一种机器人辅助髋关节置换术中随动技术研究OA

Objective:To research,develop and verify a motion-following compensation technique of end-effector of surgical robot for joint,which aimed at the deviation of direction and depth of acetabular reamer caused by intraoperatively pelvic displacement during total hip arthroplasty(THA).Methods:A system consisted of a cart with robotic arm,a navigation cart[three dimension(3D)vision/navigation software],and a platform for patient(fixed device/pelvic marker).The relative pose of"tool-pelvis"was calculated,and the motion-following of end-effector was realized at the closed loop of Cartesian spatial error on the basis of real-time tracking of robot tool and pelvic volumetric position.Twenty pelvic models were simply randomized into a motion-following group and a non-motion-following group,with 10 cases in each group.Under perturbations of simulated pelvis,the difference between the terminal pose of acetabular reamer,and the pose of reposition based on the final posture of pelvis was recorded,and the displacement error(mm)and angular error(°)were extracted.The above indicators were compared between two groups.Results:The displacement error of motion-following group was(1.18±0.43)mm,and that of the non-motion-following group was(3.76±1.11)mm.The angular error of motion-following group was(0.84±0.32)°,and that of non-motion-following group was(3.21±1.03)°.The differences both of displacement error and angular error between two groups were statistically significant(t=6.857,6.941,P<0.001).Conclusions:By real-time tracking of relative pose and motion-following compensation,the system can stably control the drift distance of acetabular reamer pose at at the millimeter level,and control the drift angle of the posture at<1° when the pelvis occurred movement,which can significantly reduce the dependency for rigid fixation of pelvis,and enhance the precision,accuracy and consistency of THA acetabular acetabular reamer.It has potential of further conducting transformation in clinical practice.