基于聚类分析的心电节拍分类算法

为提高计算机辅助心电节拍分类算法的准确率和普适性,提出一种基于聚类分析的心电节拍分类算法,该算法利用心电节拍个体内差异性较小的特性,采用两级聚类分析、抽样代表性心电节拍的方法,结合心电医师的辅助诊断,实现对心电节拍的准确分类。为了验证算法的准确性,采用国际公认的标准数据库--MIT-BIH心律失常数据库,AAMI/ANSI标准规定的心电节拍分类方法及准确率的计算方法进行仿真实验,最终总体分类准确率达到99.07%。与Kiranyaz等(KIRANYAZ S, INCE T,PULKKINEN J, et al. Personalized long-term ECG classification: A systematic approach［J］. Expert Systems with Applications, 2011, 38(4): 3220-3226.)的心电节拍分类算法相比,该算法无需进行设定的训练,且S类心电节拍分类灵敏度由40.15%提高到89.82%,显著提高了分类算法的普适性。     

基于改进残差网络的心电信号识别分类算法研究

心电图(Electrocardiogram,ECG)心拍分类是心律失常诊断的重要步骤,为了准确检测心律失常类型,提出了一种利用改进的残差网络进行ECG分类的算法.首先使用CEEMDAN-改进小波阈值算法去除心电信号中的噪声,然后构建改进残差网络实现对ECG的分类,在该改进残差网络中,首先将传统深度残差网络中的卷积层、池化层替换成Inception模块,从而提取不同尺度的特征;然后设计了残差嵌套网络,实现了ECG信号不同层次的特征融合,最后采用Softmax分类器进行分类.将该模型在MIT-BIH数据库进行训练和验证,结果表明,所提出的网络模型具有较高的分类准确率.     

结合CNN与双向LSTM的心律失常分类

心律失常是心血管疾病中常见的病症之一,实现心律失常的自动分类对心血管疾病的诊治具有重要意义.基于一维心电信号的心律失常分类方法以若干节拍作为输入,通过模型提取特征并用于分类.针对现有方法预处理时间成本高以及未按医疗仪器促进协会(AAMI)标准分类等问题,提出了一种基于原始一维心电信号并按照AAMI推荐标准类别进行心律失常自动分类的方法.该方法首先利用卷积神经网络(CNN)学习心电信号的形态特征,之后通过双向长短期记忆网络(BLSTM)获取特征中的上下文依赖关系,最后借助softmax函数完成分类任务.方法采用mish函数作为激活函数,使得模型在训练中更为稳定.在公开数据库MIT-BIH上进行五折交叉验证,评估结果达到了99.11％的平均准确率,表明该模型可以有效地提取心电信号的特征,适用于监测系统中心律失常疾病的诊断.     

基于改进遗传模拟退火 K-means的心电波形的分类研究

针对心电图自动诊断困难这一问题,提出了一种新的聚类算法：基于均方差属性加权的遗传模拟退火K-means改进聚类算法,用于改进心电图（ECG）信号的自动识别技术。利用小波变换的多分辨率和抗干扰能力好的特点,检测QRS波、P波、T波,提高了特征检测的准确性;利用聚类分析具有较好的鲁棒性和适合于大数据量分析的特点,对心电信号进行波形分类。采用MIT-BIH标准心电数据库中的部分数据对识别结果进行判断,改进后的K-means聚类算法的准确率高于传统的K-means聚类算法,实验表明该算法对心电信号可以进行有效分类。     

