Figure 1.

Pathological and physiological blood vessel stenoses and the mimicking microfluidic models. (A) Blood flow in a healthy vessel without stenosis (top), in a vessel with concentric stenosis due to atherosclerotic plaque (middle) and a vessel with eccentric stenosis due to medical device insertion (bottom). (B) CFD contour maps in the eccentric (top) and concentric (bottom) stenosis microfluidic channels. Note that the channel walls were colored to display the WSS distribution; the representative streamline of a platelet trajectory was colored to display the shear rate γ distribution. (C) Differential interference contrast microscopy image of biomechanical platelet aggregation in an eccentric stenosis microfluidic channel after whole blood perfusion at γ₀ = 1,800 s⁻¹, mimicking the physiological shear rate in arteries and arterioles⁷. To visualize platelet aggregates in better clarity, the microchannel was washed with Tyrode’s buffer after whole blood perfusion. Note that platelets aggregate at the downstream face of the stenosis. Scale bar = 20 µm. (D) ANSYS finite volume meshing scheme for the concentric stenosis model as in panel C. The entire microfluidic channel was meshed into 1,638,336 hexahedral elements for CFD analysis. The coordinate origin is located at the center of the front bottom edge. Note that for illustration purpose, a coarse mesh is shown in the figure.