[技术]Arizona眼睛模型 [复制链接]

简介 iNcZ)m/  
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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~r}c4R{7  
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模型 j{#Wn !,  
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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。 5,+\`!g  
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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. @^nu#R  
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光源 M%Ku5X6:/  
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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。 +R$?2  
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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。 ;##]G=%  
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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。 TZ^LA L'8_  
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视网膜的散射 y<r}"TAf-  
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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。 X\GM/A  
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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。 .{dE}2^  
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脚本 * UcjQ
  
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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： nW;kcS*A  
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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。 ;i)KHj'  
余下的脚本计算与屈光度有关的所有参数。 NXoK@Y  
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分析 u]vPy ria  
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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。 _'iDF  
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脚本代码 /5
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. ~ l )t|'6  
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Dim entity As T_ENTITY A!HK~yk~Q  
Dim op As T_OPERATION G\rj?%  
Dim mat As T_MODELMATERIAL ofCVbn  
Dim A As Double  ]6~k4  
Dim pupilDiam As Double OhWC}s  
Dim eID As Long iz x[  
Dim parID As Long |^5/(16  
Dim count As Integer `ut)+T V  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double H`|0-`q  
Dim tlens As Double, nlens As Double c cr
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Dim curv As Double, conic As Double g5}7y\  
Dim ok As Long : ^(nj7D  
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Sub Main `!Ln|_,d  
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    '用户输入对话框 Q]i[.ME  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 U>3 >Ex  
        TextBox 220,21,40,21,.TextBox1 'default: 0 wixD\t59X  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 5Bj77?Z  
        OKButton 40,91,90,21 Ru7L>(Njs  
        CancelButton 190,91,90,21 Uz>Yn&{y6  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 :uR>UDlPX  
        TextBox 220,49,40,21,.TextBox2 'default: 4 Yk7"XP[Y  
    End Dialog -Op@y2+c  
    Dim dlg As UserDialog TNsg pJ?\  
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    ok = Dialog (dlg) !$E~\uT  
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    If ok=0 Then    'cancel button was pressed Q<'@V@H  
        Print "Execution cancelled." "'aqb~j^  
        End KZ\dB;W<|  
    End If S~&\o\"5  
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    'Assign accommodation and pupil diameter & use defaults if field left empty "gg(tp45  
    If dlg.TextBox1 = "" Then N l|^o{#  
        A = 0           'Default accommodation J[+Tj@n'  
    Else E 8^sy*f  
        A = CDbl(dlg.TextBox1) |0DP} `~  
    End If z (#Xca  
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    If dlg.TextBox2 = "" Then VVN# $  
        pupilDiam = 4   'Default pupil diameter Ei~]iZ}  
    Else 0$
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        pupilDiam = CDbl(dlg.TextBox2) `E%(pjG  
    End If 3Pa3f >}-  
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    Print " " 1l~.R#WG&  
    Print "Accommodation = " & A & " Diopters" jqqaw  
    Print "Pupil Diameter = " & pupilDiam & " mm" yHtGp%j  
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    ' Calculate new parameters with accommodation 5 2fO)!  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness @|]iSD&T #  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens gm}C\q9  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens -MUQ\pZ  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens LNbx3W oC  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens `^`9{@~  
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    tlens = 3.767 + 0.04*A                  'Lens thickness d)9PEt
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction n<+~ zQ  
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    'Adjust parameters to account for accommodation q>c+bo 6  
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    '************************************************************************* krwf8!bI  
    'Aqueous thickness (Position of Lens) {M
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    '************************************************************************* i"KL;t[1  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) pO5v*oONz+  
    GetCustomElement eID, entity e$x4Ux7*"  
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    parID = FindFullName( "Geometry.Arizona Eye" ) 7kO
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    ' Delete any shift(s) in z KgL<}=S  
    count = 0 %oMWcgsdJi  
    While GetOperationCount(eID)>count +6wx58.B&  
        GetOperation eID, count, op TIKEg10I  
        If op.Type="ShiftZ" Then u;QH8LK  
            DeleteOperation eID,count <)=3XEcb  
            count=count-1 WNl&v]   
        End If aKaR  
        count=count+1 t.gq5Y.[  
    Wend G!-7ic_4  
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    'Set new shift in m`[oT\  
    op.Type = "ShiftZ" `\nON  
    op.val1 = taq ^7J~W'hI  
    op.parent = parID k{zs578h2  
    AddOperation eID, op qAnA=/k`  
    Print "Set aqueous humor thickness = " & taq-0.55 #IH<HL)t%e  
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    '************************************************************************* |C&%S"*+D  
    'Radius and conic constant of anterior lens z%++\.g_  
    '************************************************************************* s0_-1VU  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) ^mS.HT=X  
    GetConic eID, entity, curv, conic dxk;@Tz  
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    SetConic eID, entity, 1/Rant, CCant -ryDsq  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant myEGibhK  
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    '************************************************************************* ppPG+[cz  
    'Radius and conic constant of posterior lens Xp<A@2wt?  
    '************************************************************************* :|*Gnu  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) 4Z<]4:o  
    GetConic eID, entity, curv, conic p} t{8j>  
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    SetConic eID, entity, 1/Rpost, CCpost V:nMo2'hb  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost +,ZUTG  
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    '************************************************************************* 3ybK6!g`[  
    'Lens thickness (Position of posterior lens surface) ]}UeuF\  
    '************************************************************************* >!:$@!6L  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) M63s(f  
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    ' Delete any z-shift(s) chvrHvByS  
    count = 0 8MYLXW6  
    While GetOperationCount(eID)>count ^&f{beU9  
        GetOperation eID, count, op P5yJO9
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        If op.Type="ShiftZ" Then f}Ne8]U/Hc  
            DeleteOperation eID,count  ?.4y
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            count=count-1 Q#yu(  
        End If &hSnB~hi  
        count=count+1 {<''OwQF~+  
    Wend Uxj<x`<1x  
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    'Set new z-shift j]@x Q,y  
    op.Type = "ShiftZ" a2(D!_dZR  
    op.val1 = tlens D:ql^{~  
    op.parent = parID glOqft&>`  
    AddOperation eID, op 35]j;8N:  
    Print "Set lens thickness = " & tlens IS5.i95m  
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    '************************************************************************* m11"i=S"  
    'Lens index of refraction xdFP$Y~ogy  
    '************************************************************************* {UV<=R,E  
    eID = FindMaterial( "Lens" ) m2-fi*Mgg  
    GetModelMaterial eID, mat XudH
 
