[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 j94=hJVKi  
人眼光学模型可用来设计眼科用设备，光学系统注定了要与人眼一起使用。本文演示了这样一个模型：Arizona眼睛模型，在Jim Schwiegerling教授的书中有详细描述：《Field Guide to Visual and Ophthalmic Optics》。AZ眼睛模型达到了基于平均临床数据所决定的轴上和轴外像差等级。FRED文件包含了此眼睛模型及几个用来分析它的光源，并包括一个基于想要的屈光度来调整模型的内嵌脚本。 )E@.!Ut4o  
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模型 }mq6]ZrK  
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模型的定义如表1种所示，由半径、圆锥常数、折射率、阿贝数、到下一面的距离等一系列表面组成。一些参数由屈光度（A）来决定。 OXSmt DvJ  
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在FRED中使用0屈光度来创建的，光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. (%e.:W${  
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光源 JG!m
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多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 mD0f<gJ1  
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除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处，并增加了pre-propagation distance= -8。尽管光线在光瞳处创建，规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射，而不是在光瞳处入射。 >WQMqQ^t@  
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在往下看是内置的脚本用来修改屈光度，使其为4（250mm），光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 6YLj^w] %  

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视网膜的散射 B^Nf #XN(  
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在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 qL&[K>2z  
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注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 U;V7 u/{  
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脚本 q J=~Y|(  
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内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： be{H$9'
 
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如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 :q7Wy&ow  
余下的脚本计算与屈光度有关的所有参数。 I^]2K0+x x  
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分析 FQ2  
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屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 /W30~y  
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脚本代码 el<s8:lA  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. mpEK (p  
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Dim entity As T_ENTITY Ae^~Cz1qz  
Dim op As T_OPERATION swoQ'  
Dim mat As T_MODELMATERIAL @=Uh',F  
Dim A As Double -.@r#d/  
Dim pupilDiam As Double
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Dim eID As Long Z{Qu<vy_  
Dim parID As Long }wjw:M  
Dim count As Integer };bEU wGWf  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double {G0T$,'DR  
Dim tlens As Double, nlens As Double ksqQM
 
Dim curv As Double, conic As Double V/LLaZTE  
Dim ok As Long 9y8&9<#  

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Sub Main <X^
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    '用户输入对话框 4*#18<u5  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 UWJ8amA  
        TextBox 220,21,40,21,.TextBox1 'default: 0 B=T'5&  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 |t&>5HM  
        OKButton 40,91,90,21 S_4?K)n #  
        CancelButton 190,91,90,21 Ugt/rf5n  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 VUGmi]qd  
        TextBox 220,49,40,21,.TextBox2 'default: 4 $}q23  
    End Dialog \?ZB]*Fu  
    Dim dlg As UserDialog |A9F\A->4  
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    ok = Dialog (dlg) @#>rYAb8,  
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    If ok=0 Then    'cancel button was pressed -1_)LO&H  
        Print "Execution cancelled." Jk11fn;\>  
        End f=Gg9bnm3  
    End If ")5":V~fN  
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    'Assign accommodation and pupil diameter & use defaults if field left empty ,vawzq[oSy  
    If dlg.TextBox1 = "" Then !cLo>,4  
        A = 0           'Default accommodation z`}qkbvi  
    Else S-b/S5  
        A = CDbl(dlg.TextBox1) aQcleTb  
    End If ]t,BMu=%  
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    If dlg.TextBox2 = "" Then uc\Kg1{  
        pupilDiam = 4   'Default pupil diameter KYhwOGN  
    Else {.|CdqwY  
        pupilDiam = CDbl(dlg.TextBox2) 
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    End If aEWWP]  
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    Print " " }W8;=$jr  
    Print "Accommodation = " & A & " Diopters" nYSiS}?S.  
    Print "Pupil Diameter = " & pupilDiam & " mm" 7#a-u<HF"  
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    ' Calculate new parameters with accommodation l0m-$/  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness D|p9qe5%  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens 1{.|+S Z!  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens Y%^w:|f^  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens 2(+
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    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens 'ya{9EdlT  
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    tlens = 3.767 + 0.04*A                  'Lens thickness At>DjKx]O  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction iByf{I>+  
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    'Adjust parameters to account for accommodation ]^7@}Ce_  
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    '************************************************************************* UHkMn  
    'Aqueous thickness (Position of Lens) q!7ANib6O  
    '************************************************************************* Y=I'czg  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) OLGE!&!>  
    GetCustomElement eID, entity i$#;Kpb`^  
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    parID = FindFullName( "Geometry.Arizona Eye" ) _8J.fT$${  
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    ' Delete any shift(s) in z -f^tE,
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    count = 0 q`7PhA
  
