Flexible endoscopic surgery robot with high payload asymmetric rolling joint and ergonomic master device

Abstract

How should a flexible endoscopic surgery robot be designed to be used effectively? Surgical instruments should be able to move freely within the narrow gastrointestinal tract while exerting enough force to perform the surgical operation. Especially, if a surgical instrument which is capable of suturing that conventional endoscopy cannot be performed is developed, it can be expected that advanced endoscopic operation such as gastrointestinal perforation suture and bleeding hemostasis are possible, and stable surgical performance can be improved.

In this dissertation, flexible surgical instrument and ergonomic master device, which are the core parts of flexible endoscopic surgery robot. were proposed. First of all, the requirements of the proposed surgical instrument were derived by analyzing the endoscopic submucosal dissection (ESD) which is most generally performed in endoscopic surgery and the suture process, which is an advanced technique. After that, a surgical instrument with asymmetric rolling joint was proposed to exert high payload in dominant direction which is required for performing ESD and suturing task. To compensate for the asymmetric hysteresis caused by the asymmetric rolling joint, a control method that can change the kinematics of the actuating wire depending on the bending angle of the surgical instrument is presented. Furthermore, an intuitive and ergonomic master device with redundant joint were proposed for manipulating flexible endoscopic instrument. The performance of the proposed master device was quantitatively evaluated through an experiment simulating endoscopic surgery. An end-effector to stably grasp tissue and needles and a triangulation mechanism to secure a workspace and field of view were designed, and an orientation mapping was applied between the master device and the surgical instrument to perform a stitching motion during suturing task. Endoscopic submucosal dissection and suturing were performed on the excised organs using an integrated flexible endoscopic surgery robot system, and the surgical performance was evaluated.

It is hoped that this study will help to design a small surgical instrument with high payload and an intuitive and ergonomic control device, and to get ideas on how to evaluate the performance of the integrated system.