Mesoscale Analysis of Blood Flow

Abstract

Blood flow in the cardiovascular system and its interaction with the vessel walls plays a crucial role in health and disease. Individual blood cells play varied and vital roles in the circulation, including transport of nutrients and dissolved gases (red blood cells), fighting infections and disease (white blood cells), and healing of wounds (platelets). Malfunctioning of blood cells can result in pathologies such as sickle cell disease (red blood cells), ischemia (white blood cells), atherosclerosis (white blood cells and platelets) and thrombosis (platelets and red blood cells). To better understand the behavior of blood cells and their role in health and disease, microscale models that capture the dynamics of individual cells and their interactions with other cells/vessel walls can be very useful. However, since even micro-volumes of blood contain extremely large numbers of cells, connecting blood flow phenomena to cell dynamics and cell-cell/cell-wall interactions limits the usefulness of micro-scale models. Mesoscale models that do not model individual cells in detail, but allow for the treatment of large numbers of cells can provide important insights into the impact of the particulate nature of blood; such mesoscale models can represent transport phenomena, aggregation/disaggregation of cell clusters, collisional interactions of cells with each other and with walls and other phenomena important to healthy and pathological states in the circulation. This chapter describes the important features of such mesoscale models of blood; the treatment of the particulate nature of blood and the modeling and simulation of cell-cell and cell-surface interactions are covered. The examples presented illustrate the state of the art in mesoscale modeling of blood flow.