A new, updated version of a wireless medical device under development at Georgia Tech places sensors inside the mouths of quadriplegics--essentially working off a glorified tongue stud--enabling them to use a computer and move their wheelchairs around. The sensors are placed on a dental retainer, which sits against the roof of the mouth, and detect the movement of a small magnet attached to the users' tongues, the scientists explain. Those sensor signals are then transmitted wirelessly to an iPod or iPhone that includes software able to translate the tongue commands based on the magnet position. That data can then control a computer cursor or send a powered wheelchair in different directions. University engineers debuted their new version, dubbed the intraoral Tongue Drive System, at the IEEE International Solid-State Circuits Conference in San Francisco. Story