Modeling of Ex-Vivo Flow Cone System to Study Platelet Activation

Disturbed blood flow in arteries affected by Fibromuscular Dysplasia (FMD) may lead to clot formation due to mechanical platelet activation. Understanding the role of hemodynamics in platelet activation allows for the creation of drug therapies targeting mechanical activation. Rotating flow cones have been used to replicate shear stresses experienced by platelets in arterial flow. Platelets are subjected to mechanical stress by cones rotating at various speeds to replicate different shear environments, resulting in platelet activation and exocytosis of alpha granules. In our study, the flow fields in these experiments were numerically simulated to quantify platelet exposure to various levels of shear stress. The computed velocity fields were used to calculate the VonMises stress, defining the maximum local fluid shear stress. Lagrangian Particle Tracking was then used to compute stress exposure history for each particle in order to evaluate the resulting Platelet Activation State (PAS). Predicted risk of platelet activation from the models was compared to the platelet activation levels based on p-selectin measurements in the experiments. These initial results provide the groundwork for CFD-based assessment of PAS in subject-specific flow conditions.