The geometric approach to human stress based on stress-related surrogate measures

• Published in: PloS one Vol. 16; no. 1; p. e0219414
• Main Authors: Kloucek, Petr, von Gunten, Armin
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 25.01.2021; Public Library of Science (PLoS)
• Subjects: Algorithms; Analysis; Biological markers; Biology and Life Sciences; Complexity; Computer and Information Sciences; Entropy; Exercise; Health aspects; Heart rate; Heart Rate - physiology; Human subjects; Humans; Hyperplanes; Medicine and Health Sciences; Optical reflection; Oxygen - blood; Oxygen saturation; Physical Sciences; Physiology; Psychological stress; Research and Analysis Methods; Risk factors; Social Sciences; Stress; Stress (Physiology); Stress (Psychology); Stress, Physiological - physiology; Switzerland
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0219414

We present a predictive Geometric Stress Index (pGSI) and its relation to behavioural Entropy ( b E ). b E is a measure of the complexity of an organism’s reactivity to stressors yielding patterns based on different behavioural and physiological variables selected as Surrogate Markers of Stress (SMS). We present a relationship between pGSI and b E in terms of a power law model. This nonlinear relationship describes congruences in complexity derived from analyses of observable and measurable SMS based patterns interpreted as stress. The adjective geometric refers to subdivision(s) of the domain derived from two SMS (heart rate variability and steps frequency) with respect to a positive/negative binary perceptron based on a third SMS (blood oxygenation). The presented power law allows for both quantitative and qualitative evaluations of the consequences of stress measured by pGSI. In particular, we show that elevated stress levels in terms of pGSI leads to a decrease of the b E of the blood oxygenation, measured by peripheral blood oxygenation S p O 2 as a model of SMS.