第一心音

为此，需要消除PCG信号中的噪声，并用分段算法定位第一心音。

To achieve this , noise in the PCG signal should be removed , and a segmentation method should be used to locate the first heart sound .

方法：受试者完成规定的运动量，把不同负荷下运动后第一心音（S1）幅值对安静时S1幅值增加的相应倍数定义为心力变化趋势（cardaccontractilitychangetrend，CCCT）。

Method The subjects accomplished the designed exercise workload and the increase of the amplitude of the first heart sound after accomplishing different exercise workloads , with respect to the amplitude of the first heart sound recorded at rest was defined as cardiac contractility change trend ( CCCT ) .

基于心音包络信号的第一心音S1、第二心音S2波峰提取和定位；

Thirdly , the peaks of S1 and S2 are picked up and detected based on the extracted envelope of heart sound signal ;

目的本文介绍一种在心音图（PCG）中定位第一心音（S1）和第二心音（S2）的算法。

Objective An algorithm located the first sound ( S 1 ) and the second sound ( S 2 ) on phonocardiogram ( PCG ) was introduced .

本文提出一种基于数学形态学的心音包络提取方法，并在提取出的心音包络信号中识别第一心音（S1）与第二心音（S2）。

This study put forward a heart sound envelope detection method based on the mathematical morphology . Then on the heart sound envelope , S1 and S2 were recognized .

本文采用经验模态分解（EMD）包络算法进行心音包络的提取，为第一心音和第二心音的定位以及时域特征的提取奠定了基础。

This paper uses the Empirical Mode Decomposition ( EMD ) envelope algorithm for the extraction of heart sound envelope . It lays a foundation for the positioning and time-domain characteristics extraction of the first and second heart sound . 3 .

心音信号的第一心音幅值提取算法的研究

A Study on the Amplitude Extraction Algorithm of the First Heart Sound

对第一心音信号的分析研究，在临床上对心脏疾病的诊断有重要意义。

Analysis of the first heart sound will be helpful to diagnose the clinic heart diseases .

说明这2例心脏病患者的第一心音正常，第二心音不正常。

This indicated that the S , of 2 patients was normal while the S2 was abnormal .

然后应用心脏生理特征参数和阈值方法对第一心音进行了定位。

Then , physiological parameters of heart feature and threshold method are used to locate the first heart sound .

记录运动前后心脏活动所产生的振动信号，测量第一心音幅值和6分钟步行试验中步行的距离。

The vibration signal from heart activity was recorded , and the walking distance during the 6 minute walk test was measured .

试验结果表明，在正常组和返流性心脏杂音组间，第一心音能量分数存在显著性差异。

The results showed that the first heart sound energy fraction were significantly different in the normal group and the heart murmur group .

实验证明：利用本文采用的算法及提出的方案，提取第一心音幅值，达到了预期的效果。

It is proved that it is effective to extract the amplitude of S1 using the algorithm and scheme proposed in the paper .

利用数学形态学和归一化香农能量两种方法分别提取了心音的包络，突出了第一心音、第二心音等特征。

Methods : withdraw the envelope of heat sounds by using Mathematic Morphology and normalized Shannon energy , extract first heart sound and the second heart sound .

本文进行了3项工作。（1）提出了基于血流动力的第一心音和第二心音产生模型。

The main work of this paper is focused on three aspects as follows . ( 1 ) A hemodynamics-based first and second heart sound generation model is proposed .

研究发现第一心音的幅值是心肌收缩力的标准量度，因此可以用心音图来对心肌收缩能力进行评估。

It has been discovered in previous research that the phonocardiogram can be used for cardiac performance assessment since the amplitude of S1 is the standard measure for myocardium contractility force .

结果表明：5例中3例正常人和2例心脏病患者的第一心音辨识区域重合，而第二心音辨识区域不重合。

The results showed that in the 5 participants , the S1 recognition area of 3 normal subjects and 2 patients with heart diseases overlapped , though the S2 area did not .

心音和心肌收缩能力关系的大量研究表明，第一心音幅值的变化与左心室压力上升最大速率的变化呈正相关。

The massive researches of the relationship between heart sound and cardiac muscle contraction ability indicate the amplitude of the first heart sound is connected with the fastest rate of the pressure rising in left ventricle .

它通过对信号处理电路的巧妙设计和数据包传输格式的合理组织，能够实现心力（第一心音幅度）与心率信号的同时遥测；

Through flexible design of the signal procession circuit and reasonable organization of the data packet format , it can telemeter cardiac contractility ( amplitude of the first heart sound ) and heart rate signals simultaneously .

传统意义上讲，第一心音、第二心音的产生被认为是心脏瓣膜在开合过程中碰撞所产生的振动信号，这些信号包含多种瞬态非平稳成分。

The first heart sound and the second heart sound are considered to be the vibration signals which are generated by the collision in the process of value opening and closing . All of the vibration signals contain many kinds of transient non-steady ingredients .

基于小波多分辨分析的第一第二心音提取

Extraction of the First and the Second Heart Sounds Based on Multi-resolution Analysis of Wavelet Transform

第一和第二心音产生的原理、特点及其生理意义；心电图各波的意义；

The principles , characters and physiological meaning of first heart sound and second heart sound .

以3例正常人6个心动周期的第一和第二心音辨识置信区域为判别标准，对2例心脏病患者进行对比辨识讨论。

The S1 and S2 recognition areas of 6 cardiac cycles of 3 normal subjects were employed as discrimination standard so as to compare and analyze the recognition results of 2 patients with heart diseases .