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提出了一种希尔伯特黄变换(HHT)与香农能量相结合的包络提取方法,使包络更加平滑,分段更加准确。针对希尔伯特包络不平滑的问题,提出一种希尔伯特黄变换(HHT)与香农能量相结合的包络提取方法,使得所得包络更加平滑;针对经验模态分解(EMD)时采用三次样条插值而造成的端点效应问题,采用镜像闭合端点延拓方法予以解决。实验表明使用提出的新方法可以得到更好的结果。最后对心音信号进行包括心率、S1/S2和D/S在内的医学指标的提取和分析,这为临床上评估心脏储备提供了便利。 相似文献
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从心音图中准确提取第一心音和第二心音的时域特性.是一个巨大的挑战.特别是在心脏出现病理的情况下。一个检测心脏疾病的系统.需要对心音信号的心动周期进行适当的边界估计。边界估计算法能够从心音图中给出准确的第一、第二心音的边界。提出一种新颖的边界估计算法,采用生物域特征.大大减少计算的时间和复杂度.而且更加准确。在此算法基础上,对50例心音样本进行分段识别。准确率达到96.30%.为下一步心音分析与诊断奠定基础. 相似文献
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基于Hilbert-Huang Transform的心音信号谱分析 总被引:8,自引:1,他引:7
心音信号是一种典型的非平稳信号,传统信号处理方法的应用受到很大限制.针对此本文提出了基于Hilbert-Huang Transform(HHT) 的心音信号的分析方法,对冠心病患者的心音信号进行了分析.通过把心音信号分解为内蕴模式函数,利用Hilbert变换建立了心音信号的时间-频率-能量三维Hilbert谱分布以及边界谱分布;Hilbert谱及其边界谱在时域以及频域以较高的分辨率表征了心音信号的时频变化特性,揭示了冠心病患者心音信号的病理特征;为冠心病的早期无损诊断奠定了坚实基础,临床实践中有较大的指导价值. 相似文献
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心音信号是一种典型的非平稳信号,传统信号处理方法的应用受到很大限制。针对此本文提出了基于
Hilbert - Huang Transform(HHT) 的心音信号的分析方法,对冠心病患者的心音信号进行了分析。通过把心音信号分
解为内蕴模式函数,利用Hilbert 变换建立了心音信号的时间- 频率- 能量三维Hilbert 谱分布以及边界谱分布;
Hilbert 谱及其边界谱在时域以及频域以较高的分辨率表征了心音信号的时频变化特性,揭示了冠心病患者心音信
号的病理特征;为冠心病的早期无损诊断奠定了坚实基础,临床实践中有较大的指导价值。 相似文献
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B.A. Reyes S. Charleston-Villalobos R. González-Camarena T. Aljama-Corrales 《Computer methods and programs in biomedicine》2014
A step forward in the knowledge about the underlying physiological phenomena of thoracic sounds requires a reliable estimate of their time–frequency behavior that overcomes the disadvantages of the conventional spectrogram. A more detailed time–frequency representation could lead to a better feature extraction for diseases classification and stratification purposes, among others. In this respect, the aim of this study was to look for an omnibus technique to obtain the time–frequency representation (TFR) of thoracic sounds by comparing generic goodness-of-fit criteria in different simulated thoracic sounds scenarios. The performance of ten TFRs for heart, normal tracheal and adventitious lung sounds was assessed using time–frequency patterns obtained by mathematical functions of the thoracic sounds. To find the best TFR performance measures, such as the 2D local (ρmean) and global (ρ) central correlation, the normalized root-mean-square error (NRMSE), the cross-correlation coefficient (ρIF) and the time–frequency resolution (resTF) were used. Simulation results pointed out that the Hilbert–Huang spectrum (HHS) had a superior performance as compared with other techniques and then, it can be considered as a reliable TFR for thoracic sounds. Furthermore, the goodness of HHS was assessed using noisy simulated signals. Additionally, HHS was applied to first and second heart sounds taken from a young healthy male subject, to tracheal sound from a middle-age healthy male subject, and to abnormal lung sounds acquired from a male patient with diffuse interstitial pneumonia. It is expected that the results of this research could be used to obtain a better signature of thoracic sounds for pattern recognition purpose, among other tasks. 相似文献
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基于心音传感阵列ICA 信号处理的冠心病诊断的研究 总被引:3,自引:0,他引:3
通过研究冠脉血流动力学和心脏心音产生的机理,首次提出了将独立分量分析(ICA)方法应用于心音信号处理并达到自动检测冠心病的目的。在本系统中,信号采集系统采用了高灵敏度传感器列阵对正常人及冠心病患者胸部的多个部位进行检测。经预处理后的信号最后通过计算机进行数据采集。应用独立分量分析的方法将心脏舒张期的心音信号进行分离,并将各心音分量的统计特征参数作为输入参量输入到径向其函数网络(RBF网络)进行训练和识别。实验结果说明,独立分量分析结合人工神经网络的心音信号的分析方法是一种较为有效的诊断冠状动脉疾病的无创伤方法。 相似文献
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Ana Gavrovska Vesna Bogdanović Irini Reljin Branimir Reljin 《Computer methods and programs in biomedicine》2014
Having in mind the availability of electronic stethoscopes, phonocardiograms (PCGs) have become popular for cardiovascular functionality monitoring and signal processing applications. Detection of fundamental heart sounds (HSs), S1s and S2s, is considered to be a crucial step in PCG analysis. Electrocardiogram (ECG), noted as a reference signal, is often synchronously recorded in order to simplify the S1/S2 detection process. Nevertheless, electronic stethoscopes are frequently used without additional ECG equipment. We propose a new algorithm for automatic fundamental HSs detection via: joint time-frequency representation based on pseudo affine Wigner–Ville distribution (PAWVD), Haar wavelet lifting scheme (Haar-LS), normalized average Shannon energy (NASE) and autocorrelation. The performance of the proposed algorithm was calculated on both normal (50) and pathological (75) PCG recordings, eight seconds long each, contributed by 125 different pediatric patients. The algorithm showed relatively high recall (90.41%) and precision (96.39%) rates of S1/S2 detection procedure in a variety of PCG signals, without ECG as a reference. Furthermore, it indicated the ability to overcome splitting within the S1/S2 heart sounds. 相似文献
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耿成月 《数码设计:surface》2014,(7):134-136
水声,顾名思义就是水体发出的声音。水声,既可以是供人们享受的声音,也可以变成影响人们生活工作的噪音。在艺术作品中,水声是被精心设计过的,是令人愉悦的声音。通过对水声在艺术作品中的设计应用分析,总结水声多样性塑造的方法。 相似文献
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结合小波阈值去噪和清浊音分离技术,提出了一种优化的语音去噪新方法。首先,针对语音清音部分往往包含有许多类似噪声的高频成分的特点,对其直接进行小波阈值去噪很可能误除了这些高频成分,造成失真,因此有必要先对语音进行清浊音分离。其次,通过对不同小波函数、阈值选取规则以及阈值处理函数的优化,选择最佳的小波去噪方法。仿真结果表明,与经典小波阈值去噪方法相比,提出的方法既尽可能地去除噪声,又保留了原来语音的特征,较大地提高了语音质量。 相似文献
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Research on heart sound identification technology 总被引:1,自引:0,他引:1
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驻极体电容式呼吸音传感器 总被引:2,自引:0,他引:2
介绍了用CNZ—15型驻极体电容传声器制作的呼吸音传感器,及在多功能呼吸音分析仪上的应用,该传感器灵敏度高,频率响应好,还可应用于其他低频声学测量场合。 相似文献
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