基于深度学习的临床心电图分类算法

心电图反映了人体心脏健康状况,是临床诊断心血管类疾病的重要依据。随着心电图数量的快速增长,计算机辅助心电图分析的需求愈加迫切,心电图自动分类作为实现计算机辅助心电图分析不可或缺的技术手段,具有重要的医学价值。由于心电信号非常微弱、抗干扰性差,传统心电图分类算法存在测试集上效果好,实际临床应用效果欠佳的问题。为此,本文研究一种基于多导联二维结构的一维卷积ResNet网络结构,通过平移起始点、“加噪”等数据增强手段增 加训练样本多样性,并采用Focal Loss损失函数优化病人个体的心电图分类模型。该模型利用2万条完整的8导联心电图数据,共计34类心电异常事件进行分类实验,取得了0.91的F1值、93.96%的准确率和87.89%的召回率的分类性能。实验结果表明,该心电图分类算法模型具有较优的深层特征挖掘与分类能力,验证了其在心电异常自动分类上的有效性。     

基于物联网的社区心电监护系统设计

将物联网与传统心电图（ ECG）监护系统相结合,以Zig Bee无线通信技术为核心,设计了一种具有自动报警功能的社区心电监护系统,实现了心电数据的自动采集、处理、诊断、异常报警与无线传输。该系统采用无线通信技术传输数据,可以减少系统的连线。系统中的心电分析算法可以实时显示和在线分析心电信号,提取心电信号中的疾病特征,实现心脏疾病的自动诊断和预测。实验结果表明：所设计的心电监护系统,能够准确采集心电信号。将物联网技术应用在智能心电监护系统上,便于对社区患者进行统一监管。     

基于小波变换和粗糙集的早搏信号识别算法

心电特征参数的选择和提取是心电图(ECG)分析的基础,提升检测算法的识别率和特征分类的精度是自动分析技术的关键。提出了基于小波变换和属性约简的心电早搏信号识别算法。该算法首先依据心血管专家的诊断标准选择了12个心电特征参数;然后运用基于小波变换的特征检测算法进行了特征提取,并利用基于粒计算的属性约简算法对特征参数进行了属性约简;最后,将约简后的数据用于模式分类并通过MIT-BIH数据库对结果进行验证。实验表明,约简后的分类精度大大高于约简前的数据,特征参数的合理选择(约简)是提高识别效率的重要因素。     

基于深度学习的ECG信号分类

心电图(ECG)能够实时反映心脏状态,可用于心律失常和其它心血管疾病的准确诊断。针对ECG信号采集时的噪声干扰,重构Db6小波的4级分解量并使用巴特沃斯低通滤波实现双重去噪。将降噪后的ECG信号进行R波提取,并截取P-QRS-T波片段输入到一维改进GoogLeNet模型中进行训练。一维改进GoogLeNet是原始二维GoogLeNet的优化结构,可减少网络深度并在稀疏连接中添加最大池化层和扩张卷积加大感受野,降低计算量来提高训练性能。在MIT-BIH数据集中进行实验得到99.39%的分类准确率,比一维GoogLeNet和原始GoogLeNet分别提升了0.17个百分点和0.22个百分点,训练效率均有提升。与其他先进的技术相比,心电信号分类有了显著的改进。     

基于准确率爬坡的动态加权集成分类算法

传统集成分类算法中,一般将集成数目设置为固定值,这可能会导致较低分类准确率。针对这一问题,提出了准确率爬坡集成分类算法（C-ECA）。首先,该算法不再用一些基分类器去替换相同数量的表现最差的基分类器,而是基于准确率对基分类器进行更新,然后确定最佳集成数目。其次,在C-ECA的基础上提出了基于爬坡的动态加权集成分类算法（C-DWECA）。该算法提出了一个加权函数,其在具有不同特征的数据流上训练基分类器时,可以获得基分类器的最佳权值,从而提升集成分类器的性能。最后,为了能更早地检测到概念漂移并提高最终精度,采用了快速霍夫丁漂移检测方法（FHDDM）。实验结果表明C-DWECA的准确率最高可达到97.44%,并且该算法的平均准确率比自适应多样性的在线增强（ADOB）算法提升了40%左右,也优于杠杆装袋（LevBag）、自适应随机森林（ARF）等其他对比算法。     

