[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 C26vH#C  
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。 Idq&0<I  
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模型 2WKYf0t  
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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。 dNQR<v\IL  
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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. <=]wh
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光源 Ch3{q/-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。 =dVPx<l5  
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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。 Z*9Qeu-N:  
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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。 W%3<"'eP  
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视网膜的散射 =5a|'O  
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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。 3#=%2\  
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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。 R2]2#3`  
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脚本 f
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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： Ia>07av  
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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。 }bU1wIW9I  
余下的脚本计算与屈光度有关的所有参数。 4pYscB  
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分析 vlygS(Y_7  
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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。 e`N/3q7  
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脚本代码 OoG Nij  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. m1d*Lt>F@  
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Dim entity As T_ENTITY +7`7cOqXg  
Dim op As T_OPERATION RotWMGNK  
Dim mat As T_MODELMATERIAL c.<bz  
Dim A As Double uR;m<wPH,f  
Dim pupilDiam As Double 2YS1%<-g*  
Dim eID As Long }K rQPg  
Dim parID As Long Wu{cE;t  
Dim count As Integer (IE\}QcK  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double xcVF0%wVC  
Dim tlens As Double, nlens As Double ^]{)gk8P~2  
Dim curv As Double, conic As Double Eku+&f@RB  
Dim ok As Long GLS`1!  
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Sub Main <Qx]"ZP%  
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    '用户输入对话框 =!?4$vW  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 y3^>a5z!x  
        TextBox 220,21,40,21,.TextBox1 'default: 0 u{Rgk:bn  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 qm!&(8NfK  
        OKButton 40,91,90,21 MBjo9P(
 
        CancelButton 190,91,90,21 [v,Y-}wQ)  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 .huk>   
        TextBox 220,49,40,21,.TextBox2 'default: 4 8<2 [ F  
    End Dialog w1N-`S:  
    Dim dlg As UserDialog oP%'8%tk  
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    ok = Dialog (dlg) (E*pM$   
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    If ok=0 Then    'cancel button was pressed aRc2#:~;  
        Print "Execution cancelled." UA%tI2  
        End oMw#ROsvC  
    End If JX $vz*KF  
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    'Assign accommodation and pupil diameter & use defaults if field left empty *# 7 1aZ  
    If dlg.TextBox1 = "" Then uhf% zG  
        A = 0           'Default accommodation axpn*
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    Else %]KOxaf_z  
        A = CDbl(dlg.TextBox1) ~HM,@5dFC
 
    End If x&['g*[L0  
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    If dlg.TextBox2 = "" Then ?h1r6?Sug{  
        pupilDiam = 4   'Default pupil diameter )W0zu\fL =  
    Else ;_TPJy  
        pupilDiam = CDbl(dlg.TextBox2) 0|L%)'F  
    End If Iu=n$H  
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    Print " " 7hq$vI%0  
    Print "Accommodation = " & A & " Diopters" iN]#
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    Print "Pupil Diameter = " & pupilDiam & " mm" $I$ B8  
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    ' Calculate new parameters with accommodation :'+- %xUM  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness w~lxWgaY7  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens 1P '_EJ]M  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens wpW3
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens o'hwyXy/S  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens {] Zet}2  
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    tlens = 3.767 + 0.04*A                  'Lens thickness '(S@9%,aK1  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction ,|Xib
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    'Adjust parameters to account for accommodation qe@ctHpn  
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    '************************************************************************* IFd2r;W8  
    'Aqueous thickness (Position of Lens) +j">Ju6Q;.  
    '************************************************************************* 9D+B~8[SQ  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) )V6<'>1WZ  
    GetCustomElement eID, entity ~a RK=i$F  
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    parID = FindFullName( "Geometry.Arizona Eye" ) D?Y j5eOa
 