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    mat.Nd = nlens mK7^:(<.LO  
    SetModelMaterial eID, mat qb>|n1F_  
    Print "Set lens index of refraction = " & nlens ^cKv JSY  
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    '************************************************************************* &F<J#cfe8  
    'Pupil diameter 6\)8mK  
    '************************************************************************* jFJW3az@z  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) BM=V,BZy  
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    'Adjust pupil diameter (trimming volume inner hole) OTNZ!U/)j  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" oneSgJ  
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    ' Adjust pupil location to just in front of the lens Sug~FV?k$e  
    parID = FindFullName( "Geometry.Arizona Eye" ) 8vX*SrM  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) ^cPo{xf  
    count = 0 u$Pf.#  
    While GetOperationCount(eID)>count i SAidK
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        GetOperation eID, count, op l7D4`i<F  
        If op.Type="ShiftZ" Then VAF:Z  
            DeleteOperation eID,count Un8#f+odR  
            count=count-1 NejsI un%  
        End If V!kQuQJ>  
        count=count+1 Us@ {w`T  
    Wend *'`3]!A  
    op.Type = "ShiftZ" y ? {PoNI  
    op.val1 = taq-0.01 vBCZ/F[  
    op.parent = parID &ESR1$)'P  
    AddOperation eID, op ,,C~j`F  
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    Print "Set pupil diameter = " & pupilDiam %xbz&'W,  
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    'Update AZ Eye subassembly Description J7
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    eID = FindFullName( "Geometry.Arizona Eye" ) 1Hk<_no5  
    GetEntity eID, entity 3'
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    entity.Description = "Accommodation = " & A & "D" :+
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    SetEntity eID, entity 0
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    Update u{E^<fW]  
    Print "DONE!" tUAY]BJ*s  
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End Sub ru6HnLhL  
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如果屈光度是4，光瞳直径是4，则会输出如下数据： |V~(mS747:  
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Accommodation = 4 Diopters )*$  
Pupil Diameter = 4 mm qS/71Kv'  
Set aqueous humor thickness = 2.81  ]5)&36  
Set anterior lens radius = 10.4 and conic constant = -2.375869 Q'Jpsmwu  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 9(FcA5Y  
Set lens thickness = 3.927 7PQj7&m  
Set lens index of refraction = 1.42672 )l!&i?h%  
Set pupil diameter = 4 xUYN\Pc-  
DONE! U0|j^.)