Strain-based Blood Damage Estimation for Computational Design of Ventricular Assist Devices

Abstract

Aims

Computational fluid dynamics (CFD) is used to predict damage of red blood cells (RBCs) in ventricular assist devices (VADs). The damage is measured by the hemoglobin ratio in the blood plasma.

Methods

A power law is used to relate the hemoglobin ratio to shear stress and exposure time. For the shear stress measure, the common stress-based model is compared to a strain-based model, which predicts the deformation of RBCs in the VAD. For both models an Eulerian approach is used.

In this study, new parameters are determined for the power law of the strain-based model. Hereby, the power law is fitted to data of experiments performed at the University of Maryland, Baltimore.

Results

As an example, blood damage in a benchmark blood pump of the U.S. Food and Drug Administration (FDA) is computed with a stress-based and a strain-based model using the new parameter set as well as parameter sets that were obtained in previous studies.

Conclusions

Critical locations in the pump, as identified with the stress-based and the strain-based model, differ significantly between the two models.