[技术]Arizona眼睛模型 [复制链接]

简介 LyH1tF  
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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。 4-m6e$p;  
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模型 lF
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模型的定义如表1种所示，由半径、圆锥常数、折射率、阿贝数、到下一面的距离等一系列表面组成。一些参数由屈光度（A）来决定。 `I.pwst8i-  
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在FRED中使用0屈光度来创建的，光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. EpH_v`  
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光源 RdBIbm  
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多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 }OY/0p-Z  
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除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处，并增加了pre-propagation distance= -8。尽管光线在光瞳处创建，规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射，而不是在光瞳处入射。 _n1[(I  
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在往下看是内置的脚本用来修改屈光度，使其为4（250mm），光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 ,x$^^  
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视网膜的散射 DD2K>1A1  
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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。 Z&O6<=bg!  
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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。 v&bG`\!  
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脚本 @S=9@3m{w;  
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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： 6tFi\,)E  
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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。 2,wwI<=E'  
余下的脚本计算与屈光度有关的所有参数。 ()48>||  
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分析 'NZ=DSGIy  
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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。 T;?k]4.X  
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脚本代码 2j}DI"|h  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. H>A6VDu  
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Dim entity As T_ENTITY /0 4US5En  
Dim op As T_OPERATION =MMd&  
Dim mat As T_MODELMATERIAL g4eW<  
Dim A As Double 6y~F'/ww  
Dim pupilDiam As Double 
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Dim eID As Long Mx$&{.LFJ  
Dim parID As Long W"^=RY  
Dim count As Integer ~7U~   
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double fum.G{}  
Dim tlens As Double, nlens As Double T4HJy|  
Dim curv As Double, conic As Double a5GLbanF  
Dim ok As Long EG;E !0  
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Sub Main r`.N?  
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    '用户输入对话框 ZGDT 6,  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 Rh?bBAn8  
        TextBox 220,21,40,21,.TextBox1 'default: 0 tw>2<zmSi%  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 EgU#r@
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        OKButton 40,91,90,21 u;gO+)wqv  
        CancelButton 190,91,90,21 Z sTtSM\Ac  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 z8'1R6nq  
        TextBox 220,49,40,21,.TextBox2 'default: 4 Iz5NA0[=2  
    End Dialog > :IWRc2  
    Dim dlg As UserDialog {VL@U$'oI  
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    ok = Dialog (dlg) Pps-,*m  
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    If ok=0 Then    'cancel button was pressed %^pi  
        Print "Execution cancelled." RHg-Cg`  
        End ]mb8R:a1  
    End If ]MV8rC[\  
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    'Assign accommodation and pupil diameter & use defaults if field left empty $Sgf jm  
    If dlg.TextBox1 = "" Then o^\Pt<~W  
        A = 0           'Default accommodation \ph.c*c  
    Else fq]PKLW'  
        A = CDbl(dlg.TextBox1) *iEtXv  
    End If lGl'A}]#$  
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    If dlg.TextBox2 = "" Then >F7w]XH  
        pupilDiam = 4   'Default pupil diameter `X6J
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    Else Aw |;C  
        pupilDiam = CDbl(dlg.TextBox2) GWnIy6TH l  
    End If 6!ve6ZB[p  
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    Print " " /Hyz]46  
    Print "Accommodation = " & A & " Diopters" Sw\*$g]  
    Print "Pupil Diameter = " & pupilDiam & " mm" ViPC Yt`of  
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    ' Calculate new parameters with accommodation sQvRupYRO  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness (Q^sK\  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens <EpL<K%  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens bf"'xn9  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens a/sjW  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens G^~[|a4`  
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    tlens = 3.767 + 0.04*A                  'Lens thickness gB
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction Q+^&  
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    'Adjust parameters to account for accommodation
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    '************************************************************************* Nr~$i%[  
    'Aqueous thickness (Position of Lens) c=oDzAzuV\  
    '************************************************************************* cz>,sz~i  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) 2 |s ohF  
    GetCustomElement eID, entity I,j4 BU4  
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    parID = FindFullName( "Geometry.Arizona Eye" ) WQK<z!W5  
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    ' Delete any shift(s) in z $YL9 vJV  
    count = 0 ~~tTr$  
    While GetOperationCount(eID)>count ~t`^|cr|  
        GetOperation eID, count, op L
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        If op.Type="ShiftZ" Then 5p;AON  
            DeleteOperation eID,count K,E/.Qe\C  
            count=count-1 .+9hm|  
        End If Dqx#i-L23  
        count=count+1 SB_Tzp  
    Wend tIsWPt]Y  
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    'Set new shift in :Ha/^cC/3  
    op.Type = "ShiftZ" zM9#1^X  
    op.val1 = taq 06&J!,p :  
    op.parent = parID Q`ua9oIJ=  
    AddOperation eID, op I"07x'Ahq3  
    Print "Set aqueous humor thickness = " & taq-0.55 'wND  
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    '************************************************************************* XE}gl&\  
    'Radius and conic constant of anterior lens > H!sD\b  
    '************************************************************************* ;H_/o+  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) ZZw`8 E  
    GetConic eID, entity, curv, conic e~o
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    SetConic eID, entity, 1/Rant, CCant e7vm3<m4  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant _C?j\Wy  
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    '************************************************************************* J1?

