A self-contact electromechanical framework for intestinal motility

This study introduces a comprehensive multiphysics and multiscale modeling framework for simulating intestinal motility, explicitly incorporating the effects of contact mechanics. The proposed approach couples finite elasticity electromechanics, which captures the microstructural architecture and mechanical behavior of the intestinal wall, with tissue-level electrophysiology, enabling the representation of slow wave propagation and active contractile dynamics. To model mechanical interactions accurately, the framework integrates a self-contact detection algorithm that combines a nearest-neighbor search strategy with the penalty method, ensuring robust enforcement of non-interpenetration constraints. In addition, the model accommodates inhomogeneous boundary conditions that simulate the mechanical influence of adjacent organs on the intestinal tissue. The active strain governing equations are solved via a staggered finite element scheme, implemented within the open-source FEniCS environment. The model is applied to clinically relevant scenarios, including moderate and severe strangulation hernia as well as intestinal adhesion syndrome. Simulation results reveal a marked reduction in peristaltic activity in pre-strangulation regions, accompanied by elevated intraluminal pressure in the strangulated segment. In cases of self-adhesion, the model predicts a complete suppression of motility within the adherent zone. Overall, the computational analyses successfully reproduce the spatiotemporal dynamics of electromechanical wave propagation under conditions of distributed contact boundaries, representative of pre- and post-surgical states. The proposed framework demonstrates significant potential for advancing our understanding of self-contact in active soft tissues, and provides a valuable tool for predicting and analyzing motility disorders in the gastrointestinal tract.