Du Haiman, Bian Ting, Xiong Peng, Yang Jianli, Zhang Jieshuo, Liu Xiuling
Key Laboratory of Digital Medical Engineering of Hebei Province, College of Electronic and Information Engineering, Hebei University, Baoding, Hebei 071002, P.R.China.
Sheng Wu Yi Xue Gong Cheng Xue Za Zhi. 2022 Aug 25;39(4):702-712. doi: 10.7507/1001-5515.202110015.
ST segment morphology is closely related to cardiovascular disease. It is used not only for characterizing different diseases, but also for predicting the severity of the disease. However, the short duration, low energy, variable morphology and interference from various noises make ST segment morphology classification a difficult task. In this paper, we address the problems of single feature extraction and low classification accuracy of ST segment morphology classification, and use the gradient of ST surface to improve the accuracy of ST segment morphology multi-classification. In this paper, we identify five ST segment morphologies: normal, upward-sloping elevation, arch-back elevation, horizontal depression, and arch-back depression. Firstly, we select an ST segment candidate segment according to the QRS wave group location and medical statistical law. Secondly, we extract ST segment area, mean value, difference with reference baseline, slope, and mean squared error features. In addition, the ST segment is converted into a surface, the gradient features of the ST surface are extracted, and the morphological features are formed into a feature vector. Finally, the support vector machine is used to classify the ST segment, and then the ST segment morphology is multi-classified. The MIT-Beth Israel Hospital Database (MITDB) and the European ST-T database (EDB) were used as data sources to validate the algorithm in this paper, and the results showed that the algorithm in this paper achieved an average recognition rate of 97.79% and 95.60%, respectively, in the process of ST segment recognition. Based on the results of this paper, it is expected that this method can be introduced in the clinical setting in the future to provide morphological guidance for the diagnosis of cardiovascular diseases in the clinic and improve the diagnostic efficiency.
ST段形态与心血管疾病密切相关。它不仅用于表征不同疾病,还用于预测疾病的严重程度。然而,ST段持续时间短、能量低、形态多变以及受到各种噪声干扰,使得ST段形态分类成为一项艰巨任务。在本文中,我们解决了ST段形态分类中单一特征提取和分类准确率低的问题,并利用ST段表面的梯度来提高ST段形态多分类的准确率。在本文中,我们识别出五种ST段形态:正常、上斜型抬高、弓背型抬高、水平型压低和弓背型压低。首先,我们根据QRS波群位置和医学统计规律选择一个ST段候选片段。其次,我们提取ST段面积、均值、与参考基线的差值、斜率和均方误差特征。此外,将ST段转换为一个表面,提取ST段表面的梯度特征,并将形态特征形成一个特征向量。最后,使用支持向量机对ST段进行分类,进而对ST段形态进行多分类。以麻省理工学院贝斯以色列医院数据库(MITDB)和欧洲ST-T数据库(EDB)作为数据源来验证本文算法,结果表明本文算法在ST段识别过程中分别达到了97.79%和95.60%的平均识别率。基于本文结果,期望该方法未来能够引入临床环境,为临床心血管疾病诊断提供形态学指导,提高诊断效率。