[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 |4mvB2r  
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。 zz*P
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模型 `2 <:$]  
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模型的定义如表1种所示，由半径、圆锥常数、折射率、阿贝数、到下一面的距离等一系列表面组成。一些参数由屈光度（A）来决定。 4<-Kd~uL  
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在FRED中使用0屈光度来创建的，光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. t.ulG *  
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光源 '
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多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 )5b_>Uy  
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除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处，并增加了pre-propagation distance= -8。尽管光线在光瞳处创建，规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射，而不是在光瞳处入射。 } [#8>T  
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在往下看是内置的脚本用来修改屈光度，使其为4（250mm），光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 MZz9R*_VS  
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视网膜的散射 5b:1+5iF-  
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在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 J,Ki2'=  
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注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 g!~SHW)l  
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脚本 GUu8 N  
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内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： =wX;OK|U(^  
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如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 us.[wp'Sh  
余下的脚本计算与屈光度有关的所有参数。 Kk}, P
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分析 W$jRS  
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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。 Y)k"KRW+  
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脚本代码 ]lA}5  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. =-oP,$k  
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Dim entity As T_ENTITY _t-6m2A  
Dim op As T_OPERATION <9&GOaJ  
Dim mat As T_MODELMATERIAL p|gVIsg[-e  
Dim A As Double :W
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Dim pupilDiam As Double FZgf"XM>  
Dim eID As Long ,IhQ%)l  
Dim parID As Long M;XU"8  
Dim count As Integer N_ ODr]L  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double Vl$RMW@Ds  
Dim tlens As Double, nlens As Double oPs asa  
Dim curv As Double, conic As Double iY`[dsT  
Dim ok As Long RK@K>)"f  
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Sub Main h*^JFZb  
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    '用户输入对话框 cWnEp';.  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 }'vQUGu8z  
        TextBox 220,21,40,21,.TextBox1 'default: 0 9=}#.W3.  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 1;m?:|6K{  
        OKButton 40,91,90,21 \#bi
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        CancelButton 190,91,90,21 5xr2  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 =,*/Ph&  
        TextBox 220,49,40,21,.TextBox2 'default: 4 V #vkj  
    End Dialog yx#!2Z0hw  
    Dim dlg As UserDialog ,8DC9yM,  
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    ok = Dialog (dlg) KOR*y(*8  
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    If ok=0 Then    'cancel button was pressed MA{ZmPm)  
        Print "Execution cancelled." rk%pA-P2  
        End _H U>T  
    End If PM@_ZJ'x  
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    'Assign accommodation and pupil diameter & use defaults if field left empty _l)3pm6  
    If dlg.TextBox1 = "" Then Lwtp,.)pR  
        A = 0           'Default accommodation z
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    Else jKcl{',  
        A = CDbl(dlg.TextBox1) ]hlQU%&  
    End If k3LHLJZ#  
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    If dlg.TextBox2 = "" Then 7lYf+&JZ  
        pupilDiam = 4   'Default pupil diameter {y{O ze  
    Else ?pQ0* O0  
        pupilDiam = CDbl(dlg.TextBox2) 43=)akJi  
    End If \*5z0A9)5)  
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    Print " " L5:1dF  
    Print "Accommodation = " & A & " Diopters" `E;xI v|  
    Print "Pupil Diameter = " & pupilDiam & " mm" b$Ei>%'/";  
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    ' Calculate new parameters with accommodation iqoMQ7%  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness 2I suBX\[  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens |pknaz  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens wg k[_i  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens jc32s}/H  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens lV./K;\T  
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    tlens = 3.767 + 0.04*A                  'Lens thickness RHd no C  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction T#e|{ZCbq  
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    'Adjust parameters to account for accommodation !gsrPM  
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    '************************************************************************* ]2&RN@   
    'Aqueous thickness (Position of Lens) f6(1jx"  
    '************************************************************************* wqjR-$c  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) :v45Ls4J  
    GetCustomElement eID, entity ;xFB /,  
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    parID = FindFullName( "Geometry.Arizona Eye" ) {a2Gb  
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    ' Delete any shift(s) in z 9%Vy,  
    count = 0 19[.&-u"  
    While GetOperationCount(eID)>count Ag{)?5/d_  
        GetOperation eID, count, op H:Q4!<  
        If op.Type="ShiftZ" Then re4z>O*  
            DeleteOperation eID,count :"nh76xg<  
            count=count-1 GAs.?JHd  
        End If :Ez*<;pF'  
        count=count+1 p? w^|V  
    Wend vXM{)
  
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    'Set new shift in ".pQM.T  
    op.Type = "ShiftZ" x*X{*?5@  
    op.val1 = taq ;Ob^@OM  
    op.parent = parID Ss+  
    AddOperation eID, op [T3%Xt'4  
    Print "Set aqueous humor thickness = " & taq-0.55 dtG>iJ  
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    '************************************************************************* 8"[{[<-   
    'Radius and conic constant of anterior lens fC}u
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    '************************************************************************* "2tKh!?Q  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) {XC[Ia6jtL  
    GetConic eID, entity, curv, conic A&jR-%JG  
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    SetConic eID, entity, 1/Rant, CCant XQOM6$~,  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant 7pyaHe  
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    '************************************************************************* =<TJ[,h et  
    'Radius and conic constant of posterior lens soLmr's  
    '************************************************************************* ?5%o-hB|  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) XrXW6s;Z  
    GetConic eID, entity, curv, conic z63
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    SetConic eID, entity, 1/Rpost, CCpost & \C1QkI  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost yI-EF)A@;  
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    '************************************************************************* zW`a]n.  
