モデリング・数値解析 - yamaguchi uds.cc.yamaguchi-u.ac.jp/~tsaito/common/pdf/common01.pdf7...
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Applied Medical Engineering ScienceApplied Medical Engineering Science
Graduate School of Medicine, Yamaguchi UniversityGraduate School of Medicine, Yamaguchi University
モデリング・数値解析モデリング・数値解析Modeling・Numerical analysis
齊藤齊藤 俊 俊
山口大学大学院医学研究科山口大学大学院医学研究科//応用医工学系応用医工学系//バイオマテリアル医療工学講座バイオマテリアル医療工学講座//生体医療工学研究分野生体医療工学研究分野
Takashi Saito /Biomedical EngineeringTakashi Saito /Biomedical Engineering/Biomaterial and Biomedical Engineering division/Biomaterial and Biomedical Engineering division/Applied Medical Engineering Science/Applied Medical Engineering Science/Graduate School of Medicine/Graduate School of Medicine/Yamaguchi University/Yamaguchi University
http://ds0.cc.http://ds0.cc.yamaguchiyamaguchi--uu.ac..ac.jpjp//~tsaito~tsaito/Common//Common/
Applied Medical Engineering ScienceApplied Medical Engineering Science
Graduate School of Medicine, Yamaguchi UniversityGraduate School of Medicine, Yamaguchi University
科学者/技術者の活動科学者/技術者の活動○基礎研究(Basic Research) 知識の獲得を目的とし,文明の技術的レベルを高め
ることに利用するということまで考えていない.
○応用研究(Applied Research) 基礎研究の直接の結果,あるいは,その副産物を実
際的に応用することを目標に知識の獲得をしようとするもの.
○研究開発(Research & Development) 特定の工夫の開発を目的とするもので,一つの可能
なモデルをうまく作り上げる点にまで持っていくことのできる知識を獲得することを目的とする.
○デザイン工学(Design Engineering)○生産工学(Production Engineering)
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Applied Medical Engineering ScienceApplied Medical Engineering Science
Graduate School of Medicine, Yamaguchi UniversityGraduate School of Medicine, Yamaguchi University
実学としての医療,工学実学としての医療,工学
生物・化学・物理現象の利用生物・化学・物理現象の利用
超音波エコー,CT,MRI....
実際に何が起こっているのかを知りたい...
音,光,磁気などの物理現象を利用した診断
磁場解析Applied Medical Engineering ScienceApplied Medical Engineering Science
Graduate School of Medicine, Yamaguchi UniversityGraduate School of Medicine, Yamaguchi University
Fig. MRI apparatus (Siemens Magnetom Vision)
山口大学医学部付属病院放射線科
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マクスウェルの方程式
ttrBtrE
∂∂
−=×∇),(),(
),(),(),( trJt
trDtrH +∂
∂=×∇
(1.1)
(1.2)
E : 電界 [V/m] ,H : 磁界 [A/m] ,D : 電束密度 [C/m ]B : 磁束密度 [T] ,J : 電流密度 [A/m ]
2
2
式(1.1),(1.2)を時間,空間領域で差分化する
Applied Medical Engineering ScienceApplied Medical Engineering Science
Graduate School of Medicine, Yamaguchi UniversityGraduate School of Medicine, Yamaguchi University
電磁波の解析
コイルが生じる磁界の分布(空気中)
線径 1 mm巻数 8
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Applied Medical Engineering ScienceApplied Medical Engineering Science
Graduate School of Medicine, Yamaguchi UniversityGraduate School of Medicine, Yamaguchi University
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Applied Medical Engineering ScienceApplied Medical Engineering Science
Graduate School of Medicine, Yamaguchi UniversityGraduate School of Medicine, Yamaguchi University
コイルが生じる磁界の分布(誘電体が存在)
誘電体(水)
空気
コイル
誘電体(皮膚)
Applied Medical Engineering ScienceApplied Medical Engineering Science
Graduate School of Medicine, Yamaguchi UniversityGraduate School of Medicine, Yamaguchi University
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Applied Medical Engineering ScienceApplied Medical Engineering Science
Graduate School of Medicine, Yamaguchi UniversityGraduate School of Medicine, Yamaguchi University
Applied Medical Engineering ScienceApplied Medical Engineering Science
