A paddling mechaism based robotic colonoscope harnessing flexible shaft

Nowadays the colonoscopy is known as the best way of detecting colorectal cancer. However, conventional colonoscope has critical disadvantages as follows: Bloated stomach after colonoscopy, Occurrence of bleeding and perforating, Necessity of experienced endoscopists, etc. In order to overcome these limitations, a variety of robotic colonoscopes have been developed. In this article, a paddling mechanism based robotic colonoscope harnessing flexible shaft is presented. The robot advances relying on the motion of six paddling legs, which is generated by outer DC motor via flexible shaft. Since flexible shaft is utilized to transmit power from the motor, the operator can operate effectively by exploiting pushing/pulling techniques. Theoretical velocity is calculated as 3.322 mm/s and optimal stroke is selected as 32 mm to guarantee locomotion of the robot. To evaluate performance of the robot, in-vitro test was implemented with acrylic pipe and excised porcine colon, which was hemisected. Conclusively, the robot achieved velocity of 2.130 mm/s and 2.394 mm/s in the acrylic pipe and the porcine colon, respectively.