## 3 Experiments and Results
### Guideline for Fabricating Pressure Sensors for Individual Applications
#### 3.2.2 Experimental Participant Information  
In order to conduct the experiment according to the application process of the lower limb movement intention detection system, one male amputee, one male non-amputee, and one female non-amputee with various physical conditions were selected. Subject 1 was a rectus amputee, and Figure 10(a) shows the appearance of Subject 1 when wearing the prosthetic leg. The socket worn by Subject 1 was a boa-type socket designed to increase adhesion by making four cuts to the front, rear, left, and right sides to fix the socket and the amputated lower limb. Figure 10(b) shows the simple experimental prosthetic leg and a diagram showing the sensor attachment position of the experimental prosthetic leg. The sockets worn by Subjects 2 and 3 were simple experimental prosthetic legs fabricated for experiments based on the wearing of prosthetic legs by non-amputated subjects. The experimental prosthetic leg had a structure that was not able to identify pressure changes at the lower part of the biceps femoris. Therefore, the sensor at the lower part of the biceps femoris was attached to the lower part of the knee joint to check the change in pressure in the vertical direction occurring at the lower part of the biceps femoris. Figure 10(c) shows the prior information on the three subjects. Figure 10: Schematic diagram and specifications of the pressure sensor data acquisition system. Figure 11: Appearance when wearing the prosthetic leg and prior information of subjects. : (**a**) Subject1 wearing the prosthetic leg; (**b**) Subject3 wearing the experimental prosthetic leg; (**c**) Prior information of subjects. 3.2.3. Experiments according to the Application Process of the Lower Limb Movement  
Intention Detection System: Initial Sensor Application Step  
Since the pressure range inside the socket varies depending on the physical characteristics of each subject, it is necessary to apply appropriate individual sensors. To this end, standing up, maximum pressure application, and minimum pressure application were applied, as shown in Figure 12, in order to determine the pressure pattern inside the socket of each subject. The size of the pressure sensor suitable for the individual pressure range was selected, and the cutting ratio was designated according to flexion to prevent an unfastened state from occurring inside the socket. The sensors fabricated at the specified size and cutting ratio were attached to the inside of the socket to configure an individual in-socket sensor system. Table 4 summarizes the sensors selected according to the physical characteristics of the subjects and the pressure range and flexion of each attachment part. \begin{table}
\begin{tabular}{l c c c} \hline \hline  & **Subject 1** & **Subject 2** & **Subject 3** \\ \hline Physical & Height 171 cm, Weight 82 kg, Male & Height 155 cm, Weight 50 kg, Female & Height 174 cm, Weight 75 kg, Male \\ Conditions & Rectus Amputee & Non-Amputated & Non-Amputated \\ \hline Selected & Sensor 1 1600 (about 150 kPa) & Sensor 1 800 (about 100 kPa) & Sensor 1 1600 (about 150 kPa) \\ Sensor & Sensor 2 1600 (about 150 kPa) & Sensor 2 800 (about 100 kPa) & Sensor 2 800 (about 100 kPa) \\ Sensor & Sensor 3 2400 (over 180 kPa) & Sensor 3 2500 (over 180 kPa) & Sensor 3 2500 (over 180 kPa) \\ Sensor & Sensor 4 2400 (over 180 kPa) & Sensor 4 2500 (over 180 kPa) \\ \hline \multirow{4}{*}{Cutting} & Sensor 1 Base 8\%, Height 16\% & Sensor 1 Base 8\%, Height 16\% \\  & (flexion radius about 120) & (flexion radius about 120) \\ Sensor & 2 Base 10\%, Height 20\% & Sensor 2 Base 10\%, Height 20\% \\ (flexion radius about 100) & (flexion radius about 100) \\ Sensor 3 Base 10\%, Height 20\% & Sensor 3 Base 14\%, Height 28\% \\ (flexion radius under 60) & (flexion radius under 60) \\ Sensor 4 Base 8\%, Height 16\% & Sensor 4 Base 8\%, Height 16\% \\ (flexion radius about 120) & (flexion radius about 120) \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Configuration of the individual in-socket sensor system in subjects.