Numerical simulation of spatiotemporal red blood cell aggregation under sinusoidal pulsatile flow

Area of Science:

• Biophysics
• Computational Biology
• Hemodynamics

Background:

• Red blood cell (RBC) aggregation typically shows an inverse relationship with shear rate in steady flow.
• Observed parabolic rouleaux patterns in arterial flow lack explanation from shear rate alone.
• Understanding RBC aggregation in pulsatile arterial flow requires quantitative analysis of spatiotemporal variations.

Purpose of the Study:

• To investigate the influence of spatiotemporal shear rate variations on RBC aggregation under pulsatile flow.
• To analyze the formation of parabolic rouleaux patterns in simulated arterial flow.
• To elucidate the role of axial and radial shear rates in RBC aggregation dynamics.

Main Methods:

• Developed a 2D computational model simulating red blood cell (RBC) motion.
• Incorporated interactional and hydrodynamic forces based on depletion theory.
• Simulated RBC behavior under sinusoidal pulsatile flow, analyzing radial and axial shear rates.

Main Results:

• Specific ranges of axial shear rate and its ratio to radial shear rate significantly impact RBC aggregation.
• These shear rate components are critical for the formation of local parabolic rouleaux.
• Demonstrated a strong correlation between spatiotemporal shear rate variations and aggregate formation.

Conclusions:

• Spatiotemporal variations in shear rate are crucial for RBC aggregation and parabolic rouleaux formation in pulsatile flow.
• The interplay between axial and radial shear rates dictates local aggregation patterns.
• Findings provide a quantitative basis for understanding RBC dynamics in arterial circulation.