A Compact Surgical Robot System for Craniomaxillofacial Surgery and its Preliminary Study

Craniomaxillofacial surgery has the characteristics of complex anatomical structure, narrow surgical field, and easy damage to nerves, blood vessels, and other structures. Compared with the traditional bare-hand operation, robot-assisted craniofacial surgery is expected to achieve a more stable and accurate surgical operation. So we have developed a robot-assisted craniofacial surgery system. A compact mechanism design was adopted for the robot system, integrates with visual and force perception modules. The motion analysis and working space analysis are carried out on the mechanical structure. The binocular vision module is integrated and the robot hand-eye calibration process was completed. The target tracking method based on staple is used to achieve tracking and monitoring of the target area. A distributed robot control system based on CAN bus technology is designed, and a position-based visual servo control method is adopted. Then the precision test of the robot system prototype and the drilling experiment of the 3D printed mandible model were carried out. The average pixel error of the vision module is 0.15 pixels. Based on the staple tracking method, the average center error rate of the image is 0.3175 mm, and the overlap rate is 88.76%. The drilling experiment of the mandible model showed that the average entrance position error is 1.76 ± 0.36 mm, the average target position error is 1.62 ± 0.27 mm, and the angle error is 5.36 ± 0.31 degrees. The designed craniofacial robot system can better assist surgeons to complete the mandibular osteotomy.