Development of a medical robot system for minimally invasive surgery

Background: Robot-assisted systems have been widely used in minimally invasive surgery (MIS) practice, and with them the precision and accuracy of surgical procedures can be significantly improved. Promoting the development of robot technology in MIS will improve robot performance and help in tackling problems from complex surgical procedures. Methods: A medical robot system with a new mechanism for MIS was proposed to achieve a two-dimensional (2D) remote centre of motion (RCM). An improved surgical instrument was designed to enhance manipulability and eliminate the coupling motion between the wrist and the grippers. The control subsystem adopted a master-slave control mode, upon which a new method with error compensation of repetitive feedback can be based for the inverse kinematics solution. A unique solution with less computation and higher satisfactory accuracy was also obtained. Tremor filtration and trajectory planning were also addressed with regard to the smoothness of the surgical instrument movement. Results: The robot system was tested on pigs weighing 30-45kg. The experimental results show that the robot can successfully complete a cholecystectomy and meet the demands of MIS. Conclusions: The results of the animal experiments were excellent, indicating a promising clinical application of the robot with high manipulability.