针对目前的脑立体定向手术导航注册方法存在较大误差和可能出现奇异点等缺点，提出了一种基于四元数电磁定位的新注册方法．利用四元数的快速迭代特性和计算过程无奇异解的特性实现注册过程中的3 个空间映射过程，根据单位四元数中的刚体姿态变换描述及奇次坐标理论求解从实时手术空间到计算机空间的最优转换矩阵．实验结果表明，文中所提算法得到的注册误差均在2mm 以下，当注册点在7 ～ 12 个范围内，并且排放对称、均匀紧凑地围绕着病灶区域时，系统注册精度更高．

In order to avoid the gross registration error and the singular point in the current registration method of the navigation of stereotactic brain surgery,a novel registration method with electromagnetic positioning is proposed based on unit-quaternion. In this method,by using the characteristics of fast iteration and nonsingular solution of unit-quaternion,three space mappings are realized during the registration. Moreover,the optimal transformation
matrix from the surgery space to the computer space is solved according to the description of the rigid body posture transform in unit-quaternion and to the theory of odd coordinates. Experimental results show that the registration errors of the proposed algorithm are all less than 2mm,and the registration accuracy of the system is higher when 7 ~12 registration points lie symmetrically and surround the lesion uniformly and compactly.