Evaluation of Eulerian and Lagrangian models for hemolysis estimation

Area of Science:

• Biomedical Engineering
• Fluid Mechanics
• Hematology

Background:

• Flow-induced mechanical damage to red blood cells, known as hemolysis, is a critical issue in medical devices like ventricular assist devices (VADs), artificial lungs, and mechanical heart valves.
• Power law-based models (HI(%)=Ct(α)τ(β)) are widely used for calculating hemolysis due to their simplicity and broad applicability.

Purpose of the Study:

• To evaluate the accuracy of different power law-based hemolysis models.
• To compare computational predictions with experimental hemolysis measurements in a shearing device and a clinical VAD.

Main Methods:

• Experimental measurement of hemolysis in a custom shearing device and a clinical VAD.
• Computational modeling using Eulerian scalar transport and Lagrangian approaches to predict hemolysis.
• Comparison of model predictions against experimental data.

Main Results:

• Both Eulerian and Lagrangian models exhibited substantial percentage errors in predicting the magnitude of hemolysis (minimum Eulerian 91%, minimum Lagrangian 57%).
• The Eulerian approach demonstrated high correlation coefficients (>0.99) with experimental data, indicating its capability in predicting relative hemolysis.

Conclusions:

• Current power law-based models, including Eulerian and Lagrangian methods, are not sufficiently accurate for predicting the absolute magnitude of hemolysis.
• The Eulerian approach is valuable for comparative analyses, such as ranking medical device designs or optimizing device performance based on relative hemolysis.
• Further refinement of hemolysis models is necessary for accurate quantitative predictions in medical device applications.