[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 Y)HbxFF`/  
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。 "X1vZwK8N  
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模型 _+QwREP  
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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。 a<Uqyilm  
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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. :iCM=k  
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光源 -f>'RI95>  
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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。 tm)*2lH6  
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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。 TQ9'76INb  
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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。 u}jrfKdE  
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视网膜的散射 #s"B-sWE  
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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。 T%I&txl  
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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。 =MSu3<y,  
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脚本 
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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： J+2R&3;_O  
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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。 h([0,
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余下的脚本计算与屈光度有关的所有参数。 :C%47qv  
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分析 7%CIt?Z%  
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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。 oh&Y<d0  
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脚本代码 BX$hAQ(6Q  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. wItzcY1m  
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Dim entity As T_ENTITY +89o`u_l%  
Dim op As T_OPERATION v*DFiCQD  
Dim mat As T_MODELMATERIAL v MWC(m  
Dim A As Double T46{*(  
Dim pupilDiam As Double iEhDaC[e(b  
Dim eID As Long g{a d0.y,  
Dim parID As Long tc/jY]'32  
Dim count As Integer M(S{1|,V  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double z(UX't (q  
Dim tlens As Double, nlens As Double :yD@5)  
Dim curv As Double, conic As Double 8|<f8Z65!  
Dim ok As Long rk|a'&  
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Sub Main ):E'`ZP!F  
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    '用户输入对话框 '%O\E{h  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 X,53c$  
        TextBox 220,21,40,21,.TextBox1 'default: 0 s}!"a8hU`  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 s=jO;K$  
        OKButton 40,91,90,21 j&}B<f _6J  
        CancelButton 190,91,90,21 Ja=N@&Z#  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 h>Rpb#]  
        TextBox 220,49,40,21,.TextBox2 'default: 4 R7t bxC  
    End Dialog p,^>*/O>  
    Dim dlg As UserDialog fW[.r==Kf  
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    ok = Dialog (dlg) *EE|?vn  
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    If ok=0 Then    'cancel button was pressed `R ]&F$i(E  
        Print "Execution cancelled." ^ N_`^m  
        End B2"+Hwbk  
    End If / GZV_H%v  
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    'Assign accommodation and pupil diameter & use defaults if field left empty &@Yoj%%  
    If dlg.TextBox1 = "" Then lMPbLF%_  
        A = 0           'Default accommodation +{bh  
    Else 6KBHRt  
        A = CDbl(dlg.TextBox1) N>T=L0`  
    End If vev8l\  
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    If dlg.TextBox2 = "" Then Ae3#>[]{  
        pupilDiam = 4   'Default pupil diameter p!V)55J*  
    Else vKV{ $|  
        pupilDiam = CDbl(dlg.TextBox2) '4Y*-!9  
    End If 'j
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    Print " " /iTH0@Kw;  
    Print "Accommodation = " & A & " Diopters" c{ZqQtfM  
    Print "Pupil Diameter = " & pupilDiam & " mm" fY2l.H\f  
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    ' Calculate new parameters with accommodation EID(M.G  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness OQ 0b$qw  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens vV2o[\o^  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens [kQ"6wh8  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens 9yp^zL  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens $Jt8d|UP  
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    tlens = 3.767 + 0.04*A                  'Lens thickness Oym]&SrbS  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction NdaM9a#TZ  
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    'Adjust parameters to account for accommodation f2 Vpe
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    '************************************************************************* 1Z=;Uy\  
    'Aqueous thickness (Position of Lens) d u_O}x  
    '************************************************************************* y;*My#  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) </~1p~=hAt  
    GetCustomElement eID, entity %,h!: Ec^c  
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    parID = FindFullName( "Geometry.Arizona Eye" ) pPU2ar  
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    ' Delete any shift(s) in z t4*aVHT  
    count = 0 (p}9^Y  
    While GetOperationCount(eID)>count 6B4hSqjh  
        GetOperation eID, count, op 7UY('Q[  
        If op.Type="ShiftZ" Then S;G"L$&\  
            DeleteOperation eID,count QLxXp
 
            count=count-1 Ul7,k\q@  
        End If |v,}%UN2  
        count=count+1 V/+H_=|  
