Global sensitivity analysis of a model for venous valve dynamics

Area of Science:

• Biomedical Engineering
• Cardiovascular Physiology
• Mathematical Modeling

Background:

• Chronic venous disease (CVD) involves venous valve dysfunction and hemodynamic alterations.
• Accurate assessment of CVD severity is challenging due to complex interacting factors.
• Mathematical models offer a way to understand venous pathophysiology.

Purpose of the Study:

• To determine the sensitivity of a venous valve model to its input parameters.
• To identify critical parameters influencing venous valve dynamics for clinical applications.

Main Methods:

• A 1D pulse wave propagation model of the tibial vein with a venous valve was used.
• Simulations were performed under head-up tilt conditions.
• Variance-based sensitivity analysis using generalized polynomial chaos expansion was applied.

Main Results:

• The opening/closing pressure drop (dp_valve,0) significantly impacts the valve's opening state.
• Venous radius (r_vein,0), related to venous filling, is most important for venous filling time.
• Parameter importance and interactions influencing valve dynamics were globally assessed.

Conclusions:

• Improved assessment of r_vein,0 and dp_valve,0 is essential for reducing uncertainty in venous valve models.
• Ultrasound imaging and fluid-structure interaction simulations can enhance parameter assessment.
• This modeling approach can support clinical decision-making for chronic venous disease.