System Design of a Novel Minimally Invasive Surgical Robot That Combines the Advantages of MIS Techniques and Robotic Technology

Existing minimally invasive surgical (MIS) robots are generally large, complex and expensive, which greatly increases the operation cost and limits the applications of MIS robot technology. To solve these problems, a small table-attached MIS robot that combines the high efficiency of the traditional MIS technique and the dexterity of robotic operations is proposed in this paper. The master and slave manipulators of the new robot are integrated, which allows the surgeon to manipulate the robot next to the operation table. Moreover, the novel design can be used with existing MIS instruments, providing surgeons dexterous operation and intuitive motion control with guaranteed operation efficiency. To simplify the structure of the robotic system, a multistage cable transmission structure is established. In addition, to reduce the difficulty of operations, especially suturing operations, a novel surgical instrument is developed with a "roll-pitch-distal roll" wrist and a quick-exchange interface. To overcome the uncoordinated hand-eye movement caused by the fulcrum effect, a motion mapping model is established for the robot. A prototype of the robot is developed and subsequently subjected to various tests. The results show that the instrument quick-exchange time is less than 20 s and that the maximum position and orientation trajectory errors are 0.46 mm and 0.87 degrees, respectively. Finally, the feasibility and effectiveness of the proposed MIS robot are systematically verified through an in vivo animal experiment.