Graduate School of Medicine, Yamaguchi UniversityGraduate School of Medicine, Yamaguchi University
生体組織(手首)における伝播生体組織(手首)における伝播
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Applied Medical Engineering ScienceApplied Medical Engineering Science
Graduate School of Medicine, Yamaguchi UniversityGraduate School of Medicine, Yamaguchi University
Applied Medical Engineering ScienceApplied Medical Engineering Science
Graduate School of Medicine, Yamaguchi UniversityGraduate School of Medicine, Yamaguchi University
t = 94 [ps]
t = 708 [ps] t = 1061 [ps]
t = 413 [ps] t = 531 [ps]
t = 884 [ps]
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モデリング・数値解析モデリング・数値解析Modeling・Numerical analysis
自然や工学において遭遇する様々な現象自然や工学において遭遇する様々な現象
数式・法則・原理などの適応によりモデル化数式・法則・原理などの適応によりモデル化
数学的記述数学的記述
予測・推定
予測・推定
Applied Medical Engineering ScienceApplied Medical Engineering Science
Graduate School of Medicine, Yamaguchi UniversityGraduate School of Medicine, Yamaguchi University
狭窄部位までカテーテルの先端を誘導
先端のバルーンカテーテルが拡張し,ステントも拡張
ステントが狭窄部位に残り,血管壁を支持
冠動脈に生じた狭窄を押し広げ血流を確保Applied Medical Engineering ScienceApplied Medical Engineering Science
Graduate School of Medicine, Yamaguchi UniversityGraduate School of Medicine, Yamaguchi Universityステント
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ステント拡張時の映像
→ねじりが生じる
Applied Medical Engineering ScienceApplied Medical Engineering Science
Graduate School of Medicine, Yamaguchi UniversityGraduate School of Medicine, Yamaguchi University
拡張実験拡張実験
⇒⇒臨床的に問題にならない?臨床的に問題にならない?
モデルモデル
モデル形状 CLCLCモデル→
全体図 展開図
(C:Cell L:Link)
Applied Medical Engineering ScienceApplied Medical Engineering Science
Graduate School of Medicine, Yamaguchi UniversityGraduate School of Medicine, Yamaguchi University
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荷重ステップ荷重ステップ
0th step
Applied Medical Engineering ScienceApplied Medical Engineering Science
Graduate School of Medicine, Yamaguchi UniversityGraduate School of Medicine, Yamaguchi University
荷重ステップ荷重ステップ
1st step
バルーンによりステント拡張Applied Medical Engineering ScienceApplied Medical Engineering Science
Graduate School of Medicine, Yamaguchi UniversityGraduate School of Medicine, Yamaguchi University
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解析結果例解析結果例
Ca_100%, +-, Offset_10%
Applied Medical Engineering ScienceApplied Medical Engineering Science
Graduate School of Medicine, Yamaguchi UniversityGraduate School of Medicine, Yamaguchi University
目的
・構造的特性
・力学的特性
・生体に及ぼす影響
などを解析的に調査
DES:Drug Eluting Stent
治療前 治療後
DES
Strut Drug
冠動脈
用途
構造
Applied Medical Engineering ScienceApplied Medical Engineering Science
Graduate School of Medicine, Yamaguchi UniversityGraduate School of Medicine, Yamaguchi University
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DES:Drug Eluting Stent
機械的特性
流体力学的特性
Radial-force Flexibility
etc…
Blood
DistributionApplied Medical Engineering ScienceApplied Medical Engineering Science
Graduate School of Medicine, Yamaguchi UniversityGraduate School of Medicine, Yamaguchi University
機械的特性
流体力学的特性
Radial-force Flexibility
etc…
Blood
目的
Distribution
・DESからの薬剤分布を数値解析により調査・高性能なDES設計への指針を提案
Applied Medical Engineering ScienceApplied Medical Engineering Science
Graduate School of Medicine, Yamaguchi UniversityGraduate School of Medicine, Yamaguchi University
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Implant:0%
解析モデルVessel wall :直管
Stent :トーラス6つ 等間隔
Lumen
Vessel wall
