## 3 Results and Discussion
### Evaluation of Conformity of Shape and Dimensions
#### 3.2.2 Evaluation by Shape Deviation Analysis  
A handheld Artec Eva 3D scanner by Artec was used to extract the human body shape data of 10 persons with paraplegia. To obtain a surface shape close to the actual human body shape of the subject, 3D scanning was performed, while the subject wore tights in a standing posture using a traction device (Figure 12a). Figure 12b shows the human body shape data of 10 persons with paraplegia generated by 3D scanning. In preparation for shape deviation analysis, each position from the data was primarily adjusted in the 3D coordinate space by reflecting the position where the 3 DP-pHRI was equipped to the wearable robot to determine the relative locations of the human body and the 3 DP-pHRI model data. The shape deviation comparison function of Artec Studio 9 software was used for shape deviation analysis, calculated using the data of 10 human body and 3 DP-pHRI model pairs completed using a matching process (Figure 13). Artec Studio 9 software can analyze the mean and standard deviation of shape deviations in the normal direction from two 3D data items with morphological similarity.  
As a result of analyzing shape deviation, the average deviation of the trunk 3 DP-pHRI showed a minimum value of 4.2 mm in sub2, and a maximum value of 9.32 mm in sub4. The average shape deviation of the shank 3 DP-pHRI showed a minimum value of 1.9 mm in sub5, and a maximum value of 7.58 mm in sub10 (Table 12). The following three data sources were referenced for the tolerance range for evaluating the suitability of the analyzed shape deviation. In ISO 20685-1 (2018), the tolerance range of body depth is 5 mm [37], and the result report of the 2016 Korean human body size survey suggested the tolerance range of large width as 5.44-10.0 mm [38]. In the study of [24], the tolerance range of the human body cross section in the normal direction was suggested as 10 mm. The tolerance range for conformance evaluation was set to 10 mm by additionally considering the error range of 5-10 mm suggested in the above reference materials and the allowable error range due to the characteristics of the open structure of 3 DP-pHRI.  
\begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline  & **Sub1** & **Sub2** & **Sub3** & **Sub4** & **Sub5** & **Sub6** & **Sub7** & **Sub8** & **Sub9** & **Sub10** \\ \hline Trunk section & 10 & 5 & 6 & 9 & 4 & 16 & 16 & 5 & 4 & 9 \\ \hline Shank section & 5 & 14 & 7 & 10 & 7 & 7 & 7 & 2 & 7 & 2 \\ \hline \hline \end{tabular}
\end{table}
Table 11: Results of selecting 3 DP-pHRI size systems.  
As a result of analyzing the average of the shape deviation in the normal direction for 10 human body 3 DP-pHRI model pair data, all values were within 10 mm of the error  
\begin{table}
\begin{tabular}{l c c c c c c c c c c c} \hline \hline  & & **Sub1** & **Sub2** & **Sub3** & **Sub4** & **Sub5** & **Sub6** & **Sub7** & **Sub8** & **Sub9** & **Sub10** \\ \hline \hline \multirow{2}{*}{\begin{tabular}{c} [PERSON] \\ pHRI \\ \end{tabular} } & \multirow{2}{*}{Mean} & 5.44 & 4.20 & 6.83 & 9.32 & 4.10 & 5.37 & 7.32 & 4.54 & 4.52 & 8.12 \\ \hline \hline \multirow{2}{*}{\
\begin{tabular}{c} [PERSON] \\ pHRI \\ \end{tabular} } & \multirow{2}{*}{Mean} & SD & 5.26 & 4.73 & 7.22 & 9.17 & 4.72 & 4.23 & 4.57 & 5.00 & 6.03 & 7.65 \\ \hline \hline \multirow{2}{*}{
\begin{tabular}{c} [PERSON] \\ pHRI \\ \end{tabular} } & \multirow{2}{*}{Mean} & 4.94 & 2.91 & 3.71 & 3.27 & 1.90 & 2.39 & 2.54 & 2.72 & 2.56 & 7.58 \\ \hline \hline \end{tabular}
\end{table}
Table 12: Results of evaluation by shape deviation analysis (unit: mm).  
Figure 12: Secure human body shape data: (**a**) 3D scanning of human body shape and (**b**) 10 subjects’ human body shape data.  
Figure 13: Results of evaluation by shape deviation analysis.  
range, confirming that the developed 3 DP-pHRI based on the sizing system had conformity in shape and dimensions at an appropriate level.