Computer Engineering and Applications ›› 2015, Vol. 51 ›› Issue (1): 218-222.

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Surface EMG signal preamplifier system

XIONG Ping, TANG Jian   

  1. School of Geosciences and Info-Physics, Central South University, Changsha 410083, China
  • Online:2015-01-01 Published:2015-01-06

表面肌电信号前端处理系统

熊  平,唐  建   

  1. 中南大学 地球科学与信息物理学院,长沙 410083

Abstract: The high CMRR(Common Mode Rejection Ratio) preprocessor of SEMG(Surface Electromyography) signal is designed. It amplifies the weak SEMG signal by preamplifier constituted by dual Op Amp in parallel form, resistive and capacitive coupling circuit and INA128, with which the preprocessor can get high input impedance and high CMRR. Shielding driver and right leg driver as well as floating power are introduced to further improve the CMRR and anti-interference ability. Then high-pass and low-pass filter, and 50 Hz notch filter are designed to filter out the noise of different bands. Through experimental tests, the preprocessor has a high anti-interference ability, and can effectively filter out the noise, suppress power frequency interference, and can meet the requirements of SEMG signal de-noising and amplification.

Key words: Surface Electromyography(SEMG), preprocessor, Common Mode Rejection Ratio(CMRR), anti-interference

摘要: 设计了高共模抑制比的表面肌电信号前端处理系统。采用并联型双运放差动放大器、阻容耦合电路以及仪器放大器INA128构成初级放大电路对微弱的表面肌电信号进行放大,并获得高输入阻抗和高共模抑制比;引入屏蔽驱动、右腿驱动以及浮地电源来进一步提高系统的共模抑制比和抗干扰能力;设计高通和低通滤波器以及50 Hz工频陷波器,对不同频段的噪声进行滤除。通过实验测试,该系统具有较强的抗干扰能力,并且能够有效滤除噪声、抑制工频干扰,满足表面肌电信号去噪和放大的要求。

关键词: 表面肌电信号, 前端处理, 共模抑制比, 抗干扰