[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 f'S"F  
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。 NBX/V^  
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模型 :Ib\v88WIv  
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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$m?if=  
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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. 0M?}S~p]  
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光源 mr? ii  
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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。 |~Iw  
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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。 f`e.c_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。 z?xd\x  
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视网膜的散射 MZ'HMYed   
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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。 \N30SG?o  
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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。 Eh+lLtZ  
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脚本 -84Z8
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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： eR CGr?e4  
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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。 W3b\LnUa  
余下的脚本计算与屈光度有关的所有参数。 2r,fF<WQ  
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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。 (ZYOm
  
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脚本代码 #!2gxm;g  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. kQ +   
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Dim entity As T_ENTITY j[9B,C4  
Dim op As T_OPERATION 2rxdRg'YLQ  
Dim mat As T_MODELMATERIAL .#X0P=  
Dim A As Double f5N~K>  
Dim pupilDiam As Double 2.6,c$2tB  
Dim eID As Long U+KbvkX wj  
Dim parID As Long B~^\jRd"  
Dim count As Integer gU`QW_{  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double  6?6 u  
Dim tlens As Double, nlens As Double R~`Y6>o~9:  
Dim curv As Double, conic As Double [f'7/w+  
Dim ok As Long PSRGlxdO  
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Sub Main @wo9;DW`  
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    '用户输入对话框 yHCc@`1.  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 ,"D1!0  
        TextBox 220,21,40,21,.TextBox1 'default: 0 |A2.W8`o  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 '@$?A>.cj  
        OKButton 40,91,90,21 F?UL0Q|uv  
        CancelButton 190,91,90,21 oR+Fn}mG  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 p'H5yg3h  
        TextBox 220,49,40,21,.TextBox2 'default: 4 7l?=$q>k"  
    End Dialog ?}W:DGudZ  
    Dim dlg As UserDialog .8"o&%$`V  
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    ok = Dialog (dlg) |Oo WGVc  
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    If ok=0 Then    'cancel button was pressed 8'zwyd3  
        Print "Execution cancelled." b^v.FK46G  
        End F*a+&% Q  
    End If *@O;IiSE  
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    'Assign accommodation and pupil diameter & use defaults if field left empty '8dqJ`Gj  
    If dlg.TextBox1 = "" Then "$WZd  
        A = 0           'Default accommodation |_O1V{Q=  
    Else }>grGr%oR  
        A = CDbl(dlg.TextBox1) 7
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    End If  "dA"N$  
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    If dlg.TextBox2 = "" Then 3mx7[Q  
        pupilDiam = 4   'Default pupil diameter FCg,p2  
    Else y_\d[  
        pupilDiam = CDbl(dlg.TextBox2) +ux,cx.U"  
    End If 2hquE_1S[w  
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    Print " " &)rm
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    Print "Accommodation = " & A & " Diopters" L:~ "Vw6]_  
    Print "Pupil Diameter = " & pupilDiam & " mm" _Wgg=A"G  
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    ' Calculate new parameters with accommodation r> NgJf,  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness  HSTtDTo  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens oqG 0 @@  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens $PNR?  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens 3uN;*f  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens e\\ I,  
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    tlens = 3.767 + 0.04*A                  'Lens thickness w@hm>6j  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction qF>}"m  
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    'Adjust parameters to account for accommodation ,;UVQwY  
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    '************************************************************************* N'TL &]  
    'Aqueous thickness (Position of Lens) d6wsT\S  
    '************************************************************************* K4y4!zz  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) |',MgA  
    GetCustomElement eID, entity S?;&vs9j  
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    parID = FindFullName( "Geometry.Arizona Eye" )  $l Y  
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    ' Delete any shift(s) in z "`16-g97  
    count = 0 NCBS=L:  
    While GetOperationCount(eID)>count -fYgTst2  
        GetOperation eID, count, op l\a 0 k4  
        If op.Type="ShiftZ" Then c_+}`  
            DeleteOperation eID,count h%pgdix  
            count=count-1 m\[r6t]V  
        End If HjLY\.S  
        count=count+1 S$ dFz  
    Wend ]r{y+g|  
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    'Set new shift in Wcw$ Zv  
    op.Type = "ShiftZ" !fjDO!,!  
    op.val1 = taq [.dF)I3  
    op.parent = parID ~gmj/PQ0  
    AddOperation eID, op c:M~!CXO  
    Print "Set aqueous humor thickness = " & taq-0.55 o[
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    '************************************************************************* Y0 Ta&TYZ0  
    'Radius and conic constant of anterior lens &")ON[|b  
    '************************************************************************* Bk*AO?3p  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) p
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    GetConic eID, entity, curv, conic g7rn|<6FI  
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    SetConic eID, entity, 1/Rant, CCant ,)|nxX  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant hxGZ}zq*S  
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    '************************************************************************* ymiOtA Z  
    'Radius and conic constant of posterior lens ^,qi`Tk  
    '************************************************************************* N\BB8<F  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) cE$7CSR  
    GetConic eID, entity, curv, conic UW_fn  
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    SetConic eID, entity, 1/Rpost, CCpost fKb8)PDP  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost e3}`]  
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    '************************************************************************* y}Oc^Fc  
    'Lens thickness (Position of posterior lens surface) Cj#$WZga%  
    '************************************************************************* 4[v %]g`  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) CI{? Kb  
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    ' Delete any z-shift(s) j|c  
    count = 0 &A)AV<=>T  
    While GetOperationCount(eID)>count K!;Z#$iw[  
        GetOperation eID, count, op KLrxlD4\  
        If op.Type="ShiftZ" Then 5ro^<P0f**  
            DeleteOperation eID,count W_8N?coM  
            count=count-1 FCgr  
        End If qwM71B!r  
        count=count+1 JTA65T{3  
    Wend Nk*d=vj  
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    'Set new z-shift i=j
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    op.Type = "ShiftZ" PUZH[-:c  
    op.val1 = tlens -fKo~\Pr  
    op.parent = parID Wa7-N4  
    AddOperation eID, op +"Flu.+['  
    Print "Set lens thickness = " & tlens P|%uB'|H  
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    '************************************************************************* z3x/Y/X$S  
    'Lens index of refraction %38HGjS  
    '************************************************************************* )_BQ@5NK  
    eID = FindMaterial( "Lens" ) BJC$KmGk  
    GetModelMaterial eID, mat ^h\& l{e  
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    mat.Nd = nlens =z#6mSx|W  
    SetModelMaterial eID, mat &8$Gyu  
    Print "Set lens index of refraction = " & nlens g9C/Oj`I  
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    '************************************************************************* a|S6r-_;s  
    'Pupil diameter ynY(
 
