CAJ | 학술논문

为研究去除心音信号中的环境噪声、工频噪声和肌电噪声等多种噪声，获得最优的心音去噪方法。论文基于平稳小波变换选取db5小波对心音信号进行3尺度分解，对分解后的高频系数分别选择了硬阈值函数以及软阈值函数，并对固定阈值、Stein无偏似然估计阈值、启发式阈值、极大极小阈值以及Penalized阈值进行了对比分析。通过去噪衡量指标对心音信号不同阈值以及阈值函数的去噪效果对比分析，硬阈值的去噪效果要好于软阈值的去噪效果，去噪效果最好的是S tein无偏似然估计阈值，有效地去除了参杂在心音信号中的多种噪声。
위연구거제심음신호중적배경조성、공빈조성화기전조성등다충조성，획득최우적심음거조방법。논문기우평은소파변환선취db5소파대심음신호진행3척도분해，대분해후적고빈계수분별선택료경역치함수이급연역치함수，병대고정역치、Stein무편사연고계역치、계발식역치、겁대겁소역치이급Penalized역치진행료대비분석。통과거조형량지표대심음신호불동역치이급역치함수적거조효과대비분석，경역치적거조효과요호우연역치적거조효과，거조효과최호적시S tein무편사연고계역치，유효지거제료삼잡재심음신호중적다충조성。
To remove three kinds of noise in heart sound signal including environmental noise、powerline interference and electromyographical interference and obtain the optimal denoising method of heart sounds ,based on stationary wavelet transform ,heart sound signal is decomposed into three layers using db5 wavelet .Hard threshold function and soft threshold function are applied to high frequency coefficients respectively .Then ,the comparison and analysis of denoising effect are car‐ried by Sqtwolog , Rigrsure , Heursure , Minimaxi , Penalizd high , Penalizd medium and Penalizd low threshold . Hard threshold denoising effect is better than the soft threshold and the Rigrsur threshold method is the best in all the thresholds . Rigrsur threshold method based on stationary wavelet transform can achieve good denoising effect and effectively remove vari‐ety of noise of heart sound signal .