Design Of Detection System Of Heart Sounds Based On Wavelet Analysis

Heart disease is always a threat to people’s lives and health, it is one of themajor diseases that cause human deaths. Heart sounds auscultation method has animportant role in the detection of heart disease, although the ECG, echocardiographyhas a larger development in the practical application of heart disease detected, butstill can not replace the heart sound auscultation. Traditional heart soundsstethoscope has many defects, which makes diagnosis of heart sounds ResearchMedical relatively slow, need a product in the family which heart sounds cancollected and analyze heart sound, and the data stored for further diagnosis of thedoctor.The hardware design of the system includes analog signal circuit design anddigital signal circuit design, the analog signal circuit design, including pre-amplification, filtering, notch, and power level conversion circuit, mainly tocomplete signal conditioning of heart sounds signal. Digital signal circuitSTM32F103as the control center, including the AD converter module, SD cardstorage circuit, LCD display circuit and USB communication circuit design. Bycomparing the common heart sounds signal processing methods, Describes thereason for the use of wavelet analysis in the heart sounds analysis. Wavelet analysisalgorithm uses Mallat algorithm, including the wavelet decomposition, the thresholdquantization, wavelet reconstruction process, to achieve a de-noising and extractionof heart sound signals. Finally, using MATLAB simulation software by comparingnormal and diseased heart sounds heart sounds, proved that the system caneffectively improve the recognition rate of heart sound signal.The design uses a wavelet analysis of heart sound signal de-noising andextraction, compared to the previous way of filtering only using the hardwaredetection system has great advantages, improving the recognition rate of the heartsound signal. This design also explored to achieve a lower cost to the patient heart sound signal detection, recording and analysis, has some practical significance.