    '************************************************************************* a4aM.o  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) |I \&r[J  
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    'Adjust pupil diameter (trimming volume inner hole) 1seWR"  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" b$FK}D5  
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    ' Adjust pupil location to just in front of the lens +guCTGD:  
    parID = FindFullName( "Geometry.Arizona Eye" ) v *icoj  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) hvW FzT5  
    count = 0 gOb"-;Zw  
    While GetOperationCount(eID)>count 5?l8;xe`{f  
        GetOperation eID, count, op %[S-"k
 
        If op.Type="ShiftZ" Then &FrUj>i  
            DeleteOperation eID,count KEfN!6
 
            count=count-1 ,i RUR8  
        End If *{y({J  
        count=count+1 ;Qn)~b~  
    Wend m4\e`nl  
    op.Type = "ShiftZ" xB4}9zN s  
    op.val1 = taq-0.01 nIZ;N!r=i  
    op.parent = parID 0nr5(4h  
    AddOperation eID, op J(>T&G;  
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    Print "Set pupil diameter = " & pupilDiam
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    'Update AZ Eye subassembly Description -XASS%  
    eID = FindFullName( "Geometry.Arizona Eye" ) @tT2o@2Y^  
    GetEntity eID, entity VEsIhjQ  
    entity.Description = "Accommodation = " & A & "D" ?i{/iH~Sf  
    SetEntity eID, entity 4yK{(!&i+  
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    Update >;Ag7Ex  
    Print "DONE!"
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End Sub g{6FpuA|0  
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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： /6y9u}  
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Accommodation = 4 Diopters "%I<yUP]U  
Pupil Diameter = 4 mm ]A=yj@o$xN  
Set aqueous humor thickness = 2.81 w%1-_;.aU6  
Set anterior lens radius = 10.4 and conic constant = -2.375869
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Set posterior lens radius = -4.424557 and conic constant = -3.081019 N?EeT}m_  
Set lens thickness = 3.927 sEymwpm9  
Set lens index of refraction = 1.42672 6%^A6U  
Set pupil diameter = 4 <EKTFHJ!  
DONE! 1SF8D`3  
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