Realistic and accurate computer simulations of the particle-hemodynamics
in arterial systems can be a valuable tool for numerous biomedical applications. Examples
include optimal by-pass grafting and optimal drug-delivery, as well as best
medical management concerning the cardio-vascular system. However, such numerical
analyses require large computer resources which may become prohibitive for extended
sets of arterial bifurcations. A remedy is to develop a hybrid model where the
first few generations of the bifurcating arteries of interest are simulated in full 3-D,
while a 1-D model is then coupled for subsequent bifurcations. Alternatively, a 1-D
computer model can be directly employed to simulate fluid-particle transport in complex
bifurcating networks.
Relying on a representative axial velocity profile, a physiological 1-D model has
been developed and validated, which is capable of predicting with reasonable accuracy
arterial flow, pressure field and elastic wall interaction as well as particle transport.
The usefulness of the novel 1-D simulation approach is demonstrated via a comparison
to 3-D blood flow and microsphere transport in a hepatic artery system, featuring
as outlets one major branch and four small daughter vessels. Compared to the
3-D simulation, the 1-D analysis requires only about 1% of computational time. The
hybrid modeling approach would be also applicable to the human respiratory tract to
evaluate the fate of inhaled aerosols.
A simple and cost-effective way to simulate particle-hemodynamics is using a 1-D
model for simulating arterial pressures and flow rates as well as microsphere transport,
based on assumptions involving the use of a simple algebraic pressure-area relation, an
exponential elasticity model for the vessels, and considering only unidirectional flow
with a representative skewed velocity profile. In summary, the novel contributions are:
• Particle tracking in arteries via 1-D fluid modeling and selection of an averaged, skewed velocity profile based on 3-D simulation results to provide more realistic friction and inertia term values for modeling a flow system with bifurcations.
• The 1-D model can be coupled to a 3-D model so that simulations can be run for larger regions of vascular or lung-airway systems.