Three-dimensional coupled fluid-structure simulation of pericardial bioprosthetic aortic valve function

Area of Science:

• Biomedical Engineering
• Computational Fluid Dynamics
• Structural Dynamics

Background:

• Bioprosthetic aortic valves are crucial for treating aortic valve disease.
• Accurate simulation of valve dynamics is essential for improving bioprosthetic valve design.
• Existing models may not fully capture the complex fluid-structure interactions.

Purpose of the Study:

• To develop and validate a computational, three-dimensional coupled fluid-structure dynamics model for a generic pericardial aortic valve.
• To assess the model's ability to predict aortic flow fields and valve structural behavior.
• To evaluate the potential of this model as a design tool for bioprosthetic aortic valves.

Main Methods:

• Developed a coupled fluid-structure dynamics model using finite volume and finite element methods.
• Modeled blood flow as pulsatile, laminar, Newtonian, and incompressible.
• Incorporated material and geometric nonlinearities and leaflet coaptation in the structural model.
• Coupled fluid and structural equations using an implicit "influence coefficient" technique.

Main Results:

• The model accurately predicted aortic flow fields and transient variations in valve orifice area.
• Computed results showed close agreement with experimental in vitro data.
• Simulated leaflet stresses and structural configurations under physiologic pressure waveforms.

Conclusions:

• The developed computational model effectively simulates pericardial aortic valve dynamics.
• Model predictions align well with experimental data, indicating its validity.
• This coupled fluid-structure dynamics model presents significant potential as a design tool for next-generation bioprosthetic aortic valves.