Indian Journal of Science and Technology

Abstract

SeveralPhysicallyChallenged people arenot able tohandle thehome applications oftheir own.Itwillbe easy for suchpeople to handle those things without using their hands, if directional discrimination of the movements of the eye is achieved. It is important to increase the standard of life of handicapped people by establishing an secondary channel without speaking and moving hands. The theory of bio potential and electrodes is explained, to know how the the signals are collected from the human body and how the electrodes are implanted in specific points near the eye. An electro-oculogram (EOG) bio potential amplifier is constructed to obtain the signals due to eye movements. These signals control the mouse pointer in computers. The selection of bio potential over other possible methods was made based on the ease of usage and the cost effective production. The EOG bio potential amplifier is capable of detecting low frequency ranges from 0.010-10.0Hz, the range at which most of ocular movements operates. Similar to the EOG based system, the Electromyography (EMG) based system is also a bio potential amplifier. During the muscle contraction in the jaw, the frequency detection range is from 80-4500Hz, at which action potential are fired during. As the range of EOG signals is in µv while the EEG signals are in the mv range, it is challenging to obtain a strong usable signals. Therefore, sufficient gain is necessary to analyze the signals. Systems based on EOG are more efficient than systems based on EEG, due to its easy acquisition, higher amplitude and easily classified.
Keywords: Bio-Potential, Elecro-Oculogram (EOG), Eye Movement Detection, Human Computer Interface