Wednesday, May 27, 2009
seeing by the tongue
This technology has been in development for some time now and it appears it's about to be released. When you've read this you'll know as much as we do about it.Seeing with your tongue. By RON SEELY, 608-252-6131,rseely@madison.comRoger Behm lost his sight at 16, the victim of an inherited disease that destroyedhis retinas. Both of his eyes were surgically removed.Now 55, Behm has made himself at home in a sightless world. He started his own businessin Janesville selling devices that help the blind cope with day-to-day tasks. Heand his wife have raised five children and just adopted another child from Chinawho is also blind. He fishes, canoes, camps and scuba dives.But Behm can remember seeing. Which is why he couldn't believe it when, three yearsago, he slipped a device over his head, turned it on, and was once again able todiscern light and dark, shapes and shadows, letters and numbers, and even a rollinggolf ball."I could look down and and see the ball, white on black, and I could see myself swingingmy putter," Behm said. "And, of course, I missed. But I could reach down and pickup my ball, like any other sighted person."The device is called BrainPort and, though it seems like a gadget from Star Trek,it may be available commercially by the end of the year.It works by converting images from a video camera to electrical impulses that aretransmitted via the tongue to the brain of the blind person and turned again intoblack-and-white images that the user sees.It takes advantage of groundbreaking work by a UW-Madison scientist that showed thebrain will reprogram itself to accept and use different sensory signals - in thiscase touch instead of sight - to replace signals that can no longer be received dueto injury or disease.The device, which consists of a miniature camera mounted on a pair of sunglasses,a tongue sensor and a small control unit, was developed by Wicab of Middleton. Itbuilds on another of the company's devices that uses the same underlying ideas tohelp restore users' balance.The company is applying to the federal Food and Drug Administration to get approvalfor a marketable version of the vision device that could be available by the endof the year, Wicab CEO Robert Beckman said.Trying circumstances.Few have tested BrainPort under more trying circumstances than Erik Weihenmayer,the only blind man to reach the summit of Mt. Everest. Weihenmayer, totally blindsince the age of 16, has used the device to help him hike in the woods, even ascendclimbing walls. But he has most appreciated it for letting him do such simple butrewarding tasks as playing tic-tac-toe with his daughter or reaching down to pethis dog."I have a climbing friend who didn't believe me when I told him about this," Weihenmayersaid. "So he put a Pepsi can on my table in my kitchen while I was out of the room.Then he called me back in and told me to grab it. I reached out and grabbed the Pepsican. He was blown away. He was speechless. He had tears in his eyes."I mean, it may not seem like a real big deal to people, but to be able to see yourcoffee cup ... ."Neither Behm nor Weihenmayer are paid consultants to Wicab, although the companypays some of their expenses.The late Paul Bach-y-Rita, a UW-Madison physician and specialist in rehabilitation,first came up with the ideas that inspired BrainPort in the 1960s. The technologywas patented by UW-Madison in 1998, and commercial development has been under wayfor more than 10 years.New ways to work.Bach-y-Rita's earliest thinking about the brain's ability to adapt to new ways ofreceiving and processing information - its "plasticity," as it is known now - waslikely sparked by the dramatic struggle of his father, Pedro, to recover from a devastatingstroke in the mid-1960s, Beckman said.Neurologists in those days believed brain damage could not be reversed. But Bach-y-Rita'sbrother, George, soon put their father to work doing chores such as sweeping theporch of the house. Forced to accomplish more and more difficult tasks, their fathereventually recovered completely and even went back to his job teaching.He died at the age of 73 of a heart attack while climbing in the mountains of Columbia.Remarkably, studies of Pedro's brain after his death showed massive damage to hisbrain from the stroke. Yet he recovered. Somehow, his brain had found new ways towork.At the UW-Madison, Bach-y-Rita focused his studies on sensory substitution, the ideathat the brain can learn how to use other senses to replace one that has been lostor damaged. He concentrated on the power of touch, studying what happens in the brainwhen visual cues come from the sensitive nerves of the skin, such as those on thefingertips.Perfect organ.Those studies buttressed others that showed the brain can indeed learn how to usenerve impulses, delivered through touch, to create images. Exactly what happens remainssomewhat of a mystery. But more recently, MRI images taken of the brain while itis working do show the visual cortex of the brain lighting up when receiving sensorydata retrieved through touch."The information does get to the area of the brain that is responsible for vision,"said Kurt Kaczmarek, a UW-Madison engineer and scientist who was involved in theearly work on BrainPort.The tongue is the perfect organ for the task, Beckman said, because it is moist andan excellent transmitter of electrical signals, and it has more tactile nerve endingsthan any other part of the body except for the lips.Though one can read the science over and over again, it still requires somewhat ofa leap of faith to grasp the idea of "seeing" through the tongue. Simply, the patternsof light picked up by the camera are converted by a tiny computer into electricalpulses across 100 stainless steel electrodes. Users say it feels similar to touchinga weak battery to your tongue, a bubbly or tingling sensation.The pulses are spatially encoded, meaning the person receiving those signals on thetongue can perceive depth, perspective, size and shape. That information is translatedby the brain into images - fuzzy images, because of the low resolution, but imagesnonetheless. Those who have used the device explain that they perceive the objectsin front of them, separate from their own bodies.A milestone of sorts.Weihenmayer recalled how when he first tried BrainPort, the researchers sat him downat a table, fitted him with the device, and then rolled a ball toward him."It's a hard thing to wrap your brain around," said Weihenmayer. "But when they rolleda white tennis ball toward me, I could feel the ball rolling. First I could feelthe ball starting at the back of my tongue and getting bigger and bigger, comingtoward me. And then I reached out and grabbed it."When he ascends a rock climbing wall with BrainPort, Weihenmayer said, he can seethe handholds, their differences in shape and the contrast in light between themand the background. What he sees, he explained, is largely shapes and light variations,sort of an out-of-focus image.Last month, Weihenmayer joined Beckman at the National Eye Institute's 40th anniversarycelebration to demonstrate BrainPort and some of its powers. It seemed a milestoneof sorts.But the man whose genius led to the creation of such a useful invention was not present.Bach-y-Rita died of cancer in November of 2006."He would have loved to have been there," said Beckman.Source URL:http://www.madison.com/wsj/topstories/451
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