Robotic colonoscopy system that facilitates insertion of the curved colon and ensures positional stability against external forces

Abstract

However, the tasks that can be performed are extremely limited due to problems such as the unintuitive operation and insufficient degrees of freedom (DOF) of surgical tools. In order to overcome these shortcomings, flexible surgery robot platforms capable of controlling two or more surgical tools have been developed in recent years. However, the developed robots have not been sufficiently considered for difficulties that may occur in a clinical environment. In order for a robot to perform a surgery ideally in the large intestine, two major problems should be considered, each of which is to provide a method of inserting unfixed sites and a work environment in which the surgery can be stably performed. Since the sigmoid colon is one of the most difficult nonfixed sites for insertion, straightening it is a major step in colonoscopy. The first goal of this study was to assist medical doctors to straighten the sigmoid colon using peristaltic motions generated with a soft actuator mounted on a robotic colonoscopy system. The peristaltic motions of the soft actuator were implemented using two balloons and a tendon-sheath mechanism. After the robot reaches the target lesion in the large intestine, it is essential to provide a stable environment for performing the surgery. Therefore, the second goal of this study is to minimize the positional change of the end-tip caused by external force through the structural stiffness reinforcement function of the overtube. The proposed method does not increase the outer diameter of the overtube and is easy to apply as it only needs to insert the tendon into the optimized path in the joint without designing an additional mechanism structure.

A colonoscopy is the most typical method to inspect for colorectal cancer