    Wend F^J&g%ql  
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    'Set new shift in <5C=i:6%  
    op.Type = "ShiftZ" * <Nk%`  
    op.val1 = taq jTGS6{E  
    op.parent = parID g#pIMA#/  
    AddOperation eID, op >:(6{}b  
    Print "Set aqueous humor thickness = " & taq-0.55 ~M|NzK_9  
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    '************************************************************************* hA$c.jJr.Z  
    'Radius and conic constant of anterior lens _S[Rvb1e   
    '************************************************************************* $NH`Iu9t  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) 6tCV{pgm  
    GetConic eID, entity, curv, conic W\ZV0T;<]  
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    SetConic eID, entity, 1/Rant, CCant IX > j8z[  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant !c3Qcva  
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    '************************************************************************* |~1rKzZwF  
    'Radius and conic constant of posterior lens OoA5!HEh  
    '************************************************************************* 
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    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) T% jjs  
    GetConic eID, entity, curv, conic @p?b"?QaB  
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    SetConic eID, entity, 1/Rpost, CCpost ?kG#qt]Q5  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost Vb"T],N1m  
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    '************************************************************************* ~50y-  
    'Lens thickness (Position of posterior lens surface) c+YYM :S  
    '*************************************************************************
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) iLI.e rm  
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    ' Delete any z-shift(s) H_xQ>~b
 
    count = 0 .j]OO/,  
    While GetOperationCount(eID)>count x1BDvTqW  
        GetOperation eID, count, op T5X'D(\|  
        If op.Type="ShiftZ" Then HT1dvC$COo  
            DeleteOperation eID,count HCn]#  
            count=count-1 EzeDShN=J  
        End If C$]%1<-Iv]  
        count=count+1 K[3D{=  
    Wend b*F :l#  
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    'Set new z-shift _sCJ3ZJ  
    op.Type = "ShiftZ" e P,XH{s  
    op.val1 = tlens Q'%5"&XFD  
    op.parent = parID R)DNFc:  
    AddOperation eID, op WP#_qqO  
    Print "Set lens thickness = " & tlens 0ga1Yr]  
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    '************************************************************************* p.W*j^';Q  
    'Lens index of refraction 2
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    '************************************************************************* W> -E.#!_  
    eID = FindMaterial( "Lens" ) y9l.i@-  
    GetModelMaterial eID, mat M}KM]<  
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    mat.Nd = nlens zi DlJ3]^  
    SetModelMaterial eID, mat o\:f9JL  
    Print "Set lens index of refraction = " & nlens spoWdRM2  
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    '************************************************************************* VTgbJ{?  
    'Pupil diameter (^s&#_w03  
    '************************************************************************* &l!{!f4  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) CFS3);'<|  
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    'Adjust pupil diameter (trimming volume inner hole) {dr&46$p  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" yPxG`w'  
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    ' Adjust pupil location to just in front of the lens 4\eX=~C>:  
    parID = FindFullName( "Geometry.Arizona Eye" ) nAba
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    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) d ;7pri)B  
    count = 0 G*wW&R)  
    While GetOperationCount(eID)>count 1b]PCNz  
        GetOperation eID, count, op GO GXM4I  
        If op.Type="ShiftZ" Then cTIwA:)D  
            DeleteOperation eID,count +` Y ?-  
            count=count-1 'rq#q)1MT  
        End If *e"GQd?  
        count=count+1 p31rhe   
    Wend g KmRjK  
    op.Type = "ShiftZ" elHarey`f  
    op.val1 = taq-0.01 O[(HE8E  
    op.parent = parID uW-- nXMs  
    AddOperation eID, op j
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    Print "Set pupil diameter = " & pupilDiam AL$Ty  
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    'Update AZ Eye subassembly Description kpreTeA]  
    eID = FindFullName( "Geometry.Arizona Eye" ) ;>8TNB e!  
    GetEntity eID, entity $^D(%  
    entity.Description = "Accommodation = " & A & "D" R{Kd%Y:2Y  
    SetEntity eID, entity 5Z1Do^  
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    Update 4l!Yop0h  
    Print "DONE!" a:%5.!Vd  
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End Sub ?;#3U5$v  
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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： 8sjHQ)<  
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Accommodation = 4 Diopters Fh4w0u*Q  
Pupil Diameter = 4 mm PdN\0B`  
Set aqueous humor thickness = 2.81 kkBV
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Set anterior lens radius = 10.4 and conic constant = -2.375869 Oi&w_ Z0  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 |iJZC  
Set lens thickness = 3.927 gx9sBkoq5D  
Set lens index of refraction = 1.42672 VGUDUM.8  
Set pupil diameter = 4 \V- Y,!~5  
DONE! 7<'i#E~  
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