由于卷积滤波尺寸等限制,U-net无法学习到心电(Electrocardiographic,ECG)信号的长时序关联性以及标签间的相关性。对此提出一种基于U-net-BiLSTM-CRF的心律失常多目标检测方法,可同时输出目标心拍所属类型和位置信息。使用U-net学习融合特征,再将其输入到双向长短时记忆网络(Bi-directional Long Short-Term Memory,BiLSTM)中学习长时序依赖特征,最后使用条件随机场(Conditional Random Field,CRF)对标签间的关系建模,优化分类结果。依据ANSI/AAMI EC57:2012的心搏分类标准,对MIT-BIH心律失常数据库中共85 609个心拍记录进行划分,在划分后数据集上的实验结果表明,该方法对心拍分类的准确率达99。11%,特异性为99。76%,灵敏度为97。21%,优于传统U-net在MIT-BIH心律失常数据库上的分类性能。
MULTI-TARGET DETECTION METHOD FOR ARRHYTHMIA BASED ON U-NET-BILSTM-CRF
Due to limitations such as the size of the convolution filter,U-net cannot learn the long timing correlation of electrocardiographic(ECG)signals and the correlation between tags.Therefore,this paper proposes a multi-target detection method for arrhythmia based on U-net-BiLSTM-CRF,which can simultaneously output the type and location of the target heartbeat.U-net was used to learn the fusion features.The fusion features were input into the bi-directional long short-term memory(BiLSTM)to learn long time-dependent features.Conditional random field(CRF)was used to model the relationship between tags to optimize the classification results.According to the heartbeat classification standard of ANSI/AAMI EC57:2012,a dataset was built in this paper based on a total of 85 609 heartbeat records in the MIT-BIH arrhythmia database,which was used to verify the proposed method.The results show that the accuracy of this method for heartbeat classification is 99.11%,the specificity is 99.76%,and the sensitivity is 97.21%,all of which are better than the classification performance of traditional U-net on the MIT-BIH arrhythmia database.