Design and characterization of an EOG signal acquisition system based on the programming of saccadic movement routines.

It is estimated that by 2030 the number of people with disabilities will rise, thereby increasing the demand for assistive devices. Eye tracking has served as an alternative for the development of assistive technologies. Electrooculography (EOG) is an eye tracking technique used to measure the eye’s electrical activity. In this work, an AC-coupled EOG acquisition system composed of an instrumentation amplifier, low-pass, high-pass, and notch filters was designed. A graphical user interface (GUI) with programmed routines was made in order to characterize the system by the performance of saccadic eye movements. The peaks of the EOG signals in the horizontal and vertical directions at different viewing angles were analyzed to establish a relation between peak magnitude and gaze angle. Due to eye blinking, amplifier saturation, and subject fatigue, the vertical EOG was discarded for system characterization. A linear relationship was obtained between the horizontal EOG magnitude and the horizontal gaze angles in a range from 9.4° to 39.7°, with a coefficient of determination of 0.9991. The proposed EOG system is linear in the horizontal direction; however, DC coupling of the system is sought in a future stage to improve the characterization of eye movements.