简单导联胎儿心电信号提取的程控放大器设计

Design for simple-lead program-controlled extraction of fetal ECG amplifier

为构建简单导联胎儿心电信号提取系统,提出一种基于简单导联的前端微弱信号程控放大器设计方法。设计中引入自动增益控制(AGC)方法,在满足输出信号幅度相对稳定的情况下,调整总放大倍数在10000倍范围内变化。自动记录信号和放大倍数的拟合关系,自动增益控制范围可达69dB,保证了在母体腹壁混合信号采集时,细节信号不丢失,便于微弱胎儿心电信号的恢复。工程应用测试表明,设计的放大器用于胎儿心电信号提取时,可以提取出清晰胎儿心电。

To build a simple-lead Fetal Electro Cardio Graph（FECG） extraction system,a simple lead-based weak-signal programmable front-end amplifier design method is presented.The introduction of Automatic Gain Control（AGC） method can adjust the total magnification at the range of 10 000 when the output signal amplitude is relatively stable.The fitting of the relationship between the signal and magnification can be recorded automatically;the automatic gain range is up to 69 dB.This method can ensure that the details of the mixed-signal in the maternal abdominal wall will not be lost and will be easy to recover.Engineering application tests show that clear fetal ECG image can be obtained for fetal ECG extraction by using this amplifier.