## 7 Results and Discussion  
For each task and each interface presented in the previous section, the completion times were noted. The distributions of these data are shown bv the plots in Figure 12.  
Figure 11: Five steps to execute with both the hand gesture interface and the AssystMouse to complete the first task. Figure 12: Distributions of the total completion times by task and interfaces. Figure 12 presents the data by task (mouse control and copy-paste) and interface (hand gesture and AssystMouse), shown in a boxplot. The boxplots are wrapped in a violin-like area that shows the estimated probability densities. The means of the completion times, plus or minus the standard deviations, are also displayed in the figure. The distributions show that a webcam-based system, for the control of the mouse, is still much faster. However, the standard deviation of the times for the hand gesture mouse control task being relatively low indicates that the system is reliable and robust, since all the participants were able to complete the task in similar times. In other words, it does not seem to require any specific skills to work. On the other hand, the copy-paste task's data shows that the integration of the hand gesture interface with the AssystMouse consistently improved the participants' time by 77%, on average. In addition, a one-tailed, non-parametric Wilcoxon signed-rank test also confirmed that the usage of the hand gesture interface significantly decreases the time to perform the second task (\(p\)-value = 0.043 \(<\) 0.050). Another metric to look at for the experiments is the setup time for the first usage of the hand gesture interface. In general, the average time to record the three gestures was 99 s, and the time to set up the five sequences and map them to the five modes was about 69 s. These actions are only executed the first time a participant uses the interface. The participant's data are then kept in memory. Therefore, it might be cumbersome to use the hand gesture solution the first time. However, because these actions are only required once (at the installation of the hand gesture interface) and are kept in memory from day to day, the payback increases rapidly with time. Finally, some qualitative data has been gathered from the experiments, as the participants answered a questionnaire after completing the tasks. This allowed the participants to rate their appreciation of the system. The results of this questionnaire are presented in Figure 13.  
The results show that the participants appreciated using the hand gesture interface. They felt that it would get easier to use with time, but still needed a fair level of concentration when using it. However, they did not find it cumbersome, counterintuitive, or difficult to use. They also noted in the comments that they especially liked using the hand gesture interface in combination with the AssystMouse, as it gave them quick access to shortcuts that were easy to execute. The tasks chosen for the experiments aimed to evaluate the user's control over the cursor, while being able to execute various commands (e.g., clicks). Many users living with muscular dystrophy or spinal cord injury, for instance, can move their wrist or fingers. However, they might not be able to move their arm enough to control a mouse, and it is even more difficult to lift the arm to control a keyboard. With the device, they can rest their arm on an armrest and move the wrist so the system can recognize different movement signatures, which can help them to control different shortcuts, such as those tested in the experiments. In a case where they can't control their arm or wrist, the device can be installed on another body part such as a foot or the head. The choice to compare the hand gesture interface against the AssystMouse technology also brings interesting results to the experiment. The AssystMouse is used in practice and is easily available; it represents a valid reference point to compare the hand gesture interface, since both interfaces may be used by the same population.