Abstract
We are developing a real-time monitoring system of a human condition in order to reduce worker's health and safety problems. In the last paper, we reported having succeeded in real-time calculation of the correlation dimension of ECG time series (not heart rate variability time series). Next, we select a largest Lyapunov exponent (LLE) as a new index of a human condition. In order to reduce a calculation cost, we investigate a minimum length of ECG time series required for reliable analysis. Analysis results of the LLE of ECG time series during a calculation task show that the reliable analysis is possible even from the very short time series such as 10-30 s.
