The Research And Design Of SEMG Detection System

SEMG detection system, that is surface EMG detection system, is of great significance in clinical diagnosis,rehabilitation engineering,sports medicine and the bionic man-machine systems as a noninvasive detection method. EMG means that when skeletal muscle contraction, the weak electrical signals generated by the muscle fibers gathered in the skin surface. EMG detection system mainly researches and designs for the surface EMG signal acquisition,conditioning and treatment. The system which is composed of surface EMG signal acquisition module,the system module and stimulator module has the function of detecting spontaneous and evoked EMG, and processing and analysing the extracted eigenvalue by using the time-domain analysis and frequency domain analysis methods. Generally speaking, EMG is particularly weak, the spectrum is in the range of 10～500Hz, and the amplitude is about 15～1000μV, it is vulnerable to be interferfered by noise outside and 50HZ frequency noise, So the key of this studying is that how to suppress all sorts of interference and noise and then extract the effective surface EMG.Besides, in order to solve the appearance of the polarization problem of Ag-Agcl surface electrodes in the course of the use, we have designed a new nonpolarizable electrode on the basis of it as electrodes of the electromyography detection signal system.The subject has designed the detection system that cores in ARM, and processed acquisition signal by combing analog filters and digital filters in order to achieve suppression of noise and interference, so as to obtain the effective surface EMG. Using ARM Processor reduces power consumption and improves the system performance, meanwhile improving system reliability.The results of experiments show that the system can extract the spontaneous EMG of the effective range, has the function of detection evoked EMG, and can accurately measure the nerve conduction velocity.