Jian Zhang1, Weishi Li2, Lei Hu1, Tianmiao Wang1. 1. School of Mechanical Engineering and Automation, Beihang University, Beijing, China. 2. Department of Orthopaedic Surgery, Peking University Third Hospital, Beijing, China.
Abstract
BACKGROUND: In recent years, surgeons have explored minimally invasive methods of percutaneous pedicle screw implantation which can effectively reduce human injuries. This article presents an accurate and efficient positioning method and robot system for percutaneous needle placement under c-arm fluoroscopy. METHODS: A simple five degree of freedom (DOF) robot with a unique end-effector is designed to perform perspective calibration and image space registration. The principle of pedicle standard axis positioning is adopted to make the axis of the pedicle overlap with the x-ray axis of c-arm. RESULTS: Then the clinical operation is carried out to verify the clinical feasibility of the designed robot and positioning method. The experimental results show that a total of 26 pedicle screws were accurately implanted. The accuracy of Grade A is 96.15%. The positioning time of a single guide pin is about 154.77 s, and three x-ray films need to be taken on average. CONCLUSIONS: The positioning accuracy is increased by using the present method. In addition, this method is simple in operation, short in operation time, low in X-ray exposure.
BACKGROUND: In recent years, surgeons have explored minimally invasive methods of percutaneous pedicle screw implantation which can effectively reduce human injuries. This article presents an accurate and efficient positioning method and robot system for percutaneous needle placement under c-arm fluoroscopy. METHODS: A simple five degree of freedom (DOF) robot with a unique end-effector is designed to perform perspective calibration and image space registration. The principle of pedicle standard axis positioning is adopted to make the axis of the pedicle overlap with the x-ray axis of c-arm. RESULTS: Then the clinical operation is carried out to verify the clinical feasibility of the designed robot and positioning method. The experimental results show that a total of 26 pedicle screws were accurately implanted. The accuracy of Grade A is 96.15%. The positioning time of a single guide pin is about 154.77 s, and three x-ray films need to be taken on average. CONCLUSIONS: The positioning accuracy is increased by using the present method. In addition, this method is simple in operation, short in operation time, low in X-ray exposure.