血流 :Navier-Stokes, 連続の式血管壁内:Darcy’s Law薬剤溶出:Convection and Diffusion
Strut
Applied Medical Engineering ScienceApplied Medical Engineering Science
Graduate School of Medicine, Yamaguchi UniversityGraduate School of Medicine, Yamaguchi University
Implant:0%
解析モデル
Vessel wall :直管
Stent :トーラス6つ 等間隔
Lumen
Vessel wall
血流 :Navier-Stokes, 連続の式血管壁内:Darcy’s Law薬剤溶出:Convection and Diffusion
Strut
Applied Medical Engineering ScienceApplied Medical Engineering Science
Graduate School of Medicine, Yamaguchi UniversityGraduate School of Medicine, Yamaguchi University
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Implant:0%
解析モデル
Vessel wall :直管
Stent :トーラス6つ 等間隔
Lumen
Vessel wall
血流 :Navier-Stokes, 連続の式血管壁内:Darcy’s Law薬剤溶出:Convection and Diffusion
Strut
Applied Medical Engineering ScienceApplied Medical Engineering Science
Graduate School of Medicine, Yamaguchi UniversityGraduate School of Medicine, Yamaguchi University
モデル 支配方程式
血液流れ
血管壁内流れ
薬剤溶出
S8
strut
S1
S5
S3
S6
S2
S7
S4
0)(2 =∇+∇•+∇− puuu∂ t∂u ρηρ
0=•∇ u
:Navier-stokes
:Darcy’s law
:Convection and Diffusion
pku ∇−=η
RcucD∂ t∂ c =∇•+∇−•∇+ )(
Applied Medical Engineering ScienceApplied Medical Engineering Science
Graduate School of Medicine, Yamaguchi UniversityGraduate School of Medicine, Yamaguchi University
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モデル 支配方程式
血液流れ
血管壁内流れ
薬剤溶出
S8
strut
S1
S5
S3
S6
S2
S7
S4
0=•∇ u
:Navier-stokes
:Darcy’s law
:Convection and Diffusion
pku ∇−=η
RcucD∂ t∂ c =∇•+∇−•∇+ )(
0)(2 =∇+∇•+∇− puuu∂ t∂u ρηρ
Applied Medical Engineering ScienceApplied Medical Engineering Science
Graduate School of Medicine, Yamaguchi UniversityGraduate School of Medicine, Yamaguchi University
モデル 支配方程式
血液流れ
血管壁内流れ
薬剤溶出
S8
strut
S1
S5
S3
S6
S2
S7
S4
0)(2 =∇+∇•+∇− puuu∂ t∂u ρηρ
0=•∇ u
:Navier-stokes
:Darcy’s law
:Convection and Diffusion
pku ∇−=η
RcucD∂ t∂ c =∇•+∇−•∇+ )(
Applied Medical Engineering ScienceApplied Medical Engineering Science
Graduate School of Medicine, Yamaguchi UniversityGraduate School of Medicine, Yamaguchi University
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モデル 支配方程式
血液流れ
血管壁内流れ
薬剤溶出
S8
strut
S1
S5
S3
S6
S2
S7
S4
0)(2 =∇+∇•+∇− puuu∂ t∂u ρηρ
0=•∇ u
:Navier-stokes
:Darcy’s law
:Convection and Diffusion
pku ∇−=η
RcucD∂ t∂ c =∇•+∇−•∇+ )(
Applied Medical Engineering ScienceApplied Medical Engineering Science
Graduate School of Medicine, Yamaguchi UniversityGraduate School of Medicine, Yamaguchi University
Strut周辺の薬剤分布
Target range
1.0
0.0
C/C
0[-]
→ Strut周辺では大きな薬剤効果の集中
1 2 3 4 5 6
Applied Medical Engineering ScienceApplied Medical Engineering Science
Graduate School of Medicine, Yamaguchi UniversityGraduate School of Medicine, Yamaguchi University
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Strut周辺の薬剤分布
Target range
1.0
0.0
C/C
0[-]
→ Strut周辺では大きな薬剤効果の集中
1 2 3 4 5 6
Applied Medical Engineering ScienceApplied Medical Engineering Science
Graduate School of Medicine, Yamaguchi UniversityGraduate School of Medicine, Yamaguchi University
機械的特性
流体力学的特性
Radial-force Flexibility
etc…
Blood
目的
Distribution
・DESからの薬剤分布を数値解析により調査・高性能なDES設計への指針を提案
Applied Medical Engineering ScienceApplied Medical Engineering Science
Graduate School of Medicine, Yamaguchi UniversityGraduate School of Medicine, Yamaguchi University
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Applied Medical Engineering ScienceApplied Medical Engineering Science
