CFD Assisted Evaluation of In Vitro Experiments on Bearingless Blood Pumps

Area of Science:

• Biomedical Engineering
• Fluid Dynamics
• Medical Devices

Background:

• Bearingless centrifugal blood pumps are crucial for treating heart failure.
• Understanding and minimizing hemolysis (red blood cell damage) is vital for blood pump safety and efficacy.
• Computational Fluid Dynamics (CFD) offers a potential tool for predicting hemolysis.

Purpose of the Study:

• To comparatively analyze computational fluid dynamics (CFD) simulations and in vitro hemolysis tests for a bearingless centrifugal blood pump.
• To validate CFD hemolysis models against experimental data.
• To utilize validated CFD models to elucidate the mechanisms of cell damage within the blood pump.

Main Methods:

• Manufacturing and testing of multiple bearingless centrifugal blood pump prototypes.
• Implementation of pump designs within a CFD framework.
• Simulation using various Eulerian hemolysis models and comparison with in vitro experimental data.

Main Results:

• A double-stage CFD model demonstrated the highest correlation with experimental results.
• CFD simulations exhibited lower sensitivity compared to in vitro tests.
• The radial gap was identified as the primary region for cell destruction, followed by the bottom volume and shroud clearance gap.
• Less than 0.5% of the priming volume experienced overcritical shear stress.

Conclusions:

• CFD models can effectively predict and analyze blood damage in centrifugal pumps.
• Design modifications such as increasing radial gap, reducing clearance gaps, and enhancing fillet radius can improve hemocompatibility.
• CFD simulations serve as a valuable tool for interpreting in vitro hemolysis data and optimizing blood pump design.