Application research of master-slave cranio-maxillofacial surgical robot based on force feedback

Background: The complex anatomical structure, limited field of vision, and easily damaged nerves, blood vessels, and other anatomical structures are the main challenges of a cranio-maxillofacial (CMF) plastic surgical robot. Bearing these characteristics and challenges in mind, this paper presents the design of a master-slave surgical robot system with a force feedback function to improve the accuracy and safety of CMF surgery. Methods: A master-slave CMF surgical robot system based on force feedback is built with the master tactile robot and compact slave robot developed in the laboratory. Model-based master robot gravity compensation and force feedback mechanism is used for the surgical robot. Control strategies based on position increment control and ratio control are adopted. Aiming at the typical mandibular osteotomy in CMF surgery, a scheme suitable for robot-assisted mandibular osteotomy is proposed. The accuracy and force feedback function of the robot system under direct control and master-slave motion modes are verified by experiments. Results: The drilling experiment of the mandible model in direct control mode shows that the average entrance point error is 1.37 +/- 0.30 mm, the average exit point error is 1.30 +/- 0.25 mm, and the average posture error is 2.27 degrees +/- 0.69 degrees. The trajectory tracking and in vitro experiment in the master-slave motion mode show that the average position following error is 0.68 mm, and the maximum force following error is 0.586 N, achieving a good tracking and force feedback function. Conclusion: The experimental results show that the designed master-slave CMF robot can assist the surgeon in completing accurate mandibular osteotomy surgery. Through force feedback mechanism, it can improve the interaction between the surgeon and the robot, and complete tactile trajectory movements.