[Study on visual display terminal mental fatigue status based on physiological information].

A visual display terminal (VDT) mental fatigue task was designed to search for the objective indicator to diagnose and evaluate the VDT mental fatigue status. The signals of temperature and electrocardiograph (ECG) are collected from the subjects. The temperature, heart rate (HR) and heart rate variability (HRV) are extracted as the objective parameters after analyzing the temperature signals in time domain and the ECG signals in time domain and frequency domain. Compared with mental fatigue pre-experiment, the temperature increased significantly (P<0.001), and the RR-PNN50 increased obviously (P<0.05), while the S wavelet of ECG signals decreased obviously (P<0.05) after mental fatigue experiment. Compared with the end of mental fatigue experiment, the temperature increased, the changes of RR-PNN50 were not obvious, the S wavelet increased significantly (P<0.01), and the mental fatigue was somewhat remittance after natural recovery. The results showed that the objective indicator to evaluate the VDT mental fatigue status would be hopeful to be found out by analyzing the signals of temperature and ECG.