Transient stress-based and strain-based hemolysis estimation in a simplified blood pump.
We compare two approaches to numerical estimation of mechanical hemolysis in a simplified blood pump model. The stress-based model relies on the instantaneous shear stress in the blood flow, whereas the strain-based model uses an additional tensor equation to relate distortion of red blood cells to a shear stress measure. We use the newly proposed least-squares finite element method (LSFEM) to prevent negative concentration fields and show a stable and volume preserving LSFEM for the tensor equation. Application of both models to a simplified centrifugal blood pump at three different operating conditions shows that the stress-based model overestimates the rate of hemolysis. The strain-based model is found to deliver lower hemolysis rates because it incorporates a more detailed description of biophysical phenomena into the simulation process.
Chair for Computational Analysis of Technical Systems (CATS), RWTH Aachen University, 52056 Aachen, Germany.
Lutz
L
Pauli
Jaewook
J
Nam
Matteo
M
Pasquali
Marek
M
Behr
D003198:Computer Simulation; D006439:Hemodynamics / Q000502:physiology*; D006461:Hemolysis; D008962:Models, Theoretical; D013314:Stress, Mechanical
computational hemodynamics; finite element method; hemolysis modeling; residence time; ventricular assist device