高共模抑制比的肌电传感器的电路设计

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关键词：肌电图；传感器；运放；电路；共模抑制比

中图分类号：TN709；TP212

文献标识码：A

DOI：10.14106/j.cnki.1001-2028.2025.1004

引用格式：杨成英. 高共模抑制比的肌电传感器的电路设计 [J]. 电子元件与材料， 2025， 44（1）： 95-102.

Reference format： YANG Chengying. Circuit design of electromyographic sensor with high common mode rejection ratio [J]. Electronic Components and Materials， 2025， 44（1）： 95-102.

Circuit design of electromyographic sensor with high common mode

rejection ratio

YANG Chengying

（School of Materials Science and Engineering， Guangdong Ocean University， Yangjiang 529500， Guangdong Province，

China）

Abstract： Electromyography （EMG） is widely regarded as an essential objective diagnostic tool for neuromuscular diseases. However， the common mode rejection ratio （CMRR） is often low for the EMG sensor circuits， and incomplete filtered signals could lead to large fluctuations and low accuracy for the EMG sensors. A high-precision acquisition circuit for the EMG sensors was designed using the ADI chip AD8221 amplifier with low offset voltage and low gain drift， and using the operational amplifier TL084 with low input bias current， low input offset current， and high conversion rate. This circuit utilized the operational amplifier to effectively integrate the differential circuit and the absolute value circuit， which could achieve low-frequency （DC） filtering and full wave rectification functions. Meanwhile， the integral circuit and low-pass filter worked synergically to filter out the high-frequency interference signals， which fully ensured the CMRR for the sensor. The test results show that the waveform amplitude indication error is less than ±5% for the EMG output signal from the circuit with signal amplitude deviations between +2.5% and -15%， and the CMRR up to 130 dB. It is very suitable for high-precision electromyographic sensors.

Keywords： electromyography; sensors; operational amplifier; circuit; CMRR

肌电图（Electromyography， EMG）是指将同心圆针电极插入肌肉或者肌电仪电极线接头紧密接触肌肉表面后，记录肌肉在安静状态下、不同程度随意收缩状态下以及周围神经受刺激时，各种电生理特性的电活动的一种技术[1-2]。（剩余9093字）