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    ' Delete any shift(s) in z NMCMY<o  
    count = 0 \'}? j-8  
    While GetOperationCount(eID)>count d7)EzW|I;  
        GetOperation eID, count, op #sg^l>/*  
        If op.Type="ShiftZ" Then gbclk~kX  
            DeleteOperation eID,count :~gG]|F  
            count=count-1 *^WY+DV  
        End If E#I^D/0  
        count=count+1 kNnI$(H"H  
    Wend B+w< 0No  
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    'Set new shift in x8v2mnk  
    op.Type = "ShiftZ" >qT4'1S*g  
    op.val1 = taq 9bVPMq7}i  
    op.parent = parID v_s(  
    AddOperation eID, op Hb:@]!r>  
    Print "Set aqueous humor thickness = " & taq-0.55 !U?Z<z
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    '************************************************************************* hiM nU  
    'Radius and conic constant of anterior lens }c1?:8p  
    '************************************************************************* }-8ZSWog6f  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) P!*G"^0<  
    GetConic eID, entity, curv, conic gWZz
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    SetConic eID, entity, 1/Rant, CCant PE7D)!d T  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant X$4MpXx  
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    '************************************************************************* c&rS7%  
    'Radius and conic constant of posterior lens lMN3;}K  
    '************************************************************************* I_\#(  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) #;WKuRv  
    GetConic eID, entity, curv, conic [fjP.kw;J  
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    SetConic eID, entity, 1/Rpost, CCpost 2xEG s Q  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost '9R.$,N  
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    '************************************************************************* =,4iMENm!  
    'Lens thickness (Position of posterior lens surface) =Co[pt  
    '************************************************************************* 1[&V6=n  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) 0qPbmLMK  
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    ' Delete any z-shift(s) v.~uJ.T  
    count = 0 Z<2j#rd  
    While GetOperationCount(eID)>count %0<-5&GE  
        GetOperation eID, count, op E#L"*vh  
        If op.Type="ShiftZ" Then PAUepO_  
            DeleteOperation eID,count -{tB&V~+v  
            count=count-1 ~s[St0  
        End If }bZcVc2  
        count=count+1 P nxxW?  
    Wend -? |-ux  
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    'Set new z-shift MkCq$MA  
    op.Type = "ShiftZ" )8rN  
    op.val1 = tlens TcP (?v  
    op.parent = parID d>f.p"B.gj  
    AddOperation eID, op
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    Print "Set lens thickness = " & tlens ;:/<XfZ  
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    '************************************************************************* km(Mv  
    'Lens index of refraction hj_%'kk-A  
    '************************************************************************* R;{y]1u  
    eID = FindMaterial( "Lens" ) IB sQaxt.  
    GetModelMaterial eID, mat *NEA(9  
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    mat.Nd = nlens pFZ2(b&  
    SetModelMaterial eID, mat 7Y?=ijXXx\  
    Print "Set lens index of refraction = " & nlens JTw3uM, e  
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    '************************************************************************* rpZ^R}B%*v  
    'Pupil diameter bhqs%B!:  
    '************************************************************************* o_K. +^$  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) Bn5O;I13  
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    'Adjust pupil diameter (trimming volume inner hole) Uo7V)I;o  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" @/w($w"  
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    ' Adjust pupil location to just in front of the lens ]0+5@c  
    parID = FindFullName( "Geometry.Arizona Eye" ) Y5Ub[o  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) fF\s5f#:  
    count = 0 kp4(_T7R  
    While GetOperationCount(eID)>count \U0p?wdr:  
        GetOperation eID, count, op (1|_Nr  
        If op.Type="ShiftZ" Then b/I_iJ8t  
            DeleteOperation eID,count Jbmi[`O  
            count=count-1 YXdd=F  
        End If %O!~!'
 
        count=count+1 [ ;$(;  
    Wend k!^Au8Up?  
    op.Type = "ShiftZ" 0rjH`H]M  
    op.val1 = taq-0.01 6;:s N8M+1  
    op.parent = parID $GR 3tLzK:  
    AddOperation eID, op CXZO  
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    Print "Set pupil diameter = " & pupilDiam T/A[C  

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    'Update AZ Eye subassembly Description rTgCmr'&  
    eID = FindFullName( "Geometry.Arizona Eye" ) Fk(+S:{yQ  
    GetEntity eID, entity sI7<rI.t){  
    entity.Description = "Accommodation = " & A & "D" lhyWlO  
    SetEntity eID, entity RkrZncBgV<  
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    Update 4^Ke
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    Print "DONE!" AaVj^iy/X  
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End Sub P{'T9U|O-  
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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|Du9_0  
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Accommodation = 4 Diopters  u Z(vf  
Pupil Diameter = 4 mm h7}D//~p  
Set aqueous humor thickness = 2.81 ^
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Set anterior lens radius = 10.4 and conic constant = -2.375869 6eUM[C.  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 S#kA$yO  
Set lens thickness = 3.927 xcF:moL  
Set lens index of refraction = 1.42672 #`1@4,iC  
Set pupil diameter = 4 aQMUC6cPM@  
DONE! /4]<ro67E6  
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