Graduate School of Medicine, Yamaguchi UniversityGraduate School of Medicine, Yamaguchi University
分布を有する構造の解析分布を有する構造の解析
生体における法則性に基づく構造モデルの構築
出来上がったものに対する解析を実施
6000 9000 12000 15000 18000 210000
20
40
60
80
100
Wavelength (nm)
Tran
smitt
ance
(%) Control
CollagenaseHyaluronidase
軟骨の分光測定軟骨の分光測定
Applied Medical Engineering ScienceApplied Medical Engineering Science
Graduate School of Medicine, Yamaguchi UniversityGraduate School of Medicine, Yamaguchi University
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赤外吸収スペクトル赤外吸収スペクトル
wavenumber [cm-1]
abso
rban
ce
04000 3000 2000 1000
Applied Medical Engineering ScienceApplied Medical Engineering Science
Graduate School of Medicine, Yamaguchi UniversityGraduate School of Medicine, Yamaguchi University
赤外吸収スペクトル赤外吸収スペクトル
wavenumber [cm-1]
abso
rban
ce
2000 80012001600
AmideⅠCollagenの量に比例[1]
960~1185 [cm-1]Proteoglycanの量に比例[1]
Applied Medical Engineering ScienceApplied Medical Engineering Science
Graduate School of Medicine, Yamaguchi UniversityGraduate School of Medicine, Yamaguchi University
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16002000 1200 800
0.6
0.4
0.2
0
abso
rban
ce
wavenumber [cm-1]
2.0%1.5%1.0%0.5%KBrのみ
collagen
AmideⅠ
比例
0 25 50 75 1000
30
20
10
125
40
density of collagen (%)
area
積分
AmideⅠ
r2=0.99
Applied Medical Engineering ScienceApplied Medical Engineering Science
Graduate School of Medicine, Yamaguchi UniversityGraduate School of Medicine, Yamaguchi University
wavenumber [cm-1]
abso
rban
ce
2000 1600 8001200
PorteoglycanPorteoglycanのの分量分量
[1] Nancy P. Camacho et.al. “FTIR Microscopic Imaging of Collagen and Proteoglycan in Bovine Cartilage”, Biopolymers, Vol.62, 1-8 (2001)
960~1185 [cm-1]この領域の積分値と
Proteoglycanの量には比例関係が成立[1]
proteoglycan量に比例
Collagenのみ
軟骨
Applied Medical Engineering ScienceApplied Medical Engineering Science
Graduate School of Medicine, Yamaguchi UniversityGraduate School of Medicine, Yamaguchi University
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豚大腿骨豚大腿骨 Superficial zone
0
10処理なし 1h 2h 4h 8h
Deep zoneApplied Medical Engineering ScienceApplied Medical Engineering Science
Graduate School of Medicine, Yamaguchi UniversityGraduate School of Medicine, Yamaguchi University
骨3次元的に複雑形状
力学環境に適応して形態を変化
体幹の支持,運動の伝達機能
運動によって様々な力が負荷
皮質骨 海綿骨
骨単位(オステオン)
構造 見るスケールで異なる形状,特性
Applied Medical Engineering ScienceApplied Medical Engineering Science
Graduate School of Medicine, Yamaguchi UniversityGraduate School of Medicine, Yamaguchi University
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オステオン
Boskey ら HAp結晶サイズとその分布が重要…
骨粗鬆症 骨構造の異常,骨量減少による骨折しやすい状態
骨軸方向
Collagen 線維
HApが沈着,成長
Collagen分子
Applied Medical Engineering ScienceApplied Medical Engineering Science
Graduate School of Medicine, Yamaguchi UniversityGraduate School of Medicine, Yamaguchi University
Collagen線維のモデル化
Collagen 線維
3次元的な構造は未解明
Collagen分子
Collagen分子の長軸 Collagen線維の軸
HAp結晶がCollagen分子に沈着し,成長
HAp結晶が沈着した後の典型的なCollagen分子の分布
線維内の構造はCollagen分子が螺旋状に集合と仮定
骨軸方向にずれて配列2次元のCollagen線維のモデル化
Applied Medical Engineering ScienceApplied Medical Engineering Science
Graduate School of Medicine, Yamaguchi UniversityGraduate School of Medicine, Yamaguchi University
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Collagen線維 (2D)のモデル化
座標は一様な擬似乱数
(モンテカルロ法)
Collagen線維内のHAp結晶の含有率65%
周期 Tstep毎にHApを N 個析出
rmax = R/10y方向の成長
x
y
R
HAp析出2
HAp析出1
HAp成長
計算終了
析出周期 T を一定とし,析出数 N をパラメータとして変化
x,y方向の2点で他のHAp結晶と接触Collagen線維の境界
オステオンの力学特性にどのように影響するか?
