表面肌电信号拾取与预处理电路设计

表面肌电信号(SEMG)是指当骨骼肌收缩时,肌纤维所产生的微弱电信号在皮肤表面的募集。一般情况下,表面肌电信号特别微弱,频率主要集中在10～500 Hz范围内,幅值在10～5 000μV,很容易受到工频50 Hz噪声干扰。针对表面肌电信号的特点,采用Ag/AgCl电极拾取SEMG信号,设计了仪表放大电路,带通信号调理电路。实验证明,所设计的电路能有效提取带宽为10～1 000 Hz的表面肌电信号,实现了简捷有效的表面肌电信号拾取。

SEMG Acquisition and Preprocessing Circuit Design

SEMG is when skeletal muscle contract, the muscle fiber produce the weak electrical signals in the skin surface and raise them. Usually, SEMG is so weak, its frequency mainly concentrated in 10-500Hz range and amplitude in 10-5000uV, very vulnerable to fifty Hz Power frequency noise interference. According to the SEMG characteristics, we used Ag/AgCl electrode to pickup SEMG signal and designed the instrumentation amplifier circuit, bandpass signal conditioning circuit. Experiments have proved that the circuit can effectively cover bandwidth for 10-1000 Hz of SEMG signal and realize the simple effective SEMG signal acquisition.