Question

Explain briefly the main challenges in modeling blood flow in the body.

Answer 1

• Clinical information necessary for patient-specific simulations (vessel geometry at various time points, measurements of pressure and/or flow, etc.) is necessary.
• On a small domain (typically a few vessels), which is still part of the entire circulation, simulations are performed. At these artificial limits, the latter is defined by the boundary conditions. However, measurements of hemodynamics (pressure, flow) are usually not obtained at these sites. Therefore, a multiscale approach is warranted .
• Another difficulty is to estimate model parameters that are not explicitly extractable from the measurements (boundary conditions or parameters of the decreased models, vessel wall compliance, etc.).
• A complex flow also arises from the interaction of patient-specific geometry and physiological flows. This induces numerical uncertainty at the limits of the artificial.
• In order to obtain the information that is necessary for the application, simulations need to be post-processed. Local or global (power loss, etc.) quantities are computed (wall shear stress, lagrangian coherent structures, etc.).
• Evaluation or connection with clinical indexes, comparison or optimization of surgical design, input parameter sensitivity analysis, clinical data validation.