2021 Fiscal Year Final Research Report
Characteristics of elasticity on suppression for progress and rupture in cerebral aneurysm
| Project/Area Number |
19K04163
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Multi-year Fund |
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| Section | 一般 |
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| Review Section |
Basic Section 19010:Fluid engineering-related
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| Research Institution | Tohoku University |
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Principal Investigator |
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| Co-Investigator(Kenkyū-buntansha) |
田中 学 千葉大学, 大学院工学研究院, 教授 (20292667)
太田 信 東北大学, 流体科学研究所, 教授 (20400418)
TUPIN SIMON 東北大学, 流体科学研究所, 特任助教 (40816394)
安西 眸 東北大学, 流体科学研究所, 助教 (50736981)
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| Project Period (FY) |
2019-04-01 – 2022-03-31
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| Keywords | Cerebral aneurysm / Elasticity / Wall shear stress / Kinetic energy cascade / PIV |
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| Outline of Final Research Achievements |
Mechanisms underlying growth and rupture of aneurysms are poorly understood. Although wall shear stress (WSS) in elastic aneurysms is examined using fluid structure interaction, it has not been sufficiently validated using experimental modalities, such as particle image velocimetry (PIV) or phase contrast magnetic resonance imaging. We investigated pulsatile flow in elastic patient-specific cerebral aneurysm using PIV. Phantom model was carefully fabricated using a specialized technique by silicone. We explored WSS and kinetic energy cascade (KEC) in elastic compared with a rigid models, at apex of bifurcation of middle cerebral artery in vitro. Effects of elasticity on WSS, WSS gradient, and tensile strength of aneurysm wall were also investigated, in addition to effect of wall elasticity on KEC compared to a rigid wall. Although WSSG around stagnation point had a large positive value, wall elasticity suppressed WSS magnitude around stagnation point and attenuated KEC.
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| Free Research Field |
弾性壁脳動脈瘤の血行力学
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| Academic Significance and Societal Importance of the Research Achievements |
薄膜の脳動脈瘤をシリコンで作製し、PIVで検証し、CFDの領域に新たなる概念を注入する。その根拠は、瘤壁が膨張・収縮すれば変形が生じ、無視できない。流れは拍動流、作動流体は血液と同じ動粘度のグリセリン水溶液、流量, 無次元振動数は生体とほぼ同じ、動脈瘤大きさ10mmである。弾性効果は、流れ衝突点付近でWSSは８%抑制され、同時にWSSG は淀み点回りで10Pa/mmと病理学的に適合する大きさである。流れの不安定性の指標であるKEC の値は、弾性壁モデルでは低周波域で減衰勾配が大きく、同時に高周波域でも 10-2 と大きく減衰する。これらの新しい知見はCFDでは予測できない。
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