[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 \9dC z;  
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。 D|!^8jHj  
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模型 4 5\%2un  
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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。 8'Ph/L,  
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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. pUaGrdGxzQ  
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光源 vZpt}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。 "5R8Zl+  
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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。 Y r^C+Oyg  
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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。 nr<&j#!L  
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视网膜的散射 Pz1[ b$%  
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在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 T6ajWUw  
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注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 9RoN,e8!  
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脚本 ?qt>;o|Ue  
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内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： 6 2r%q^r`i  
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如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 9ci=]C5o3K  
余下的脚本计算与屈光度有关的所有参数。 T&=1IoOg  
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分析 FXPw5  
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屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 Ii,Lj1Q  
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脚本代码 i!30f^9D-S  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. ^t=Hl  
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Dim entity As T_ENTITY MeqW/!72$L  
Dim op As T_OPERATION K
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Dim mat As T_MODELMATERIAL Brh<6Btl  
Dim A As Double $*bd})y)I  
Dim pupilDiam As Double R)"Y40nW  
Dim eID As Long A`4j=OF\  
Dim parID As Long Z;aQ/n[`  
Dim count As Integer =3J&UQL  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double c_]$UM[7L  
Dim tlens As Double, nlens As Double ^<R*7mB*  
Dim curv As Double, conic As Double $Blo`'  
Dim ok As Long fo$iV;x`  
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Sub Main `7P4O   
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    '用户输入对话框 Eoug/we  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 DT_HG|  
        TextBox 220,21,40,21,.TextBox1 'default: 0 2yhtJ9/  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 Uc6BI$Fmz  
        OKButton 40,91,90,21 Y%b 5{1  
        CancelButton 190,91,90,21 5rqjqfFa  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 !Jw   
        TextBox 220,49,40,21,.TextBox2 'default: 4 /H=fK  
    End Dialog @ba5iIt  
    Dim dlg As UserDialog z)'dDM D"  
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    ok = Dialog (dlg) \eE0Rnaf-  
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    If ok=0 Then    'cancel button was pressed 1%|+yu1  
        Print "Execution cancelled." !ec\8Tj  
        End .9WJ/RKZ\D  
    End If `!HGM>  
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    'Assign accommodation and pupil diameter & use defaults if field left empty lcij}-z:%e  
    If dlg.TextBox1 = "" Then K3&v6 #]  
        A = 0           'Default accommodation KUVsCmiT  
    Else '|<+QAc  
        A = CDbl(dlg.TextBox1) eP-q[U?$n  
    End If FfN==2:b  
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    If dlg.TextBox2 = "" Then Z mF}pa,gd  
        pupilDiam = 4   'Default pupil diameter ;uNcrv0J  
    Else eMVfv=&L<3  
        pupilDiam = CDbl(dlg.TextBox2) L@w|2  
    End If ;"\e aKl  
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    Print " " 'MPt K  
    Print "Accommodation = " & A & " Diopters" ^q@.yL  
    Print "Pupil Diameter = " & pupilDiam & " mm" j|9;") 1  
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    ' Calculate new parameters with accommodation &F[/@  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness Y4}!9x  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens @#1k+tSA,  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens e|+U7=CK  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens 1agyT  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens Q <EFd   
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    tlens = 3.767 + 0.04*A                  'Lens thickness ZebXcT ,41  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction 3'O+  
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    'Adjust parameters to account for accommodation R~CQ=KQ.  
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    '************************************************************************* p8Di9\}  
    'Aqueous thickness (Position of Lens) q*TH),)J  
    '************************************************************************* 9M:wUYHT  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) eP|:b &  
    GetCustomElement eID, entity b4!(~"b.  
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    parID = FindFullName( "Geometry.Arizona Eye" ) S&8gZ~B  
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    ' Delete any shift(s) in z B%Dy;zdWd/  
    count = 0 U2=5Nt5  
    While GetOperationCount(eID)>count (ta!4h,  
        GetOperation eID, count, op rv1kIc5Za<  
        If op.Type="ShiftZ" Then |!i3Y=X  
            DeleteOperation eID,count j./3)  
            count=count-1 /}-]n81m  
        End If [#kfl  
        count=count+1 n`? j. s  
    Wend ..3TB=Z#  
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    'Set new shift in wy<m&M<Gr  
    op.Type = "ShiftZ" ++F #Z(p  
    op.val1 = taq ,Ww)>O+  
    op.parent = parID /_l%Dm?  
    AddOperation eID, op n>)CCf@H  
    Print "Set aqueous humor thickness = " & taq-0.55 `+1+0
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    '************************************************************************* 5Az=)q4Q  
    'Radius and conic constant of anterior lens cBBc^SR  
    '************************************************************************* 1mgLH  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) !>Db  
    GetConic eID, entity, curv, conic }H!c9Y  
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    SetConic eID, entity, 1/Rant, CCant Y[i>  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant +^Eruv+F  
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    '************************************************************************* f%` =>l
 
