摘要
针对生物肌电信号频率低、信号微弱以及干扰信号多等特点,设计完成1个生物肌电信号前置放大器。采用并联型双运放构成前级放大器获得高输入阻抗和高共模抑制比,通过共模信号取样驱动电路抑制阻容耦合电路中阻、容元件参数不匹配带来的差模干扰,利用仪用放大器AD620放大微弱的生物肌电信号;由低通和高通滤波电路滤除生物肌电信号中的低频和高频噪声;采用有源双T型陷波电路滤除50 Hz的工频干扰。通过实验测试,该前置放大电路可以有效滤除噪声、抑制工频干扰和极化电压,满足肌电信号放大的要求。
Designed a preamplifier of biological EMG signal,which is characterized by low frequency and weak signal with many interference signals.The preamplifier can get high input impedance and high CMRR by dual op amp in parallel form,and suppress the differential mode interference by common mode signal sampling circuit.And it amplified the weak biological EMG signal by AD620.Then it eliminated the low and high frequency noise by the high pass filter and low pass filter,and eliminated the power frequency interference by active double T-notch filter.Through experimental tests,the preamplifier can effectively filter noise,suppress power frequency interference and polarization voltage and can meet the requirements of EMG signal amplification.
出处
《电子测量技术》
2011年第4期53-55,92,共4页
Electronic Measurement Technology
基金
国家大学生创新性实验计划项目(91048613)
关键词
肌电信号
放大
共模抑制比
工频干扰
EMG signal
amplify
CMRR
power frequency interference
