胎儿心率采集信号噪声滤波电路设计及仿真  

Fetal Heart Rate Acquisition Signal Noise Filtering Circuit and Simulation

作　　者：尹文姝 王意 张成俊 YIN Wenshu;WANG Yi;ZHANG Chengjun(School of Mechanical Engineering and Automation,Wuhan Textile University,Wuhan Hubei 430200,China)

机构地区：[1]武汉纺织大学机械工程与自动化学院,湖北武汉430073

出　　处：《武汉纺织大学学报》2024年第1期81-88,共8页Journal of Wuhan Textile University

摘　　要：胎心仪使用硅晶传感器对孕妇孕期体内胎儿心率进行无创监测,胎儿心率是一种微弱信号,信噪比低且母体干扰信号强,包含大量与胎儿心率相似的低频信号,都使胎心信号解析十分困难。本文提出了一种应用于单晶片收发模式胎心仪的多级MFB(Multiple Feedback,无限增益多路反馈电路)滤波电路,此电路对微弱的胎心音进行放大和滤波预处理,并使用软件仿真的方法合理选择滤波电路参数,经过滤波预处理的心率信号进入CPU进行自相关算法得到心率数值。最终实验结果表明:经过此多级MFB滤波电路的胎心音信号信噪比高,滤除高频干扰和大部分低频信号的同时有效保留胎儿心脏搏动波形,从而使胎心计探头在胎心30mm范围内能准确的得到胎儿心率,且扬声器播放音频无杂音。Fetal heart rate is noninvasively monitored by a silicon sensor during pregnancy.Fetal heart rate is a weak signal with low signal-to-noise ratio and strong maternal interference signal,which makes it very difficult to parse fetal heart signal.In this paper,a filter circuit of multistage MFB(Multiple Feedback circuit with infinite gain)based on single chip transceiver fetal heart rate meter is proposed.This circuit amplifies and filters the weak fetal heart sound,and uses software simulation method to select the filter circuit parameters reasonably.The filtered and pre-processed heart rate signal is entered into the CPU for the autocorrelation algorithm to obtain the heart rate value.The final experimental results show that through this multistage MFB filter circuit,the signal to noise ratio of fetal heart sound signal is high,and the high-frequency interference and most of the low-frequency signals are filtered out,while the fetal heart beat waveform is effectively preserved,so that the fetal heart rate can be accurately obtained by the fetal heart meter probe within 30mm range,and the audio played by the loudspeaker with no noise.

关 键 词：低通滤波器 高通滤波器 胎儿心率(FHR) MULTISIM仿真 

分 类 号：TS183.1[轻工技术与工程—纺织材料与纺织品设计]