A robotic colonoscope with long stroke and reliable leg clamping

Previously developed robotic colonoscopes have shown low locomotion performance since they have not had reliable clamping modules or a long stroke. Therefore, a clamping module consisting of six legs and two triggers is installed on the front and rear of the robot, enabling the robot to clamp effectively onto the colon. Locomotion capability is then improved via the on-time folding and unfolding of the legs according to the elongation and contraction of the bellows of the robot body. In addition, one pneumatic line based locomotive mechanism, which had been developed previously for in-pipe inspection, is adopted to reduce the friction force between the pneumatic lines and the locomotion environment. In order to evaluate locomotion performance, the robot and robot control system are constructed and are tested in an acrylic pipe and under condition of in-vitro. The robot can move regardless of slope in the case that the locomotion path has more than 25 mm of radius. In straight and vertical paths, it travels 33 mm/s and 12.1 mm/s, respectively. Next, a locomotion test under in-vivo condition is carried out with the optimized configuration and maneuvering parameters. Conclusively, a pneumatic bellows based locomotive mechanism with a dependable clamping module shows the reliable locomotion performance of about 8.5 mm/sec under in-vivo condition.