# Reduced-order modeling of hemodynamics across macroscopic through mesoscopic circulation scales

## TL;DR

This paper introduces a reduced-order hemodynamic model that bridges macroscopic and mesoscopic blood flow scales, accurately simulating vascular responses across different vessel types and scales.

## Contribution

It presents a novel multi-scale modeling approach combining stochastic vascular geometries, scale-specific pruning, and diverse structural models for blood flow simulation.

## Key findings

- Numerical results agree well with experimental data.
- Model captures transition in flow pulsatility and wall shear stresses.
- Effective in simulating microcirculation responses.

## Abstract

We propose a hemodynamic reduced-order model bridging macroscopic and meso-scopic blood flow circulation scales from arteries to capillaries. In silico tree like vascular geometries, mathematically described by graphs, are synthetically generated by means of stochastic growth algorithms constrained by statistical morphological and topological principles. Scale-specific pruning gradation of the tree is then proposed in order to fit computational budget requirement. Different compliant structural models with respect to pressure loads are used depending on vessel walls thicknesses and structures, which vary considerably from macroscopic to mesoscopic circulation scales. Nonlinear rheological properties of blood are also included and microcirculation network responses are computed for different rheologies. Numerical results are in very good agreement with available experimental measurements. The computational model captures the dynamic transition between large-to small-scale flow pulsatility speeds and magnitudes and wall shear stresses, which have wide-ranging physiological influences.