Influences Of Computer Work Under Time Pressure On The Autonomic Cardiovascular Neural Regulation Systems

Although computer work has greatly reduced the work load, prolonged work under time pressure in front of the visual display terminal (VDT) also results in negative influence on the cardiovascular system. Literatures have showed that long-term working under time pressure could lead to the disorder of autonomic neural regulation. Heart rate variability (HRV) analysis has been proved to be useful in studying the deficit in autonomic nervous system..In this study, we modified the existing experimental protocols to study the influences of graded time pressure on HRV in VDT work.. Spectral analysis by AR model showed that the spectral ratio between low frequency (LF) and high frequency (HF) bands, i.e. LF/HF, decreased during time pressure VDT work compared with that in baseline without pressure (P<0.05). While LF/HF significantly increased in the rest session after time pressure VDT task (p<0.05). Nevertheless, there was no significant statistical difference between the LF/HF under different pressures. DFA analysis result shows that different stages of HRV time series has long-term relevance, means the time series has long-term memory. In the stress sectionαindex dropped markedly compare to non-stress section, means that the long-range correlation of time sequence of weakened, and in the rest section haveαindex increased significantly. We also found that the smallest ofαindex was not appeared in the section of greatest time pressure, means it is not the greater the pressure is the lower ofαindex. But there were no significantly different between different stress sections.This study provides foundation for the future research on different stimulus, or different difficulty on heart rate variability during computer work under time pressure.