Efficient Cardiovascular Parameters Estimation for Fluid-Structure Simulations Using Gappy Proper Orthogonal...

Area of Science:

• Biomedical Engineering
• Computational Fluid Dynamics
• Cardiovascular Physiology

Background:

• Full-scale hemodynamic simulations of the entire vasculature are computationally infeasible.
• Numerical analysis requires lumped parameters to represent unsimulated regions of the cardiovascular system.
• Accurate parameter estimation is crucial for patient-specific modeling.

Purpose of the Study:

• To present a novel technique for estimating cardiovascular model parameters using gappy Proper Orthogonal Decomposition (g-POD).
• To enable accurate patient-specific hemodynamic modeling by integrating simulation data with clinical measurements.
• To overcome limitations of traditional simulation approaches by focusing on specific vascular regions.

Main Methods:

• Constructing a POD basis using Fluid-Structure Interaction (FSI) simulations with varying lumped parameter values.
• Applying a linear operator to retain comparable information between simulations and patient measurements.
• Computing POD coefficients via projection of patient measurements or constrained minimization.
• Estimating cardiovascular model parameters from the POD reconstruction.

Main Results:

• Achieved less than 4.2% relative error in approximating a 3-element Windkessel model with artificial data.
• Obtained less than 8% error for flow and 5% for pressure when approximating Windkessel models in patient aorta geometry.
• Demonstrated accuracy even with noisy patient data.
• Successfully calculated the delay between patient measurements and simulations.

Conclusions:

• The gappy POD method provides an accurate and flexible approach for estimating cardiovascular model parameters.
• The technique is robust to noisy data and automatically handles time delays.
• It is easily implementable in general-purpose FSI software for patient-specific cardiovascular modeling.