基于蝙蝠算法的贝叶斯分类器优化研究

朴素贝叶斯分类器是一种应用广泛且简单有效的分类算法,但其条件独立性的"朴素贝叶斯假设"与现实存在差异,这种假设限制朴素贝叶斯分类器分类的准确率。为削弱这种假设,利用改进的蝙蝠算法优化朴素贝叶斯分类器。改进的蝙蝠算法引入禁忌搜索机制和随机扰动算子,避免其陷入局部最优解,加快收敛速度。改进的蝙蝠算法自动搜索每个属性的权值,通过给每个属性赋予不同的权值,在计算代价不大幅提高的情况下削弱了类独立性假设且增强了朴素贝叶斯分类器的准确率。实验结果表明,该算法与传统的朴素贝叶斯和文献[6]的新加权贝叶斯分类算法相比,其分类效果更加精准。     

Integration of independent component analysis and neural networks for ECG beat classification

In this paper, we propose a scheme to integrate independent component analysis (ICA) and neural networks for electrocardiogram (ECG) beat classification. The ICA is used to decompose ECG signals into weighted sum of basic components that are statistically mutual independent. The projections on these components, together with the RR interval, then constitute a feature vector for the following classifier. Two neural networks, including a probabilistic neural network (PNN) and a back-propagation neural network (BPNN), are employed as classifiers. ECG samples attributing to eight different beat types were sampled from the MIT-BIH arrhythmia database for experiments. The results show high classification accuracy of over 98% with either of the two classifiers. Between them, the PNN shows a slightly better performance than BPNN in terms of accuracy and robustness to the number of ICA-bases. The impressive results prove that the integration of independent component analysis and neural networks, especially PNN, is a promising scheme for the computer-aided diagnosis of heart diseases based on ECG.     

Wearable ECG signal processing for automated cardiac arrhythmia classification using CFASE-based feature selection

Classification of electrocardiogram (ECG) signals is obligatory for the automatic diagnosis of cardiovascular disease. With the recent advancement of low-cost wearable ECG device, it becomes more feasible to utilize ECG for cardiac arrhythmia classification in daily life. In this paper, we propose a lightweight approach to classify five types of cardiac arrhythmia, namely, normal beat (N), atrial premature contraction (A), premature ventricular contraction (V), left bundle branch block beat (L), and right bundle branch block beat (R). The combined method of frequency analysis and Shannon entropy is applied to extract appropriate statistical features. Information gain criterion is employed to select features that the results show that 10 highly effective features can obtain performance measures comparable to those obtained by using the complete features. The selected features are then fed to the input of Random Forest, K-Nearest Neighbour, and J48 for classification. To evaluate classification performance, tenfold cross validation is used to verify the effectiveness of our method. Experimental results show that Random Forest classifier demonstrates significant performance with the highest sensitivity of 98.1%, the specificity of 99.5%, the precision of 98.1%, and the accuracy of 98.08%, outperforming other representative approaches for automated cardiac arrhythmia classification.     

ECG arrhythmia classification based on optimum-path forest

An important tool for the heart disease diagnosis is the analysis of electrocardiogram (ECG) signals, since the non-invasive nature and simplicity of the ECG exam. According to the application, ECG data analysis consists of steps such as preprocessing, segmentation, feature extraction and classification aiming to detect cardiac arrhythmias (i.e., cardiac rhythm abnormalities). Aiming to made a fast and accurate cardiac arrhythmia signal classification process, we apply and analyze a recent and robust supervised graph-based pattern recognition technique, the optimum-path forest (OPF) classifier. To the best of our knowledge, it is the first time that OPF classifier is used to the ECG heartbeat signal classification task. We then compare the performance (in terms of training and testing time, accuracy, specificity, and sensitivity) of the OPF classifier to the ones of other three well-known expert system classifiers, i.e., support vector machine (SVM), Bayesian and multilayer artificial neural network (MLP), using features extracted from six main approaches considered in literature for ECG arrhythmia analysis. In our experiments, we use the MIT-BIH Arrhythmia Database and the evaluation protocol recommended by The Association for the Advancement of Medical Instrumentation. A discussion on the obtained results shows that OPF classifier presents a robust performance, i.e., there is no need for parameter setup, as well as a high accuracy at an extremely low computational cost. Moreover, in average, the OPF classifier yielded greater performance than the MLP and SVM classifiers in terms of classification time and accuracy, and to produce quite similar performance to the Bayesian classifier, showing to be a promising technique for ECG signal analysis.     

