Tongue controlled wheelchair

Maysam Ghovanloo, left, points to a small magnet attached to graduate student Xueliang Huo's tongue that allows him to operate a powered wheelchair and computer mouse. (Georgia Tech)

Tongue-controlled power wheelchairs could allow some people who are paralyzed to do tasks like using a phone and navigate obstacles more quickly, researchers say. 

In Wednesday's issue of the journal Science Translational Medicine, scientists in Atlanta and Chicago describe their initial tests of a wireless device that allows people paralyzed from the neck down to complete tasks by moving their magnet-pierced tongues.
 
The performances of people with spinal cord injuries were up to three times faster with the "tongue drive system" than with the traditional sip-and-puff device — a straw-like tube that patients inhale and exhale into to operate a powered wheelchair in four directions.  
 
The level of accuracy was the same, even though more than half the patients were already experienced with sip-and-puff technology, the researchers said.  
 
"That was a very exciting finding,"  study author Maysam Ghovanloo, a professor in the school of electrical and chemical engineering at the Georgia Institute of Technology, said in a release. "It attests to how quickly and accurately you can move your  tongue."   
 
The goal is to provide intuitive, efficient and accurate access to computers, smartphones and environment controls to adjust lights and temperature, for example, as well as to increase mobility.
 
The technology fits in a retainer along the roof of the mouth.  
 
Here's how it works:

  • Sensors track the movement of a tiny magnet on the tongue.  
  • Pointing the tongue in different directions changes the magnetic field around the mouth, which is picked up by four sensors on a headset.  
  • The information is sent wirelessly to an iPod, which then delivers the commands to the powered wheelchair or computer.

The researchers tested the technology in 23 able-bodied participants and 11 with tetraplegia. Within 30 minutes of  training, the researchers said all the subjects were able to do tasks like tapping on targets that randomly appeared on a screen, navigating a cursor through a maze on a computer screen, dialing a keypad and driving a powered wheelchair through an obstacle course. 

Jason DiSanto, 39,  was among the first patients with a spinal cord injury to try it. DiSanto was pleased with how intuitive it was.

"Somebody that's in a wheelchair already has a stigma," DiSanto said. "If there was something that could be developed to control my wheelchair and the environment around me, to make me more independent without having to have medical devices coming out of my mouth, it would be a huge benefit."

The participants' performances improved with practise.

Ten other patients signed up but dropped out for reasons such as dissatisfaction with the location of the piercing, scheduling and caregiver problems, unrelated medical issues or loss of interest.

This research was funded by the U.S. National Institute of  Biomedical Imaging and Bioengineering, and the U.S. National Science Foundation. Ghovanloo's company is negotiating a licence for the technology.

With files from The Associated Press