[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 h`D+NZtWm  
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。 rW2l+:@c  
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模型 H284 ]i  
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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。 Sr-!-eC  
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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. Va
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光源 CMfR&G,)  
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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。 t.]e8=dE  
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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。 eSSv8[u  
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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。 @qB1:==@7  
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视网膜的散射 SI;SnF'[7  
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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。 k5)e7Lb(  
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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。 ,IG?(CK|  
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脚本 } mEsb?  
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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： `L {dF  
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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。 e[J0+ x#;r  
余下的脚本计算与屈光度有关的所有参数。 b{l
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分析 G1:2MPH  
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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。 RLX?3u&  
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脚本代码 #:M)a?E/%  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. >-YWq  
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Dim entity As T_ENTITY k{j (Gb2sp  
Dim op As T_OPERATION 9oJ=:E~CP  
Dim mat As T_MODELMATERIAL *dm?,~f%<  
Dim A As Double lBnG!!VrWa  
Dim pupilDiam As Double I4^}C;p0?  
Dim eID As Long _J`q\N K  
Dim parID As Long q=h~zjQ?R  
Dim count As Integer &d^u$Y5  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double ]V
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Dim tlens As Double, nlens As Double Ga}&%  
Dim curv As Double, conic As Double aqAWaO  
Dim ok As Long JOJ?.H&su  
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Sub Main R2$;f?;:  
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    '用户输入对话框 wH Q$F(by  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 G' 'l,\3  
        TextBox 220,21,40,21,.TextBox1 'default: 0 \Q<Ur&J]%  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 _oJq32  
        OKButton 40,91,90,21 _P*<T6\J>  
        CancelButton 190,91,90,21 Y l1sAf/  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 )R`w{V  
        TextBox 220,49,40,21,.TextBox2 'default: 4 *P
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    End Dialog |4s`;4c&  
    Dim dlg As UserDialog 30v 3C7o=  
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    ok = Dialog (dlg) Z;#Ei.7p|  
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    If ok=0 Then    'cancel button was pressed Y|iJO>_Uu=  
        Print "Execution cancelled." GKNH{|B$D  
        End |Skk1#  
    End If a}+7MEUmZ/  
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    'Assign accommodation and pupil diameter & use defaults if field left empty Xbb('MoI63  
    If dlg.TextBox1 = "" Then PDnwaK   
        A = 0           'Default accommodation }#/,nJm'  
    Else 1MCHwX3/  
        A = CDbl(dlg.TextBox1) P]@m0f  
    End If 'e4 ;,m  
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    If dlg.TextBox2 = "" Then IP`;hC  
        pupilDiam = 4   'Default pupil diameter + fQ=G/  
    Else u8Au `  
        pupilDiam = CDbl(dlg.TextBox2) b1}P3W  
    End If a N|MB
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    Print " " bX:ARe O  
    Print "Accommodation = " & A & " Diopters" DM*mOT  
    Print "Pupil Diameter = " & pupilDiam & " mm" 6uYCU|JsU  
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    ' Calculate new parameters with accommodation &Oq&ikw  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness T/"6iv\1  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens K>TdN+Z}=  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens wPDA_ns~  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens | 1Fy  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens .ya^8
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    tlens = 3.767 + 0.04*A                  'Lens thickness tVZjtGz=  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction L_.
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    'Adjust parameters to account for accommodation .VVY]>bJg@  
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    '************************************************************************* bGvALz'  
    'Aqueous thickness (Position of Lens) 0)V<)"i  
    '************************************************************************* b:Lp`8Du  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" )
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    GetCustomElement eID, entity bmEo5f~C!  
