On the Sensitivity Analysis of Porous Finite Element Models for Cerebral Perfusion Estimation

Area of Science:

• Computational physiology
• Biomedical engineering
• Medical device development

Background:

• Organ-scale hemodynamic models are increasingly used for virtual patient perfusion evaluation.
• Verification, validation, and uncertainty quantification (VVUQ) principles are crucial for medical engineering software safety.

Purpose of the Study:

• To establish guidelines for a 3D steady-state porous cerebral perfusion model of the human brain.
• To apply the American Society of Mechanical Engineers' Verification and Validation 40 standard.
• To assess brain perfusion alterations in ischemic stroke patients before, during, and after treatments.

Main Methods:

• Utilized a 3D steady-state porous cerebral perfusion model based on the finite element method.
• Compared simulations with analytical solutions and performed comprehensive sensitivity analyses.
• Developed a 1D model as a computationally efficient alternative for parameter optimization and uncertainty quantification.

Main Results:

• Porous models reliably approximate blood pressure and perfusion distributions, even with coarse grids and first-order elements.
• Higher-order elements are necessary for accurate volumetric blood flow rate estimation in cortical regions.
• Matching volumetric flow rates in major cerebral arteries is a key validation metric; constant pressure inlets are feasible alternatives to difficult-to-obtain velocity conditions.

Conclusions:

• The developed guidelines enhance the applicability of computational tools for stroke and cerebrovascular treatment development.
• The findings are generalizable to other organ-scale porous perfusion models.
• Computational models offer valuable insights for clinical trial design and decision-making in cerebrovascular disease management.