Simulation of thrombus formation in shear flows using Lattice Boltzmann Method

Area of Science:

• Biomedical Engineering
• Computational Fluid Dynamics
• Hemodynamics

Background:

• Thrombus formation in blood flow is a critical issue in medical devices like rotary blood pumps.
• Understanding the complex fluid dynamics and multiphase flow of blood is essential for predicting clot formation.
• Existing models often simplify the intricate interactions within blood flow, necessitating advanced computational approaches.

Purpose of the Study:

• To develop and validate a computational model for predicting thrombus formation in shear blood flow.
• To apply the Lattice Boltzmann Method (LBM) to a backward-facing step flow model, simulating conditions in medical fluid devices.
• To investigate the influence of multiphase blood flow properties, surface tension, and adhesion forces on clot initiation.

Main Methods:

• Utilized computational fluid dynamics (CFD) with the Lattice Boltzmann Method (LBM) for blood flow simulation.
• Modeled blood as a multiphase flow of plasma and activated fibrinogen, incorporating surface tension and wall adhesion.
• Applied the model to a backward-facing step flow geometry, a relevant analogue for medical device internal flows.

Main Results:

• Thrombus formation was predicted to occur downstream of the reattachment point and behind the step in the simulated flow.
• The model's predictions aligned with observed thrombus formation patterns.
• The study identified critical thresholds for shear rate and adhesion force necessary for accurate thrombus prediction.

Conclusions:

• The LBM-based CFD model effectively predicts thrombus formation in shear blood flow.
• The findings provide insights into clot development in complex geometries relevant to medical devices.
• Accurate prediction of thrombus formation relies on precise threshold estimations for physical parameters like shear rate and adhesion.