# Portable RGB-D Camera-Based System for Assessing Gait Impairment Progression in ATTRv Amyloidosis
## 3 Results
In most cases where there was no accordance (30 out of 48 cases), the Kinect did not detect an actual significant difference in the parameter's values (14 out of 30 cases), while the opposite happened for 10 cases. For the remaining six parameter/patient pairs, both systems found significant differences, but the trend over time was opposite (the mean parameter value decreased for Qualisys, while it increased for Kinect, or vice-versa). Furthermore, when performing the Cohen's Kappa inter-rater agreement (CK-IRA) test over all gait parameters and subjects, a fair strength of agreement (\(\kappa\) = 0.360, 95% CI [0.194, 0.505], \(p\)-value \(\leq\) 0.001) was achieved. When taking into account only the kinematic parameters, there was a moderate strength of agreement (\(\kappa\) = 0.546, 95% CI [0.440, 0.617], \(p\)-value \(\leq\) 0.001). A substantial strength of agreement (\(\kappa\) = 0.757, 95% CI [0.645, 0.840], \(p\)-value \(\leq\) 0.001) was obtained when considering only the spatiotemporal gait parameters. The strength of agreement was almost perfect (\(\kappa\) = 0.932, 95% CI [0.837, 0.970], \(p\)-value \(\leq\) 0.001) when considering the following six parameters that showed the best accordance between systems when analyzing Table 3: stride duration, gait speed, arm swing velocity, stride length, foot swing velocity, and gait speed variability. Table 4 provides a representation of Table 3's results. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**Spatiotemporal Gait Parameter**} & \multicolumn{5}{c}{**Mean Difference (T1\(-\)T0)**} \\ \cline{2-6}  & **P1** & **P2** & **P3** & **P4** & **P5** & **P6** \\ \hline
**Stride duration (s)** & & & & & & \\
**Step duration (s)** & & & & & & \\
**Stance duration (s)** & & & & & & \\
**Swing duration (s)** & & & & & & \\
**Single support duration (s)** & & & & & & \\
**Double support duration (s)** & & & & & & \\
**Stride length (cm)** & & & & & & \\
**Step length (cm)** & & & & & & \\
**Step width (cm)** & & & & & & \\
**Gait speed variability (m/s)** & & & & & & \\
**Foot swing velocity (m/s)** & & & & & & \\
**Arm swing velocity (m/s)** & & & & & & \\
**TBCM-ML * sway (cm)** & & & & & \\
**TBCM-V * sway (cm)** & & & & & & \\
**Spine shoulder angle** & & & & & & \\
**Spine middle angle** & & & & & \\
**Maximum elbow angle** & & & & & \\
**Minimum elbow angle** & & & & & & \\
**Maximum knee angle** & & & & & \\
**HiP angle range** & & & & & \\
**Ankle angle range** & & & & & \\ \hline \hline \end{tabular}  
* TBCM-ML and TBCM-V stand for total body center of mass mediolateral and vertical sway, respectively.  
\end{table} 
Table 4: Representation of the difference between the two used systems for each parameter and patient. When both systems have the same result it is shown in green, it is shown in yellow when they have the same tendency but one does not show a statistically significant difference, and in orange when the tendency and the difference are not the same. “—” indicates that it was not possible to perform the statistical test due to the small amount of available data.