On this model basis the first step method is used for optimization of the archaxis coefficient of the arch bridge.
在此模型基础上，使用一阶方法对拱桥的拱轴系数进行优化。
2
Result the parameters of posterior arch, lateral mass, vertebral artery groove, axis length of screw pass via posterior arch and lateral mass, projection and direction of screw were measured.
结果测量出寰椎后弓、侧块、椎动脉沟、后弓侧块螺钉通道的轴线长度，及后弓进钉点和进钉方向等参数。
3
To resolve the problem of the point and direction of the fixation ofAxis lateral arch screw, using navigator finds the safe trajectory.