A Smooth Trajectory Planning for High Tibial Osteotomy Surgery with Robot-assisted Based on NURBS and S-curve Method

Compared to conventional freehand procedures, robot-assisted surgery is more efficient and minimally invasive. The planning procedures decide the quality of robot-assisted surgery. However, the traditional polynomial function method and spline method can lead the robot to oscillate when executing the trajectory for puncture or location. To generate a smooth and steady trajectory to improve the quality of robot-assisted surgery, this paper proposes a trajectory planning method for the planning of puncture points in High Tibial Osteotomy (HTO). First, the coordinates of puncture points are obtained by creating a computer-aided design (CAD) model of the leg bone with the osteotomy plate. Then, the non-uniform rational B-spine (NURBS)method is applied to generate a smooth trajectory for puncture points. The S-curve method is used to plan the velocity and acceleration. Finally, simulations are conducted to verify the correctness and effect of the proposed method, which show that the proposed method can improve the trajectory of surgery in terms of smoothness and jerk reduction.