基于子宫肌电的宫缩监测系统设计

Design of monitoring system of uterine contraction based on electrohysterogram

目的:开发一款便携式子宫肌电宫缩监测系统,通过记录子宫肌电(EHG)信号、压力分娩计(TOCO)采集的信号和孕妇感知的打标信号监测孕妇宫缩情况。方法:系统主要由电极和压力传感器、信号采集模块构成,基于微控制器单元(MCU)的下位机固件开发以及上位机采集界面的设计,选择八导联方式获取孕妇腹部表面的EHG信号,使用TOCO记录孕妇腹部的形变程度,同时设计打标按键,当孕妇感知有宫缩时用于手动记录。将采集到的信号在单片机部分进行整合和发送,当缓存数据包满后,以蓝牙的方式发送数据,上位机的应用软件完成数据接收、显示和存储。使用开发的子宫肌电宫缩监测系统采集20名健康孕妇的临床数据,对其功率谱(PSD)、均方根(RMS)、峰值频率(PF)、中值频率(MDF)和样本熵(SamEn)进行特征值分析。结果:EHG记录系统可以实时记录孕妇EHG信号,且记录的TOCO和EHG信号具有良好的一致性,对于足月有宫缩的孕妇均能监测到宫缩情况,而宫缩与非宫缩的PSD、RMS、PF及SamEn结果存在显著性差异。结论:子宫肌电宫缩监测系统可有效实时记录EHG信号,为实现长时间监测孕妇宫缩和预测早产提供便利。

Objective: To develop a portable monitoring system of uterine contraction based on electrohysterogram (EHG), which can monitor the uterine contraction of pregnant women through recorded EHG signal, tocodynamometer (TOCO) signal and mark signals which were felt by pregnant women. Methods: The clinical data of 20 healthy pregnant women were collected by using the developed monitoring system which based on EGH for uterine contraction. And its power spectral density (PSD), root mean square (RMS), peak frequency (PF), median frequency (MDF) and sample entropy (SamEn) were implemented feature value analysis. Results: The signals of EHG of pregnant women could be real-time recorded by EHG monitoring system. And there was good consistency between recorded TOCO signals and EHG signals, and this monitoring system could monitor uterine contraction of pregnant women with uterine contraction who were full-term pregnancy. And the differences of PSD, RMS, PF and SamEn between uterine contraction and nonuterine contraction were significant. Conclusion: The EHG monitoring system can effectively record EHG signal in realtime, and it can provide convenient to achieve monitoring uterine contraction in long time and predict premature delivery.