    While GetOperationCount(eID)>count &`
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        GetOperation eID, count, op 9:|{6_Y  
        If op.Type="ShiftZ" Then k%#E
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            DeleteOperation eID,count `UaD6Mc<Mz  
            count=count-1 ZvX*t)VjTz  
        End If s^9Voi.y  
        count=count+1 ^ VyKd  
    Wend exUFS5d  
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    'Set new shift in lb3bm)@:  
    op.Type = "ShiftZ" RSRS wkC  
    op.val1 = taq #gN&lY:CFn  
    op.parent = parID ,w4(kcg%iQ  
    AddOperation eID, op T3<4B!UB&  
    Print "Set aqueous humor thickness = " & taq-0.55
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    '************************************************************************* :eCwY  
    'Radius and conic constant of anterior lens Pmx-8w  
    '************************************************************************* }R2u@%n{  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) V2EUW!gn 2  
    GetConic eID, entity, curv, conic b_taC^-l  
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    SetConic eID, entity, 1/Rant, CCant \*?~Yj#  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant _;
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    '************************************************************************* Q3~H{)[Kq  
    'Radius and conic constant of posterior lens Hvi49c]]  
    '************************************************************************* t{9GVLZ  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) $%d*@'c  
    GetConic eID, entity, curv, conic oZgjQM$YP  

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    SetConic eID, entity, 1/Rpost, CCpost F/{!tx  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost ="H`V V_  
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    '************************************************************************* 0#hlsfc]\  
    'Lens thickness (Position of posterior lens surface) !f[_+CD  
    '************************************************************************* q?yVR3]M  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) >+1duAC  
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    ' Delete any z-shift(s) tcI*a>  
    count = 0 !e<^? r4  
    While GetOperationCount(eID)>count 0s[Hkhls  
        GetOperation eID, count, op 2%m BK  
        If op.Type="ShiftZ" Then X+9>A.92  
            DeleteOperation eID,count b8UO,fY q  
            count=count-1 v\ )W?i*l  
        End If ~36!?&eA8  
        count=count+1 {VRf0c  
    Wend {!L~@r  
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    'Set new z-shift C1)!f j=  
    op.Type = "ShiftZ" Bwxd&;E  
    op.val1 = tlens 6bC3O4Rw  
    op.parent = parID
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    AddOperation eID, op ZY+qA  
    Print "Set lens thickness = " & tlens 5t]H?b8  
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    '************************************************************************* Q197mN+0  
    'Lens index of refraction Y:[u1~a  
    '************************************************************************* ~$^XP.a.  
    eID = FindMaterial( "Lens" ) L="}ErmK  
    GetModelMaterial eID, mat :"c*s4  
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    mat.Nd = nlens rV#ch(  
    SetModelMaterial eID, mat onzxx4bax  
    Print "Set lens index of refraction = " & nlens #"~<HG}bR/  
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    '************************************************************************* #_p\Ie*rd  
    'Pupil diameter UCjld  
    '************************************************************************* H.MI5O(Q  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) e\L8oOk#r  
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    'Adjust pupil diameter (trimming volume inner hole) .ioEIsg  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" 5$k:t  
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    ' Adjust pupil location to just in front of the lens &^jXEz;  
    parID = FindFullName( "Geometry.Arizona Eye" ) L!xi  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) tWcHb #  
    count = 0 Dlvz)  
    While GetOperationCount(eID)>count +M/%+l  
        GetOperation eID, count, op @q)d  
        If op.Type="ShiftZ" Then YT,{E,U;  
            DeleteOperation eID,count 3Y$GsN4ln  
            count=count-1 cvL;3jRo  
        End If K
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        count=count+1 y:uE3Apm  
    Wend tCt#%7J;a  
    op.Type = "ShiftZ" <a3WKw  
    op.val1 = taq-0.01 eHUOU>&P]  
    op.parent = parID r~['VhI!;E  
    AddOperation eID, op (E1~H0^  
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    Print "Set pupil diameter = " & pupilDiam $XH^~i;  
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    'Update AZ Eye subassembly Description Ny/MJ#Lq  
    eID = FindFullName( "Geometry.Arizona Eye" ) p]c%f2E>d  
    GetEntity eID, entity 5z)~\;[ -  
    entity.Description = "Accommodation = " & A & "D" J{G?-+`  
    SetEntity eID, entity A04U /;  
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    Update GM<9p_ B  
    Print "DONE!" jPkn[W# 6  
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End Sub E]r?{t`]  
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如果屈光度是4，光瞳直径是4，则会输出如下数据： F!K>Kz  
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Accommodation = 4 Diopters u*9V&>o  
Pupil Diameter = 4 mm (QB2T2x  
Set aqueous humor thickness = 2.81 )+Pus~w  
Set anterior lens radius = 10.4 and conic constant = -2.375869 9>#6*/Oa7  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 u ^RxD^=L  
Set lens thickness = 3.927 M',?u  
Set lens index of refraction = 1.42672  %;!.n{X  
Set pupil diameter = 4 _q^E,P  
DONE! _@/8gPT*i  
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