Preliminary Study of Ambulatory Monitoring of Physiological Responses under Mental Stress in Daily Life Using a Digital Biosignal Memory Device

In this paper, we have tried to measure physiological responses under mental stress in some daily scenes with a portable digital biosignal memory device. The aim of this study is to search for the method to evaluate objectively the mental stress in daily life. Here we chose the heart rate and the respiratory rate as non-invasive measuring objects and have developed an ambulatory mental stress monitoring system. Daily life stress scenes used here was the graduation thesis presentation, an unexpected police checkup during a car driving and the getting on a roller coaster, and in addition the calculation experiment under the laboratory was done for the comparison with other previous results reported.As a result, the heart rate and the respiratory rate were getting higher, and the respiration was getting irregular under strong mental stress, that is, getting on a jet coaster, presenting a graduation thesis, and a police checkup while driving. Under weak stress, like the calculation in the laboratory and the car driving, the respiratory rate was getting higher and irregular, but the heart rate wasn't remarkably high. From these results, it was suggested that the heart rate, the respiratory rate, and the respiratory irregularity are effective to evaluate the mental stress in daily life.