Congenital Heart Disease Heart Sound Acquisition And Analysis System Design And Implementation And Analysis Of Systolic Murmur

About15million children with congenital heart disease were born in China annually and the disease incidence as high as0.7to1.1%. However, less than half of the patients can be treated. Relatively complete medical standards would be better to diagnosis and treat timely in developed areas, while many poverty-stricken areas have poor medical conditions so that doctor only can use the method of auscultation. Auscultation often results in a high rate of misdiagnosis for the inexperienced doctors. Which not only increase the burden of families greatly, but also the missed children can not receive treatment timely. The Phonocardiogram make up for the lack of auscultation which can help doctors reduce the rate of misdiagnosis to a great extent.The main.subject is based on the characteristics of the heart sounds and achieves the acquisition and analysis system in the LabVIEW platform. The system includes three modules:PCG and ECG acquisition and display synchronization, data analysis and the database of cases. Data acquisition module includes the auscultation area of mitral, pulmonary valve, aortic valve, aortic valve and tricuspid valve which are collected and recorded simultaneously. Data acquisition card USB6009is used to acquire PCG and ECG signals which amplifies from analog circuit and connect with PC by DAQ module in LabVIEW. Audio amplifier in the analog circuit is used to amplify PCG signal so that doctor can use the earphone auscultation directly. Reduce the noise by wavelet decomposition’before data analysis. The envelope extraction which is mainly for the signal positioning uses three methods:wavelet transform, normalized Shannon energy and Hilbert transform. Normalized Shannon energy is used to extract PCG envelop and wavelet transform is to ECG envelop derived by comparing and analysis. The method of PCG and ECG positioning which is for extracting systolic signal is according to the window in one cardiac cycle. In the end position the first and second heart sound and their start and end position by the duration of the first and second sound in general. EMD decomposition of the systolic signal is used to extract features of normal heart sound and ASD heart sounds. Analyzing and summary the features by10sets of normal signals and10ASD heart sounds and conclude which can provide a reference for the heart sound recognition. Fisher linear classifier method is applied to separate normal heart sounds and heart sounds with ASD.The free kit LabSQL is used to connect the SQL Server2005with Lab VIEW and achieve the database management. The functions of database login, exit, query, delete, modify and display cases records can be managed by Lab VIEW.Experimental results show that the system can be acquire clear PCG and ECG signal, the method of EMD can extract the features of the reference value and the ’systolic signal features can provide clinical evidence for the diagnosis of congenital heart disease.