# eJamar: A Novel Exergame Controller for Upper Limb Motor Rehabilitation
## 4 Preliminary System Validation
### USE Questionnaire: Usefulness, Satisfaction, and Ease of Use  
The questionnaire consisted of five sections. The first section collected participant information, such as gender, age, and dominant hand. The second section, with 12 questions, evaluated the playability of the two proposed games. The third section, consisting of \begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**ID**} & \multirow{2}{*}{**Age**} & \multirow{2}{*}{**Gender**} & \multicolumn{2}{c}{**Dominant**} & \multirow{2}{*}{**Years of**} & \multicolumn{1}{c}{**Prior**} \\  & & & & **Hand** & **School** & **Computer** \\  & & & & & **Usage** \\ \hline P1 & 33 & F & Right & 18 & Yes \\ P2 & 36 & F & Left & 18 & Yes \\ P3 & 55 & F & Right & 12 & No \\ P4 & 62 & F & Right & 12 & No \\ P5 & 64 & M & Left & 14 & Yes \\ P6 & 65 & M & Right & 18 & Yes \\ P7 & 68 & F & Right & 12 & No \\ P8 & 71 & M & Right & 14 & Yes \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Demographic information of participants. 7 questions, assessed the usability of the ejamar GC. The fourth section evaluated player satisfaction during the overall gameplay experience. Additionally, a suggestions section was included, where participants provided feedback on potential system improvements. The responses were recorded on a Likert scale ranging from \(-2\) to \(2\), where \(-2\) indicated \"strongly disagree\", \(-1\) \"disagree\", \(0\) \"neutral\", \(1\) \"agree\", and \(2\) \"strongly agree\". Table 4 shows the three main sections of questionnaire and answers of participants. In the Playability section, participants consider that both games are user-friendly (Q1 and Q7). However, Andromeda (Q8 = \(1.4\pm 0.52\)) is considered more engaging than PJG (Q2 = \(0.63\pm 1.19\)). This result is further supported by the suggestions section, where participants note that PJG could benefit from having more levels or improving the game environment. On the other hand, both games are found to be intuitive and easy to use (Q5 and Q11), as participants mention that they could play these exergames at home (Q3 and Q9) without the help of a therapist (Q6 and Q12). In the Usability section, participants consider that the ejamar controller and its respective control actions for each game are easy to manage (Q13 and Q14 = \(1.8\pm 0.46\)). The controller's weight received the lowest rating (Q15 = \(1\pm 0.93\)), prompting us to consider a possible reduction in the device's weight. Participants report feeling comfortable using the ejamar (Q17 = \(1.5\pm 0.76\)), despite having to hold the controller in mid-air without support. We believe this comfort could be further improved if participants rest their hand on a table, a modification we plan to implement during future patient trials. No Bluetooth communication disconnections were reported (Q18 = \(1.9\pm 0.35\)). The controller's electronic system is designed to provide feedback to the user through ejamar's vibration, but, as shown in Table 4, question Q19, participants P3 and P8 had difficulty distinguishing the vibration from the controller. In the Satisfaction section, it is notable that all participants were able to complete all levels of the games (Q20), which aligns with the responses from the Playability section, where the games were found to be easy to play (Q5 and Q11). Additionally, participants generally did not experience fatigue during gameplay and felt that the difficulty level of the games was appropriate (Q22 and Q23). The controller features a knob that must be manually adjusted to fit the user's hand size and enhance comfort. However, participants found this knob difficult to calibrate due to its rigidity (Q23 = \(0.25\pm 1.49\)). As a result, we suggest that this adjustment should be performed by a specialist prior to gameplay.