Analysis of Thrombosis Formation and Growth Using Microfluidic Chips and Multiphase Computational Fluid Dynamics

Thrombosis is a vascular disease associated with severe risks such as heart attack and stroke. Extensive research has been conducted worldwide to identify the underlying causes of thrombus formation due to its potential implications. Many thrombosis studies have investigated hemodynamic effects by assuming blood as a single-phase fluid. However, since the behavior of blood is greatly influenced by red blood cells (RBCs), it is necessary to analyze blood as a mixture (two-phase). In this paper, computational fluid dynamics (CFD) was performed assuming that blood is a two-phase fluid composed of plasma and RBCs. In addition, microchannels with circular cross-sections similar to human blood vessels were fabricated and used for blood experiments. The thrombus formed in the microchannel was visualized using image processing technology. Three-dimensional models incorporating the visualized thrombus were created and utilized to investigate the physical factors affecting the thrombus surface. In conditions where the shear rates were too high, the thrombus did not grow because of the drag force. Thrombus overcame the drag force and grew in areas with reduced shear stress. Also, the volume fraction of plasma calculated by the two-phase fluid model increased after the apex of stenosis and behind the thrombus. Thrombus growth was identified in areas with increased plasma volume fraction.