Transient stress-based and strain-based hemolysis estimation in a simplified blood pump

Area of Science:

• Biomedical Engineering
• Computational Fluid Dynamics
• Hemolysis Research

Background:

• Mechanical hemolysis is a critical concern in blood pump design.
• Accurate numerical estimation of hemolysis is essential for device safety and efficacy.
• Existing stress-based models may oversimplify the biophysical processes involved.

Purpose of the Study:

• To compare the accuracy of stress-based and strain-based models for numerical hemolysis estimation.
• To implement and validate a stable least-squares finite element method (LSFEM) for a strain-based hemolysis model.
• To evaluate model performance under varying operating conditions in a simplified centrifugal blood pump.

Main Methods:

• Numerical simulation of blood flow in a simplified centrifugal blood pump.
• Implementation of a stress-based hemolysis model.
• Development and application of a strain-based hemolysis model using a novel LSFEM for tensor equations.
• Validation of LSFEM for stability and volume preservation.

Main Results:

• The stress-based model was found to overestimate mechanical hemolysis rates.
• The strain-based model, incorporating detailed red blood cell distortion, yielded lower and more accurate hemolysis rates.
• The LSFEM demonstrated stability and volume preservation for the tensor equation used in the strain-based model.

Conclusions:

• The strain-based hemolysis model offers a more accurate approach for numerical simulations compared to stress-based models.
• Advanced numerical methods like LSFEM are crucial for accurately modeling complex biophysical phenomena in blood flow.
• Improved hemolysis prediction can lead to safer and more efficient blood pump designs.