[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 hWo=;#B*  
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。 'b/<x|  
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模型 X|DO~{-au  
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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。 `^9(Ot $  
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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. !yOeW0/2[  
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光源 BxK^?b[E8  
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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。
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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。 <plC_{Y:wu  
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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。 .lgPFr6X  
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视网膜的散射 3q:n'PC)C  
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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。 sOCs
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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。 KInk^`C/H  
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脚本 hwN?/5  
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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： c#IYFTz  
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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。 wkqX^i7ls  
余下的脚本计算与屈光度有关的所有参数。 38DT2<qC  
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分析 sVk$x:k1M  
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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。 BBG3OAyg_  
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脚本代码 p Dx-2:}  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. +YLejjQ  
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Dim entity As T_ENTITY hQ6a~?f  
Dim op As T_OPERATION N,2s?Y_!  
Dim mat As T_MODELMATERIAL :l7U>~ o  
Dim A As Double =[\s8XH,  
Dim pupilDiam As Double ;,i]w"*  
Dim eID As Long 'TH15r@  
Dim parID As Long a22Mufl  
Dim count As Integer r<F hY  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double *_E|@y  
Dim tlens As Double, nlens As Double }g#&Q0
 
Dim curv As Double, conic As Double @/ZF` :  
Dim ok As Long bY}eUL2i4  
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Sub Main uZfnzd)c  
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    '用户输入对话框 Xc"&0v%;#  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 |#1(Z-}  
        TextBox 220,21,40,21,.TextBox1 'default: 0 U9D!GKVp  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 \AL f$88>@  
        OKButton 40,91,90,21 +xc'1id@[  
        CancelButton 190,91,90,21 "S3wk=?4  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 fwK}/0%  
        TextBox 220,49,40,21,.TextBox2 'default: 4 sY?,0T_m  
    End Dialog bAKiq}xG%i  
    Dim dlg As UserDialog p!k7C&]E  
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    ok = Dialog (dlg) nhIa175'  
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    If ok=0 Then    'cancel button was pressed O6IB. >T  
        Print "Execution cancelled." 5~mh'<:  
        End >pU:Gr  
    End If 6[OzU2nB  
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    'Assign accommodation and pupil diameter & use defaults if field left empty GA7}K:LP'k  
    If dlg.TextBox1 = "" Then 6JKqn~0Kk  
        A = 0           'Default accommodation JQ4{` =,b  
    Else dnV[ P  
        A = CDbl(dlg.TextBox1) ~T) Q$  
    End If @?YRuwp L  
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    If dlg.TextBox2 = "" Then
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        pupilDiam = 4   'Default pupil diameter ]4;PR("aU  
    Else @+atBmt  
        pupilDiam = CDbl(dlg.TextBox2) fN'HE#W1Xa  
    End If wywQ<n  
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    Print " " ?nP*\8  
    Print "Accommodation = " & A & " Diopters" "M|zv  
    Print "Pupil Diameter = " & pupilDiam & " mm" TLoz)&@  
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    ' Calculate new parameters with accommodation gi0W;q  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness MwmUgN"g  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens =XXZ?P  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens rj6#
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens Ur*6Gi6  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens _E@:O+K  
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    tlens = 3.767 + 0.04*A                  'Lens thickness X/N0LU
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction 0
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    'Adjust parameters to account for accommodation Qx[t/~  
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    '************************************************************************* ?JL:CBvCp  
    'Aqueous thickness (Position of Lens) ,\qs4&  
    '************************************************************************* _x!7}O#k  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) A45A:hqs  
    GetCustomElement eID, entity ei rzYt  
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    parID = FindFullName( "Geometry.Arizona Eye" ) Y5F]:gs@  
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    ' Delete any shift(s) in z $z+8<?YD  
    count = 0 -%L6#
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    While GetOperationCount(eID)>count 1 5A*7|  
        GetOperation eID, count, op }!6\|;Qsz,  
        If op.Type="ShiftZ" Then a{[x4d,z  
            DeleteOperation eID,count 1
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            count=count-1 kYLM&&h
 
