Exploring the dynamics of a vibro-impact capsule moving on the small intestine using finite element analysis

Abstract

This paper aims to study a realistic finite element (FE) model to depict the nonlinear dynamics of a vibro-impact capsule moving on the small intestine for active capsule endoscopy. The FE model takes both the nonlinear vibro-impact mechanism and the viscoelastic deformation of the small intestine into account. FE results are compared with the simulation results obtained using non-smooth differential equations and experimental results. It is found that the FE model can provide a more realistic prediction of the system in the complex intestinal environment in terms of capsule’s tilted motion and asymmetric distribution of capsule-intestine contact pressure. In particular, the capsule’s dynamics is very sensitive to the surface condition of the intestine, so a comprehensive bifurcation analysis is needed for fully understanding its dynamics under intestinal peristalsis.