Tongue piercing allows tetraplegics to operate wheelchairs and computers

US researchers say they have developed a wireless device that operates specially rigged wheelchairs by means of a tiny titanium barbell pierced through the tongue.

By moving their tongues left or right across their mouths, paralysed patients have been able to move their motorised wheelchairs, as well as computer cursors. Tapping the tongue against a cheek controls the chair's speed.

The advance "is more than just a wheelchair control", said Jason Disanto, 39, who has been paralysed from the neck down since a 2009 diving accident. "It's an independence system."

The innovation is a boon to the most seriously paralysed. Tetraplegics cannot use a joystick to operate chairs, and in many cases they cannot even use voice commands as their voices are often so weak that even sensitive recognition systems work poorly or not at all.

Even more advanced assistive technologies fall short. Brain-computer interfaces have slow response times and are vulnerable to electronic interference.

The most popular technology for operating a motorised wheelchair, called the sip-and-puff device and based on inhaling or exhaling into a tube, offers only forward, back, left and right commands and is also slow and cumbersome.

About five years ago, engineer Maysam Ghovanloo of the Georgia Institute of Technology in Atlanta and some colleagues began developing the tongue-based system. An early version used magnets glued to the tongue, but they fell off.