Development of pointing device using DC-coupled electrooculogram

The purpose of this study is to support communication of individuals with motor paralysis having difficulty verbally communicating due to illnesses such as Guillain-Barre Syndrome or brain-stem infarction. We have developed and describe a pointing device controlled by DC-coupled electrooculograms (EOGs). The visual angle of the subject is estimated from the amplitude of vertical and horizontal EOGs for determining the two-dimensional pointing position on a PC screen in real time. The eye blinking artifact is reduced using a median filter. Electrode displacement is corrected by considering the potential gradient. Moreover, the position error caused by drift phenomenon is adjusted using head movement based on the vestibule-ocular reflex. The accuracy and operating speed of the proposed method were evaluated among a group of human subjects.