ABSTRACT
The lymphatic system comprises a series of elements, lymphangions, separated by valves and possessed of active, contractile walls to pump interstitial fluid from its collection in the terminal lymphatics back to the main circulation. Despite its importance, there is a dearth of information on the fluid dynamics of the lymphatic system. In this article, we describe linked experimental and computational work aimed at elucidating the biomechanical properties of the individual lymphangions. We measure the static and dynamic mechanical properties of excised bovine collecting lymphatics and develop a one-dimensional computational model of the coupled fluid flow/wall motion. The computational model is able to reproduce the pumping behavior of the real vessel using a simple contraction function producing fast contraction pulses traveling in the retrograde direction to the flow.
Subject(s)
Lymph/physiology , Lymphatic Vessels/physiology , Models, Biological , Muscle Contraction , Animals , Cattle , Computer Simulation , Elasticity , Pressure , Reproducibility of Results , Rheology , Time FactorsABSTRACT
Computational fluid dynamics (CFD) has been used to investigate the flow of air through the human orotracheal system. Results from an idealised geometry, and from a patient-specific geometry created from MRI scans were compared. The results showed a significant difference in the flow structures between the two geometries. Inert particles with diameters in the range 1-9 microm were tracked through the two geometries. Particle diameter has proved to be an important factor in defining the eventual destinations of inhaled particles. Results from our calculations match other experimental and computational results in the literature, and differences between the idealised and patient-specific geometries are less significant.
