[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 y 8./)W&/  
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。 x:Nd>Fb  
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模型 6BPZ2EQ  
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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。 9gz"r  
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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. ,;_D~7L  
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光源 kOe~0xoT@u  
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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。 wq( m%F  
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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。 L
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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。 C+WHg-l  
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视网膜的散射 P80z@!  
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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。 #0-!P+c[  
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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。 ax0:v!,e  
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脚本 dk
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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： OpwZTy}1}  
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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。 Ih}I`wY-  
余下的脚本计算与屈光度有关的所有参数。 6,'!z ?d%  
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分析 b; SFnZa8  
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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。 (8s]2\/Ar  
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脚本代码 5eC5oX>  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. VI%879Z\e  
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Dim entity As T_ENTITY r*/Pyh  
Dim op As T_OPERATION ^zGgvFf>  
Dim mat As T_MODELMATERIAL g1\4Jb  
Dim A As Double OwP9=9};  
Dim pupilDiam As Double :^SpKe(7  
Dim eID As Long G'( %8\  
Dim parID As Long yZ,k8TJ",  
Dim count As Integer i:WHql"Kw_  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double oll~|J^sg  
Dim tlens As Double, nlens As Double (ju-r*0  
Dim curv As Double, conic As Double qy@gW@IU  
Dim ok As Long }H{{@RU  
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Sub Main xIF z@9+k  
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    '用户输入对话框 %^"Tz,f  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 vj
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        TextBox 220,21,40,21,.TextBox1 'default: 0 @Qx|!%  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 i^uC4S~  
        OKButton 40,91,90,21 f?F i{m  
        CancelButton 190,91,90,21 o lNL|WJ`w  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 >"F~%D<.  
        TextBox 220,49,40,21,.TextBox2 'default: 4 G=3/PYp  
    End Dialog ~0fT*lp  
    Dim dlg As UserDialog mN?'Aey  
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    ok = Dialog (dlg) ##u+[ !  
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    If ok=0 Then    'cancel button was pressed ,I=ClmR  
        Print "Execution cancelled." )QTk5zt  
        End %kJ:{J+w]  
    End If _OcgD<  
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    'Assign accommodation and pupil diameter & use defaults if field left empty ;FZ\PxN  
    If dlg.TextBox1 = "" Then 5S$HDO&  
        A = 0           'Default accommodation )X\.Xr-6q  
    Else $7)O&T*q'  
        A = CDbl(dlg.TextBox1) ;lX:EU  
    End If v!@/  
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    If dlg.TextBox2 = "" Then %8$JL=c  
        pupilDiam = 4   'Default pupil diameter R^](X*  
    Else 2k"a%#H8  
        pupilDiam = CDbl(dlg.TextBox2) uA!T@>vl  
    End If uh#PZ xnP  
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    Print " " #jr;.;8sQ  
    Print "Accommodation = " & A & " Diopters" 'xStA  
    Print "Pupil Diameter = " & pupilDiam & " mm" u{H,i(mx?  
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    ' Calculate new parameters with accommodation 9aZ3W<N`M  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness j\dkv_L  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens Cqg}dXn'  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens 6{lWUr  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens T,7Y7MzF  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens (P`{0^O"}  
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    tlens = 3.767 + 0.04*A                  'Lens thickness jI;bVG  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction mu"]B]
 
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    'Adjust parameters to account for accommodation d*A>P  
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    '************************************************************************* K/\#FJno  
    'Aqueous thickness (Position of Lens) }%k"qW<Y  
    '************************************************************************* yH#;k:O=  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) ~O1*]  
    GetCustomElement eID, entity #(aROTV5a  
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    parID = FindFullName( "Geometry.Arizona Eye" ) "mPa>`?
 
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    ' Delete any shift(s) in z 1v2wP2]|;  
    count = 0 34;c0
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    While GetOperationCount(eID)>count g=U?{<8.m  
        GetOperation eID, count, op 7vj[ AOq3l  
        If op.Type="ShiftZ" Then XIjSwR kYJ  
            DeleteOperation eID,count pHg8(ru|  
            count=count-1 sM5 w~R>Y  
        End If ?sS'T7r v  
        count=count+1 M\v4{\2l0  
    Wend "apv)xdW  
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    'Set new shift in .k*2T<p$rC  
    op.Type = "ShiftZ" V'mpl  
    op.val1 = taq !zJ.rYZ=g`  
    op.parent = parID M;iaNL(  
    AddOperation eID, op 3@"VS_;?  
    Print "Set aqueous humor thickness = " & taq-0.55 )<^ ~${$U  
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    '************************************************************************* <BU|?T6~  
    'Radius and conic constant of anterior lens GrQl3 Xi  
    '************************************************************************* 8OFrW.>[  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) \3LD^[qi  
    GetConic eID, entity, curv, conic >8JvnBFx=  
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    SetConic eID, entity, 1/Rant, CCant NXmj<azED  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant =u'/\nxCF  
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    '************************************************************************* &pba~X.u  
    'Radius and conic constant of posterior lens S~TJF}[k^6  
    '************************************************************************* h{JVq72R
 
