【摘要】：心音信號是一種重要的生理信號，其中包含著心臟系統(tǒng)各種生理和病理信息。因為心臟是一個復(fù)雜的非線性動力系統(tǒng)，決定了由其振動產(chǎn)生的心音信號也是一種非線性信號，具有內(nèi)在的復(fù)雜性。而現(xiàn)有的心音信號分析方法多是建立在心音信號線性模型基礎(chǔ)之上，不足以研究本質(zhì)上為非線性的生命活動。分形理論作為非線性科學(xué)的一個重要分支，可以很好的揭示出非線性過程內(nèi)在所具有的特殊規(guī)律。本論文試圖從非線性角度，將分形理論應(yīng)用到心音信號的分析研究，從本質(zhì)上更深入的探索心音信號的內(nèi)在特征規(guī)律。同時將分形理論的定性分析和定量分析結(jié)合起來，利用計盒維數(shù)算法估算人群心音信號的分形維數(shù)值，并將其應(yīng)用到心臟功能評估，以一個全新角度實現(xiàn)對心音信號的分析研究。 論文首先分析了心音信號的時頻域特點(diǎn)，并對心音信號和雜音信號進(jìn)行短時傅里葉變換和Welch功率譜估計，研究結(jié)果表明正常心音信號和心雜音成分的頻率區(qū)間不同。而且心音信號的時域和頻域特征都有一定的規(guī)律性，為后續(xù)對心音信號進(jìn)行非線性分析奠定基礎(chǔ)。 然后利用小波閾值去噪方法對心音信號進(jìn)行預(yù)處理，通過分析噪聲在小波分解下的特性和小波函數(shù)的性質(zhì)，基于重構(gòu)因子方法選取coif3小波去除心音信號噪聲，并通過實驗結(jié)果對比證明coif3小波對心音信號的去噪效果較好。 將分形理論應(yīng)用到心音信號研究的前提需保證心音信號具有分形特征，本文利用分形布朗運(yùn)動模型和心音信號模型進(jìn)行對比分析，定性證明了心音信號具有自相似性和無標(biāo)度性這兩個重要的分形特征，為后續(xù)利用分形理論研究心音信號提供依據(jù)。接著論文介紹了計盒維數(shù)、關(guān)聯(lián)維數(shù)、信息維數(shù)、Hausdorff維數(shù)和相似維數(shù)五種分形維數(shù)估算方法，由于計盒維數(shù)算法原理簡單且計算量小，本課題最終選擇該算法對人群心音信號進(jìn)行研究分析。 最后論文分別對健康孕婦(153例)和妊娠期疾病孕婦(64例)、健康孕婦(153例)和健康未孕婦女(161例)及普通大學(xué)生(65例)和運(yùn)動員(97例)三組人群心音信號樣本的計盒維數(shù)值進(jìn)行調(diào)研統(tǒng)計，結(jié)果顯示健康孕婦分形維數(shù)值(1.27±0.29)相比健康未孕婦女(1.31±0.41)較低，健康孕婦分形維數(shù)值(1.27±0.29）相比妊娠期疾病孕婦（1.38±0.05）較低，第三組樣本運(yùn)動員運(yùn)動后的分形維數(shù)值(1.30±0.065)與靜息狀態(tài)(1.39±0.037)相比降低，普通大學(xué)生運(yùn)動后的分形維數(shù)值(1.32±0.054)與靜息狀態(tài)(1.41±0.065)相比降低，均具有統(tǒng)計學(xué)差異，而靜息狀態(tài)運(yùn)動員與普通大學(xué)生的分形維數(shù)值相對比沒有顯著性差異，且運(yùn)動后運(yùn)動員與普通大學(xué)生的分形維數(shù)值相對比也沒有顯著性差異。并將計盒維數(shù)值與D/S比值、S1/S2比值、HR三種指標(biāo)進(jìn)行對照研究，，分析結(jié)果說明應(yīng)激情況下會調(diào)用人體的心力儲備和心率儲備，使D/S比值下降、S1/S2比值升高、HR變快，通過這些指標(biāo)可以對人群心臟功能進(jìn)行綜合評估。 研究結(jié)果初步表明，分形維數(shù)值可定量描述心音信號的復(fù)雜程度，而且不同人群心音信號的分形維數(shù)值具有一定的統(tǒng)計學(xué)差異。探索性的將分形維數(shù)值作為一個評估人群心臟功能的指標(biāo)，讓醫(yī)生和科研人員了解應(yīng)激狀態(tài)下心臟功能的變化，為臨床提供有價值的信息，為更細(xì)致的保護(hù)心臟提供依據(jù)。
[Abstract]:The heart sound signal is an important physiological signal, which contains various physiological and pathological information of the heart system. Because the heart is a complex nonlinear dynamical system, it is determined that the heart sound signal produced by its vibration is also a non-linear signal, which has inherent complexity. The existing method of heart sound signal analysis is based on the linear model of the heart sound signal, which is not enough to study the vital activity which is non-linear in nature. As an important branch of non-linear science, the fractal theory can well reveal the special rules inherent in the nonlinear process. In this paper, from the non-linear angle, the fractal theory is applied to the analysis and study of the heart sound signal, and the intrinsic characteristic of the heart sound signal is further explored from the essence. At the same time, the qualitative analysis and quantitative analysis of the fractal theory are combined, the fractal dimension value of the human heart sound signal is estimated by using the box-counting dimension algorithm, and the fractal dimension value of the human heart sound signal is estimated by using the box-counting dimension algorithm, and the method is applied to the cardiac function evaluation, and the analysis and research of the heart sound signal are realized by a new angle. In this paper, the characteristics of the time and frequency domain of the heart sound signal are analyzed, and the short time Fourier transform and the Welch power spectrum estimation are carried out on the heart sound signal and the noise signal. The results show that the frequency range of the normal heart sound signal and the cardiac murmur component is not and the time domain and the frequency domain characteristic of the heart sound signal have certain regularity, which lays the foundation for the follow-up of the non-linear analysis of the heart sound signal In this paper, the wavelet threshold de-noising method is used to pre-process the heart sound signal, and by analyzing the characteristics of the noise and the properties of the wavelet function under the wavelet decomposition, the coif3 wavelet is selected to remove the heart sound signal based on the reconstruction factor method. The noise of the coif3 wavelet to the heart sound signal is proved by the comparison of the experimental results. It is better to apply the fractal theory to the study of the heart sound signal. It is necessary to ensure that the heart sound signal has the fractal feature. This paper makes a comparative analysis with the fractal Brownian motion model and the heart sound signal model, and it is proved that the heart sound signal has both self-similarity and non-scaling. The fractal feature of the study of the heart sound in the follow-up of the fractal theory In this paper, five fractal dimension estimation methods of the dimension of the box, the correlation dimension, the information dimension, the Hausdorff dimension and the similarity dimension are introduced. The box dimension of heart sound signal samples from three groups of healthy pregnant women (153 cases) and pregnant women (64 cases), healthy pregnant women (153 cases) and non-pregnant women (161 cases) and general college students (65 cases) and athletes (97 cases) were analyzed. The results showed that the fractal dimension of healthy pregnant women (1.27-0.29) was lower than that of pregnant women (1.31-0.41) and that of pregnant women (1.38%) compared with that of pregnant women (1.27-0.29). The fractal dimension (1.30-0.065) after the movement of the third group of sample athletes was lower than that of resting state (1.39-0.037). The fractal dimension (1.32-0.054) after the normal college students' movement was lower than that of resting state (1.41-0.065). There is a statistical difference, while the relative ratio of the rest state athletes to the fractal dimension of the normal college students is no significant difference, and the relative ratio of the post-sports athletes to the fractal dimension of the normal college students is also There was no significant difference in the ratio of D/ S, S1/ S2 and HR, and the results of the analysis indicated that the heart and heart rate reserve of the human body was called under the stress condition, and the ratio of D/ S was decreased and the ratio of S1/ S2 was decreased. Increased HR, through which the heart work of the population can be achieved. The results of the study show that the fractal dimension value can quantitatively describe the complexity of the heart sound signal, and the fractal dimension value of the heart sound signal of different people There is a certain statistical difference. The exploratory fractal dimension value is used as an index for evaluating the heart function of the population, so that the doctors and the researchers can understand the changes of the heart function in the state of the heart, provide valuable information for clinic, and provide more detail
【學(xué)位授予單位】：重慶大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2012
【分類號】：R318.0

