniature video camera. This camera scanned >> objects in front of her and then stimulated different combinations of >> electrodes in her brain via the prosthesis, thereby creating simple >> visual images. >> The glasses ultimately allowed Gomez to discriminate between the >> contrasting borders of black and white bars on cardboard. She could >> even find the location of a large white square on either the left or >> right half of a computer screen. The more Gomez practiced, the faster >> she got. >> The results are encouraging, but they only exist for a single subject >> over the course of six months. Before this prototype becomes available >> for clinical use it will need to be tested among many more patients >> for much longer periods of time. >> Other studies have implanted the same microelectrode arrays, known as >> Utah Electrode Arrays, into other parts of the brain to help control >> artificial limbs, so we know they're safe in at least the short term. >> But it's still early days for the tech, which risks a steady drop in >> functionality over just a few months of operation. >> While engineers beef up the reliability of the devices, we still need >> to know exactly how to program the software that interprets the visual >> input. >> Last year, researchers at Baylor College of Medicine in Houston >> inserted a similar device into a deeper part of the visual cortex. >> Among five study participants, three of whom were sighted and two of >> whom were blind, the team found the device helped blind people trace >> the shapes of simple letters like W, S, and Z. >> In Gomez's case, there was no evidence of the device triggering neural >> death, epileptic seizures, or other negative side effects, which is a >> good sign, and suggests microstimulation can be safely used to restore >> functional vision, even among those who have suffered irreversible >> damage to their retinas or optic nerves. >> "One goal of this research is to give a blind person more mobility," >> says bioengineer Richard Normann from the University of Utah. >> "It could allow them to identify a person, doorways, or cars easily. >> It could increase independence and safety. That's what we're working >> toward." >> Right now, it seems only a very rudimentary form of sight can be >> returned with visual prostheses, but the more we study the brain and >> these devices among blind and sighted people, the better we will get >> at figuring out how certain patterns of stimulation can reproduce more >> complex visual images. >> Perhaps one day, other patients in the future will be able to trace >> the whole alphabet with this prosthesis because of what Gomez has >> done. Four more patients are already lined up to try out the device. >> "I know I am blind, that I will always be blind," Gomez said in a >> statement a few years ago. >> "But I felt like I could do something to help people in the future. I >> still feel that way." >> Gomez's name is listed as co-author on the paper for all her insight >> and hard work. >> The study was published in the Journal of Clinical Investigation. >> >> -- >> Disclaimer: >> 1. Contents of the mails, factual, or otherwise, reflect the thinking of >> the person sending the mail and AI in no way relates itself to its >> veracity; >> >> 2. AI cannot be held liable for any commission/omission based on the >> mails >> sent through this mailing list.. >> >> >> Search for old postings at: >> http://www.mail-archive.com/[email protected]/ >> --- >> You received this message because you are subscribed to the Google Groups >> "AccessIndia" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected]. >> To view this discussion on the web visit >> https://groups.google.com/a/accessindia.org.in/d/msgid/accessindia/CALLUjUYTfjQ8y%3DJmF7XYC6fodm%2BXFi%3DJt-Vwr%3DNwJ3LOCO%3Dh0A%40mail.gmail.com >> . >> > > -- > Disclaimer: > 1. Contents of the mails, factual, or otherwise, reflect the thinking of the > person sending the mail and AI in no way relates itself to its veracity; > > 2. AI cannot be held liable for any commission/omission based on the mails > sent through this mailing list.. > > > Search for old postings at: > http://www.mail-archive.com/[email protected]/ > --- > You received this message because you are subscribed to the Google Groups > "AccessIndia" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To view this discussion on the web visit > https://groups.google.com/a/accessindia.org.in/d/msgid/accessindia/CAMDaTCYyZZawHVR1nPCyWLJSfv34UJM%3DCq%2BBvvuzYi2w8%3DAdMw%40mail.gmail.com. >
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