Non-contact Sensing for VDT Worker State Assessment （Part 2）

Evaluation of Accuracy in Gaze Estimation and Blink Analysis

Abstract

Technology to assess the state of VDT （Visual Display Terminal） workers is useful for improving work efficiency and health management. We developed a measurement method using an RGB camera, which imposes no burden on the user, with the aim of utilizing physiological responses that can capture the worker’s condition and unconscious reactions. While the first report focused on autonomic nervous system measures, this report centers on blinks and gaze estimation, which serve as indicators of concentration and cognitive load. As in the first report, data from 13 healthy adult males for 8 min of VDT work were included in the analysis. Facial feature points were extracted from facial video data using image processing, enabling the estimation of blink waveforms and gaze positions on the display. Blink detection evaluated using electrooculogram as the reference achieved better results than existing studies. For gaze estimation, waveforms showing the point and direction of gaze point were obtained, however the target accuracy for gazing region estimation was not achieved. The proposed method’s advantages include real-time processing using only a CPU without requiring specialized hardware and the ability to estimate blink waveforms from low-resolution videos. These results indicate that this method has high practicality for on-site use.