Applied Medical Engineering ScienceApplied Medical Engineering Science
Graduate School of Medicine, Yamaguchi UniversityGraduate School of Medicine, Yamaguchi University
解析手法
均質化法材料の周期性を仮定することで微細構造の影響を考慮し均質化した全体構造の特性
ユニットセル
微細構造における支配方程式を,ユニットセル全体の領域を離散化し有限要素法を用いて解くEH =
sym
E11
E22
E33
E12 E13
E23
Applied Medical Engineering ScienceApplied Medical Engineering Science
Graduate School of Medicine, Yamaguchi UniversityGraduate School of Medicine, Yamaguchi University
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ユニットセル
HApCollagen
140 pixel
30 pixel
0.27
0.27
均質化法の適用
x
y
・要素数 4200
・総節点数 4371
・要素の材料特性 各pixel要素の輝度値
・材料定数
HAp 110 [GPa]
Collagen 1.5 [GPa]縦弾性係数 ポアソン比
Applied Medical Engineering ScienceApplied Medical Engineering Science
Graduate School of Medicine, Yamaguchi UniversityGraduate School of Medicine, Yamaguchi University
解析結果 - 1< Model 1 > N = 20
< Model 2 > N = 10
< Model 3 > N = 5
小
大
HApの軸方向長さ
Applied Medical Engineering ScienceApplied Medical Engineering Science
Graduate School of Medicine, Yamaguchi UniversityGraduate School of Medicine, Yamaguchi University
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解析結果 - 2
4.090623.2767603 (N = 5)
4.104817.4646802 (N = 10)
4.006614.23471001 (N = 20)
rave [nm]lave [nm]nModel
HAp結晶
r
l
HAp
x
y・x方向の長さ
・y方向の長さ
・総析出数 n
l
r
( lの平均をlave , r の平均をrave )
Applied Medical Engineering ScienceApplied Medical Engineering Science
Graduate School of Medicine, Yamaguchi UniversityGraduate School of Medicine, Yamaguchi University
解析結果 - 3Ex Ey Exy
10 15 20 25 300
10
5
20
15
25
Homogenized elastic constants [GPa]
Average length of l [nm]
EH =
sym
E11
E22
E33
E12 E13
E23
Ex Ey Exy
Model1
Model2
Model3
HAp結晶サイズの異なるModel 1,2,3から得られた弾性係数行列EH(骨質)を比較
Applied Medical Engineering ScienceApplied Medical Engineering Science
Graduate School of Medicine, Yamaguchi UniversityGraduate School of Medicine, Yamaguchi University
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解析結果 – 4 -Ⅰ
δ= 0.2 × 10-2 [mm] / 20 step
平面ひずみ状態
1000 [mm]
0.2 [mm] EH =
sym
E11
E22
E33
E12 E13
E23
Applied Medical Engineering ScienceApplied Medical Engineering Science
Graduate School of Medicine, Yamaguchi UniversityGraduate School of Medicine, Yamaguchi University
解析結果 – 4 -Ⅱ
0 1.0 1.5 2.00.50
0.5
1.0
1.5
2.0
2.5
3.0
Deflection δ [μm]
Load P [mN]
Model 3Model 1 Model 2
Applied Medical Engineering ScienceApplied Medical Engineering Science
Graduate School of Medicine, Yamaguchi UniversityGraduate School of Medicine, Yamaguchi University
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Applied Medical Engineering ScienceApplied Medical Engineering Science
Graduate School of Medicine, Yamaguchi UniversityGraduate School of Medicine, Yamaguchi University
微視的な構造を確率的にモデル化
巨視的な手法により解析を実施
Differential equation models Macroscopic definition of a phenomenon by differential equations
A complex phenomenon
Top down Numerical calculation method
Science, Engineering (Quantum dynamics, Turbulence, Space science)A natural phenomenon (Earthquake, El Nino phenomenon)Life Phenomenon (Tissue formation, Heredity, Immunity, Brain functions)Social Phenomenon (Business fluctuations)