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) ,3n}*"K  
    GetConic eID, entity, curv, conic f:UN~z'yr  
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    SetConic eID, entity, 1/Rpost, CCpost hT]p8m aRZ  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost <
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    '************************************************************************* 'PYl%2  
    'Lens thickness (Position of posterior lens surface) eoL)gIM%  
    '************************************************************************* B}FF |0<  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) ^7''x,I  
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    ' Delete any z-shift(s) uB^]5sqfk  
    count = 0 3AL.UBj&}  
    While GetOperationCount(eID)>count }GC{~ SZ4  
        GetOperation eID, count, op jF5JpyOc  
        If op.Type="ShiftZ" Then U^YPL,m1  
            DeleteOperation eID,count gU%GM  
            count=count-1 g Q9ff,  
        End If 8&;dR  
        count=count+1 T*ic?!  
    Wend Sh*P^i.]+  
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    'Set new z-shift &p%ctg  
    op.Type = "ShiftZ" PaZYs~EO  
    op.val1 = tlens Iymz2  
    op.parent = parID 950b9Vn&  
    AddOperation eID, op Rq9gtx8,=  
    Print "Set lens thickness = " & tlens :ox CF0Y  
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    '************************************************************************* #.='dSj  
    'Lens index of refraction MDq@:t  
    '************************************************************************* \*N1i`99  
    eID = FindMaterial( "Lens" ) o MAK[$k;  
    GetModelMaterial eID, mat fI|1@e1  
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    mat.Nd = nlens \[&]kPcDl  
    SetModelMaterial eID, mat Ygl!fC 4b  
    Print "Set lens index of refraction = " & nlens F)IP~BE-k  
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    '************************************************************************* `otQ'e~+t  
    'Pupil diameter f1{ckHAY55  
    '************************************************************************* 8B+uNN~%]  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) k);!H+  
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    'Adjust pupil diameter (trimming volume inner hole) ;$i'A&)OC  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" x'qgpG}?]  
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    ' Adjust pupil location to just in front of the lens ep!.kA=\  
    parID = FindFullName( "Geometry.Arizona Eye" ) 9T1G/0k-  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) |H4'*NP"  
    count = 0 U&XoT-p$L  
    While GetOperationCount(eID)>count 1:t>}[Y  
        GetOperation eID, count, op 34=0.{qn  
        If op.Type="ShiftZ" Then =jN]ckn  
            DeleteOperation eID,count 9wC; m:  
            count=count-1 Xy{+=UY  
        End If j$^]WRt  
        count=count+1 2$91+N*w9  
    Wend vn<S"  
    op.Type = "ShiftZ" C0%%
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    op.val1 = taq-0.01 UPYM~c+}  
    op.parent = parID }0( Na  
    AddOperation eID, op nM`)`!/  
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    Print "Set pupil diameter = " & pupilDiam K?4(ou  
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    'Update AZ Eye subassembly Description `{Jb{L@f  
    eID = FindFullName( "Geometry.Arizona Eye" ) 'gGB-=yvbO  
    GetEntity eID, entity Nt8(  
    entity.Description = "Accommodation = " & A & "D" ^n/uY94E)p  
    SetEntity eID, entity 0 *\=Q$Yy  
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    Update q~n2VU4L*  
    Print "DONE!" "ivqh{ ,  
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End Sub 8=~>B@'  
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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： U\
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Accommodation = 4 Diopters eW0=m:6  
Pupil Diameter = 4 mm meR2"JN'  
Set aqueous humor thickness = 2.81 3p4?-Dd|_$  
Set anterior lens radius = 10.4 and conic constant = -2.375869  D;]%  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 7o. 'F  
Set lens thickness = 3.927 }H=OVbQor  
Set lens index of refraction = 1.42672 ">3@<f>  
Set pupil diameter = 4
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DONE! wY#mL1dF  
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