Putting Motion Where Your Mouth Is

It lets us converse with others, sing along to the radio and play a flute. Without it, we couldn't taste that chocolate cake and lick our lips. But since when can a tongue open a door, operate a wheelchair or type?

That's exactly what Maysam Ghovanloo, Ph.D., has in mind, with something he calls the Tongue Drive system. The new assistive technology dreamed up by this electrical engineer and assistant professor at the Georgia Institute of Technology (Georgia Tech) in Atlanta promises to transform the lives of people with severe disabilities, even those with high-level spinal cord injuries.

With the Tongue Drive, a magnet the size of a grain of rice is attached to the tip of the tongue with tissue adhesive, or by implantation or piercing. The person also wears something like a phone headset, mounted with two extensions along both cheeks, or an orthodontic brace inside the mouth. Here, an array of magnetic field sensors detects specific tongue movements for an unlimited number of different commands, each tailored for the person's abilities, oral anatomy and personal preferences.

As the tongue (without much thought or effort) quickly and oh-so-accurately turns and stretches, curls and pokes, the sensor's signals are immediately transmitted, wirelessly, to a laptop computer that is programmed to perform a variety of functions — everything from moving a computer cursor to changing TV channels. The research team has also begun to develop software to connect the system to communication tools such as text generators, speech synthesizers and readers. The user can also switch the system to standby mode so he or she can eat, talk or sleep, for instance, without wasting battery power.

Ghovanloo and his graduate research assistant Xueliang Huo are working on eventually chucking the bulky laptop by connecting the Tongue Drive system to a smartphone (a mobile phone with PC-computer capabilities) or PDA (personal digital assistant) attached to the person's clothing or wheelchair. “Theoretically, it's also possible to assign a letter of the alphabet or certain command to each tooth, so just by touching your tongue to your teeth, you can type or do other things,” says Ghovanloo, who began the project three years ago.