Electrocardiograph Acquisition System And Mental Stress Identification Algorithm

Chronic psychological stress is a threat to the health of human body. Effectivepsychological stress evaluation system can help prevent the spread of chronicpsychological stress by identifying the state of psychological stress. ECG signals containrich emotional information. In this article a circuit is designed used for12-lead ECGsignal acquisition, and a stress evaluation system is built based on multiple physiologicalparameters as ECG, EMG and PPG.First of all, an ECG signal acquisition and processing circuit is designed based on thecharacteristics of ECG signal. The ECG signal acquisition system includes four modulesas signal amplification part, signal filtering part, A/D conversion part and serialcommunication part. The circuit can collect ECG of the body surface on chest and limbs,amplify the ECG signal for two-stage, and then filter and A/D convert the ECG signalbased on MSP430, and finally transfer the signal into computer via the serial port forsubsequent processing by algorithms.And then, according to the principle of stress-induced theory, a psychologicalstress-induced program is designed to stimulate the target person, while the ECG signalsare collected by ECG signal acquisition system designed in this article and SEMG signaland finger PPG signal are collected by the American multi-channel physiology recordernamed MP150. There are9target persons in this study, and36groups of ECG signal,18groups of SEMG signal and18groups of PPG signal are collected as the data source toidentify psychological stress state; among these signals,18groups of ECG signal,9groups of SEMG signal and9groups of PPG signal are collected in resting state ascontrast data.Finally, a method with the fusion of multiple physiological parameters decision forpsychological stress identification is built based on D-S evidence theory. The ECG signal,SEMG signal and finger PPG signal are processed for feature extraction and primarypsychological stress recognition. And then, the signals are fused by the fusion method inthis article to evaluate stress statement. The highest trust value after fusion is0.9987 which is0.1320higher than the highest trust value of single parameter:0.8667. Theevaluation result shows the validity of the ECG signal acquisition and the superiority ofthe fusion method which is based on multiple physiological parameters for stressevaluation.