基于心音的病理特性研究

发布时间：2018-03-02 07:01

本文关键词： 心音信号小波分析 HHT变换特征识别　出处：《燕山大学》2012年硕士论文　论文类型：学位论文

【摘要】：心音信号(PCG)是人体心脏及心血管系统机械运动状况的反映，它包含了体内心血管状态的大量信息，是临床上用于诊断和评估人体心血管系统功能及病理生理状态的重要依据。由于心音信号的复杂性，传统的声学听诊方法难以达到令人满意的效果。本课题研究的主要目的即在于通过利用现代工程和计算机技术，实现人体心音信号采集和分析。首先需要实现对心音信号的准确采集和记录，然后再利用相关算法对信号进行研究和分析，克服传统听诊方法易受医生主观判断影响的缺陷，提高心血管疾病的诊断和鉴别水平，实现心音听诊的形象化和心音的病理特性研究。本文先后在信号的采集、消噪、分段、特征提取及分类等领域进行了研究和探讨：首先，，在信号采集方面，本课题设计出了一套基于STM32的便携式心音信号采集系统，利用该系统采集患者的心音信号，实现心音数据的采集、放大、硬件滤波去噪、A/D转换、波形显示、信号存储、与上位机通信等功能。其次，在信号处理方面，课题在研究了一些传统信号去噪理论的基础上，采用了基于小波变换的阈值去噪算法，去除了信号中残留的杂质和干扰信号，得到了比较纯净的心音信号，这对于后续心音信号的特征值提取有十分非常重要的意义。最后，在心音病理特性研究方面，课题利用改进的HHT变换来提取心音包络，对心音包络信号进行分段识别，提取了心音信号的成分，实现了信号成分的定位，并结合心音信号的特征值和信号频谱、能量分布对心音信号的特性进行了研究。本课题通过研究构造一套完整的心音采集和分析系统，为心音信号的临床诊断提供了帮助。
[Abstract]:PCG is a reflection of the mechanical movement of the human heart and cardiovascular system. It contains a great deal of information about the state of the cardiovascular system in the body. It is an important basis for clinical diagnosis and evaluation of cardiovascular system function and pathophysiological state of human body. Due to the complexity of heart sound signal, the traditional acoustic auscultation method is difficult to achieve satisfactory results. The main purpose of this research is to realize the acquisition and analysis of human heart sound signal by using modern engineering and computer technology. First of all, it is necessary to realize the accurate acquisition and recording of heart sound signal. Then the related algorithms are used to study and analyze the signals to overcome the defects of traditional auscultation methods which are easily influenced by the subjective judgment of doctors and to improve the level of diagnosis and differentiation of cardiovascular diseases. To realize the visualization of cardiac sound auscultation and the study of pathological characteristics of heart sound. In this paper, the signal acquisition, de-noising, segmentation, feature extraction and classification have been studied and discussed. First of all, in the aspect of signal acquisition, a portable heart sound signal acquisition system based on STM32 is designed in this paper. The system is used to collect the heart sound signal of the patients, to realize the acquisition, amplification, and hardware filter denoising of the heart sound signal. Waveform display, signal storage, communication with host computer and other functions. Secondly, in the aspect of signal processing, based on the research of some traditional signal denoising theory, the threshold de-noising algorithm based on wavelet transform is adopted to remove the residual impurities and interference signals. The purer heart sound signal is obtained, which is very important to extract the eigenvalue of the subsequent heart sound signal. Finally, in the research of the pathological characteristics of heart sound, we use the improved HHT transform to extract the envelope of heart sound, recognize the envelope signal of heart sound in sections, extract the components of the signal of heart sound, and realize the localization of the component of the signal. The characteristic of the heart sound signal is studied by combining the characteristic value of the heart sound signal, the spectrum of the signal and the energy distribution. In this paper, a complete heart sound acquisition and analysis system is constructed, which can help the clinical diagnosis of heart sound signal.
【学位授予单位】：燕山大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：R318.0

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