## 3 Results  
A total of 40 pedicle screws were stimulated using a conventional probe and a newly developed magnetic stimulating probe, respectively, and the triggered threshold was measured. The raw data measured in this experiment are summarized in Table 1. The triggered threshold obtained from the usually inserted pedicle screws (Group A) showed no statistical difference between the conventional probe and the magnetic stimulating probe (\(p\) = 0.702, Figure 6). Similarly, there was no significant difference between the two groups from the experiment on Group B assuming neural injury during lumbar pedicle screw placement (\(p\) = 0.816, Figure 6). Therefore, there was no difference in the triggered threshold between the two groups in the overall pedicle screw stimulation, including Groups A and B (\(p\) = 0.828, Figure 6). In addition, there were no differences between the two groups in the subgroup analysis based on the pedicle level and laterality (Figure 6). No complications or unexpected events were observed during the experiment when using a magnetic stimulating probe, and the results were comparable to those obtained using a conventional stimulating probe. The process of separating the driver after the instrumentation of the pedicle screw could be omitted in the magnetic stimulating probe. Thus, there was less hassle than in the conventional probe.  
\begin{table}
\begin{tabular}{c c c c c c c} \hline  & & & \multicolumn{2}{c}{**Group A (Normal)**} & \multicolumn{2}{c}{**Group B (Abnormal)**} \\ \hline \hline \multirow{2}{*}{**Triggered Threshold**} & \multirow{2}{*}{L4} & \multirow{2}{*}{\begin{tabular}{c} **Conventional** \\ **Stimulator** \\ \end{tabular} } & \multirow{2}{*}{\begin{tabular}{c} **Magnetic** \\ **Stimulator** \\ \end{tabular} } & \multirow{2}{*}{\begin{tabular}{c} **Conventional** \\ **Stimulator** \\ \end{tabular} } & \multirow{2}{*}{\begin{tabular}{c} **Magnetic** \\ **Stimulator** \\ \end{tabular} } & \multirow{2}{*}{\
\begin{tabular}{c} **Conventional** \\ **Stimulator** \\ \end{tabular} } & \multirow{2}{*}{
\begin{tabular}{c} **Magnetic** \\ **Stimulator** \\ \end{tabular} } \\ \hline \multirow{2}{*}{**Pig 1**} & \multirow{2}{*}{L4} & Rt. & 16 & 17 & 3.5 & 3.5 \\  & & Lt. & 12 & 12 & 1.0 & 0.8 \\  & & Rt. & 11 & 12 & 0.7 & 0.7 \\  & & Lt. & 10 & 10 & 3.0 & 3.5 \\ \hline \multirow{2}{*}{**Pig 2**} & \multirow{2}{*}{L4} & Rt. & 13 & 14 & 3.5 & 3.5 \\  & & Lt. & 10 & 10 & 2.5 & 2.0 \\  & & Rt. & 8 & 8 & 2.0 & 2.0 \\  & & Lt. & 9 & 10 & 1.5 & 1.5 \\ \hline \multirow{2}{*}{**Pig 3**} & \multirow{2}{*}{L4} & Rt. & 10 & 10 & 0.8 & 1.0 \\  & & Lt. & 8 & 7 & 3.0 & 3.0 \\  & & Rt. & 9 & 9 & 2.5 & 2.5 \\  & & Lt. & 12 & 12 & 3.0 & 2.5 \\ \hline \multirow{2}{*}{**Pig 4**} & \multirow{2}{*}{L4} & Rt. & 15 & 16 & 1.0 & 1.5 \\  & & Lt. & 13 & 13 & 2.5 & 2.5 \\  & & Rt. & 12 & 13 & 0.7 & 1.0 \\  & & Lt. & 15 & 15 & 1.5 & 1.5 \\ \hline \multirow{2}{*}{**Pig 5**} & \multirow{2}{*}{L4} & Rt. & 11 & 11 & 2.0 & 2.5 \\  & & Lt. & 9 & 9 & 3.0 & 3.0 \\  & & Rt. & 11 & 12 & 3.0 & 3.5 \\  & & Lt. & 10 & 10 & 3.0 & 3.0 \\ \hline \multicolumn{2}{c}{Mean \(\pm\) SD} & \multicolumn{2}{c}{\(11.2\pm 2.25\)} & \(11.5\pm 2.56\) & \(2.19\pm 0.95\) & \(2.25\pm 0.94\) \\ \hline \hline \end{tabular} SD: standard deviation; Rt.: right; Lt.: left.  
\end{table}
Table 1: Raw data of triggered threshold according to the use of conventional stimulator and novel magnetic stimulator.