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 曹漢強(qiáng),朱光喜,李旭濤,夏文芳;多重分形及其在地形特征分析中的應(yīng)用[J];北京航空航天大學(xué)學(xué)報;2004年12期

2 方向林,郭興明,彭承琳,詹直夫,肖守中;運(yùn)動和呼吸對心率及心音幅值影響的探討[J];北京生物醫(yī)學(xué)工程;2002年02期

3 姚麗慧;高井祥;王堅;;動態(tài)變形信號小波閾值降噪模型研究[J];測繪工程;2011年05期

4 王琳;郭興明;成敏;郭瑋珍;肖守中;廖克龍;;孕期和產(chǎn)程心臟儲備無創(chuàng)性檢測和評估方法的初步研究[J];第三軍醫(yī)大學(xué)學(xué)報;2006年04期

5 陳果;;非線性時間序列的動力學(xué)混沌特征自動提取技術(shù)[J];航空動力學(xué)報;2007年01期

6 孫博文,張本祥;上證指數(shù)的分形結(jié)構(gòu)及盒維數(shù)測量的研究[J];哈爾濱理工大學(xué)學(xué)報;2001年06期

7 駱懿;趙治棟;;一種便攜式心音信號記錄儀研究[J];杭州電子科技大學(xué)學(xué)報;2011年04期

8 許可;孟o

本文編號：2503987