Thesis Title: Modelling flow and mixing in the proximal small intestine.

The small intestine is the primary site of enzymatic digestion and nutrient absorption in humans. Intestinal contractions facilitate digesta mixing, transport and contact with the absorptive surfaces. Motility patterns consist of two types of contractions when the intestine is filled with digesta: longitudinal (peristaltic) contractions that propel digesta towards the colon and segmentation contractions that mix the digesta. The role of the different motility patterns in the mixing and emptying of food contents remains poorly understood. In addition, the effect of digesta rheology on flow is also not well understood. Existing computational fluid dynamics (CFD) models of small intestinal mobility use artificial and simplistic geometries and mechanical contractions (boundary condition) for the fluid simulations. This thesis will develop new CFD simulations that will be based on realistic anatomical geometry and mechanical contractions derived from electrophysiological recordings. Such models can be used to facilitate the design of “functional foods” for targeted delivery of nutrients and/or treatment of diseases and to provide an improved understanding of intestinal flow.


Auckland Bio-Engineering Institute