How does this system work? Well, a tiny magnet as small as the size of a grain of rice, can be attached to the participant’s tongue with tissue adhesive. Any movement of this magnetic tracer can be detected by a bunch of magnetic field sensors mounted on wireless headphones worn by the subject. These sensor output signals were then wirelessly transmitted to a portable computer that surprise, surprise, was placed on the wheelchair at all times. After processing the signals to determine the relative motion of the magnet with respect to the array of sensors in real-time, it will be translated to movement of the wheelchair, making it an ideal substitute for a joystick function.
The tongue was used to operate the system since it is directly connected to the brain via a cranial nerve which more or less escapes damage even in severe spinal cord injuries or neuromuscular diseases, unlike our hands and feet that are normally the first to go. Patients need to train the computer beforehand so that they can get used to the movement regiment, but thankfully the learning curve isn’t steep in any way.
Source: Medgadget