Gaze tracker by electrooculography (EOG) on a head-band

Abstract

A compact gaze tracker was developed by processing electrooculogram (EOG) signals taken from electrodes secured to an elastic head band. We confirmed that eye position is perceived by an observer in normal social interaction within 5°. We developed the prototype named PANTOJO after its pantographic potential to move a prosthetic eye following the healthy eye movements. We also confirmed that the EOG correlates with gaze angle. PANTOJO was implemented with a 1Hz to 20Hz bandwith, 66dB amplification and digital signal processing to output the position of the eye to within 2°. After initial calibration PANTOJO acts as a state machine, detecting and classifying eye movements according to saccades. A 75% success rate was achieved to detect transitions from discretized eye positions in 5° multiples from +40° to -40°. With its transport delay of 100 ms, update rate of 46Hz and an accuracy of 2.5° PANTOJO may prove to be a versatile gaze tracker for multiple applications, including communication devices for the disabled (e.g. tetraparesis), gait research or driving analysis in real life.