Experimental Evaluation of a Surgical Robot System (ARTHROBOT) for Hip Surgery using Sawbones and Pig Femurs

This paper presents the experimental results of ARTHROBOT, a new surgical robot system for hip surgery, using sawbones and pig femurs. This surgical robot system has been developed to improve the surface conformity and position/orientation accuracy of the arthroplastic surgery. Since the surface conformity and position/orientation accuracy are directly related to the recovery time of the patient, it is desirable to keep the surface conformity and position/orientation accuracy as high as possible. The system consists of four components: a small bone-mountable surgical robot, a reamer-shaped block gauge, a femoral frame and a compact distance-measuring device. In this paper, the performance of ARTHROBOT is evaluated through measuring the position/orientation accuracy and the surface conformity between the implant and the carved sawbones and pig femurs. To measure the position and orientation accuracy, we compared the intended position/orientation to the position/orientation of the machined cavity using an imitation implant. For surface conformity measurement, the cross-sectional gap between the machined cavity and the plastic implant were measured after inserting the plastic implant into the cavity and slicing the bone. The experimental results with sawbones and pig femurs show that ARTHROBOT has sufficient accuracy and precision for clinical application.