Shear stress evaluation on blood cells using computational fluid dynamics.

Area of Science:

• Biomedical Engineering
• Fluid Dynamics
• Hematology

Background:

• Thrombus formation and hemolysis are critical issues in blood pumps and mechanical heart valves.
• Flow properties, particularly high shear stress, induce damage to platelets and red blood cells.
• Computational fluid dynamics (CFD) is used to analyze fluid shear stress and blood cell pathlines.

Purpose of the Study:

• To investigate blood cell damage within a pulsatile blood pump.
• To develop and propose a method for quantifying blood damage using CFD analysis.

Main Methods:

• Analysis of a pulsatile blood pump designed as a totally implantable left ventricular assist system.
• Utilized CFD software to simulate and analyze shear stress experienced by blood cells.
• Calculated the history of shear stress on individual particles.

Main Results:

• Proposed a novel damage parameter (D) to estimate blood damage, specifically platelet damage.
• The calculated damage parameter is independent of the time step used in the simulation.
• Simulation results demonstrated strong agreement with Giersiepen's experimental equation.

Conclusions:

• CFD analysis effectively calculates the shear stress history on blood particles.
• The developed damage parameter D provides accurate estimations of blood damage, closely matching experimental findings with minimal error.