    'Radius and conic constant of posterior lens 3_~V(a
 
    '************************************************************************* 3bu VU&ap  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) {'E%SIRZ)  
    GetConic eID, entity, curv, conic 2aX|E4F  
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    SetConic eID, entity, 1/Rpost, CCpost %N7b XKDP  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost L&MR%5  
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    '************************************************************************* ^](sCE7  
    'Lens thickness (Position of posterior lens surface) {3@f(H m  
    '************************************************************************* Dz
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) & V^Z  
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    ' Delete any z-shift(s) Xa=oryDt  
    count = 0 yhJH3<  
    While GetOperationCount(eID)>count 6x)7=_:0  
        GetOperation eID, count, op <iuESeDG  
        If op.Type="ShiftZ" Then LdwWB `L  
            DeleteOperation eID,count f <fa+fB  
            count=count-1 Q&@Ls?pu  
        End If ~m8".Z"  
        count=count+1 D+P(  
    Wend juG?kL.  
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    'Set new z-shift ,
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    op.Type = "ShiftZ" JS<S?j?*/  
    op.val1 = tlens ukpbx;O:hc  
    op.parent = parID _v bCC7Bf8  
    AddOperation eID, op 3}(6z"r  
    Print "Set lens thickness = " & tlens 3)88B"E  
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    '************************************************************************* 4~xKW2*`K  
    'Lens index of refraction Q)c3=.[>  
    '************************************************************************* WvR-0>E
 
    eID = FindMaterial( "Lens" ) yiO!ZT  
    GetModelMaterial eID, mat  a?S5 =  
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    mat.Nd = nlens +wc8rE6+W  
    SetModelMaterial eID, mat 3.@"GS#"[  
    Print "Set lens index of refraction = " & nlens n75)%-  
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    '************************************************************************* 7'Z-VO  
    'Pupil diameter pqe7a3jr  
    '************************************************************************* pMB!I9q  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) VK*Dm:G0  
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    'Adjust pupil diameter (trimming volume inner hole) ve($l"T  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder"
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    ' Adjust pupil location to just in front of the lens v+Eub;m   
    parID = FindFullName( "Geometry.Arizona Eye" ) jq%%|J.x  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) scX'>\w&c  
    count = 0 \4Uhc3  
    While GetOperationCount(eID)>count !q\MXS($#u  
        GetOperation eID, count, op \ vn!SO7  
        If op.Type="ShiftZ" Then ypU-/}Cf,  
            DeleteOperation eID,count ~_Q~AOFM  
            count=count-1 b S-o86u  
        End If (xpt_]Q!H  
        count=count+1 5~D(jHY;  
    Wend i(T[   
    op.Type = "ShiftZ" C7*n<+e  
    op.val1 = taq-0.01 =LXjq~p  
    op.parent = parID wcH,!;3z+  
    AddOperation eID, op r1<dZtb  
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    Print "Set pupil diameter = " & pupilDiam 1WjNFi  
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    'Update AZ Eye subassembly Description u7&q(Z&&O  
    eID = FindFullName( "Geometry.Arizona Eye" ) 6/Iq@BZ&  
    GetEntity eID, entity I3gl+)Q  
    entity.Description = "Accommodation = " & A & "D" q QcQnd2K  
    SetEntity eID, entity e"oTlB  
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    Update Zd5Jz+f  
    Print "DONE!" ~c,CngeL0  
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End Sub CbGfVdw/c  
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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： n6AA%? 5  
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Accommodation = 4 Diopters IG+g7kDCY  
Pupil Diameter = 4 mm QC,fyw\  
Set aqueous humor thickness = 2.81 (E;+E\E  
Set anterior lens radius = 10.4 and conic constant = -2.375869 ;b{yu|  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 {FQ@eeU  
Set lens thickness = 3.927 {N3&JL5\"E  
Set lens index of refraction = 1.42672 za%gD  
Set pupil diameter = 4 <%o9*)F  
DONE! 3Fb9\2<H  
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