Development of Wireless Electronic Stethoscope System and Abnormal Cardiac Sound Analysis Method (Sound Characteristic Waveform Analysis)

Abstract

This paper is concerned with the development of a wireless electric stethoscope system and cardiac sound analytical method for cardiovascular disease diagnosis. This system consists of an electronic stethoscope, data acquiring amplifier/filter circuits, wireless transmitter and receiver modules, and a notebook computer. The cardiac sound acquired by the electronic stethoscope and can be easily transmitted to the computer by wireless transmitter and receiver modules. The input-output characteristics of the electronic stethoscope and wireless modules are investigated in detail. Furthermore, one-DOF analytical model based on the consideration of the eardrum property is proposed for abnormal cardiac sound analysis. With the analytical model the original heart sound signal can be converted to a simple characteristic waveform which fits the behaviors of some cardiovascular diseases. Some case studies using the characteristic waveforms show that the normal sound can be distinguished visually from the abnormal cases such as the mitral regurgitation, aortic incompetence, allorhythmic pulse and so on.