# Biosignals Monitoring of First Responders for Cognitive Load Estimation in Real-Time Operation
## 4 Experimental Tests
### In-Lab Scenario  
A total of 80 FRs (24 doctors, 29 nurses, 22 technicians, and 5 firefighters) were selected for the in-lab tests (see Table 2). They performed a CL test based on The Sky Test ATCO ([[https://www.skytest.com/](https://www.skytest.com/)]([https://www.skytest.com/](https://www.skytest.com/)), accessed on 12 June 2023). The Sky Test ATCO is a software tool that provides several tests aimed at improving the concentration and performance, specifically designed for air traffic controllers. One of the tests consists of a divided attention exercise that has been selected for its CL implications.  
Figure 3: Biosignals monitoring software architecture.  
This test consists of one to nine boxes (see Figure 4) with a ball and a stick inside moving randomly. Each of the boxes has a number on its lower right corner. When the ball and the stick get in touch in a box, the volunteer must press the number of the box. The users sit in front of a computer for around 30 min with a specific sequence in three trials (see Figure 5a). The first trial is devoted to the basal approach to the divided attention test, where the user performs the experiment with one box for 3 min, fills up the NASA-TLX for the trial and rests for 3 min. This trial allows the system to obtain basal and rest information from biosignals, as well as calculating the user's performance of the computer-based program. The second trial focuses on a sequence of four levels of difficulties with two, three, four, and five boxes with 1 min rest in between. After it, a NASA-TLX questionnaire is filled up followed by a three-minute rest. In the last trial, a three-minute test of nine boxes is performed followed by the completion of the last NASA-TLX test.  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline  & **Profession** & \multicolumn{2}{c}{**Number**} & \multicolumn{2}{c}{**Age (Years)**} & \multicolumn{2}{c}{**Experience (Years)**} \\  & **Male** & **Female** & **(Mean \(\pm\) Std)** & **(Mean \(\pm\) Std)** \\ \hline \multirow{3}{*}{**In-Lab**} & **Doctors** & 6 & 18 & 47.50 \(\pm\) 7.33 & 20.38 \(\pm\) 7.67 \\  & **Nurses** & 9 & 20 & 45.34 \(\pm\) 4.94 & 22.14 \(\pm\) 5.40 \\
**Scenario** & **Technicians** & 2 & 6 & 46.59 \(\pm\) 7.63 & 19.32 \(\pm\) 7.53 \\  & **Firefighters** & 5 & 0 & 39.40 \(\pm\) 7.91 & 9.60 \(\pm\) 9.85 \\ \hline \multirow{3}{*}{**Practice**} & **Doctors** & 1 & 2 & 41.67 \(\pm\) 5.73 & 15.00 \(\pm\) 7.12 \\  & **Nurses** & 3 & 6 & 42.33 \(\pm\) 6.86 & 18.89 \(\pm\) 6.23 \\
**Scenario** & **Technicians** & 8 & 0 & 40.75 \(\pm\) 10.49 & 13.88 \(\pm\) 8.18 \\  & **Firefighters** & 5 & 0 & 33.33 \(\pm\) 2.87 & 1.67 \(\pm\) 0.47 \\ \hline \hline \end{tabular}
\end{table}
Table 2: Profession, gender, age, and years of experience of the FRs involved in the in-lab and practice scenarios.  
Figure 4: Divided attention in-lab scenario screens. (**a**) 1 screen, (**b**) 2 screens, (**c**) 3 screens, (**d**) 4 screens, (**e**) 5 screens, and (**f**) 9 screens.  
Figure 5: Protocol established for the (**a**) in-lab tests and (**b**) practice scenario.