Nonsteady model of peristaltic transport applied to swallowing

Lubrication theory is used in the development of a mathematical model to describe peristaltic transport for arbitrary peristaltic wave shapes and tube length. The model has been applied in two studies relevant to bolus transport in the esophagus: a general study pointing to the differences in transport characteristics between a train of periodic peristaltic waves and a single peristaltic wave, and simulations of normal and abnormal transport in the esophagus, with emphasis on the relationship between manometrically measured pressure distributions and the contractile characteristics of the esophageal wall during retrograde leakage of bolus fluid. It is found that reflux of fluid particles is much more significant with single-bolus transport than with a periodic train of peristaltic contractions. Simulations of retrograde leakage in esophageal bolus transport point to a tight coupling between the intrabolus pressure distribution and the characteristics of the leakage process. It is concluded that manometric pressure signatures measured in the esophagus during swallowing are associated with particular abnormal contractile characteristics