Design of a novel wearable human computer interface based on electrooculograghy

People with severe motor disabilities are not able to move their limbs voluntarily and speech overtly, though the cognitive parts of their brain are intact. Human computer interfaces, as an assistive technology, provide a new channel of communication to help these people. In this study, a novel wearable miniaturized human computer interface system was designed and tested allowing these people to state their intentions and feelings just by using their eyes. The system that can be installed on glasses, records the electrooculogram signal and transfers the digitized data wirelessly to a laptop. By analyzing the signals, eight directions of eye movements consist of up, down, right, left and four diagonal directions, as well as the voluntary blinking were recognized and used in a high performance graphical user interface to type alphabetical letters and numbers, just by two moves and two selections. Two experiments were conducted to evaluate the performance of the developed system. Precision, sensitivity and accuracy of recognizing the user intention were obtained 95%, 98% and 93% respectively and the average rate of communication was 5.88 character per minute. This low-cost wearable device is light-weight with small size which assures high level of mobility and comfort. The users could learn to type with the system in a short time, and easily work with it without fatigue.