Design and Experimental Investigation of a Vibro-Impact Capsule Robot for Colonoscopy

Abstract

Uptake of capsule endoscopy in the large intestine has been very limited due to both the risk of missed lesions and the often prolonged transit time, making it an unviable alternative to standard colonoscopy. In this letter, we presented a controllable and easy-to-use diagnostic tool, equipping a novel vibration module inside a capsule robot for colonoscopy. The capsule's motion was controlled by applying an external alternating electromagnetic field to the capsule's inner magnet to generate vibrations and impacts on the main body of the capsule. To optimise its motion, we provided a numerical solution for calculating its electromagnetic force and used it to guide a hand-held control panel for navigating the robot. The robot was firstly examined in a large intestine simulator modelled based on the colon-rectal morphometrics, and then tested in an ex vivo environment using porcine intestines. We verified the performance of the robot travelling through the entire intestine with the maximum speeds of 54 mm/s and 40 mm/s in the simulator and the ex vivo environment, respectively. It was found that altering the control frequency of the panel can help the robot to pass through various morphometrics, in particular the sharp turnings at the segment junctions.