Computational fluid dynamics based Taguchi analysis on shear stress in microfluidic cerebrovascular channels

Area of Science:

• Biomedical Engineering
• Fluid Dynamics
• Computational Science

Background:

• Cerebrovascular blood vessels supply the brain, but the blood-brain barrier limits drug entry for neurological disorders.
• Fluid shear stress in these vessels may influence drug delivery across the blood-brain barrier.
• Factors affecting shear stress in cerebrovascular vessels require further investigation.

Purpose of the Study:

• To evaluate the influence of geometrical and operating factors on shear stress in microfluidic cerebrovascular channels.
• To analyze the non-Newtonian behavior of blood flow and its impact on shear stress.
• To propose an optimized microfluidic model for achieving in-vivo level shear stress.

Main Methods:

• A hybrid approach combining computational fluid dynamics (CFD) and Taguchi analysis was employed.
• Six non-Newtonian fluid models (Carreau, Carreau-Yasuda, Casson, Cross, Ostwald-de Waele, Herschel-Bulkley) and Newtonian models were tested.
• Taguchi analysis (L16 orthogonal array) evaluated factors like flow rate, channel dimensions, and fluid properties on shear stress.

Main Results:

• Porosity was identified as the most influential factor on shear stress, followed by flow rate, channel width, and height.
• Shear stress decreased with increased channel width/height and decreased viscosity.
• A modified shear stress equation incorporating porosity, dimensions, flow rate, and viscosity was proposed with 0.96 accuracy.

Conclusions:

• The study provides a quantitative understanding of factors influencing shear stress in cerebrovascular microfluidic channels.
• The proposed methodology and findings can guide the design and manufacturing of in-vitro microfluidic models.
• Optimized models can better mimic in-vivo shear stress levels, aiding in the development of effective neurological disorder treatments.