Pulsatile Driving Stabilizes Loops in Elastic Flow Networks

TL;DR

This paper demonstrates that incorporating pulsatile driving and vessel compliance into models of biological flow networks reveals resonance phenomena that stabilize loops, challenging previous rigid-vessel assumptions and offering new insights into vascular pathologies.

Contribution

It introduces a novel adaptation framework accounting for pulsatility, fluid inertia, and compliance, showing these factors can stabilize loops in elastic flow networks.

Findings

Pulsatility induces resonances that stabilize network loops.

Stability extends to broader cost functions than previously predicted.

Disruption of pulsatility may lead to vascular pathologies.

Abstract

Existing models of adaptation in biological flow networks consider their constituent vessels (e.g. veins and arteries) to be rigid, thus predicting a non physiological response when the drive (e.g. the heart) is dynamic. Here we show that incorporating pulsatile driving and properties such as fluid inertia and vessel compliance into a general adaptation framework fundamentally changes the expected structure at steady state of a minimal one-loop network. In particular, pulsatility is observed to give rise to resonances which can stabilize loops for a much broader class of metabolic cost functions than predicted by existing theories. Our work points to the need for a more realistic treatment of adaptation in biological flow networks, especially those driven by a pulsatile source, and provides insights into pathologies that emerge when such pulsatility is disrupted in human beings.