Finite element analysis of a self-propelled capsule robot moving in the small intestine

Abstract In order to optimise the passage of the self-propelled capsule robot in the small intestine, capsule-intestine interactions were studied in this paper via finite element (FE) analysis and experimental investigation. Different contact conditions were considered to reflect the structural complexity and motility of the intestinal tract, including the flat-open, collapsed, contractive and curved intestines. Capsule’s geometric shape and progression speed are the two major factors to be optimised against the intestinal trauma caused by capsule-intestine contact and friction. In addition, the mesentery was also considered as the intestinal boundary to restrict the mobility of the intestine. By comparing with the experimental results, the proposed FE model can provide quantitative estimations of contact pressure and resistance force under different capsule-intestine conditions. The findings of this work are valuable to provide design guidelines and an evaluation means for the researchers and engineers who are developing medical robots for bowel examination as well as the clinical practitioners working in capsule endoscopy.