A novel soft device for assisting magnetically-driven soft-tethered capsule navigation

This paper presents a novel approach for supporting the navigation of magnetically-driven soft-tethered capsules in colonoscopy. The interaction between the capsule soft-tether and the colon leads to high resistance to the capsule navigation. To restore proper navigable conditions, authors developed a custom-made soft device, which functionalities are inspired by the inchworm-like locomotion mechanism. Three specifically-designed pneumatic soft actuators, together with a suitable activation sequence, enable the soft device to: i) pull the tether towards the capsule in order to reduce the resistance forces and, ii) ascend the colon using the tether as wire-guide, thus reaching autonomously the desired position.The pneumatic soft actuators geometry has been defined and optimized based on FEM simulations analysis and implemented by indirect rapid prototype technique.Each actuators behavior has been tested before the assembling the entire device; finally, the soft device functionalities have been experimentally tested in-vitro inside a Plexiglas tube used to mimic the colon tract. Preliminary results were promising and prove the ability of the soft device to enhance and assist the magnetically-driven navigation of the soft tethered capsule.