Ultrasonic Friction-Modulated Inchworm Locomotion for Endoscopy

Abstract

Endoscopy is an essential medical procedure that is used to diagnose a large variety of conditions. Endoscopes are traditionally manually inserted by an operator and during this process the mechanical movements of the endoscope may cause complications. Self-propelling endoscope designs have been proposed which pull themselves through a lumen. This may reduce trauma and operator skill required in comparison to traditional endoscope designs. This study proposes a novel locomotion mechanism for use in self-propelling endoscopes and seeks to assess its feasibility.

A robot was built which may locomote using in an inchworm-like manner using ultrasonic friction modulation. It was then tested on tracks designed to model the conditions in which an endoscope operates. It's performance and robustness of motion was then measured and evaluated for use in endoscopy.

The robot locomoted at a maximum speed of 15.6mm/s when actuated inside a PLA track, achieving faster performance than other self-propelling endoscope designs. However, it was prone to perturbations and was unable to traverse an elastic substrate or a track modeling a human airway. These findings validated that inchworm-like locomotion using friction modulation is feasible and that it currently presents some potential benefits in endoscopy. Further work is required to assess the performance of this locomotion mechanism over natural tissues and to improve its resistance to perturbations.