Design And Implementation Of Low-cost Electronic Heart Sound Acquisition And Analysis System

Heart sound is one of the important human physiological signals, pathological phenomenon exhibited by heart or cardiovascular disease will be reflected in heart sound signal relatively early, such as the appearance of waveform distortion as well as heart murmur, therefore, heart sound analysis can earlier find signs of heart disease. Simultaneously, analysis of heart sound signals can understand the health condition of the heart, assess cardiac functional status, assist doctors diagnose heart disease, which has important clinical value. With the worldwide increase in cardiovascular disease, the analysis of heart sound signals can improve people’s health to a certain extent, and has some economic significance.With the growth in life expectancy about China and the world and the surge in the number of aging population, as well as the people’s aspirations to improve the health level, the role of home health care is increasingly prominent. Home health care system can collect temperature, pulse, respiration, blood pressure, blood oxygen, heart and lung sounds and other physiological signals of the human body, the changes of vital signs can reflect that if the body is ill and whether the patient’s condition improves or deteriorates. While, with the advancement of technology, as a component of home health care system, various physiological signal acquisition instrument evolves towards miniaturization, low power consumption, convenient direction. These needs can be well solved by mobile medical. Mobile medical mainly refers to the use of smartphone to collect user’s physiological data anytime and anywhere, and then through the transmission and processing of doctors end, let it convenient for doctors to communicate with patients about disease.Based on family care and mobile health concept, we design and implement low-cost electronic heart sound acquisition and analysis system. The system has two heart sounds collection methods. The first one is through an external MIC port, we sent heart sound signals to the PCs. Signals obtained can be played to facilitate direct auscultation. Using heart sounds obtained by MIC port, we implement system performance evaluation. Through subjective evaluation and objective evaluation methods, we found that the system has good performance in the case of a low cost. The second one is transmitting data via Bluetooth to the intelligent terminal (mobile phone). Heart sounds acquisition and analysis program runs on the intelligent terminal end, can draw PCGs in real-time, after initial analysis it can provide heart rate to users as well as determine whether the heart rate is normal. Then the user can transmit heart sound data through the intelligent terminal to the doctor side, which runs on computer. After signal preprocessing, we utilize S transform time-frequency analysis method to extract heart sound feature, and finally uses support vector machine (SVM) method to classify heart sound signal pattern in order to assist diagnosis.