A coupled one dimension and transmission line model for arterial flow simulation

Area of Science:

• Biomedical Engineering
• Computational Fluid Dynamics
• Cardiovascular Physiology

Background:

• Blood flow simulations require accurate boundary conditions for reliable results.
• Traditional Windkessel models for outflow conditions have complex parameter determination.
• One-dimensional (1D) flow solvers often rely on lumped parameter models for distal boundaries.

Purpose of the Study:

• To develop and validate a simplified outflow boundary condition for 1D arterial flow simulations.
• To introduce a reflection coefficient (RC) as a single parameter for distal boundary conditions.
• To investigate the capability of the RC model in reproducing subtle arterial pressure propagation features.

Main Methods:

• Coupling transmission line theory for peripheral resistance with a 1D arterial flow solver.
• Deriving the theoretical foundation for the reflection coefficient (RC) parameter.
• Applying the coupled model to simulate blood flow in healthy and stenosed virtual aortas.

Main Results:

• The reflection coefficient (RC) reduces the number of required parameters to one.
• The method successfully reproduces features like steepened pressure waveforms.
• Simulations show accurate modeling of wave reflections from aortic terminals and stenotic sites.

Conclusions:

• The reflection coefficient (RC) offers a physically meaningful and simplified approach to distal boundary conditions in arterial flow modeling.
• This novel coupled model enhances the accuracy of blood flow simulations by explicitly modeling wave reflections.
• The RC parameter holds significant potential for use in flow simulations requiring explicit reflection modeling.