基于移动智能终端的单通道胎儿心电监护系统

Design of single channel fetal ECG monitoring system based on mobile intelligent terminal

目的设计基于移动智能终端的单通道胎儿心电监护系统,以实现扩展卡尔曼滤波(extended Kalman filtering,EKF)和奇异值分解(singular value decomposition,SVD)相结合的单通道胎儿心电提取算法,实时获取高信噪比的胎儿心电信号,完成胎心监护的远程移动医疗。方法利用STM32单片机控制24位采样芯片ADS1298,对单通道的孕妇腹部信号进行采集,并将采集后的数据经蓝牙传送给移动智能终端,在基于Android的移动智能终端上实现EKF和SVD相结合的单通道胎儿心电提取算法,完成对胎儿心电的实时提取、显示、存储与分析,计算心律变异率,实现对整个监护系统进行控制等功能。结果测试结果表明,该系统可从单通道孕妇腹部信号中准确提取出胎儿心电信号,准确度为95.60%,阳性预测率为98.71%,系统工作稳定,连续处理5个胎心周期的数据用时约为70μs,小于一个母体心动周期(约0.8 s)的时间,适于临床对胎儿心电的实时监护。结论该系统实时性强、准确率高、工作稳定、操作简单、便于携带,实现了对胎心监护的可穿戴式远程移动医疗,适合社区医院和家庭使用。

Objective A single channel fetal ECG monitoring system based on mobile intelligent terminal is designed,and a single channel fetal ECG extraction algorithm combining extended Kalman filter(EKF)and singular value decomposition(SVD)is realized.The fetal ECG signal with high signal-to-noise ratio is obtained in real time,and the remote mobile medical treatment of fetal heart monitoring is realized.Methods By using STM32 single chip microcomputer to control 24 bit sampling chip ADS1298,the single channel pregnant women’s abdominal signal is collected,and the collected data is transmitted to the mobile intelligent terminal via bluetooth.On the Android-based mobile intelligent terminal,a single channel fetal ECG extraction algorithm based on the combination of EKF and SVD is realized,and the functions of real-time extraction,display,storage and analysis of fetal ECG,calculation of heart rate variability and control of the whole monitoring system are completed.Results The test results show that the system can accurately extract fetal ECG signals from single-channel pregnant women’s abdominal signals,with an accuracy of 95.60%and a positive prediction rate of 98.71%.The system works stably,and it takes about 70μs to continuously process the data of 5 fetal cardiac cycles,which is less than the time of one maternal cardiac cycle(about 0.8 s),which is suitable for clinical real-time monitoring of fetal ECG.Conclusions The system has strong real-time performance,high accuracy,stable work,simple operation and portability.It realizes wearable remote mobile medical care for fetal heart monitoring,and is suitable for community hospitals and families.