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    'Radius and conic constant of posterior lens {i5?R,a)  
    '************************************************************************* TR"C<&y$j  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) gq+SM i=  
    GetConic eID, entity, curv, conic :RaQ =C  
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    SetConic eID, entity, 1/Rpost, CCpost zC?'Qiuh*  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost {keZ_2  
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    '************************************************************************* (m~>W"x/  
    'Lens thickness (Position of posterior lens surface) 88
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    '************************************************************************* jkAjYR.  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) Wh[QR-7Ew  
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    ' Delete any z-shift(s) =$>=EBH,cm  
    count = 0 `KJ(.m  
    While GetOperationCount(eID)>count mzgt>Qtkz=  
        GetOperation eID, count, op H?$dnwR  
        If op.Type="ShiftZ" Then !ifU}qFzK  
            DeleteOperation eID,count &qv~)ZM$  
            count=count-1 ZlT }cA/n  
        End If ,/;Aew;  
        count=count+1 wq)*bIv  
    Wend 9^gYy&+>6]  
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    'Set new z-shift qt"D!S
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    op.Type = "ShiftZ" =7Ln&t
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    op.val1 = tlens ?w3RqF@}  
    op.parent = parID peQwH  
    AddOperation eID, op L\:|95Yq  
    Print "Set lens thickness = " & tlens
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    '************************************************************************* xL}i9ozZ  
    'Lens index of refraction &?<uR)tl  
    '************************************************************************* LC%ococ  
    eID = FindMaterial( "Lens" ) c4JV~VS+  
    GetModelMaterial eID, mat ^Hd[+vAvR  
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    mat.Nd = nlens ;kFD769DLw  
    SetModelMaterial eID, mat 5mH[|_  
    Print "Set lens index of refraction = " & nlens { 3G  
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    '************************************************************************* .<x6U*)\O  
    'Pupil diameter p{f R$-d  
    '************************************************************************* Y(Q 0m|3P  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) 2d)Dhxzxk  
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    'Adjust pupil diameter (trimming volume inner hole) #'L<7t K  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" 5`;SI36"  

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    ' Adjust pupil location to just in front of the lens Gh;\"Qx
  
    parID = FindFullName( "Geometry.Arizona Eye" ) Fmk:[hMw  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) i:lc]B  
    count = 0 $)lkiA&;  
    While GetOperationCount(eID)>count +^.Yt0}  
        GetOperation eID, count, op ^q7V%{54  
        If op.Type="ShiftZ" Then +! 1_Mt6  
            DeleteOperation eID,count oD)x\ )t8  
            count=count-1 byHc0ktI\  
        End If E`HoJhB  
        count=count+1 c%&,(NJ]K  
    Wend m\:^9A4HCg  
    op.Type = "ShiftZ" ^e:z ul{;]  
    op.val1 = taq-0.01 hkK>h  
    op.parent = parID -@v^. @[Z&  
    AddOperation eID, op uGU2  
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    Print "Set pupil diameter = " & pupilDiam eG=d)`.JaV  
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    'Update AZ Eye subassembly Description L+t / E`  
    eID = FindFullName( "Geometry.Arizona Eye" ) ($di]lbsT  
    GetEntity eID, entity JrP`u4f_  
    entity.Description = "Accommodation = " & A & "D" m&)/>'W  
    SetEntity eID, entity Xdvd\H=  
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    Update {^]qaQ[5N  
    Print "DONE!" }m:paB"3  
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End Sub N,`@
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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： 5'!fi]Z  
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Accommodation = 4 Diopters Kz'GAm\  
Pupil Diameter = 4 mm ZCCCuB  
Set aqueous humor thickness = 2.81 D#GuF~-F!R  
Set anterior lens radius = 10.4 and conic constant = -2.375869 v
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Set posterior lens radius = -4.424557 and conic constant = -3.081019 kQ\GVI11?  
Set lens thickness = 3.927 >+O0W)g{o  
Set lens index of refraction = 1.42672 ~Wrp
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Set pupil diameter = 4 l)r\SE1  
DONE! ~d*Q{v~3