[技术]Arizona眼睛模型 [复制链接]

简介 s%p,cz; ,  
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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。 Y9_
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模型 !3 j@gi2  
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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。 vh">Z4  
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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. byB ESyV!O  
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光源 O2 sAt3'  
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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。 X!/o7<  
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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。 k),!%6\(  
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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。 pk5
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视网膜的散射 T~"T%r  
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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。 _J+p[=[L  
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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。 M^twD*  
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脚本 L@t}UC  
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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： ds9L4zfO  
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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。 M*x1{g C/  
余下的脚本计算与屈光度有关的所有参数。  {Hp*BE   
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分析 d l<7jM?  
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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。 w?LDaSz\t  
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脚本代码 LQs>[3rK  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. OB{d^e}  
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Dim entity As T_ENTITY kUp[b~  
Dim op As T_OPERATION rnV\O L  
Dim mat As T_MODELMATERIAL ;[ag|YU$Y  
Dim A As Double v
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Dim pupilDiam As Double wgeR%#DW  
Dim eID As Long nM?mdb  
Dim parID As Long }%;o#!<N(@  
Dim count As Integer tAM t7p-  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double ",hPy[k  
Dim tlens As Double, nlens As Double Qq.ht  
Dim curv As Double, conic As Double !N@d51T=N  
Dim ok As Long 9O.okU  
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Sub Main e/p2| 4;  
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    '用户输入对话框 ^=lh|C\#  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 A=z+@b6  
        TextBox 220,21,40,21,.TextBox1 'default: 0 `~hB-Z5dI  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 N`JkEd7TT  
        OKButton 40,91,90,21 >4.K>U?0FC  
        CancelButton 190,91,90,21 ~_ 8X%uty  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 ?C[W~m P  
        TextBox 220,49,40,21,.TextBox2 'default: 4 #9a
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    End Dialog H:d@@/  
    Dim dlg As UserDialog 8?> #  
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    ok = Dialog (dlg) *&d>Vk."]  
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    If ok=0 Then    'cancel button was pressed 4zRz U  
        Print "Execution cancelled." ~'[0-_]=f  
        End xxsax/h  
    End If ds*N1[ *  
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    'Assign accommodation and pupil diameter & use defaults if field left empty tLz,t&h  
    If dlg.TextBox1 = "" Then sr=~Uq{g  
        A = 0           'Default accommodation <;R}dlBASW  
    Else :?*|Dp1  
        A = CDbl(dlg.TextBox1) ;_HG 5}i  
    End If =Z3{6y}3p  
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    If dlg.TextBox2 = "" Then 4DYa~ =w  
        pupilDiam = 4   'Default pupil diameter R0l5"l*@+  
    Else 'nrXRDb  
        pupilDiam = CDbl(dlg.TextBox2) $mV1K)ege  
    End If -8r';zR  
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    Print " "  MYD`P2F  
    Print "Accommodation = " & A & " Diopters" CTG:C5OK  
    Print "Pupil Diameter = " & pupilDiam & " mm" DxFmsjX[L  
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    ' Calculate new parameters with accommodation 8R) 0|v&;  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness Ly7|:IbC  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens co93}A,k  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens CWTPf1?eB  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens &$1ifG   
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens . paA0j  
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    tlens = 3.767 + 0.04*A                  'Lens thickness  rkF>c  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction 5Hli@:B2s  
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    'Adjust parameters to account for accommodation R 2{kS  
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    '************************************************************************* X\-IAv  
    'Aqueous thickness (Position of Lens) O3YD jas  
    '************************************************************************* Ap:mc:  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) -kGwbV}  
    GetCustomElement eID, entity MsaD@JY.y  
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    parID = FindFullName( "Geometry.Arizona Eye" ) lR[]A  
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    ' Delete any shift(s) in z 0:CIM  
    count = 0 u%o]r9xl'  
    While GetOperationCount(eID)>count DFk0"+Ky  
        GetOperation eID, count, op lBpy0lo#  
        If op.Type="ShiftZ" Then TbUouoc  
            DeleteOperation eID,count u{6b>c|,X  
            count=count-1 y:m ;_U,%c  