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    parID = FindFullName( "Geometry.Arizona Eye" ) M?4)U"_VE  
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    ' Delete any shift(s) in z Yw=Ve 0  
    count = 0 kmM1)- v  
    While GetOperationCount(eID)>count m9UI3fBX  
        GetOperation eID, count, op d*=P8QwL|  
        If op.Type="ShiftZ" Then }"<|.[V)  
            DeleteOperation eID,count /a\6&E
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            count=count-1 ln7{c #lE  
        End If edqekjh  
        count=count+1 D L_{q6ZK  
    Wend bE2^sx`(  
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    'Set new shift in maLKUSgo  
    op.Type = "ShiftZ" SUXRWFl  
    op.val1 = taq
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    op.parent = parID FW:x XK  
    AddOperation eID, op *doK$wYP  
    Print "Set aqueous humor thickness = " & taq-0.55 z!5^UD8"W  
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    '************************************************************************* ^WP`;e  
    'Radius and conic constant of anterior lens a3 <D1"  
    '************************************************************************* "P=OpFV  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) 5C/W_H+9iK  
    GetConic eID, entity, curv, conic <8p53*a  
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    SetConic eID, entity, 1/Rant, CCant *z`_U]tP  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant "jzU`  
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    '************************************************************************* 3qPj+@  
    'Radius and conic constant of posterior lens DPJ#Y -0  
    '************************************************************************* ~AxA ,  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) 3(':4Tas  
    GetConic eID, entity, curv, conic &IM;Yl  
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    SetConic eID, entity, 1/Rpost, CCpost v2:A 4Pd:+  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost Tm5]M$)  
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    '************************************************************************* FyX
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    'Lens thickness (Position of posterior lens surface) ["4h%{.  
    '************************************************************************* s_-G`xT>{  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) LY[XPV]t  
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    ' Delete any z-shift(s) <\GP\G  
    count = 0 `3^*K/K\  
    While GetOperationCount(eID)>count D)XF@z;  
        GetOperation eID, count, op EA9`-xs|  
        If op.Type="ShiftZ" Then >6Y\CixN  
            DeleteOperation eID,count y^tuybpZY<  
            count=count-1 @FKNB.>  
        End If %geiJ z  
        count=count+1 ";yCo0*  
    Wend "tB"C6b  
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    'Set new z-shift @dQIl#  
    op.Type = "ShiftZ" a:
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    op.val1 = tlens 4G0Er?D   
    op.parent = parID "5u*C#T2$  
    AddOperation eID, op .w\AyXp  
    Print "Set lens thickness = " & tlens R)d1]k8  
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    '************************************************************************* An!1>`8r  
    'Lens index of refraction YU.aZdA&V3  
    '************************************************************************* %KK6}d#  
    eID = FindMaterial( "Lens" ) [ !/u,  
    GetModelMaterial eID, mat Y&KI/]ly,L  
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    mat.Nd = nlens ?Z= %I$i  
    SetModelMaterial eID, mat ]#;;)K}>  
    Print "Set lens index of refraction = " & nlens T;qP"KWZ  
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    '************************************************************************* 6gV-u~j[#  
    'Pupil diameter P:vAU8d>  
    '************************************************************************* Meo(|U  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) ;75K:_  
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    'Adjust pupil diameter (trimming volume inner hole) +<7~yZ[Z8  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" e/JbRbZX  
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    ' Adjust pupil location to just in front of the lens "n3r,  
    parID = FindFullName( "Geometry.Arizona Eye" ) 6r{NW9y'  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) |;e K5(|  
    count = 0 ~kPHf_B;z  
    While GetOperationCount(eID)>count L#mf[a@pCn  
        GetOperation eID, count, op <VI.A" Qk~  
        If op.Type="ShiftZ" Then xX$'u"dsA  
            DeleteOperation eID,count >J!4x(;Yh  
            count=count-1 "/[xak!g  
        End If tIfA]pE  
        count=count+1 N,fEta6  
    Wend !qk+>6~A,  
    op.Type = "ShiftZ" -J*BY2LU3f  
    op.val1 = taq-0.01 ewHk (ru  
    op.parent = parID '4k l$I  
    AddOperation eID, op  #v+2W  
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    Print "Set pupil diameter = " & pupilDiam 4H'\nsM  
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    'Update AZ Eye subassembly Description 3gtQS3$4s  
    eID = FindFullName( "Geometry.Arizona Eye" ) DCr&%)Ll  
    GetEntity eID, entity T1AD(r\W5  
    entity.Description = "Accommodation = " & A & "D" 0N.B=j|  
    SetEntity eID, entity L!G]i;=:  
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    Update *YH5kX  
    Print "DONE!" mU@pRjq=  
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End Sub }2c)UQD8  
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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： Kv(2x3("  
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Accommodation = 4 Diopters !YX$4_I  
Pupil Diameter = 4 mm mY6d+  
Set aqueous humor thickness = 2.81 "LZQ1P*ef$  
Set anterior lens radius = 10.4 and conic constant = -2.375869 Ai>=n;  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 \cJ?2^Eq  
Set lens thickness = 3.927 #o`y<1rN  
Set lens index of refraction = 1.42672 KA~eOEjM  
Set pupil diameter = 4 b)ytm=7ha  
DONE! z
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