Evaluation of Mental Work Load in Vehicle Driving by Analysis of Heart Rate Variability

This paper discusses the mental work load index in vehicle driving and operation of various instruments by the use of the analysis method of heart rate variability. According to what has been reported previously, the heart rate (HR) and the respiratory sinus arrhythmia (RSA) is obtained by the FFT analysis of the R-R Interval. However, the calculation to obtain RSA by the FFT method has a drawback in that it is so complicated that it is impossible to detect dynamic mental variation. Therefore, we have devised a new method of calcurating RSA, which calculates the R-R variability (RRV) at each 3 beats. The method is referred to the RRV3 method. We succeeded to verify that this method enables simplified collection of RSA and real time measurement of mental work load in vehicle driving including dynamic variations.