Origin of blood rheology: Toward comprehensive understanding of single-, two- and many-body mechanics

2018 Fiscal Year Final Research Report

• Project/Area Number: 17K18759
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Research Field: Condensed matter physics and related fields
• Research Institution: Osaka University
• Principal Investigator: Ito Hiroaki 大阪大学, 工学研究科, 特別研究員(PD) (10783186)
• Project Period (FY): 2017-06-30 – 2019-03-31
• Keywords: 赤血球 / 細胞力学 / ヘモレオロジー / マイクロ流体工学

Outline of Final Research Achievements

Blood is a fluid in which many soft blood cells are dispersed. Fluidity of such solutions is largely different from that of simple viscous fluid. In this study, we performed microfluidic experiments with a microchannel, whose diameter is similar to that of microvasculature, to investigate the spatial pattern of red blood cells (RBCs) in blood flow. In the consequence, we found that stirring of red blood cells (RBCs) by the flow formed around other RBCs becomes more vigorous at the physiological RBC density (called hematocrit, which indicates the amount of RBCs in blood). Moreover, the specific spatial structure of velocity correlation is observed. At higher density, the spatial structure disappears due to the dense packing.

Free Research Field

ソフトマター物理学

Academic Significance and Societal Importance of the Research Achievements

血液はたくさんの柔らかい血球細胞が分散した溶液であり。このような溶液がどのように流れるのか、どのようにサラサラ・ドロドロ（粘性）の性質が現れるのかを知ることは、医療の進展にもつながる基礎科学の目標の一つである。本研究結果では、赤血球の密度に応じて流れ方が質的に異なり、特に生理濃度以上の赤血球密度では流体よりも粒子としての性質が流れに強く影響することがわかった。ここで得られた成果は、貧血や多血症、脱水症状などの異常時における血液の流れ方の理解に向けた大きな手がかりとなる。