Tongue motion-based operation of support system for paralyzed patients

This paper proposes a new control device based on tongue motions to control and communicate with a support system for a paralyzed patient. We focus on the tongue movements as one of output of human intentions, because the tongue has one of capable parts for the motions and it does not affected by spinal cord damage. The tongue motion is easily observed from his/her mouse inside, it is, however, hard to observe them from outside. We therefore propose a detection algorithm of the tongue motions by using multiple array electrodes attached on a skin surface around a neck. The tongue motions are detected based on the center position of distributions of muscle elctric potentials that are measured by the electrodes. We investigated the precisions of the detection algorithm through some experiments and then confirmed that almost accucracy of discrimination is more than 70 as for six tongue movements such as left, right, forward, back, up, and down. Additionally, we evaluated operability of the proposed algorithm quantitatively using Fitts' law based test bed GUI, and the performance of the proposed interface was compared with that of other available interfaces.