Thermodynamic Assessment of Multiple Physiological Stress Responses Using Maxwell Relations

The present study introduces a macroscopic thermodynamic methodology to quantify entropy change in a human physiological system using Maxwell relations. This approach combines three physiological measures (mean arterial pressure, heart rate, and finger skin temperature) to provide a measure of entropy change (ΔS). The experimental data was collected from a study that included eighty-two subjects (49 males and 33 females). The three physiological measures were taken under three conditions (relaxation, stressor task, and recovery) during the physiological test profile. The entropy change (ΔS) is computed using Maxwell relations in terms of measurable mean arterial pressure, heart rate, and skin temperature. The average values of the physiological responses (n=49 males and n=33 females) are used in the modified Maxwell relations to compute the entropy change from relaxed state to stressor and recovery states for male and female subjects respectively. The results demonstrate that stressor task and recovery do have an impact on human physiology, which is indicated in entropy change values. The entropy change characterizes the human body from a thermodynamics viewpoint and could be valuable for the study of human physiology.