A hybrid tracking system for image-guided spine surgery using a tracked mobile C-arm: a phantom study. - Peyman Ghobadi Azbari; Alireza Ahmadian; Hooshang Saberi; Mohammadreza Ay; Mostafa Abdolghaffar; Keyvan Amini Khoiy (Turkish J. Electr. Eng. Comput. Sci., 2017)