November 1, 2008 Electrical and computer engineers designed a system based on magnets that enables disabled persons to use the tongue to control the movement of a wheelchair. 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. The sensor output signals are wirelessly transmitted to a portable computer, which can be carried on the user's wheelchair. 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.
New assistive technology could be the key to more independence for thousands of people with disabilities. Soon, controlling their environment may be as easy as moving their tongue.
Two years ago an accident left Justin Cochran paralyzed from the neck down, but he doesn't let his wheelchair get in the way of much.
"I know what I want to do and how I want to live my life, and I'm not going to let something like a spinal cord injury stop that," said Cochran.
Cochran counts on sip-and-puff systems to help him control his environment; but soon, this tiny magnet could give him more possibilities. It allows people to control wheelchairs and countless other devices by moving their tongues.
"It lets them use their tongue motion and translate it to different commands," said Maysam Ghovanloo, Ph.D., assistant professor of electrical and computer engineering at the Georgia Institute of Technology in Atlanta, Ga.
Electrical and computer engineers at the Georgia Institute of Technology developed the system. Equipped with a magnetic sensor, the tongue acts like a joystick. A special headset tracks every move, whether the tongue moves from its resting position or it touches a certain tooth. In less than a second, each movement is translated into a command to control a wheelchair, a computer cursor or other device.
"Theoretically, there are an unlimited number of commands that the user can define in order to control their environment," Dr. Ghovanloo said.
The next step is letting people with disabilities test the system themselves. Cochran says he's ready to be the first. "Yeah, I can't wait to try it," Cochran said.
WHAT MAKES MATERIALS MAGNETIC? Magnetism is the result of the constant movement of charged electrons in atoms. As electrons swirl around an atom, they create an electrical current, and whenever electricity moves in a current, a magnetic field is created. So magnetism is a force between electric currents: two currents flowing in the same direction attract each other, while those pulling in opposite directions repel each other. The reason some materials are magnetic, while others are not, has to do with how the electrons are arranged. A magnet is an object made of magnetic materials; naturally occurring magnets are known as lodestones. Every magnet has at least one north pole and one south pole. In fact, if you take a bar magnet and break it into two pieces, each of the smaller pieces will still have a north and south pole. The Earth itself is a giant magnet with a north and south pole, which is why a magnetic compass's needle always points north/south.
ABOUT THE TONGUE: The tongue is a versatile group of muscles anchored in the mouth and throat. It is integral to creating articulate speech and other noises. Its top surface is covered by taste buds able to detect the bitter, salty, sour, sweet, and umami (or savory) qualities of food. The tongue, which acts both as a voluntary and involuntary muscle, filters germs and also moves food around within the mouth before transferring it to the esophagus.
The Human Factors and Ergonomics Society and the Institute of Electrical and Electronics Engineers, Inc. IEEE-USA, contributed to the information contained in the TV portion of this report.
Editor's Note: This article is not intended to provide medical advice, diagnosis or treatment.