Innovative PCG technique for Cardiac Spectral Analysis

Abstract

Normally the ratio of population versus physician is so feeble in most of the economically under- developed and developing countries that cause delayed diagnosis and non-availability of on-time treatment of heart patients specifically in the rural areas. It forces to think about availability of a low cost equipment in the rural health centres which may readily diagnose and alarm the critical cardiac condition of patient in absence of cardiologist too, so that the patient can immediately be carried to nearby urban health centre for early treatment. This paper presents an effective and handy PCG device which is equally useful for urban health centres to assist the cardiologist in making faster decision and control of the ailment, which is vital and critical subject in treating such patients. The equipment developed is low cost, quiet affordable by anyone or the rural health centres, portable and easy to maneuver by anyone who possess even a little knowledge to handle it and read the analysis. It does not require any specialized medical person to use the equipment. The diagnosis is carried through computer- based inference system which counts for reliability and accuracy of the diagnosis. Keywords - Phonocardiograph, PCG device, Human Heart, Osculation, Spectral Analysis, I. Introduction With the advent of the stethoscope in the year 1816, the technique of heart auscultation entered the domain of modern medical analysis. Prior to the modern practice, a remarkable number of fresh medical practicener fail to diagnose heart sounds by just listening to it due to the restriction of the human ear to detect low frequency heart sounds, and therefore the proper diagnosis of the heart was not possible. This paved the way for Phonocardiogram equipment, where study of the heart sound waveform enabled professionals to determine the nature of heart disease. The Phonocardiogram (PCG) device is quite a well-known device, which is used to listen to the heart sounds of a human being and the output from the machine is compared with the ideal heart sounds of a human being of that age and the deviation from the ideal response is then analyzed to detect the nature of ailment. The PCG devices in use today are very expensive and usually detect three peaks of the heart sounds. While the PCG device described here is such that observation and analysis of the waveforms can be done with ease. Any trained personnel, which always may not be the doctor himself, can operate this device and analyze its waveforms. This device is extremely cost effective; doctors can use it in their clinics too. Along with a cost effective alternative to the expensive options, it is sufficiently sensitive also to catch even a minute change in the heart sound. It uses computer to display and analyze the waveform which is nowadays easily available everywhere. II. The Human Heart The heart is a muscular organ responsible for pumping blood through the blood vessels by repeated, rhythmic contractions. The heart is composed of the cardiac muscle, an involuntary muscle tissue which is found only within this organ. The cardiac valves maintain unidirectional flow of blood by opening and closing, depending on the difference in pressure on each side. There are four valves of the heart (not counting the valve of the coronary sinus and valve of the inferior vena cava). The two atrioventricular (AV) valves ensure that blood flows from the atria to the ventricles, and not the other way. The two semilunar (SL) valves are present in the arteries leaving the heart, and they prevent the blood flowing back from the arteries into the ventricles. The sound of heart valves shutting causes the heart sounds. Heart's sounds are generated within the heart during cardiac cycle. The main cause of these sounds is acceleration and deceleration of blood flow, and closing and opening of the heart valves. Normally there are two heart sounds, and any additional sounds indicate diseased condition of cardiac. If a third heart sound is present it could be a sign of cardiac failure whereas a murmur indicates defective valves or an orifice in the septal wall. There are four sounds produced in the heart, namely: