A study on thrombus influenced red blood cell flow in microvasculature using moving particle semi-implicit method

Microvasculature plays a decisive role on the normal operation of the human body. Previous studies have shown that the causes of microvascular hemolytic anemia and other diseases are closely related to the interaction between micro-thrombi and RBCs. The movement and deformation of Red Blood Cells (RBCs) in microvasculature with hemicyclic micro-thrombi of different sizes on the wall are simulated based on the Moving Particle Semi-implicit method (MPS) and the spring network model of RBCs membrane. Simulation of a single RBC passing the straight blood vessel indicates the strong squeeze of the RBC caused by the thrombus, which leads to a 38.5% increasing of the RBC velocity and a greater deformation, and such squeeze effect is positively related with the size of the thrombus. When two RBCs pass through the straight blood vessel with two thrombi on the both sidewalls, the deformation of the RBCs first increases and then decreases. Results show that when the axial position between the two thrombi is 10 x d(0) different, the deformation of RBCs reaches the maximum of 3.10 (upper) and 2.79 (lower), respectively. When two side-by-side RBCs pass through a bifurcated blood vessel with a sidewall thrombus, the velocity and deformation of RBCs are greatly affected by the thrombus. When the thrombus radius changes from 0 x d(0) to 20 x d(0), the peak velocities of the two cells increase by 51.6% (upper) and 67.9% (lower), respectively.