I. Introduction
The surface electromyography (sEMG) signal contains useful information about motion intension that is extensively used for control of the prosthetic hand. However, sEMG signal is a semi-stochastic signal whose dynamic changing process is influenced by anatomical and physiological properties of the contracting muscle [1]. Furthermore, there would be other factors that have impacts on the sEMG signals. Firstly, sEMG sensors with different placements and contact conditions might collect the distinct signals. Secondly, kinetic differences between different individuals when perform the same hand gesture might result in vague corresponding relationship between sEMG and hand gesture [2]. Thirdly, due to muscles collaboration or interaction together during dynamic contractions, coordinated activation of groups of muscles might be non-stationary [3].