        End If [H=)  
        count=count+1 9'r:~O  
    Wend y~75r\"R
 
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    'Set new shift in y K"kEA[;  
    op.Type = "ShiftZ" q`pP$i:  
    op.val1 = taq )KP5WudX  
    op.parent = parID _)\c&.p]f  
    AddOperation eID, op
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    Print "Set aqueous humor thickness = " & taq-0.55 }Q";aU0^  
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    '************************************************************************* KCWc`Oz  
    'Radius and conic constant of anterior lens /c,(8{(O  
    '************************************************************************* X$yN_7|+  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) A\#iX
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    GetConic eID, entity, curv, conic $ibuWb"a  
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    SetConic eID, entity, 1/Rant, CCant CP6LHkM9  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant v'BZs   
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    '************************************************************************* f aLtdQi  
    'Radius and conic constant of posterior lens -N"&/)  
    '************************************************************************* yR4|S2D3xn  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) ;6!Pwb;hY  
    GetConic eID, entity, curv, conic kV38`s>+  
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    SetConic eID, entity, 1/Rpost, CCpost 7[.6axL  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost k2AJXw  
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    '************************************************************************* wR^RM(1  
    'Lens thickness (Position of posterior lens surface)
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    '************************************************************************* t 89!Ihk  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) G8;w{-{m  
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    ' Delete any z-shift(s) 0)m(;>'70  
    count = 0 K#U<ib-v  
    While GetOperationCount(eID)>count PP!SK2u"L  
        GetOperation eID, count, op l~M_S<4n  
        If op.Type="ShiftZ" Then yUp,NfS]o  
            DeleteOperation eID,count T,VY.ep/  
            count=count-1 8)4P Ll  
        End If Z"AQp _  
        count=count+1 >hr{JJe  
    Wend ^g`&7tX  
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    'Set new z-shift }6@pJG  
    op.Type = "ShiftZ" K=,F#kn  
    op.val1 = tlens IEzaK  
    op.parent = parID ,JEFGI{  
    AddOperation eID, op rW0FA  
    Print "Set lens thickness = " & tlens }5(Ho$S(  
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    '************************************************************************* 8:/e GM  
    'Lens index of refraction ph-ATJ"  
    '************************************************************************* Et/&^&=\-  
    eID = FindMaterial( "Lens" ) D&/L:   
    GetModelMaterial eID, mat dS<C@(  
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    mat.Nd = nlens 8A+SjJ4$  
    SetModelMaterial eID, mat T16{_  
    Print "Set lens index of refraction = " & nlens 4Z/Q=Mq2  
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    '************************************************************************* ruazOmnn~  
    'Pupil diameter EMfdBY5  
    '************************************************************************* Yx>"bv  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) iV eC=^1  
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    'Adjust pupil diameter (trimming volume inner hole) (owrdPT!  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" &w1P\4?G  
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    ' Adjust pupil location to just in front of the lens nVI!
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    parID = FindFullName( "Geometry.Arizona Eye" ) |\g5+fv9  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) !ki.t  
    count = 0 $.[#0lCI  
    While GetOperationCount(eID)>count )}_a 0bt  
        GetOperation eID, count, op :P(K2q3  
        If op.Type="ShiftZ" Then gw}Mw  
            DeleteOperation eID,count Yl.0aS  
            count=count-1 &[;HYgp  
        End If <E0UK^-}  
        count=count+1 :G<E^<M\)^  
    Wend `ck$t5:6sp  
    op.Type = "ShiftZ" -P]sRl3O;  
    op.val1 = taq-0.01 h@LHRMO  
    op.parent = parID F<(i.o(  
    AddOperation eID, op *>+,(1Fz  
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    Print "Set pupil diameter = " & pupilDiam B0ndcB-  
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    'Update AZ Eye subassembly Description ]Qe{e3p;  
    eID = FindFullName( "Geometry.Arizona Eye" ) oI#a_/w  
    GetEntity eID, entity vVgg0Y2  
    entity.Description = "Accommodation = " & A & "D" {pHM},WJ  
    SetEntity eID, entity l}lIi8  
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    Update NZ3/5%We/  
    Print "DONE!" $e /^u[~:  
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End Sub 'gt-s547  
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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@4V7;L  
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Accommodation = 4 Diopters q]\g,a  
Pupil Diameter = 4 mm c~v~2DM  
Set aqueous humor thickness = 2.81 v%RP0%%{s  
Set anterior lens radius = 10.4 and conic constant = -2.375869 zdp/|"D!  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 HWVtop/  
Set lens thickness = 3.927 9,^_<O@Q  
Set lens index of refraction = 1.42672 Zt3)]sB  
Set pupil diameter = 4 nO)X!dp}J  
DONE! EMc;^ d  
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