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October 5, 2009

Tongue Driver


Steering a wheelchair with tongue movements could one day give quadriplegics a taste of independence.

For Jason DiSanto, a quadriplegic, a measure of freedom and independence may one day be on the tip of his tongue. He is about to test drive a unique headset that should allow him to steer his wheelchair with his tongue. The system is the brainchild of Maysam Ghovanloo, a researcher at the Georgia Institute of Technology.

"There is this strong connection between brain and tongue," says Ghovanloo. "So even people with high levels of spinal cord injury don't lose their movement of the tongue."

Jason's life changed in a split second in April 2009, when he dove into a swimming pool. "I hit my head on the bottom of the pool and broke my neck," he says. "So I have my shoulders, my head and neck, but everything below my shoulders is paralyzed."

A different life

Jason sits in his wheelchair in his Atlanta, Ga., apartment as his wife prepares lunch. (She prefers we do not release her name.) She asks Jason questions and follows his instructions as she sits down next to him to feed him the ham and cheese sandwich she prepared. He can't eat without her help. She offers him water that he sips through a straw. "It takes a little while to eat," he says.

It is hard to overstate how much Jason's life has changed since the accident. He talks about the psychological battle. "What have I done to my family? My parents are really kind of upbeat as much as they can be, but they're really devastated. My wife is really upset, we try to remain upbeat as much as possible, but it's not always the case."

And, there is the stark reality of his physical limitations. During our interview, he stopped short. "Sorry, I'm having a spasm here." He showed us how, throughout the day, he has to make sure to shift positions, mechanically tilting back in his wheelchair, to keep blood flowing to his legs. "My wife takes really good care of me--feeding me, brushing my hair, brushing my teeth, turning on the TV, changing channels. I can't do much because I have no use of my hands."

Taking a test drive

For the past four years, Ghovanloo has been working with his team at Georgia Tech to improve life for quadriplegics like Jason. With support from the National Science Foundation (NSF), they have devised a headset that responds to a magnet. Using a laptop, a wireless connection and navigation software, the headset is programmed to allow Jason to steer a wheelchair by moving his tongue.

"The tongue has so many degrees of freedom that you can touch every single tooth in your mouth with the tip of the tongue," says Ghovanloo. He is testing out the latest tongue drive prototype and Jason has volunteered to be a test driver.

A course is laid out at the Shepherd Center in Atlanta, where Jason receives treatment. Using a dental adhesive, a magnet the size of a "Tic Tac" mint is temporarily glued to Jason's tongue. Two sensors are attached to each side of a headset that Jason wears. The sensors will detect changes in the magnetic field as Jason moves his tongue inside his mouth.

Jason explains the tongue movements he'll make to turn the wheelchair: "Well, for the left turn, I move my tongue to the left-hand side, and then the same for the right. And then forward and back is on the top of my mouth, I can use my cheeks as commands, and then, there might be some more commands coming where I can do a bit more."

The sensors send the information to a laptop or maybe someday, a smart phone, that transmits the information to the device--in this case, the wheelchair.

Ghovanloo says that's just the beginning of what this headset can control. "You could control the TV. You could access a computer. You could drive your wheelchair. You name it. Anything that can be connected or controlled by a computer can then be controlled by the tongue drive system."

During the test drive, Jason rolls off course a few of times as he gets used to the wheelchair's response to his tongue movements. By the end of the half-hour test drive, he is keeping on course and moving with a slow, steady confidence. Jason is pleased. "I thought it was quite easy to move around and control the chair."

Gaining control

Jason says the test system is easier than the sip-and-puff method he uses now to operate his current wheelchair. Since the tongue driver could help him control any number of devices like the TV or his computer, it could one day mean even more of the most precious commodity of all: independence.

Jason can easily shut off the tongue driver with his tongue when he wants to talk. He can appreciate the device on a professional level as well. He is an electrical engineer.

A commercial version is still years away, but Jason can see and touch the future and, for him, it tastes like freedom.

Eventually researchers hope to shrink the device into an "out-of-sight" mouth piece with the tiny magnet pierced on the tongue.

"It wouldn't stand out as much," says Jason. "Sometimes it's a little hard being in a wheelchair, you know, being out in public. People don't know how to approach you. So I think the less awkward I look, the better and easier people would be to approach me."

Miles O'Brien, Science Nation Correspondent
Ann Kellan, Science Nation Producer


Any opinions, findings, conclusions or recommendations presented in this material are only those of the presenter grantee/researcher, author, or agency employee; and do not necessarily reflect the views of the National Science Foundation.