Qian Long, Wang Wenbo, Chen Guici, Yu Min
Department of Mathematical Statistics, College of Science, Wuhan University of Science and Technology, Wuhan 430065, P.R.China.
Sheng Wu Yi Xue Gong Cheng Xue Za Zhi. 2021 Apr 25;38(2):257-267. doi: 10.7507/1001-5515.202004063.
Fetal electrocardiogram signal extraction is of great significance for perinatal fetal monitoring. In order to improve the prediction accuracy of fetal electrocardiogram signal, this paper proposes a fetal electrocardiogram signal extraction method (GA-LSTM) based on genetic algorithm (GA) optimization with long and short term memory (LSTM) network. Firstly, according to the characteristics of the mixed electrocardiogram signal of the maternal abdominal wall, the global search ability of the GA is used to optimize the number of hidden layer neurons, learning rate and training times of the LSTM network, and the optimal combination of parameters is calculated to make the network topology and the mother body match the characteristics of the mixed signals of the abdominal wall. Then, the LSTM network model is constructed using the optimal network parameters obtained by the GA, and the nonlinear transformation of the maternal chest electrocardiogram signals to the abdominal wall is estimated by the GA-LSTM network. Finally, using the non-linear transformation obtained from the maternal chest electrocardiogram signal and the GA-LSTM network model, the maternal electrocardiogram signal contained in the abdominal wall signal is estimated, and the estimated maternal electrocardiogram signal is subtracted from the mixed abdominal wall signal to obtain a pure fetal electrocardiogram signal. This article uses clinical electrocardiogram signals from two databases for experimental analysis. The final results show that compared with the traditional normalized minimum mean square error (NLMS), genetic algorithm-support vector machine method (GA-SVM) and LSTM network methods, the method proposed in this paper can extract a clearer fetal electrocardiogram signal, and its accuracy, sensitivity, accuracy and overall probability have been better improved. Therefore, the method could extract relatively pure fetal electrocardiogram signals, which has certain application value for perinatal fetal health monitoring.
胎儿心电图信号提取对于围产期胎儿监测具有重要意义。为了提高胎儿心电图信号的预测精度,本文提出了一种基于遗传算法(GA)优化的长短期记忆(LSTM)网络的胎儿心电图信号提取方法(GA-LSTM)。首先,根据母体腹壁混合心电图信号的特点,利用GA的全局搜索能力对LSTM网络的隐藏层神经元数量、学习率和训练次数进行优化,计算出参数的最优组合,使网络拓扑与母体腹壁混合信号的特征相匹配。然后,利用GA获得的最优网络参数构建LSTM网络模型,通过GA-LSTM网络估计母体胸部心电图信号到腹壁的非线性变换。最后,利用从母体胸部心电图信号和GA-LSTM网络模型获得的非线性变换,估计腹壁信号中包含的母体心电图信号,并从混合腹壁信号中减去估计的母体心电图信号,得到纯净的胎儿心电图信号。本文使用来自两个数据库的临床心电图信号进行实验分析。最终结果表明,与传统的归一化最小均方误差(NLMS)、遗传算法支持向量机方法(GA-SVM)和LSTM网络方法相比,本文提出的方法能够提取出更清晰的胎儿心电图信号,其准确率、灵敏度、精确率和总体概率都得到了较好的提高。因此,该方法能够提取出相对纯净的胎儿心电图信号,对围产期胎儿健康监测具有一定的应用价值。