，，本一致。對計算得到的腦脊液各處壓力梯度變化進行分析，發現在心臟收縮期，側腦室的腦脊力最大，而根據脊管內的腦脊力變化，驗證了腦脊液系統的循環機理。 管內。腦脊液循環系統是內體液循環的一種自然現象，了解腦脊液的生理特點對于探索有限元數值模擬是生物力學研究領域的重要，對腦脊液循環的動力學研究同樣可以采用有型并對其進行了有限元分析，SumeetGupta等人對顱骨與脊管交界面處的腦脊液流動情況進行了研幫助我們理解很多腦脊液系統的疾病，包括Chiari畸形，顱內高壓癥等等。此外，一個完整的全顱為了更加真實的模擬腦脊液系統循環的流動情況，本文基于CT圖像重建了各個腦室、顱腦及164排螺旋CT對樣本顱骨及腦組織進行了CT掃描，獲得了原始的醫學圖像，為格式CT掃描的矢狀位圖。DELL個人PC（In(R)Corei5-34703.20GHz4GB內存）CT圖像數據GeomagicStudio12.0GeomagicStudio12.0中首先對初步 1將得到的模型以IGES格式保存并導入到ANSYSICEM14.0進行有限元網格劃分，利用非結構子倍數增長。邊界層體網格數為633270，模型總網格數為。2ICEM14.0中劃分好的體網格文件導入ANSYSCFX14.0中。計算腦脊液循環系統的流體 其中???為速度矢量，腦脊液的分泌量為????由于心臟搏動循環的影響，顱內動脈的瞬態變化會引起腦組織的變形，而由于腦組織的變形會(2)重建。根據表1繪制一個心動周期內的進口流量如圖5所示8??(??)=∑

其中i=√ ，????=(?? 如表1所示。12 值 1234-5-6-7812-3-4-5678-圖3腦脊液流量變化腦脊液的流動遵循質量和動量守恒定律，即連續方程(3)和Navier-Stokes控制方程(4)~

+

=

??(?????)+????(???????)=????(?????? ??(????)+????(??????)=????(?????? ??(????)+????(??????)=????(?????? 其中為腦脊液密度，在生理條件下為常量；t為時間；p為壓力；U為速度矢量，u,v和ω為速度表2所示。

3 (a)收縮 腦脊液流速較快，并且收縮期時這幾處的流速較舒張期時快。這與臨觀察到的情況是相符的，77為四個腦室及其連接處不同時刻的速度流線圖，當處于心臟收縮期的初期時，可以觀察到各腦室的連接處的速度較快，其腦導水管的速度較大。而當心臟處于收縮期的中期時，由于此顯下降。中腦導水管處在整個心動周期期間的流速變化如圖8所示。(a)第四腦室左外側 (b)第四腦室右外側(c)9MRI計算結果4,,陳家亮,等.腦脊液循環動力學的初步計算機建模分析.中華神經外科,2012,,,曾高,等.腦脊液系統在顱內高壓動力學中作用的數學模型.,2007,377-PenaA,BoltonMD,WhitehouseH,etal.Effectsofbrainventricularshapeonperiventricularbiomechanics:afinite-elementysis.Neurosurgery,1999,45(1):107.FinL?,GrebeR.Threedimensionalmodelingofthecerebrospinalfluiddynamicsandbraininctionsintheaqueductofsylvius.Computermethodsinbiomechanicsandbiomedicalengineering,2003,6(3):GuptaS,SoellingerM,PoulikakosD,etal.Three-dimensionalcomputationalmodelingofsubject-specificcerebrospinalfluidflowinthesubarachnoidspace.Journalofbiomechanicalengineering,2009,131(2):021010.LinningerAA,SweetmanB,PennR.Normalandhydrocephalicbraindynamics:theroleofreduced37(7):1434-1447.brain.BiomedicalEngineering,IEEETransactionson,2007,54(2):291-302.CzosnykaM,CzosnykaZ,MomjianS,etal.Cerebrospinalfluiddynamics.Physiologicalmeasurement,2004,25(5):R51.LinningerAA,SomayajiMR,MekarskiM,etal.Predictionofconvection-enhanceddrugdeliverytothehumanbrain.JournalofTheoreticalBiology,2008,250(1):125-138..SaltzmanWM,OlbrichtWL.Buildingdrugdeliveryintotissueengineeringdesign.NatureReviewsDrugDiscovery,2002,1(3):177-186.HuangTY,ChungHW,ChenMY,etal.SupratentorialCerebrospinalFluidProductionRateinHealthyAdults:ficationwithTwo-dimensionalCinePhase-ContrastMRImagingwithHighTemporalandSpatialResolution1.Radiology,2004,233(2):603-608.LorenzoAV,PageLK,WattersGV.Relationshipbetweencerebrospinalfluidformation,absorptionandpressureinhumanhydrocephalus.Brain,1970,93(4):679-692.SegalMB.Transportofnutrientsacrossthechoroidplexus.Microscopyresearchandtechnique,2001,52(1):38-48.SilverbergGD,HeitG,HuhnS,etal.ThecerebrospinalfluidproductionrateisreducedinoftheAlzheimer’stype.Neurology,2001,57(10):1763-reviews,1966:238.EllingtonE,MargolisG.BlockofArachnoidVillusbySubarachnoidHemorrhage*.Journalofneurosurgery,1969,30(6):651-657.UptonML,WellerRO.Themorphologyofcerebrospinalfluiddrainagepathwaysinhumanarachnoidgranulations.Journalofneurosurgery,1985,63(6):867-875.AlperinN,VikingstadEM,Gomez‐AnsonB,etal.HemodynamicallyindependentysisofcerebrospinalfluidandbrainmotionobservedwithdynamicphasecontrastMRI.Magneticresonanceinmedicine,1996,35(5):741-754..Journalofbiomechanicalengineering,2001,123(1):71-79.WhiteDN,WilsonKC,CurryGR,etal.ThelimitationofpulsatileflowthroughtheaqueductofSylviusasacauseofhydrocephalus.Journaloftheneurologicalsciences,1979,42(1):11-51.SweetmanB,LinningerAA.Cerebrospinalfluidflowdynamicsinthecentralnervoussystem.Annalsofbiomedicalengineering,2011,39(1):484-496.,, 射 ,放

11,45(3):245-ConstructionandysisofCerebrospinalFluidBasedonReverseLi Jiang Wu(FacultyofVehicleEngineerandMechanics,DalianUniversityofTechnology,Dalian116024,Inordertoprovideatheoreticalbasisfortheclinicaltreatmentofcerebrospinalfluid(CSF)circulationsystem，a3DfiniteelementmodelofCSFwasconstructedandanumericalsimulationofCSFflowwasperformed．BasedonthehealthyadultCTdataofCSFanddigitalimageprocessingsoftwareMIMICS11，anoptimizedsurfacemodelofCSFwasconstructed．ThenthesurfacemodelwasimportedintoANSYSICEMCFD14.0togeneratevolumemesh．AtlastCSFysiswasperformedusingANSYSCFX14.0．AfiniteelementmodelsuitableforCerebrospinalfluidcirculationsystemwasestablished．Distrib