(280i) Contributions from the Modeling of Arterial Circulation to the Simulation of Wall Shear Rate in Blood Flow within Large Arterial Vessels

One important aspect in CFD modeling, is the use of accurate inlet and outlet conditions for the flow geometry, and obtaining these values are quite the challenge for blood flow within a specific component of the arterial network. An approximate model capable of providing estimates for the time-dependent blood pressure and flow profiles in all of the vessels in the human arterial network has been developed for that purpose. The model can be personalized by inputting an aortic pressure wave, geometric dimensions of large arteries, (available, for example by MRI) various blood properties, vessel elasticity etc.. A key feature of the model is that it takes into account the full circulatory network from the largest artery to the smallest capillary. The rest of the necessary network information, beyond the arteries that are specifically measured (or whose dimensions are approximated with average values taken from the literature) is taken from a physical scaling model developed recently by Geoffrey West.

This work is related and compared alongside previous literature results, while allowing easy modifications to customize to other physical parameters. However, where it differs is in providing the final model in a user friendly Matlab based format that allows for the incorporation of the specific relationship that emerges between the pressure and flux profiles as the outlet condition within more elaborate CFD simulation packages, such as Fluent.

Overall, stationary network performance at different points in the network qualitatively agrees with previous computational results, as well as with experimental data. The steady state results confirm a phenomenon similarly observed with the proportional Poiseuille conditions, in that the flow of blood through bifurcations has a compensatory effect which allows increased flow resistances within one component to be compensated with a reduction in network resistance. This model has been used to obtain more physiological relevant outlet conditions in modeling simulations of the left main coronary artery (near the bifurcation of the left anterior descending and left circumflex coronary arteries) using the commercial software, Fluent. Results are compared against more traditional outlet conditions for a normal and atherosclerotic case (developing in the left anterior descending).