Projective invariant biplanar registration of a compact modular orthopaedic robot
Issue title: Frontiers in Biomedical Engineering and Biotechnology – Proceedings of the 2nd International Conference on Biomedical Engineering and Biotechnology, 11–13 October 2013, Wuhan, China
Affiliations: School of Computer Science and Engineering, Beihang University, Beijing, China | Traumatology and Orthopaedics Institute, Beijing Jishuitan Hospital, Beijing, China | School of Mechanical Engineering and Automation, Beihang University, Beijing, China | Department of Orthopaedics, Chinese PLA General Hospital, Beijing, China
Abstract: This paper presents a compact orthopedic robot designed with modular concept. The layout of the modular configuration is adaptive to various conditions such as surgical workspace and targeting path. A biplanar algorithm is adopted for the mapping from the fluoroscopic image to the robot, while the former affine based method is satisfactory only when the projection rays are basically perpendicular to the reference coordinate planes. This paper introduces the area cross-ratio as a projective invariant to improve the registration accuracy for non-orthogonal orientations, so that the robotic system could be applied to more orthopedic procedures under various C-Arm orientation conditions. The system configurations for femoral neck screw and sacroiliac screw fixation are presented. The accuracy of the robotic system and its efficacy for the two typical applications are validated by experiments.
Keywords: Medical robotics, projective invariant, modular design
