Analysis of Conducting Waves Using Multi-channel Surface EMG Based on Difference in the Electrode Shape

Abstract

Surface electromyography (EMG) is the recording of the interference of action potentials produced by some of the motor units of a muscle. If the composition of the interference wave can be analyzed, a more detailed mechanism of muscle contraction may be elucidated. Therefore, we proposed a multi-channel method, extracted all the conducting waves that existed in the surface EMG, and examined the characteristics of each conducting wave. Consequently, we can consider the detailed mechanism of muscle contraction. In previously conducted research, two types of array electrodes with different sizes were used, and different characteristics of conduction waves were obtained. This can be attributed to the following three factors: size of electrode, time of measurement, and location of attachment. In this study, we proposed a new array electrode and used it in the experiment to consider the difference in the characteristics of the conducting wave obtained. Accordingly, the maximal voluntary contraction (100% MVC) of muscle was measured. Thereafter, the myoelectric potential data were acquired while maintaining the load at 10% MVC and 40% MVC for 30 s. The analysis was performed using the multi-channel method. The experimental results showed that when increasing the electrode size, the number of conducting waves also increased. Although the number of conducting waves was small with a small electrode, it was observed that conducting waves of various patterns could be obtained and more details regarding the muscle contraction could be considered.