Abstract: The paper is devoted to study the non-Newtonian behavior of blood flowing in an artery having a stenosis, in a situation when a catheter has been inserted into it. The blood rheology is described by Herschel-Bulkley fluid model. The flow configuration is constructed by choosing suitable curvature at the lateral junction, where the flow separation is initiated. The effects of insertion of catheter and that of yield stress of blood on the velocity distribution, rate of flow and flow resistance of blood, distribution of shear stress at the arterial wall and the location of yield plane are investigated. The results provide some useful information for the predic-tion/treatment of some arterial diseases and circulatory disorders of the cardiovascular system, in a situation, when a stenosis is developed on the endothelium of the daughter artery / bifurcated artery. The study reveals that if the ratio between the radii of the catheter and the artery is increased, the shear stress at the arterial wall diminishes. However, when the bifurcation angle is increased, the wall shear stress is enhanced.

Key words: catheterized artery, arterial bifurcation, yield plane, Herschel-Bulkley fluid model, flow resistance