The novel system allows individuals with disabilities to operate a computer, control a powered wheelchair and interact with their environments simply by moving their tongues.
“This device could revolutionize the field of assistive technologies by helping individuals with severe disabilities, such as those with high-level spinal cord injuries, return to rich, active, independent and productive lives,” said Maysam Ghovanloo, an assistant professor in the Georgia Tech School of Electrical and Computer Engineering. Ghovanloo developed the system with graduate student Xueliang Huo.
- Watch a video of Ghovanloo describing the Tongue Drive system and its applications
here.
- Watch a video of Huo operating a powered wheelchair with the Tongue Drive system
here.
The tongue-operated assistive technology, called the Tongue Drive system, was described on June 29 at the 2008 Rehabilitation Engineering and Assistive Technology Society of North America (RESNA) Annual Conference in Washington, D.C. An article about this system is also scheduled to appear in an upcoming issue of the Journal of Rehabilitation Research and Development. This research was funded by the National Science Foundation and the Christopher and Dana Reeve Foundation.
To operate the Tongue Drive system, potential users only need to be able to move their tongues. Attaching a small magnet, the size of a grain of rice, to an individual’s tongue by implantation, piercing or tissue adhesive allows tongue motion to direct the movement of a cursor across a computer screen or a powered wheelchair around a room.
“We chose the tongue to operate the system because unlike hands and feet, which are controlled by the brain through the spinal cord, the tongue is directly connected to the brain by a cranial nerve that generally escapes damage in severe spinal cord injuries or neuromuscular diseases,” said Ghovanloo, who started working on this project about three years ago at North Carolina State University. “Tongue movements are also fast, accurate and do not require much thinking, concentration or effort.”
Movement of the magnetic tracer attached to the tongue is detected by an array of magnetic field sensors mounted on a headset outside the mouth or on an orthodontic brace inside the mouth. The sensor output signals are wirelessly transmitted to a portable computer, which can be carried on the user’s clothing or wheelchair.
The sensor output signals are processed to determine the relative motion of the magnet with respect to the array of sensors in real-time. This information is then used to control the movements of a cursor on the computer screen or to substitute for the joystick function in a powered wheelchair.
The system can potentially capture a large number of tongue movements, each of which can represent a different user command. A unique set of specific tongue movements can be tailored for each individual based on the user’s abilities, oral anatomy, personal preferences and lifestyle.
“An individual could potentially train our system to recognize touching each tooth as a different command,” explained Ghovanloo. “The ability to train our system with as many commands as an individual can comfortably remember is a significant advantage over the common sip-n-puff device that acts as a simple switch controlled by sucking or blowing through a straw.”
The Tongue Drive system is also non-invasive and does not require brain surgery like some of the brain-computer interface technologies.
Ghovanloo’s group recently completed trials in which six able-bodied individuals tested the Tongue Drive system. Each participant defined six tongue commands that would substitute for computer mouse tasks – left, right, up and down pointer movements and single- and double-click. For each trial, the individual began by training the system. During the five-minute training session, the individual repeated each of the six designated tongue movements 10 times.
During the testing session, the user moved his or her tongue to one of the predefined command positions and the mouse pointer started moving in the selected direction. To move the cursor faster, users could hold their tongue in the position of the issued command to gradually accelerate the pointer until it reached a maximum velocity.
Results of the computer access test by novice users with the current Tongue Drive prototype showed a response time of less than one second with almost 100 percent accuracy for the six individual commands. This is equivalent to an information transfer rate of approximately 150 bits per minute, which is much faster than the bandwidth of most brain-computer interfaces, according to Ghovanloo.
The researchers have also tested the ability of twelve able-bodied individuals to operate an electric-powered wheelchair with the Tongue Drive system. The next step is to test and assess the usability and acceptability of the system by people with severe disabilities, said Ghovanloo. He is teaming with the Shepherd Center, an Atlanta-based catastrophic care hospital, and the Georgia Tech Center for Assistive Technology and Environmental Access, to conduct those trials.
The research team has also begun to develop software to connect the Tongue Drive system to a wide variety of readily available communication tools such as text generators, speech synthesizers and readers. In addition, the researchers plan to add control commands, such as switching the system into standby mode to permit the user to eat, sleep or engage in a conversation while extending battery life.
“We hope this technology will reduce the need of individuals with severe disabilities to receive continuous assistance from family members or caregivers, thus significantly reducing healthcare and assistance costs,” noted Ghovanloo. “This system may also make it easier for them to work and communicate with others, such as friends and family.”
Source: Georgia Institute of Technology
Related stories:
Accessory protein determines whether pheromones are detected
Pheromones are like the molecules you taste as you chomp on a greasy french fry: big and fatty. In research to be published in the October 17 advance online issue of
Nature, Rockefeller University researchers reveal an unanticipated role for a new CD36-like protein to help cells detect these invisible communication signals that drive a wide range of behaviors, from recognizing a sibling to courting a mate, a finding that may explain what pheromone communication, pathogen recognition and fat taste perception all have in common.
Birds, Bees, and Moths Drive Flower Evolution
Flowers evolve in a predictable fashion to match the mouthparts of pollinating birds and insects, rather than engaging in a gradual "arms race" between flower and pollinator, according to a new study by researchers at the University of California, Davis and the University of California, Santa Barbara. An article describing the study is published in the June 7 issue of the journal
Nature.
Why do we prefer some foods over others?
When your stomach grumbles at lunchtime, and it's your turn at the deli counter, what will it be? Wheat bread or rye bread? Turkey or pastrami? Mayonnaise or mustard? Hold the pickle!
Small device controls light, advances optical interconnects technology
An electrical engineer at the University of Texas at Austin has made a laser light blink while passing through a miniaturized silicon chip, a major step toward developing commercially viable optical interconnects for high performance computers and other devices.
Bad breath? Mouthrinses work, but some cause temporary staining
Over-the-counter mouthrinses really do put a stop to bad breath. The first systematic review on the effectiveness of mouthrinses shows that they play an important role in reducing levels of bacteria and chemicals that cause mouth odours. Pick which one you use though, because some can temporarily stain your tongue and teeth, warns this new review from
The Cochrane Library.
Calming your thoughts through mindfulness
Our worries. They're crescendoing like the finale of Beethoven's "Ninth": Bailouts, buyouts. Recession, depression.
See what I see -- machines with mental muscle
(PhysOrg.com) -- The way we use and interact with machines is undergoing a profound change as computers are programmed to learn from experience and see more how we see. European research into machine learning is pushing back the boundaries of computer capabilities.
Researchers attribute thinning of Greenland glacier to ocean warming preceded by atmospheric changes
The sudden thinning in 1997 of Jakobshavn Isbræ, one of Greenland's largest glaciers, was caused by subsurface ocean warming, according to research published in the journal
Nature Geoscience. The research team traces these oceanic shifts back to changes in the atmospheric circulation in the North Atlantic region.
