The mechanism and registration method of a surgical robot for hip arthroplasty

This paper presents the mechanism and surgical method for ARTHROBOT, a new surgical robot for hip arthroplasty. The robot is femur-mountable and capable of 4-DOF motion. It uses a new gauge-based registration method that utilizes measuring instrument consisting of a reamer-shaped block gauge and a distance-measuring device. This gauge-based registration method drastically reduces the processes in the preoperative planning by eliminating the need of inserting fiducial markers or CT scanning. From the preliminary performance evaluation, it is shown to have less than 0.3 mm machining error, which seems to be sufficiently accurate for clinical application. Since the system has low operating cost and is compatible to the conventional manual surgery, it is expected to be easily adaptable to surgical needs and practices in the operating room.