Design and Accuracy Assessment of NOR²CORS: Navigation-Operation Dual-Robot Collaborative Robotic System for Orthopedic Surgery

Optical navigation is the mainstream technology used in intraoperative navigation for the orthopedic surgical robot. The information loss problem in optical navigation system (OTS) seriously affects the surgical process. Different from the conventional orthopedic surgical robot systems, we propose to use an additional navigation robot to adjust the viewpoint of the OTS. In this navigation-operation dual-robot collaborative robotic system for orthopedic surgery (NOR2CORS), a comprehensive range of functions are realized, including CT image segmentation, path planning, intraoperative operation, and active navigation. In this paper, pedicle screw placement is adopted as an example to assess the effectiveness and performance of the NOR2CORS. An assessment criterion is also proposed to assess the accuracy of pedicle screw placement based on the widely-used Gertzbein and Robbins classification. Experiments are conducted on a human spine model (24 pedicles) and ex-vivo porcine spine (10 pedicles). According to the proposed assessment criterion, 96% pedicles on human spine model can be classified as grade A and 4% grade B, with 67% of them as grade A2 and above. In the ex-vivo porcine spine experiment, all pedicle screw placements can be classified as grade A, with 80% of them as grade A2 and above. In the surgical process, all positioning targets can be observed without any interruption in navigation. These results demonstrated the efficiency and accuracy of the NOR2CORS.