Methods of collection of biological information for fatigue evaluation during visual display terminals (VDTs) operation

A method for the analysis of fatigue parameters has been rarely researched in VDT operation. Up to now, fatigue was evaluated by changing of biological information. If signals regarding fatigue are detected, fatigue can be measured. The purpose of this study was an experiment and analysis method to extract parameters related to fatigue from the biological information during VDT operation using Independent Component Analysis (ICA). The experiment had 11 subjects, and examined light-load and heavyload VDT operation. Measurement items were amount of work, number of mistakes, subjective symptoms, surface skin temperature (forehead and apex nasi), heart rate, skin blood flow of forearm, and respiratory rate. In the heavyload operation group, number of mistakes and subjective symptom score were increased. Two-factor ANOVA was used for analysis. The result of number of mistakes was confirmed for the heavy load. After the moving averages of waveform were calculated, we extracted independent components by using ICA. The results of ICA suggest that the independent components increase according to accumulation of fatigue. Thus, the independent components would be a possible parameter of fatigue. However, further experiments should continue in order to obtain conclusive findings of our research.