Quantifying Stress Using mDFA: Heartbeats Exhibit Stress/Fear/Anxiety in Animal Model and Humans
Stress has not been fully defined in terms of neuroscience. But, it might be possible to quantify it, like body temperature. The aim of this study was to develop a method to quantify stress, fear and anxiety that has not been accomplished. In the present study, we present a method to quantify them using the biomedical vital information, i.e., the timing of heartbeat. Here electrocardiograms of both animal models and humans were analyzed by modified detrended fluctuation analysis (mDFA), which calculates a scaling exponent (SI) from the heartbeat interval time series. The SI was able to numerically distinguish between normal and abnormal hearts. SI values varied with heart conditions, i.e., healthy basal or stressful conditions. This study suggests that mDFA has potential as a practical method for the construction of a device for health management.