Cheng Xu

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° ± 0.69°. 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.

Background: Traditional craniotomy depends primarily on the experience of the surgeon. However, the accuracy of manual operation is limited and carries certain surgical risks. The interaction method of current robot‐assisted craniotomy is unnatural and inadaptive to the operating style of the surgeon. In this research, we built a hands‐on synergistic robotics craniotomy system with human–machine collaboration. Safe isometric surfaces and virtual restraint methods are combined to achieve highly accurate, efficient, minimally invasive and safe craniotomy.Materials and methods: Fifteen three‐dimensional (3D)‐printed beagle skull models were used to evaluate the system accuracy and the related image guidance process. It mainly includes the design of the surgical plan, the adopted strategy based on motion constraint and safe isometric surface, and the impedance control method based on the position inner loop via the human–machine collaboration method. The trajectory tracking experiment was performed by applying human–machine collaboration, and completed an experiment on the 3D‐printed beagle skull models involving drilling and milling of the skull performed by the robot, and evaluation of accuracy via computed tomographic (CT) scanning verification after the operation.Results: The 3D‐printed beagle skull model experiment shows that the average errors for the top surface and the bottom surface, and the angle error were 0.81 ± 0.15 mm, 0.89 ± 0.12 mm, and 1.74° ± 0.16°, respectively. The average milling position errors for the top and bottom surfaces were 0.87 ± 0.19 and 0.93 ± 0.22 mm, respectively.Conclusion: The performance of the robot system was evaluated and verified using a 3D‐printed beagle model experiment. The proposed collaborative surgical robot system is feasible and can complete a craniotomy, with improved accuracy and surgical safety.

Small incision and narrow surgical vision has restrict the development of minimally invasive surgery (MIS). The traditional MIS needs the aid of endoscopic and hand-held surgical instruments, which requires cooperation between surgeons and assistants, thus bring challenges for the accuracy and safety of the operation. Compared with the bare-handed operation, the robot can achieve stable operation with high accuracy, and reduce the trauma of the operation. According to the characteristics of MIS, a 7 degree of freedom (DOF) surgical robot system was designed and developed in the laboratory. This paper mainly introduces the construction of a teleoperation MIS robot system.