Stress Estimation Using Biological Signals: A Simple and Efficient Method

Stress is the physiological and psychological response of the body to external or internal pressures that the brain perceives as a threat, affecting both physical and mental performance. Low stress levels can enhance performance, but high stress levels can cause psychological and bodily harm. One effective method for estimating stress is mapping the features of biological signals to quantitative values for stress. In recent years, efforts have been made to continuously detect stress using biological signals and applying complex methods to estimate stress. This article introduces a simple and effective method for estimating stress. The existence of a monotonic increasing relationship between stress and biological signal features is an assumption of this study. Accordingly, EMG and ECG signals recorded under stressful conditions were preprocessed. Then, features were extracted and normalized from each time window. Subsequently, by calculating the ۲-norm of the features and applying a scaling factor based on the individual's relative heart rate, a continuous value termed estimated stress was obtained. The qualitative evaluation of the results with self-reported values and stress levels at different stages of the experiment confirms the effectiveness of this method. The simplicity, understandability, and low computational cost are characteristics of the proposed method. The proposed method can be implemented in low-cost gadgets and can transfer stress estimation from the laboratory to daily life.

کلیدواژه ها:

continuous stress ، electrocardiogram signal ، electromyogram signal ، ۲-norm