Kinematic Analysis of Needle-like Overtube Supporting Robot

This paper presents the design and structure simulation of needle-like overtube shape locking robot. This robot is designed for applying to natural orifice transluminal endoscopic surgery, or NOTES, and single port surgery, or SPS. It consists of three main parts; needle, snare, and remote center of motion (RCM) mechanism with three degrees of freedom. Using the RCM mechanism, a needle with a 3mm of outer diameter can locate at the point of fulcrum from out of the abdomen. Once the needle reaches the endoscope, a snare comes out of the end of the needle and grasps the endoscope. This method can be used to specify the position of the endoscope in the abdomen cavity. The length of needles and the design requirements of the RCM mechanism were designed in consideration of the insertion into the abdomen cavity and the range of motion of the surgical tool within the abdomen cavity. In order to analysis workspace, kinematic analysis and simulation was conducted.