3.4.3. Reference Approach

As reference experiment for direct comparison in the same population, a recent sEMG-based approach was used [14]. In this reference approach only sEMG signals were used to train the network. Similarly to the KEMG approach, each sEMG signal was split into 20-sample windows. A chronological

sequence of 160-sample vectors was created, where each vector included the eight synchronized 20-sample windows from the sEMG signals of the eight muscles (four for each leg). In details, the first sample of the first 160-sample vector of the sequence was the first sample of the sEMG signal from the muscle 1 (TA, right leg), the second sample of the first 160-sample vector was the first sample of the EMG signal from the muscle 2 (GL, right leg), and so on up to the eighth signal (MH, left leg). Labeling was performed as in the previous approaches. This approach is referred to as the 'Reference approach'. As reported in [14], this approach has been previously validated versus a feature-based method, described in [13].
