Positioning Accuracy of a Medical Robotic System for Spine Surgery

This paper discusses the absolute positioning accuracy of a medical robotic system for minimally invasive spine surgery (MISS). First, the system architecture and main working flow are briefly introduced. Then, according to the requirement of MISS operation, a five-degree-of-freedom (5-DOF) operating mechanism is designed and developed for such applications, and a detailed analysis has been performed for the robot kinematics. In view of the physical constraints imposed by mechanical joints, the operating mechanism is determined. Moreover, the kinematics analysis is carried out via the Denavit-Hartenberg (DH) representation. Furthermore, the error model of geometrical parameters is built and the influence of the link parameters error on the precision of robot is identified. Finally, the absolute positioning accuracy of the robot is measured. The results show that the positioning error of the medical robot is less than 1 mm, which is comparable to that of spine surgery.