Abstract
This paper reports on a study of how one-switch computer operating aids we have developed might provide an alternative input method for the severely physical impaired. Because we have relied on changes in skin potentials triggered by character recognition to serve as the signal to activate the switch, the new input method does not require physical movement. In the skin potentials recorded from the right palms of four normal subjects during a letter matching task, sympathetic skin responses (SSR) were observed when the subjects recognized a target character. The mean appearance rate of SSR with character recognition was 63% in the four subjects. The use of changes in skin potentials such as SSR to trigger the one-switch system has a number of advantages, such as not requiring extensive training, in comparison to Brain Computer Interface by means of electroencephalogram (EEG) signals. There are, however, still problems to solve, such as the low rate of occurrence of SSR, in making this technique fully practical.
