혈액펌프에서 멱법칙 모델과 점탄성 모델을 이용한 용혈 예측

Abstract

In medical devices for blood circulation, a predictive capability of rupture of red blood cells (RBCs) called as hemolysis is very useful for the design purpose. As a quantitative method to evaluate a hemolysis index due to mechanical reasons, the power-law model has been widely used for practical applications. Meanwhile, the viscoelastic model was proposed relatively recently and showed promising results in a few previous studies. In the present study, three-dimensional CFD simulations were carried out for a few blood pumps with experimentally measured hemolysis data to validate the power-law and the viscoelastic models. The plasma-free hemoglobin concentration and relative index of hemolysis (RIH) were obtained at the outlet in order to compare the hemolysis indices. In case of the FDA blood pump, the RIH results of the viscoelastic model showed better agreement with the experimental data compared to the power-law model. In case of two commercial blood pumps, however, the RIH results of the power-law model followed the experimental data better than the viscoelastic model. The opposite trends from two models seem to be related to different flow residence times of the blood pumps as well as the blood type. The viscoelastic model aims at improved prediction for a langer residence time, which is consistent with the present results.