Complex systemComplex system
Applied Medical Engineering ScienceApplied Medical Engineering Science
Graduate School of Medicine, Yamaguchi UniversityGraduate School of Medicine, Yamaguchi University
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A complex phenomenon
Bottom up
Science, Engineering (Quantum dynamics, Turbulence, Space science)A natural phenomenon (Earthquake, El Nino phenomenon)Life Phenomenon (Tissue formation, Heredity, Immunity, Brain functions)Social Phenomenon (Business fluctuations)
Self-organization
Automaton models Definition by microscopic interaction between each cell(Neighbourhood rules of simple level)
Applied Medical Engineering ScienceApplied Medical Engineering Science
Graduate School of Medicine, Yamaguchi UniversityGraduate School of Medicine, Yamaguchi University
Differential equation models Macroscopic definition of a phenomenon by differential equations
A complex phenomenon
Top down
Bottom up
Numerical calculation method
Science, Engineering (Quantum dynamics, Turbulence, Space science)A natural phenomenon (Earthquake, El Nino phenomenon)Life Phenomenon (Tissue formation, Heredity, Immunity, Brain functions)Social Phenomenon (Business fluctuations)
Self-organization
Automaton models Definition by microscopic interaction between each cell(Neighbourhood rules of simple level)
Applied Medical Engineering ScienceApplied Medical Engineering Science
Graduate School of Medicine, Yamaguchi UniversityGraduate School of Medicine, Yamaguchi University
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モデリング・数値解析モデリング・数値解析Modeling・Numerical analysis
自然や工学において遭遇する様々な現象自然や工学において遭遇する様々な現象
数式・法則・原理などの適応によりモデル化数式・法則・原理などの適応によりモデル化
数学的記述数学的記述
予測・推定
予測・推定
Applied Medical Engineering ScienceApplied Medical Engineering Science
Graduate School of Medicine, Yamaguchi UniversityGraduate School of Medicine, Yamaguchi University
メディア基盤センターメディア基盤センター•• NASTRAN NASTRAN 構造解析構造解析••αα--FLOW FLOW 流体解析流体解析•• MOPACMOPAC 分子軌道計算分子軌道計算
汎用ソフトウェア汎用ソフトウェア
その他その他•• ANSYS ANSYS 構造解析構造解析•• Fluent Fluent 熱流体解析熱流体解析
定式化・計算アルゴリズム・プログラム開発定式化・計算アルゴリズム・プログラム開発
Applied Medical Engineering ScienceApplied Medical Engineering Science
Graduate School of Medicine, Yamaguchi UniversityGraduate School of Medicine, Yamaguchi University
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••生体内交番磁界の分布の解析生体内交番磁界の分布の解析••生体内超音波・光伝播現象の解析生体内超音波・光伝播現象の解析••軟組織・硬組織の非線形変挙動解析軟組織・硬組織の非線形変挙動解析••医療デバイスの最適化のための解析医療デバイスの最適化のための解析 ⇒ ⇒ デバイス開発デバイス開発のための解析のための解析
•• ステント・コイル等血管内流れの解析ステント・コイル等血管内流れの解析••生体内温度分布と血流量に関する熱流動解析生体内温度分布と血流量に関する熱流動解析••薬剤効果に制御された生体組織のシミュレーション薬剤効果に制御された生体組織のシミュレーション••細胞培養・増殖シミュレーション細胞培養・増殖シミュレーション ⇒ ⇒ 臨床結果臨床結果・・生命現象解明生命現象解明のための解析のための解析
Applied Medical Engineering ScienceApplied Medical Engineering Science
Graduate School of Medicine, Yamaguchi UniversityGraduate School of Medicine, Yamaguchi University
終わり終わり
Applied Medical Engineering ScienceApplied Medical Engineering Science
Graduate School of Medicine, Yamaguchi UniversityGraduate School of Medicine, Yamaguchi University