The results of our own research on the function of erythrocyte deformation in the microcirculation process were analysed along with literary sources. It has been established that both the characteristics of the plasma membrane and the resistance to flow in the vascular system contribute to the effective deformability of erythrocytes. The impact of US field forces on blood cells served as an in vitro model for the mechanical impact on erythrocytes. An analogy was drawn between how erythrocytes behave in the bloodstream and how therapeutic ultrasonography affects blood cells, and a model of the forces at play was put out.