An In-Vitro Study On The Carotid Bifurcation And Its Influence On Arterial Haemodynamics With Newtonian And Non-Newtonian Blood Analogs

The carotid artery bifurcation is a region susceptible to atherosclerosis and cardiovascular diseases. The geometry of the bifurcation is individually unique and significant differences have been correlated to both age and gender. Identifying geometric features that produce adverse flow patterns could enable clinicians to make early assessment of an individual’s risk of developing the disease enabling proactive management. Consequently, this study aims to evaluate the influence of the carotid bifurcation angle on arterial haemodynamics using stereoscopic particle image velocimetry. Pulsatile flow conditions were applied to a Newtonian and non-Newtonian blood analog in three compliant, physiologically realistic carotid artery bifurcation phantoms with different bifurcation angles. Results indicate large bifurcation angles can produce adverse flow conditions, increasing size of stagnation regions and promoting plaque development. Additionally, an optimal bifurcation angle could exist that could be considered atheroprotective. Comparison of Newtonian and non-Newtonian blood analogs in one of the geometries show subtle yet significant differences between flow fields, suggesting the shear-thinning behaviour of blood should be carefully considered prior to adopting a Newtonian assumption, even in large vessels.