共查询到18条相似文献,搜索用时 78 毫秒
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根据癫痫脑电信号与正常脑电信号波形和能量特征的不同,研究了两种的脑电信号分类方法,一种采用支持向量机SVM(Support Vector Machines)分类器对正常脑电和癫痫脑电进行分类;另一种使用小波分析和支持向量机相结合的方法对脑电进行分类,并比较了这两种方法对正常脑电和癫痫脑电分类的正确率。实验结果表明,小波分析和SVM结合的方法对脑电信号分类可以取得更好的效果,能有效区分癫痫脑电和正常脑电。 相似文献
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基于小波变换的动态脑电节律提取 总被引:10,自引:2,他引:8
针对脑电信号和其他医学信号的非平稳性,引入小波变换处理临床脑电信号的动态特性。根据脑电信号的不同节律特性,提出应用小波包变换构造不同频率特性的滤波器,提取脑电信号的4种节律,并由各种节律对应的小波系数构造动态脑电地形图。为了研究不同脑功能状态下脑电信号4种节律的动态特性,文中对两组不同临床脑电数据进行分析与比较,给出了有关的实际分析结果。实验结果表明,利用小波包分析的滤波特性,能够有效地反映临床脑电不同节律的动态特性,也为分析其他生物医学信号提供了一条新的途径。 相似文献
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根据小波分析的多分辨率特性,重点分析了多分辨率特性在脑电诊断中的应用.首先确定小波函数和分解层数,进行小波变换,对脑电高频低频进行小波变换重构信号,接着基于在不同尺度下伪迹和异常波不会完全相同的原理,将脑电信号分解到各个尺度上.把分解后的脑电信号输入神经网络进行识别,最终输出异常波的识别结果. 相似文献
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脑电信号的若干处理方法研究与评价 总被引:6,自引:1,他引:6
脑电图(EEG)是脑神经细胞电生理活动在大脑皮层或头皮表面的总体反映,对脑电信号进行分析,可以获得大量的功能与疾病信息,从而可以根据这些信息对脑功能分析及疾病诊断提供有效的方法.从脑电信号的特点出发,通过对实测脑电信号进行时域分析、频域分析、Wigner方法、小波方法等若干算法的仿真和对比,深入分析和评价了脑电信号若干方法的特点以及存在的问题.结果表明,时频分析方法结合了时域和频域的方法对脑信号进行分析处理,能更好地反映脑电信号的本质特征,是有效和可行的.的研究为脑电信号的分析与处理提供一定的理论参考和分析依据. 相似文献
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应用小波熵理论分析抑郁症患者和健康人在安静和心算任务下自发脑电信号的复杂度:分别采集10例抑郁症患者和10例正常人在安静闭目和闭眼心算连减两种状态下的16导联脑电信号;计算这四组脑电数据的小波熵,并进行对比和统计分析。结果表明,抑郁症患者和正常人自发脑电的小波熵有着显著的差异:(1)在相同状态下,抑郁症患者各导联脑电的小波熵大于正常人对应导联的小波熵;(2)对同一个人,安静闭目状态下各导联脑电的小波熵大于心算连减状态下对应导联的小波熵。结论可为抑郁症的诊断提供参考。 相似文献
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子波分析在脑电图癫痫波提取中的应用研究 总被引:2,自引:0,他引:2
利用子波和子波变换的性质,并根据其对一小段医学信号的异常信号,可以灵敏地通过子波系数反映出来的特点,将子波分析应用于脑电图(EEG)信号处理,把癫痫波从常规EEG信号中提取出来,文中给出子波变换分析EEG信号的实例,理论和实验表明,利用子波变换检测常规EEG中的病理波有独到之处。 相似文献
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针对原始脑电波信号存在非平稳性且非常容易受到各种信号干扰等特点,对基于小波变换和小波包变换的脑电波信号的滤波降噪方法,和基于小波包变换的脑电波信号特征提取方法进行了研究。首先利用MindSet采集到原始脑电波数据,然后分别应用小波变换和小波包变换对其进行降噪处理,比较了两种方法的性能,验证了基于小波包变换的降噪方法的优越性和特征提取方法的有效性。 相似文献
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Over the past two decades, wavelet theory has been used for the processing of biomedical signals for feature extraction, compression and de-noising applications. However the question as to which wavelet family is the most suitable for analysis of non-stationary bio-signals is still prevalent among researchers. This paper attempts to find the most useful wavelet function among the existing members of the wavelet families for electroencephalogram signal (EEG) analysis. The EEGs considered for this study belong to both normal as well as abnormal signals like epileptic EEG. Important features such as energy, entropy and standard deviation at different sub-bands were computed using the wavelet functions—Haar, Daubechies (orders 2-10), Coiflets (orders 1-10), and Biorthogonal (orders 1.1, 2.4, 3.5, and 4.4). Feature vectors were used to model and train the Probabilistic Neural Network (PNN) and the classification accuracies were evaluated for each case. The results obtained from PNN classifier were compared with Support Vector Machine (SVM) classifier. From the statistical analysis, it was found that Coiflets 1 is the most suitable candidate among the wavelet families considered in this study for accurate classification of the EEG signals. In this work, we have attempted to improve the computing efficiency as it selects the most suitable wavelet function that can be used for EEG signal processing efficiently and accurately with lesser computational time. 相似文献
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由于脑电信号独立源数目的不确定性以及其他噪声的干扰,使得采集的脑电信号各导信号之间产生串扰、源信号难以估计以及噪声混杂等问题,严重影响了对脑电信号的分析研究。将小波变换与盲源分离算法相结合,并对盲源分离算法中维格纳分布存在的交叉项干扰现象进行重排处理。主要思路是首先将每一导信号进行小波变换,提取出特征波β波,然后对这些β波信号进行基于重排光滑伪维格纳分布的盲源分离,分离出关联性极大的β波成分。实验结果表明,所用方法分离出了各导信号中关联性大的脑电信号成分,并在一定程度上解决了源信号难以估计等问题,使识别结果有明显的提升。 相似文献
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The study mainly focuses on the analysis of Electroencephalogram (EEG), to classify mental tasks by using features based on wavelet transform. We have used the daubechies family wavelets, level 6, to transform obtained signal from independent component analyzed EEG signal. As Fourier analysis consists of breaking up a signal into sine waves of various frequencies. Similarly, wavelet analysis is the breaking up of a signal into shifted and scaled versions of the original wavelet. Signals with sharp changes might be better analyzed with a Wavelet than with a Fourier transform. It also makes sense that local features can be described well with wavelets that have local extent. This offers improved features to the neural networks obtaining several classified mental tasks. Through several processes, it led us more developed variety mental tasks classification results. We find that the neural networks perform over 75% success resulting with small number of electrodes better than a previous 70% resulting. 相似文献