Uncertainty quantification of inflow boundary condition and proximal arterial stiffness coupled effect on pulse wave propagation in a vascular network

TL;DR

This study quantifies how uncertainties in cardiac output and arterial stiffness affect pulse wave propagation in a human arterial network using stochastic simulations, highlighting their impact on blood flow dynamics.

Contribution

It introduces a stochastic modeling approach to analyze the combined effects of cardiac output variability and arterial stiffness heterogeneity on pulse wave behavior.

Findings

Uncertainties in inlet flow shape significantly affect blood pressure and velocity.

Spatial heterogeneity of aortic stiffness influences pulse wave reflection.

Results inform clinical data collection and model coupling strategies.

Abstract

SUMMARY This work aims at quantifying the effect of inherent uncertainties from cardiac output on the sensitivity of a human compliant arterial network response based on stochastic simulations of a reduced-order pulse wave propagation model. A simple pulsatile output form is utilized to reproduce the most relevant cardiac features with a minimum number of parameters associated with left ventricle dynamics. Another source of critical uncertainty is the spatial heterogeneity of the aortic compliance which plays a key role in the propagation and damping of pulse waves generated at each cardiac cycle. A continuous representation of the aortic stiffness in the form of a generic random field of prescribed spatial correlation is then considered. Resorting to a stochastic sparse pseudospectral method, we investigate the spatial sensitivity of the pulse pressure and waves reflection magnitude with respect to the different model uncertainties. Results indicate that uncertainties related to the shape and magnitude of the prescribed inlet flow in the proximal aorta can lead to potent variation of both the mean value and standard deviation of blood flow velocity and pressure dynamics due to the interaction of different wave propagation and reflection features. These results have potential physiological and pathological implications. They will provide some guidance in clinical data acquisition and future coupling of arterial pulse wave propagation reduced-order model with more complex beating heart models.