Coupled Modeling of External Pressure and Capillary Blood Flow: Nonlinear Dynamics of Vascular Elasticity and Collapse Effects

TL;DR

This paper introduces a nonlinear model that captures how external pressure affects capillary blood flow, considering elasticity and collapse, aiding in personalized pressure therapy planning.

Contribution

It develops a segmented nonlinear model that quantitatively describes pressure-flow dynamics including collapse effects, which was lacking in prior studies.

Findings

Model accurately predicts pressure-flow phases

Parameter sensitivity analysis validates model robustness

Framework supports personalized pressure therapy design

Abstract

External pressure significantly influences microcirculatory capillary blood flow, yet current studies lack quantitative modeling. This work proposes a nonlinear segmented coupling model between external pressure and capillary flow, incorporating vascular elasticity and collapse effects. The pressure-flow response is divided into three phases: elastic compression under low pressure (less than 30 mmHg), elliptical collapse in the transition zone (30 to 40 mmHg), and closure-induced attenuation under high pressure (above 40 mmHg), with explicit expressions derived for each. Parameter sensitivity analysis and comparison with literature demonstrate the model's capability in capturing key determinants. The proposed framework supports dose-response assessment and individualized parameter tuning in pressure-based therapies such as tourniquets and compression garments.