Feature Extraction of Surface Electromyography Using Wavelet Weighted Permutation Entropy for Hand Movement Recognition

Figure 4

Decomposition of sEMG sequence via four-level WT and extraction of five sub-bands. “a4” is the approximation at the fourth level. “d4” is the details at the fourth level. “d3” is the details at the third level. “d2” is the details at the second level. “d1” is the details at the first level.