Wheel chair that is tongue controlled

Disabled people were very happy when voice controlled wheel chair first made its presence in the market. All quadriplegics can move freely with the help of their voice. But voice systems do not always produce 100% output making the person to shout too much. Now, scientists are working on a new concept. A wheel chair that can be controlled by a tongue. A microphone connected to the ear detects the movements of the tongues and causes the movement. This still makes life very simple for all the disabled. What else they can expect???