Partitioned fluid-solid coupling for cardiovascular blood flow: left-ventricular fluid mechanics.

Area of Science:

• Cardiovascular Physiology
• Computational Fluid Dynamics
• Biomedical Engineering

Background:

• Accurate simulation of cardiovascular blood flow requires integrating fluid dynamics with cardiac mechanics.
• Existing models often use prescribed geometry movement, limiting realistic deformation analysis.
• Patient-specific data is crucial for translating computational models to clinical applications.

Purpose of the Study:

• To develop and validate a novel 3D computational fluid-structure interaction (FSI) approach for cardiovascular blood flow.
• To replace prescribed geometry movement in heart models with a coupled myocardial composite model driven by fluid forces and cardiac response.
• To investigate left-ventricular FSI using patient-specific magnetic resonance imaging (MRI) data.

Main Methods:

• Implemented a 3D code-coupling approach using Arbitrary Lagrangian-Eulerian (ALE) formulation for Navier-Stokes equations (Finite Volume Method - FVM).
• Discretized solid mechanics equations using Finite Element Method (FEM) for finite elasticity.
• Employed specialized numerical strategies for non-matching fluid-solid meshes with iterative data exchange for interface equilibrium.

Main Results:

• Successfully coupled fluid dynamics and myocardial mechanics, replacing prescribed geometry movement with a dynamic model.
• Demonstrated accurate simulation of left-ventricular fluid-structure interaction based on patient-specific MRI data.
• Observed flow patterns in good agreement with previous studies, validating the model's predictive capabilities.

Conclusions:

• The developed 3D FSI approach provides a more realistic simulation of cardiovascular blood flow and cardiac mechanics.
• This advanced modeling can enhance understanding of cavity deformation and blood flow interactions.
• Improved insights hold potential for advancing surgical treatments and clinical therapy planning in cardiology.