We are living in a world where technological advancements are so fast that with each passing day more concise, effective and user friendly equipment are introduced. The medical technology is advancing towards robust methods. Ordinary techniques and methods are become less executable after the introduction of sophisticated electronics in the field of medicine. Nowadays the growing population result in increasing heart patients, which raise demand for the cheap and efficient medical facilities. Traditionally, early diagnosis of heart diseases can be done by auscultation of heart but it has a limitation of human hearing and auscultation based diagnosis systems depends greatly on interpretation of physicians [1]. Thus, it requires the skilled cardiologists to diagnose heart sounds more accurately. Therefore, phonocardiography (PCG) has been developed to record the heart sound …show more content…
This closure of valves sets up vibrations in valves, in adjacent blood, in walls of heart and in major vessels around heart. Main components present in normal heart sound are: first prominent peak of heart sound (S1) and second peak present in heart sound (S2) that occur in sequence with each heartbeat. The first heart sound (S1) originates when mitral and tricuspid valve close and it occurs at beginning of systole. The second heart sound (S2) originates at end of systole by the closing of aortic and pulmonary valves. Besides these two normal sounds, some other sound components may be present in heart sound including thrill, gallop rhythms (S3, S4) and heart murmurs. The third heart sound (S3) is produced by vibration of blood backward and forward between walls of ventricles due to inrush of blood from atria and it may occur near mid of diastole. The fourth heart sound (S4) is produced by inrush of blood into ventricles and it occurs when atria contract, S4 is also called atrial