FEA modeling and fluid flow simulation of human rectum with inserted bowel catheters.

In this project, fluid flow and fluid-structure interaction are studied for the human lower gastrointestinal (GI) region. The study consists of two steps. First, we apply meshing methods to discretize both the human lower GI model and the catheter model at sufficient resolution suitable for importing into a Finite Element Analysis (FEA) tool. For model discretization, 3D models of the colon reconstructed from human MRI slices are used to obtain the valid inlet and outlet boundary surfaces. To resolve the viscous boundary layer in flow studies, a special structure of the near-wall volumetric mesh is built by triangular prisms that construct quasi-structured, multiple near-boundary sub-layers. Second, we study the computational fluid dynamics. Transient numerical calculation of flow profiles are conducted for velocity profiles, flow rate division, pressure gradient variation, and flow cosmetics. The analysis of biofluid interactions with medical catheters is conducted to help understand how the biofluid behaves in various conditions to address design related concerns such as leakage problems.