Cutting Edge: 'Seeing' Through Tongues

Tongue Sensors May Give Virtual Eyesight to the Blind

By Michael S. James
ABCNEWS.com

March 30, 2001

Blind people have always had to feel their way through the world. Someday
soon, they may be able to taste their way as well. 

Researchers at the University of Wisconsin at Madison are developing a device
that will allow people to "see" the world with their tongues. 

They say the tongue is an effective portal to the brain because of its
sensitivity, and electrical impulses created by a camera and a computer can
allow users to sense objects in space, as impulses from working eyes do
naturally. 

"Initially, when you first start training on it, you feel everything on the
skin [or the tongue]," says Dr. Paul Bach-y-Rita, a professor of
rehabilitation medicine and biomedical engineering at the University of
Wisconsin. "But after about 10 hours, you forget about the skin and feel
everything in space."  

After being trained with the device, subjects are able to sense their
surroundings and react to them automatically, Bach-y-Rita says. New users
tell him the array of electric stimulators on the tongue feels "like bubbly
water, or champagne bubbles," though the sensation fades into the
subconscious as users become accustomed to it. 

'Cool Approach'

It's a tasty concept to Dr. Michael D. Oberdorfer, director for the Low
Vision and Blindness Rehabilitation Program at the National Institute of
Health's National Eye Institute, who has cleared a preliminary $100,000 grant
to one of Bach-y-Rita's Wisconsin colleagues. 

Although the idea of people sensing through their tongues may seem strange at
first, Oberdorfer says it is not so odd upon considering the tongue's
sensitivity, and that its moisture creates an effective conductor of the
electrical impulses. 

"It seems obvious once you see it, but who would've thought?" Oberdorfer
says. "This is a very interesting, cool approach, and they're taking it in
several different directions."  

In addition to systems for the blind, Bach-y-Rita says the technology could
have other applications, because designers can create impulses from any
measurable source. 

He is in discussions with the military regarding devices to allow divers to
"see" more effectively through murky water using their mouthpieces, or to
allow soldiers to receive night vision readouts through their tongues. He
adds that the tongue sensors could one day be used in conjunction with video
games, and his team has received a federal grant for a system that will aid
people who've lost their sense of balance. 

Refinements Needed 

Researchers still are refining their products for the marketplace, and
predict it will be several years before they are perfected and available. 

For one thing, they still are trying to perfect an unobtrusive retainer to be
worn inside the mouth over the palate. For the time being, they still are
placing electronic ribbons in their subjects' mouths - a method that is
uncomfortable and only allows for half-hour testing sessions. 

"Technology exists now to put the whole array, the electronics, the battery,
everything into a dental retainer," Bach-y-Rita says. "It's just that to make
the whole package is expensive, and that's what we're working on."  

He believes that once the miniaturization is perfected, producing the devices
will become less expensive. 

For the vision-substitute devices, subjects still are carrying a camera and
are tethered to a computer that turns the images into electrical impulses,
Bach-y-Rita says. But he envisions a system not too far in the future where a
camera and computer are mounted in specialized glasses, and FM signals are
transmitted wirelessly to the retainer's stimulators. 

He predicts that if funding sources come through, schools could be training
blind children in visual spatial concepts with the devices in two years, and
the general blind population could be using them in five years. However, it
may be a few more years before blind people will be able to heavily rely on
the devices as a substitute for everyday vision. 

"When you walk down a street, you're getting all sorts of visual clutter,"
Bach-y-Rita says. "It's a huge amount of information that you have to deal
with. We're not comfortable in doing that yet, although we think it's doable."  

