Development of Psychological Stress Detection System Using Bio Signals

Abstract

Psychological stress is an inevitable part of the modern-day lifestyle that affects human cognitive abilities. The relation between stress and a host of behavioural and somatic pathological conditions is well-established. The low doctor-to-patient ratio in under-developed and developing economies hinders access to expert diagnosis. This emphasizes the need for computer-aided timely detection of psychological stress. The methods like Electroencephalography (EEG) and Electrocardiography (ECG) provide important biophysical diagnostic measures for psychological stress detection, however, these methods are expensive or require a proper clinical setup. Whereas, the acoustic heart sound or Phonocardiography (PCG) signals carry significant information and can be easily acquired. The purpose of this research work is to present a novel framework for psychological stress detection using PCG signal that can serve as a first-level screening method at places where EEG or ECG are not available. In this research work, the pre-competitive (or exam-related) psychological stress is used a as real-life stressor. For this study, the simultaneous ECG and PCG data of five minutes duration is acquired from 33 healthy male students in the age group of 18 to 25 years (mean = 20.11, standard deviation = 2.30) of Thapar Institute of Engineering and Technology, TIET campus who are attempting professional education institute examination. Two readings are acquired from every subject, one approximately two hours before the start of the exam and considered as the signals of subjects under psychological stress, whereas, second reading forms the baseline values for subject-specific template formation and recorded once the students returned from holidays after exams. In this study, the ECG signal is used as a reference signal for S1 peak detection of PCG signal and later for comparison of the results with that obtained from PCG-based method.