Method for assessment of mental stress during high-tension and monotonous tasks using heart rate, respiration and blood pressure

Abstract

The present paper concerns the method for the assessment of mental work stress using autonomic responses such as heart rate, heart rate variability, respiration and blood pressure. Two types of mental work stress, that is, high-tension stress and monotonous one were investigated. To simulate the high-tension work stress, tracking task was used intriducing two kinds of instructions which induce more stress. The indices obtained from electrocardiogram, blood pressure and respiration were investigated and most of them except blood pressure showed task dependent changes which can be explained by sympathetic activation and parasympathetic withdrawal, while only HR showed the effect of the instructions. The same tracking task was used but repeatedly to simulate monotonous work, that is, a sequence of eight tracking task trials. At the beginning of the sequence most indices showed task dependent changes which are similar to those in the high-tension experiment. As the trials were repeated, blood pressure went up, the irregularity of the respiration enlarged, and the Mayer wave related Heart rate variability increased, which may reflect irritation, boredom, and disgust.