WASHINGTON - A new device that uses a tiny magnet can help disabled people steer a wheelchair or operate a computer using only the tip of the tongue, U.S. researchers reported on Monday.

The magnet, the size of a grain of rice, lets people direct the movement of a cursor across a computer screen or a powered wheelchair around a room.

It is easily implanted under the tongue, the team at the Georgia Institute of Technology said.

"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 Maysam Ghovanloo, an assistant professor who helped direct the work.

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

A headset with magnetic field sensors detects the magnetic tracer on the tongue and transmits wireless signals to a portable computer, which can be carried on the user's clothing or wheelchair.

"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," Ghovanloo said in a statement.

The team reported on their device to a meeting of the Rehabilitation Engineering and Assistive Technology Society of North America in Washington.

The researchers said the computer could be programmed to recognize a unique set of specific tongue movements for each user. "An individual could potentially train our system to recognize touching each tooth as a different command," Ghovanloo said.

The researchers tested the Tongue Drive system on 12 able-bodied volunteers and now plan to test it on people with severe disabilities, Ghovanloo said.