Individuals with severe disabilities could lead more independent lives with the help of an assistive technology developed by engineers at the Georgia Institute of Technology.

To operate the Tongue Drive system, potential users only need to be able to move their tongues.

Maysam Ghovanloo, an assistant professor at the Georgia Tech School of Electrical and Computer Engineering, who helped develop the device, explained: “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.

“Tongue movements are also fast, accurate and do not require much thinking, concentration or effort.”

Movement of the small magnetic tracer attached to the individual’s tongue, is detected by an array of magnetic field sensors mounted on a headset outside the mouth, or on an arthodontic 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 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.

Ghovanloo continued: “An individual could potentially train our system to recognise touching each tooth as a different command. 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 reseach team, which also includes graduate student Xueliang Huo, co-developer of the system, has 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.

Ghovanloo concluded: “This device could revolutionise the field of assistive technologies by helping individuals with severe disabilities, such as those with high-level spinal cord injuries, return to a rich, active, independent and productive lives.

“This system may also make it easier for these individuals to work and communicate with others such as friends and family.”