A one-dimensional mathematical model for studying the pulsatile flow in microvascular networks

Area of Science:

• Physiology
• Biomedical Engineering
• Computational Fluid Dynamics

Background:

• Microvascular hemodynamics modeling is crucial for understanding physiological processes.
• Existing models often use steady flow, neglecting the significant role of pressure pulsatility.
• Dynamic models are needed to accurately assess pulsatility transmission in microcirculation.

Purpose of the Study:

• To develop and validate a one-dimensional (1D) dynamic model for microvascular blood flow.
• To investigate the transmission and characteristics of pressure pulsatility in microvascular networks.
• To simulate pulse wave velocity (PWV) and pulsatility index changes within a rat mesentery microvascular network.

Main Methods:

• A 1D dynamic model was developed to simulate microvascular blood flow.
• The model was applied to a microvascular network from rat mesentery, using intravital microscopy data for boundary conditions.
• Governing equations were solved numerically using the discontinuous Galerkin method with implicit integration for efficiency.

Main Results:

• The model successfully simulated dynamic blood flow properties, including pressure pulsatility and PWV.
• A 66.7% decrease in pulsatility index was observed from the main input arteriole to the main output venule.
• PWV decreased with vessel diameter, with mean values of 77.16, 25.31, and 8.30 cm/s for diameters of 26.84, 17.46, and 13.33 μm, respectively.

Conclusions:

• The developed 1D model effectively simulates pressure pulsatility and wave propagation in complex microvascular networks.
• The findings highlight the significant dampening of pulsatility and diameter-dependent PWV in the microcirculation.
• This dynamic modeling approach provides a valuable tool for studying microvascular hemodynamics.