Development of a virtual instrument for data acquisition and analysis of the phonocardiogram

A medical virtual instrument has been developed to acquire and analyze the phonocardiogram (PCG), the heart sound and murmur signal. This instrument consists of a Pentium 200 computer running Windows95, equipped with LabVIEW software and a plug-in data acquisition board, and a two-channel custom designed bio-signal preamplifier. The bio-signal preamplifier allows the data acquisition board to acquire both the PCG and the electrocardiogram (ECG). LabVIEW software modules have been developed to create virtual instrument's front panels for the following functions: to manage patient information and data files, to capture and display current ECG and heart sound signals while saving or analyzing previous acquired signals, to perform the spectral and time-frequency analysis of the heart sounds and murmurs, and to review the previous recordings. This instrument can be used to display the PCG and to analyze the individual heart sound and murmur for the detection of heart valve diseases. It can also be used to analyze the carotid bruit for the diagnosis of carotid artery stenosis. This study demonstrated that a LabVIEW-based medical virtual instrument provides a low-cost, reliable, and flexible solution for data acquisition and analysis of the PCG and carotid bruit.