For the physically disabled person, the computer is a convenient tool to co
mmunicate with others, operate machines and improve the quality of life. in
this paper we propose a computer input device for people who have upper li
mb disabilities. A feature of our proposed device is that the operator can
move the computer cursor on the CRT monitor using head movement. The head m
ovement is detected by an image processing technique. In order to ensure th
e accurate image processing, the operator is required to wear glasses with
three LED marks. Data obtained by measuring the head movement are used as p
ositioning signals to the computer cursor on the CRT monitor. The blinking
action of the operator's eye corresponds to the pushing action of the switc
hes. Experimental results reveal the applicability of our system.