# Smart Helmet and Insole Sensors for Near Fall Incidence Recognition during Descent of Stairs
## 3 Results
### Results of Plantar Pressure Distribution Analysis (Smart Shoe)  
Table 3 shows the results of the sensor values measured by plantar pressure in each channel and on each side of the insole sensor collected under three different experimental conditions. The average sensor value for each channel was calculated as the average of 10 subjects. Channels 1 through 6 (closer to the hindfoot area) had relatively higher pressure on both the right and left feet compared to the pressure detected in channels 7 to 10 (closer to the forefoot area). Plantar pressure results comparing the right and left foot under each experimental condition showed that channels 6, 8, and 9 had the greatest difference under all of the three conditions (Figure 10). Plantar pressure was 0.73 pF higher in the right foot (Ch 6), 0.77 pF higher in the left foot (Ch 8), and 0.26 pF higher in the right foot (Ch 9) in E1. Plantar pressure was 0.67 pF higher in the right foot (Ch 6), 0.72 pF higher in the left foot (Ch 8), and 0.23 pF higher in the right foot (Ch 9) in E2. However, E3 had slightly different results; plantar pressure was 0.40 pF in the right foot (Ch 1), 0.79 pF higher in the right foot (Ch 6), 0.69 pF higher in the left foot (Ch 8), and 0.32 pF higher in the right foot (Ch 9). \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline  & \multicolumn{2}{c}{**E1**} & \multicolumn{2}{c}{**E2**} & \multicolumn{2}{c}{**E3**} \\ \hline
**Sub No.** & **Right** & **Left** & **Right** & **Left** & **Right** & **Left** \\ \hline
1 & 48.41 & 48.64 & 48.55 & 48.71 & 50.71 & 48.62 \\
2 & 48.63 & 48.82 & 48.82 & 49.01 & 50.11 & 48.85 \\
3 & 48.40 & 48.65 & 48.56 & 48.73 & 49.65 & 48.62 \\
4 & 48.45 & 48.65 & 48.54 & 48.81 & 50.50 & 48.75 \\
5 & 48.54 & 48.68 & 48.63 & 48.84 & 50.77 & 48.60 \\
6 & 48.67 & 48.89 & 48.83 & 49.00 & 50.24 & 48.86 \\
7 & 48.33 & 48.90 & 48.39 & 49.05 & 51.10 & 48.85 \\
8 & 48.63 & 48.90 & 48.71 & 49.06 & 51.10 & 48.87 \\
9 & 48.15 & 48.49 & 48.32 & 48.63 & 50.98 & 48.49 \\
10 & 48.30 & 48.84 & 48.42 & 48.97 & 50.47 & 48.77 \\ \hline AVG & 48.45 & 48.75 & 48.58 & 48.88 & 50.56 & 48.73 \\ SD & 0.17 & 0.14 & 0.18 & 0.16 & 0.47 & 0.13 \\ \hline \hline \end{tabular}  
* E1: Natural descent, E2: Weighted descent, E3: Near fall-simulated descent.  
\end{table} 
Table 2: Results of summed average plantar pressure in each foot (unit: pF). Figure 10: Results of bilateral plantar pressure distribution changes in each insole channel (all subjects). E1: Natural descent, E2: Weighted descent, E3: Near fall-simulated descent. \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline  & \multicolumn{2}{c}{**E1**} & \multicolumn{2}{c}{**E2**} & \multicolumn{2}{c}{**E3**} \\ \hline
**Ch. No.** & **Right** & **Left** & **Right** & **Left** & **Right** & **Left** \\ \hline
1 & 5.14 & 4.99 & 5.21 & 5.02 & 5.34 & 4.94 \\
2 & 5.24 & 5.37 & 5.27 & 5.39 & 5.36 & 5.38 \\
3 & 5.05 & 5.07 & 5.08 & 5.09 & 5.12 & 5.06 \\
4 & 5.08 & 5.12 & 5.10 & 5.13 & 5.12 & 5.11 \\
5 & 5.03 & 5.20 & 5.05 & 5.22 & 5.08 & 5.19 \\
6 & 5.01 & 4.28 & 5.03 & 4.36 & 5.07 & 4.28 \\
7 & 4.85 & 4.99 & 4.88 & 5.03 & 4.91 & 4.98 \\
8 & 4.28 & 5.05 & 4.34 & 5.06 & 4.36 & 5.05 \\
9 & 4.91 & 4.65 & 4.93 & 4.70 & 4.96 & 4.64 \\
10 & 4.84 & 4.86 & 4.89 & 4.88 & 4.93 & 4.86 \\ \hline \hline \end{tabular}  
* E1: Natural descent, E2: Weighted descent, E3: Near fall-simulated descent.  
\end{table} 
Table 3: Results of average plantar pressure detected in each insole channel (unit: pF). As shown in Table 4 and Figure 11 below, plantar pressure was higher in the lateral areas of both the right and left feet. The sum of the lateral plantar pressure in the right foot gradually increased from \(25.24\pm 0.12\) pF (E1) to \(25.36\pm 0.37\) pF (E2) to \(25.59\pm 0.15\) pF (E3).