## 3 Materials and Methods
### Feature Extraction for Predefined Measurement Items and Diagnosis of ADHD
#### 3.4.1 Indicator A1--Body Movement during Wait  
The first abnormal behavior to detect is \"body movement during wait\". The child is asked to pay attention while the robot is demonstrating. However, because children with ADHD often have poor concentration, they are typically more unable to concentrate than normal children. Therefore, this factor indicates a child's inattention or hyperactivity impulsive behavior. This measurement is performed in the \"wait\" state of the child, and the total measurement time is divided into five-second intervals, and the ratio of the section in which movement occurs to the total section is recorded. At this time, the child's movement to be recorded includes not only body joints, such as arms and shoulders, but also the movement of the gaze. During wait, body movements are measured in the world coordinate system, and head, shoulder, and wrist movements are measured by Equations (2) to (4), respectively. One section is made in units of 5 s, and when the motion occurs in each section, the section is defined as 1, and when there is no motion, it is defined as 0. Then, the A1 indicator is extracted by calculating the ratio of the section in which motion occurs in the entire section. The extraction formula of the finally measured A1 is expressed as Equation (5). At this time, the threshold of Equation (2) is 30 degrees, and the threshold of Equations (3) and (4) is 200 mm, respectively.  
\[A1_{head\_section_{n}}=\left\{\begin{aligned} & Sum\;of\;degree_{head}\geq\; threshold,\;\;1\\ & Sum\;of\;degree_{head}<threshold,\;\;0\end{aligned}\right\}, \tag{2}\]  
\[A1_{shoulder\_section_{n}}=\left\{\begin{aligned} & Sum\;of\;distance_{shoulder}\geq\; threshold,\;\;1\\ & Sum\;of\;distance_{shoulder}<threshold,\;\;0\end{aligned}\right\}, \tag{3}\]  
\[A1_{wrist\_section_{n}}=\left\{\begin{aligned} & Sum\;of\;distance_{wrist}\geq\; threshold,\;\;1\\ & Sum\;of\;distance_{wrist}<threshold,\;\;0\end{aligned}\right\}, \tag{4}\]  
\begin{table}
\begin{tabular}{c c c c} \hline \hline \multirow{2}{*}{**Categories**} & **Types of Screening Diagnostic Abnormal** & **Number of Features** & **Total Number of Features** \\  & **Behavior Indicators** & **for Each Level** & **(Five Levels)** \\ \hline \multirow{3}{*}{Attitude} & A1: body movements during wait & & \\  & A2: Take a seat during wait & & 3 & 15 \\  & A3: Leave the waiting area during wait & & & \\ \hline \multirow{3}{*}{Move} & B1: Enter the game board before the start instruction & & \\  & B2: Not playing the game after the start instruction & & \\  & B3: The amount of time from the instruction to start & & \\  & until the child begins the game & & \\  & B4: The accuracy of the child’s following path & & \\  & B5: Move before the movement confirmation sound & & \\ \hline \multirow{3}{*}{Task execution} & C1: Correct response & & \\  & C2: Incorrect response before correct response & & \\  & C3: Incorrect response & & \\  & C4: correct response before incorrect response & & \\  & C5: Time taken to respond to a stimulus & & \\ \hline \multirow{2}{*}{Etc.} & D1: Total execution time & & \\  & D2: Total distance traveled & 2 & 10 \\ \hline \multicolumn{3}{c}{Total Number of Features} & 15 & 75 \\ \hline \hline \end{tabular}
\end{table}
Table 2: Abnormal behavior indicators for screening of ADHD.  
\[A1=Avg\frac{(\sum_{n}A1_{head\_section}n+\sum_{n}A1_{should\_section}n+\sum_{n}A1_{ wist\_section}n)}{Num\ of\ total\ sections}. \tag{5}\]