Science

New tech allows quadriplegics to discreetly control wheelchairs using their tongues

New tech allows quadriplegics to discreetly control wheelchairs using their tongues
Georgia Institute of Technology's new intraoral Tongue Drive system
Georgia Institute of Technology's new intraoral Tongue Drive system
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Georgia Institute of Technology's new intraoral Tongue Drive system
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Georgia Institute of Technology's new intraoral Tongue Drive system
Components of the TDS
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Components of the TDS
The TDS iPhone/wheelchair interface
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The TDS iPhone/wheelchair interface
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For those unfortunate enough to suffer from severe spinal cord injuries, the tongue is often the only extremity still under their control. To take advantage of this fact, engineers at the Georgia Institute of Technology (GIT) have developed what they call the Tongue Drive System (TDS), a wireless, wearable device that allows the user to operate computers and control electric wheelchairs with movements of the tongue. The latest iteration, which resembles a sensor-studded dental retainer, is controlled by a tongue-mounted magnet and promises its users a welcome new level of autonomy with both communication and transportation.

Previous versions of the TDS featured an externally-worn headset that tracked movements of the tongue-mounted magnet. Unfortunately, any shift of the headset meant the whole system had to be recalibrated. Maysam Ghovanloo, an associate professor of electrical and computer engineering at GIT explains how they leaped that hurdle - "By moving the sensors inside the mouth, we have created a Tongue Drive System with increased mechanical stability and comfort that is nearly unnoticeable."

"Because the dental appliance is worn inside the mouth and molded from dental impressions to fit tightly around an individual's teeth with clasps, it is protected from these types of disturbances," Ghovanloo added.

The new TDS configuration sports magnetic field sensors on each of its four corners which detect movements in the tongue-mounted magnet. Output from the sensors is then wirelessly beamed to special app-equipped iPods or iPhones which decipher the user's intended commands in real-time by ascertaining the tongue magnet's position relative to the other sensors. That data can then drive a computer's cursor or double for the joystick control of an electric wheelchair. A tiny rechargeable lithium-ion cell powers the entire unit, which is covered with water-resistant insulation and vacuum molded into a custom-made dental-acrylic appliance.

The TDS iPhone/wheelchair interface
The TDS iPhone/wheelchair interface

Over the past several months, the GIT team recruited several initial test subjects with appreciable spinal cord damage to try out the headset TDS configuration. Presumably, the biggest hurdle for the participants was the mandatory clinical tongue piercing each received to affix the magnet-topped stud, but in spite of the need for occasional unit calibration, the concept proved sound.

"During the trials, users have been able to learn to use the system, move the computer cursor quicker and with more accuracy, and maneuver through the obstacle course faster and with fewer collisions," said Ghovanloo. "We expect even better results in the future when trial participants begin to use the intraoral Tongue Drive System on a daily basis."

Source: Georgia Institute of Technology

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7 comments
7 comments
Grunchy
I don\'t understand the need for the magnet. For instance I can use a laptop trackpad with my fingertip without need of a magnet or implant of any kind, why can\'t they get the same performance inside the mouth? Believe it or not I just tried my trackpad using my tongue and it works perfectly.
AdrianV
Ok, but that means they can\'t talk and drive at the same time? And, using a magnet, they can\'t move their tongues around to pick at something between their teeth without doing the wheelchair fandango?
Ryan Gyurkovitz
Grunchy, I really hope you washed your trackpad first!
flying Spaghetti monster
That concept is amazing.
Diann Stutzman
@Grunchy, because your tongue is in constant contact with the roof of your mouth. The magnet allows for intentional moves not accidental contact. What amazing possibilities!
Carlos Grados
Is this thing safe?
Abner Acevedo
Yes it is safe. I am from this research group. Although I personally did not created the iTDS I do work for this awesome research project.
@Grunchy the use if right now as a Asssistive Technology for Quadriplegics, people who cannot access technology through the use of their hand. In the long future you can think of it as a 3rd hand for the able-bodied if not. It is SAFE and yes you can talk. Right now it is a prototype and it is too big to talk that well, but you we are still shrinking the size so that it adopts the same size and shape of the dental retainer. There are other solutions that use other parts of your face, like the eyes. But none give you the degrees of freedom and capabilities that the tongue can give you, since is the one of the most sensory and motor muscles of our entire body. Yes the magnet along with the magnetic sensors are use for voluntary movements.
http://www.ece.gatech.edu/research/labs/gt-bionics/Research3.shtml