Flow Solvers for Biofluid Dynamics

Background

Biofluid dynamics or biofluidics is a sub-discipline of biomedical engineering that mainly concentrates on how fluids move within a living body. At IT’IS, we endeavor to advance our understanding of flow phenomena through computational and experimental methods. Using our novel software framework and algorithms for computational fluid dynamics, our research efforts focus on flow obstruction prevention in thin passages, the understanding of blood interactions with vessel walls or with artificial structures, such as medical devices, the investigation of thermoregulation functionality, the exploitation of the transport role of biofluids for targeted drug delivery, and the understanding of complex blood properties during clotting. Other bodily fluids aside from blood are also part of these research efforts, for example, air flow in the respiratory tract or cerebrospinal fluid flow in the brain and spinal cord.

Selected Past Achievements

• Complete methods to study biofluid dynamics ranging from the preparation of realistic models to efficient numerical simulations to high quality representations of the results using state-of-the-art visualization techniques
• Development of models constructed from medical imaging data with realistic geometries, boundary conditions, and boundary flow profiles extracted from real measurements
• Implementation of state-of-the-art numerical schemes on top of the Portable, Extensible Toolkit for Scientific Computation (PETSc) for superior performance and functionality on typical desktop PC's as well as on the world’s fastest clusters and supercomputers
• Development of reliable methods to study flow and its interaction with vessel walls as well as complex flows in large vessel networks. The thermal impact of perfusion can be accounted for by coupling discrete vessel models with thermal simulations or by using continuum approximations, and various local and whole-body thermoregulation mechanisms can also be considered. Research to investigate the impact of local and global perfusion on the tissue heating resulting from EM exposure (e.g., for MRI safety of implants) or EM and US thermal treatments (e.g., for hyperthermia, ablation) is conducted in parallel. The development of new vasculature and complex phenomena such as clotting can be modeled by hybrid methods.
• Application of these methods to quantify and characterize blood flow in several studies, including the growth of a vascular tumor, magnetohemodynamic effect as a biomarker, and flow diversion and clotting in a cerebral aneurysm. 

Next Challenges

• To integrate the available fluid simulation techniques with our new solid mechanics solver to tackle strongly coupled fluid-solid interaction (FSI) problems
• To extend the current research in biofluidics to problems other than blood flow, e.g., airflow to study breathing disorders, or cerebrospinal fluid to study brain pressure disorders or mechanical shocks.