ECG heart beat classification method based on modified ABC algorithm

Electrocardiogram is the most commonly used tool for the diagnosis of cardiologic diseases. In order to help cardiologists to diagnose the arrhythmias automatically, new methods for automated, computer aided ECG analysis are being developed. In this paper, a Modified Artificial Bee Colony (MABC) algorithm for ECG heart beat classification is introduced. It is applied to ECG data set which is obtained from MITBIH database and the result of MABC is compared with seventeen other classifier's accuracy.In classification problem, some features have higher distinctiveness than others. In this study, in order to find higher distinctive features, a detailed analysis has been done on time domain features. By using the right features in MABC algorithm, high classification success rate (99.30%) is obtained. Other methods generally have high classification accuracy on examined data set, but they have relatively low or even poor sensitivities for some beat types. Different data sets, unbalanced sample numbers in different classes have effect on classification result. When a balanced data set is used, MABC provided the best result as 97.96% among all classifiers.Not only part of the records from examined MITBIH database, but also all data from selected records are used to be able to use developed algorithm on a real time system in the future by using additional software modules and making adaptation on a specific hardware.     

Automatic diagnosis from electrocardiograms (ECGs)

This paper deals with the development of a new algorithm for electrocardiogram (ECG) analysis for automatic diagnostic purposes. The frequency characteristic of each segment of the ECG signal is computed via a fast Fourier transform. The phase characteristic of the segments is used to identify the cardiac abnormalities. The accuracy, reliability, and consistency of the algorithm have been verified by carrying out a classification of various normal and abnormal ECG waveforms. This work is a useful step towards the goal of automatic and computerized ECG interpretation and diagnosis.     

Short Term ECG Classification with Residual-Concatenate Network and Metric Learning

Multimedia Tools and Applications - ECG classification is important to the diagnosis of cardiovascular disease. This paper develops a robust and accurate algorithm for automatic detection of heart...     

Automatic diagnosis of cardiac arrhythmia in electrocardiograms via multigranulation computing

The automatic and accurate arrhythmia diagnosis in the electrocardiogram (ECG) signals is significant for cardiac health. Typically, the arrhythmia diagnosis is automatically detected depending on single-lead signals or a simple combination of multilead signals from the ECG. However, it ignores the inter-lead correlation and the significance of different leads for different heart beats detection, which decreases the performance of arrhythmia diagnosis. In this paper, arrhythmia diagnosis is converted to a problem of multigranulation computing in the view of granular computing, and thus different lead signals can be captured to improve the effectiveness of abnormal heart beats detection. To this end, multilead ECG signals are firstly granulated into different fuzzy information granules by the fuzzy equivalence relation. An objective decision-making model based on fuzzy set theory is then proposed for describing and analyzing these granulated multilead ECG signals, which brings a self-adaptive and unsupervised decision making. As a result, the significance and correlation of different leads are analyzed by granularity selection and granular structures to make a better decision for arrhythmia diagnosis. Extensive experimental results show that the proposed algorithm can significantly improve the performance of arrhythmia diagnosis, especially better robustness to several types of cardiac arrhythmia.     

粗糙集在心电图分类诊断中的应用

心电图是诊断心血管疾病的重要依据,论文提出了基于粗糙集的多变量决策树在分类诊断中的应用,并以窦性心率失常为例创建了多变量决策树,得到相应的分类规则。使用实际数据进行测试的结果表明,可以有效、快速地进行心率失常病例判别。