title: Predicting bifurcation angle effect on blood flow in the microvasculature.
abstract: Since blood viscosity is a basic parameter for understanding hemodynamics in human physiology, great amount of research has been done in order to accurately predict this highly non-Newtonian flow property. However, previous works lacked in consideration of hemodynamic changes induced by heterogeneous vessel networks. In this paper, the effect of bifurcation on hemodynamics in a microvasculature is quantitatively predicted. The flow resistance in a single bifurcation microvessel was calculated by combining a new simple mathematical model with 3-dimensional flow simulation for varying bifurcation angles under physiological flow conditions. Interestingly, the results indicate that flow resistance induced by vessel bifurcation holds a constant value of approximately 0.44 over the whole single bifurcation model below diameter of 60μm regardless of geometric parameters including bifurcation angle. Flow solutions computed from this new model showed substantial decrement in flow velocity relative to other mathematical models, which do not include vessel bifurcation effects, while pressure remained the same. Furthermore, when applying the bifurcation angle effect to the entire microvascular network, the simulation results gave better agreements with recent in vivo experimental measurements. This finding suggests a new paradigm in microvascular blood flow properties, that vessel bifurcation itself, regardless of its angle, holds considerable influence on blood viscosity, and this phenomenon will help to develop new predictive tools in microvascular research.
authors.affiliation: Advanced Institutes of Convergence Technology, Seoul National University, Suwon 443-270, Republic of Korea.
authors.forename: Jiho
authors.initials: J
authors.lastname: Yang
authors.affiliation: Advanced Institutes of Convergence Technology, Seoul National University, Suwon 443-270, Republic of Korea.
authors.forename: Y Eugene
authors.initials: YE
authors.lastname: Pak
authors.affiliation: Advanced Institutes of Convergence Technology, Seoul National University, Suwon 443-270, Republic of Korea. Electronic address: taerinlee@snu.ac.kr.
authors.forename: Tae-Rin
authors.initials: TR
authors.lastname: Lee
mesh_terms: D000818:Animals; D001783:Blood Flow Velocity; D001809:Blood Viscosity; D003198:Computer Simulation; D006439:Hemodynamics; D006801:Humans; D051379:Mice; D008833:Microcirculation; D055806:Microvessels / Q000033:anatomy & histology / Q000502:physiology*; D008953:Models, Anatomic; D008955:Models, Cardiovascular; D012039:Regional Blood Flow; D014655:Vascular Resistance
keywords: Bifurcation angle; Blood viscosity; Hemodynamics; Microvascular modelling