# Detecting the Speed Change Intention from EEG Signals:
## 3 Results
### Exoskeleton Closed-Loop  
The subject that obtained the best results in the pseudo-online analysis was S4, with the combination of \(HJ_{A}\)(8-14)/\(HJ_{C}\)(23-30) features, the central electrodes configuration and a ratio of 8.8. This was the reason why it was selected for the pilot test E2.  
The E2 concept study was performed two weeks after the first E1 study. In E2, 40 repetitions of increment of the speed of the exoskeleton in _passive mode_ were carried out during the first phase for training the model, five trials of eight repetitions. For the creation of the model, the first trial was ruled out, since the user was adapting to the use of this mode. Thus, the model was created with 32 repetitions.  
Regarding the testing with the exoskeleton in _active mode_, only six closed-loop repetitions were performed due the user fatigue and to limit experimental duration. The training process was long, the subject had to perform a lot of force to move the exoskeleton in passive mode, being its control complex. This caused the experiment to be longer than expected and the cause of the closed-loop repetition shortening.  
Of the six repetitions performed in a closed loop, in the first 2, a false positive was detected in the validation stage _FP-Test_ (see Figure 6) 0.2 s and 3.4 s, respectively, after the _Commands-blocked, walk Speed 1_ phase (see Table 5), while in the next two there were no FP in the validation stage and in the _waiting for user intention_ stage, 2.8 s and 3.8 s, respectively, after the _rejected part_ stage was activated correctly according to the user's intention. In repetitions 5 and 6, as in repetitions 1 and 2, 3.2 s and 1.4 s were activated incorrectly after starting the stage.  
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline  & & **S1** & **S2** & **S3** & **S4** & **S5** \\ \hline \multirow{4}{*}{**F-Test**} & & \(HJ_{A}\) (8–14) & \(HJ_{A}\) (23–30) & \(HJ_{A}\) (23–30) & \(HJ_{C}\) (15–22) & \(HJ_{A}\) (23–30) \\  & Features & \(HJ_{A}\) (23–30) & \(HJ_{C}\) (15–22) & \(HJ_{C}\) (8–14) & \(HJ_{C}\) (23–30) & \(HJ_{M}\) (8–14) \\  & & All & Union & All & Left & Left \\  & TP(\%) & 40.0 & 50.0 & 37.5 & 18.8 & 25.0 \\  & FP/min & 11.1 & 10.5 & 5.0 & 8.2 & 4.6 \\  & ratio & 3.6 & 4.8 & 7.5 & 2.3 & 5.4 \\ \hline \multirow{4}{*}{**F-Test**} & & \(HJ_{A}\) (8–14) & \(HJ_{C}\) (15–22) & \(HJ_{A}\) (23–30) & \(HJ_{A}\) (8–14) & \(HJ_{A}\) (23–30) \\  & Features & \(HJ_{C}\) (8–14) & \(HJ_{C}\) (23–30) & \(HJ_{C}\) (15–22) & \(HJ_{C}\) (23–30) & \(HJ_{C}\) (8–14) \\  & & All & Central & All & Central & All \\  & TP(\%) & 42.9 & 55.6 & 33.3 & 33.3 & 62.5 \\  & FP/min & 9.9 & 17.9 & 5.6 & 3.8 & 9.1 \\  & ratio & 4.3 & 3.1 & 5.9 & 8.8 & 6.9 \\ \hline \multirow{4}{*}{**F-Test**} & & \(HJ_{A}\) (23–30) & \(HJ_{A}\) (23–30) & \(HJ_{A}\) (8–14) & \(HJ_{C}\) (15–22) & \(HJ_{M}\) (8–14) \\  & Features & \(HJ_{C}\) (8–14) & \(HJ_{C}\) (15–22) & \(HJ_{C}\) (15–22) & \(HJ_{C}\) (23–30) & \(HJ_{C}\) (15–22) \\  & & Left & Union & All & Left & Right \\  & TP(\%) & 37.5 & 57.1 & 71.4 & 28.6 & 28.6 \\  & FP/min & 15.5 & 12.3 & 15.5 & 10.0 & 7.7 \\  & ratio & 2.4 & 4.6 & 4.6 & 2.9 & 3.7 \\ \hline \hline \end{tabular}
\end{table}
Table 4: Pseudo-online results per user showing TP, FP/min and ratio (\(\frac{\text{TP}}{\text{FP/min}}\)) for the best Comb (calculated in the offline analysis) feature and electrodes combination for Both, Increase and Decrease paradigms.  
Counting the time that it was active without false activation and the total of 4 false activations, the false positives in the 6 repetitions added up to a total of 9.92 FP/min, while the number of TP was 33%.