Experimental Investigations on the Relationship Between the Navigation Accuracy and the Tracing Distance from the Registration Center.

This paper investigates the relationship between the navigation accuracy and the distance from the tracing regions to the registration center. The investigation was carried out using a 3D-printed plastic model and an infrared binocular camera. 7 registration points were set up around the nasal-orbital area as registration points. 7 groups of checking points were used to test the registration accuracy, which was at a distance of 10, 20, 30, 40, 50, 60, and 70 mm from the registration area center, respectively. The accuracy of each group of checking points was investigated. SPSS 19.0 was used to calculate the mean error of each tracing point. The tracing error of different areas was compared by t-test. The relationship between distance and error was investigated by the linear regression method. P<0.05 was considered as significant difference. Results: The deviation of navigation points in the 7 groups of registered checking points is 0.737±0.236 mm, with the largest deviation at 1.307 mm, the smallest at 0.272 mm, and the mean 95% CI at (0.6296, 0.8449). The navigation error (y) and the distance from the registration center (x) coincided with the linear regression, the regression equation was identified to be y=-0.451+0.178x. This regression model is statistically significant (P<0.05). The navigation error increases when the tracing region moves far away from the registration area.