    'Lens thickness (Position of posterior lens surface) iJKGzHvS  
    '************************************************************************* Nn?$}
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) l&Y'5k_R  
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    ' Delete any z-shift(s) r&F 6ZCw  
    count = 0 z${[Z=  
    While GetOperationCount(eID)>count u2[L^]|  
        GetOperation eID, count, op g<$2#c}  
        If op.Type="ShiftZ" Then 0<f.r~  
            DeleteOperation eID,count _ib @<%  
            count=count-1 "kVzN22  
        End If |v1* [(  
        count=count+1 v5{2hCdt  
    Wend Bob-qCBV  
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    'Set new z-shift &xt GabNk  
    op.Type = "ShiftZ" Jy('tfAHp  
    op.val1 = tlens ]9W7]$  
    op.parent = parID rJRg4Rog  
    AddOperation eID, op P%!=Rj^2m  
    Print "Set lens thickness = " & tlens PY+4OZ$  
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    '************************************************************************* 43O5|8o  
    'Lens index of refraction 1FT3d  
    '************************************************************************* `'pAiu  
    eID = FindMaterial( "Lens" ) -]n%+,3L  
    GetModelMaterial eID, mat uZI7,t-7  
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    mat.Nd = nlens G9GLRdP  
    SetModelMaterial eID, mat %
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    Print "Set lens index of refraction = " & nlens
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    '************************************************************************* }O| 9Qb  
    'Pupil diameter MGre_=Dm_  
    '************************************************************************* (<e<Q~(  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) i1bmUKZ8'L  
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    'Adjust pupil diameter (trimming volume inner hole) Jz P0D'  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" _,d<9 Y)  
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    ' Adjust pupil location to just in front of the lens \F""G,AWq{  
    parID = FindFullName( "Geometry.Arizona Eye" ) hMV>5Y[s  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) dT (i*E\j  
    count = 0 !?+q7U  
    While GetOperationCount(eID)>count ~-R2mAUK  
        GetOperation eID, count, op !aL=R)G&e  
        If op.Type="ShiftZ" Then <vD(,||  
            DeleteOperation eID,count p(Osz7K  
            count=count-1 |f.,fVVV;  
        End If h@y>QhYU0  
        count=count+1 (=EDqAZg  
    Wend ~03M
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    op.Type = "ShiftZ" :-$8u;!M  
    op.val1 = taq-0.01 t%<y^Wa=  
    op.parent = parID es=OWJt^  
    AddOperation eID, op (vvD<S*  
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    Print "Set pupil diameter = " & pupilDiam  _-9cGm v  
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    'Update AZ Eye subassembly Description 6E9/z  
    eID = FindFullName( "Geometry.Arizona Eye" ) 8B5WbS fL^  
    GetEntity eID, entity k,f/9e+#  
    entity.Description = "Accommodation = " & A & "D" gFTlP  
    SetEntity eID, entity uU^iY$w  
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    Update !ab ef.%:  
    Print "DONE!" HPJHA ,  
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End Sub Zj1bG{G=i  
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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： ,|.}6\zl*{  
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Accommodation = 4 Diopters ='m%Iq7X  
Pupil Diameter = 4 mm e0otr_)3F  
Set aqueous humor thickness = 2.81 #N'9 w .  
Set anterior lens radius = 10.4 and conic constant = -2.375869
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Set posterior lens radius = -4.424557 and conic constant = -3.081019 ?,8+1"|$A]  
Set lens thickness = 3.927 U~;tk@  
Set lens index of refraction = 1.42672 a ~W  
Set pupil diameter = 4 $$"G1<EZ  
DONE! Kr `/sWZ  
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