Design of high-accuracy eight-channel surface electromyography acquisition system and its application

The surface electromyography (sEMG) acquisition system has the advantages of small size, high precision, low power consumption and easy operation. We have developed a low-cost and portable eight-channel sEMG acquisition system, in which consists of the related analog front end (AFE), main control unit (MCU) and power supply system. The AFE circuit converts the sEMG signal to the digital signal after filtering the direct current and the two stage amplification. The MCU controls the analog-to-digital converter (ADC) using serial peripheral interface (SPI), packages the data and sends the data to the android through a high-speed wireless module. The power supply system provides stable voltage source and can be powered by battery. Experimental results show that the designed eight-channel sEMG acquisition system exhibits an excellent electrical performance with the amplifier resolution of 8.1 μV, the system noise of lower than 15.3 μV, the sampling rate of 1000 Hz and power consumption of about 30.7 mW. The recognition rate is as high as 98% using support vector machines when detecting normal and fatigue state. This device can be applied in the fields of family health monitoring and the detection of the muscle state in daily life and work.