A modularized wire-driven overtube using tube type bending mechanism for robotic NOTES system

A robotic NOTES system is recently attracting growing attention as it makes it possible to operate surgery without making any incisions on the body. In spite of the several advantages, however, an operation with a robotic NOTES system is not easy and has faced a lot of problems thus far. One of the problems is that it is difficult to locate and stabilize flexible tools during an operation. In this paper, a wire actuated, bending mechanism overtube is proposed for a robotic NOTES system. The proposed overtube can locate surgical instruments to lesions and fix the positions automatically by using high-geared motors. Furthermore, it is modularized so as to manufacture and to assemble easily. For the design of the overtube, functional requirements were first discussed and design parameters were obtained through the functional requirements. Maximum force at the tip of the overtube and bending angle of the active bending section were measured. In addition, animal surgery experiments were performed with the robotic NOTES system installed with the proposed overtube. On the basis of the animal experiments, further studies for the supplement points are considered.