Representation of a physio-psychological index through constellation graphs

Abstract

Chaos theory was applied to analysis of the time series of plethysmograms under various human physio-psychological conditions. It found that the largest Lyapunov exponent could be used to characterize physio-psychological status. A visual representation method based on constellation graphs was developed to indexing temporal changes in the largest Lyapunov exponent. Changes of constellation angles were found to clearly characterizing variations of physio-psychological status in a series of experiments. © Springer-Verlag Berlin Heidelberg 2005.