condition monitoring of heart using phonocardiogram and murmurs analysis

Abstract

newline Heart failure is the leading cause of mortality worldwide. Cardiac auscultation is one of the oldest diagnostic methods to explore the condition of the heart. Mechanical activities of heart initiated by biopotentials generated by the Sino-Atrium (SA) node of the heart causes non-stationery and non-deterministic signals commonly known as Heart Sound Signal (HSS) and the graphical representation of HSS is termed as Phonocardiogram (PCG) while recorded by an electronic stethoscope. PCG can provide most valuable diagnostic information for evaluating many cardiac abnormalities, including the valvular heart disease, the rate and rhythm, congestive heart failure, and anatomical defects of the heart. PCG normally consists of the two loudest heart sounds such as the first (S1) and second (S2) heart sounds. During the pathological and non-pathological conditions, the PCG signal may include the third heart sound (S3), the fourth heart sound (S4), murmurs, and other abnormal sounds such as clicks, snaps and rubs. newlineAnalysis of PCG thus becomes very effective in diagnosing the cardiovascular disorder, if any, in a non-invasive manner. The basic aim of the thesis is to develop an Automatic Computerized Auscultation (ACA) for effective and efficient status monitoring of the condition of the heart. ACA is a non-invasive, cost effective, fast and accurate method that may assist the physicians in early detection of cardiac illness truncating the death rate due to cardio vascular diseases by providing diagnostic and prognostic information. newlineThis thesis achieves the goal through four main phases: i) Design and Development of Digital stethoscope using electronic circuits, ii) Preprocessing of the PCG, iii) Classification of heart sounds and iv) Classification of heart Murmurs. newlineThe first phase of the work deals with the design and development of the hardware circuit to acquire the signals generated by the heart. Ordinary acoustical stethoscope is modified by incorporating a capacitive microphone followed by suitable electro