Development of a New Low-Cost EMG Monitoring System for the Classification of Finger Movement

摘要

Electromyography (EMG) signals are commonly used by researchers to study kinesiology, which can then be used to control prosthetic arms, hands and limbs [1]. Additionally, EMG signals are used in the field of Bio Robotics for gesture control applications. The aim of this work is to implement a set of affordable active electrodes for the classification of finger movement via time-domain analysis. The electromyography signals are received through the Ag-AgCI electrodes, which are conductive materials used for gathering and transferring the muscle activation potential. The proposed paper focuses on presenting a new low-cost based system for the classification of human finger movement using auto-gain adjustment active electrodes. Different people will have different EMG amplitudes; therefore, it is difficult to determine the gain required prior performing further signal processing. In this work the implementation of an auto-adjustable gain amplifier was used. This circuit monitors the maximum EMG signal amplitude and adjusts the gain stage accordingly, without any user interaction. This ensures that the gain is always automatically adjusted to get the most effective performance from the data acquisition or analogue to digital converter (ADC) module since the signal will be neither too low in amplitude to cause inefficient use of the ADC resolution, not too high to cause saturation of the signal. Additionally, the instrumentation amplifier is directly interfaced near the Ag-AgCI electrodes. Through extensive experiments, our sEMG sensor outperforms a widely used commercially available product and when tested under ten different persons our low cost EMG data acquisition system achieves reproducible and repeatable results for the detection and classification of finger movements.