        End If u . xUM  
        count=count+1 !a.|URa7  
    Wend :aIS>
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    'Set new shift in V!{}%;f  
    op.Type = "ShiftZ" Sj[iKCEKtv  
    op.val1 = taq i7%v2_  
    op.parent = parID ~$WBcqo  
    AddOperation eID, op /.1yxb#Z?,  
    Print "Set aqueous humor thickness = " & taq-0.55 @L9C_a  
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    '************************************************************************* HGwSso
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    'Radius and conic constant of anterior lens YQH=]5r  
    '************************************************************************* } xy>uT  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) ,:E*Mw:  
    GetConic eID, entity, curv, conic <Lt%[dn  
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    SetConic eID, entity, 1/Rant, CCant uZg[PS=@!X  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant dr[sSBTY"  
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    '************************************************************************* $ #*";b)QY  
    'Radius and conic constant of posterior lens ~YH'&L.O  
    '************************************************************************* YLx4qE  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) o4zX 41W  
    GetConic eID, entity, curv, conic 1@i|[dq  
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    SetConic eID, entity, 1/Rpost, CCpost ~\{a<-R  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost fK0VFN8<I  
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    '************************************************************************* ]SO-NR  
    'Lens thickness (Position of posterior lens surface) '1 }ybSG  
    '************************************************************************* X%Lhu6F  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) <27:O,I  
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    ' Delete any z-shift(s) lB(E:{6OZ  
    count = 0 Qvx[F:#Tk  
    While GetOperationCount(eID)>count -5 Q gJ  
        GetOperation eID, count, op fHLt{!O  
        If op.Type="ShiftZ" Then AW R  
            DeleteOperation eID,count l9P=1TL  
            count=count-1 4#D<#!]^  
        End If sU=7)*$  
        count=count+1 DD?zbN0X  
    Wend k$ORVU  
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    'Set new z-shift Od,P,t9  
    op.Type = "ShiftZ" 5fT"`FL?  
    op.val1 = tlens "8-;Dq'+  
    op.parent = parID '|7'dlW  
    AddOperation eID, op u^ 3,~:E  
    Print "Set lens thickness = " & tlens :f/T$fa*  
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    '*************************************************************************
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    'Lens index of refraction o?O> pK  
    '************************************************************************* WSKubn?7B  
    eID = FindMaterial( "Lens" ) (>R  
    GetModelMaterial eID, mat B*3<(eI  
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    mat.Nd = nlens i[#XYX'\  
    SetModelMaterial eID, mat ;S5J"1)O~  
    Print "Set lens index of refraction = " & nlens XZ&cTjNB&  
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    '************************************************************************* Ifu[L&U  
    'Pupil diameter DmA~Vj!a^y  
    '*************************************************************************  
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    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) ~85>.o2RDW  
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    'Adjust pupil diameter (trimming volume inner hole) Ds<~JfVl  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" w2(pgWed  
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    ' Adjust pupil location to just in front of the lens JP1XH k  
    parID = FindFullName( "Geometry.Arizona Eye" ) xo.k:F  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) [a[.tR38e  
    count = 0 ?lPyapA]  
    While GetOperationCount(eID)>count B'D\l\w  
        GetOperation eID, count, op _wp_y-"  
        If op.Type="ShiftZ" Then B4MrrW4=  
            DeleteOperation eID,count U^&,xz$Cg  
            count=count-1 7@NV|Idtd  
        End If '5r\o8RjN  
        count=count+1 M?ObK#l!_  
    Wend ]I[\Io1  
    op.Type = "ShiftZ" QnTKo&|9  
    op.val1 = taq-0.01 N!~5S`  
    op.parent = parID kc7,F
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    AddOperation eID, op L']"I^(N  
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    Print "Set pupil diameter = " & pupilDiam [lz#+~rOS  
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    'Update AZ Eye subassembly Description PY76;D*`  
    eID = FindFullName( "Geometry.Arizona Eye" ) WXs?2S*  
    GetEntity eID, entity m|]:oT`M  
    entity.Description = "Accommodation = " & A & "D" <5]ufv  
    SetEntity eID, entity EpU}~vC9C  
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    Update k4-S:kVo  
    Print "DONE!" (&!RX.i  
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End Sub I&wJK'GM`  
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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： H#/Hs#  
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Accommodation = 4 Diopters qORL 7?{  
Pupil Diameter = 4 mm WYm<_1  
Set aqueous humor thickness = 2.81  \OW.?1d  
Set anterior lens radius = 10.4 and conic constant = -2.375869 H{4_,2h=m  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 ;Xl {m`E+  
Set lens thickness = 3.927 }Y!v"DO#Q*  
Set lens index of refraction = 1.42672 }B ?_>0  
Set pupil diameter = 4 I|<`Er-;58  
DONE! PS3jCT