[技术]Arizona眼睛模型 [复制链接]

简介 ,I(PDlvtM  
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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。 2r3]DrpJ  
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模型 {nyQ]Nu"  
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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。 x~7_`=}rO  
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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. (thDv rT@2  
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光源 *O`76+iZ|_  
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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。 hq5=>p  
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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。 ;$ot,mH?T  
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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。 }]-SAM  
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视网膜的散射 B{ i5UhxD  
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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。 C:$12{I?*  
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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。 4o:
  
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脚本 *^'$YVd#  
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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： dHU#Y,v  
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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。 #y~`nyg%|  
余下的脚本计算与屈光度有关的所有参数。 "s']@Qv  
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分析 D`r^2(WW  
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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。 #S[:Q.0 ;  
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脚本代码 F,^<  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. 5S PGv}if  
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Dim entity As T_ENTITY &A=q_  
Dim op As T_OPERATION Jo1=C.V`Y  
Dim mat As T_MODELMATERIAL `pp"htm   
Dim A As Double M) 9Ss  
Dim pupilDiam As Double T-=sC=sS,  
Dim eID As Long !<"H73?fl  
Dim parID As Long ArBgg[i  
Dim count As Integer YoD1\a|  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double
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Dim tlens As Double, nlens As Double W,zlR5+Jk  
Dim curv As Double, conic As Double saOXbt(&  
Dim ok As Long *iB_$7n`  
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Sub Main I;`)1   
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    '用户输入对话框 #vhxW=L`=  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 mA5xke_)  
        TextBox 220,21,40,21,.TextBox1 'default: 0 qyMR
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        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 |H&2[B"
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        OKButton 40,91,90,21 _20nOg`o  
        CancelButton 190,91,90,21 |F36^  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 "Vp+e%cqG  
        TextBox 220,49,40,21,.TextBox2 'default: 4 TY"=8}X1  
    End Dialog sygAEL;.  
    Dim dlg As UserDialog \AOVdnM:  
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    ok = Dialog (dlg) d$<HMs:o@  
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    If ok=0 Then    'cancel button was pressed s OD>mc#%Y  
        Print "Execution cancelled." VsOn j~@  
        End :)+|q  
    End If e:IUO1#  
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    'Assign accommodation and pupil diameter & use defaults if field left empty $b;9oST  
    If dlg.TextBox1 = "" Then [3++Q-rR=  
        A = 0           'Default accommodation #SQao;>  
    Else n~\"W  
        A = CDbl(dlg.TextBox1) Y5fwmH,a-  
    End If E1:{5F5/  
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    If dlg.TextBox2 = "" Then HK>!%t0S  
        pupilDiam = 4   'Default pupil diameter 79<{cexP  
    Else DPn]de:e  
        pupilDiam = CDbl(dlg.TextBox2) IbQ3*  
    End If )sG`sET]`f  
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    Print " " l>)0OP]  
    Print "Accommodation = " & A & " Diopters" [ajF  
    Print "Pupil Diameter = " & pupilDiam & " mm" G"0YCi#I|  
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    ' Calculate new parameters with accommodation uW!',"0ER  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness D`3m%O(?  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens ]O s!=rt  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens V%?oI]" l  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens HF}%Ow  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens /02|b}{  
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    tlens = 3.767 + 0.04*A                  'Lens thickness s=Pwkte  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction j}Lt"r2F  
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    'Adjust parameters to account for accommodation N~L3 9  
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    '************************************************************************* FQ>KbZ
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    'Aqueous thickness (Position of Lens) )s1W)J?8  
    '************************************************************************* V*SKWP  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) W!4(EdT*Cq  
    GetCustomElement eID, entity <*0^X%Vf\  
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    parID = FindFullName( "Geometry.Arizona Eye" ) Epsc2TuH7  
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    ' Delete any shift(s) in z B<(v\=xZ  
    count = 0 Az
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    While GetOperationCount(eID)>count vK)^;
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        GetOperation eID, count, op .]g>.  
        If op.Type="ShiftZ" Then U
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            DeleteOperation eID,count F`-|@k  
            count=count-1 vttmSdY  
        End If F,Ec
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        count=count+1 +CtsD9PA  
    Wend "jly[M}C  
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    'Set new shift in \Fj$^I
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    op.Type = "ShiftZ" vs;T}'O  
    op.val1 = taq K?:rrd=7q  
    op.parent = parID ~|kre:j9  
    AddOperation eID, op %k @"*  
    Print "Set aqueous humor thickness = " & taq-0.55 c*$&MCh  
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    '************************************************************************* v+A$CGH96  
    'Radius and conic constant of anterior lens hX(:xc  
    '************************************************************************* CsG1HR@  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) V6Ie\+@.\  
    GetConic eID, entity, curv, conic :a#Mq9ph!  
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    SetConic eID, entity, 1/Rant, CCant yg\bCvL&  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant 9{\eE]0
  
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    '*************************************************************************
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    'Radius and conic constant of posterior lens I`:nb  
    '************************************************************************* TcA+ov>TD  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) 0G?0 Bo  
    GetConic eID, entity, curv, conic 26un=  
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    SetConic eID, entity, 1/Rpost, CCpost UO$z_ p]w  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost p>7!"RF:U  
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    '************************************************************************* ;|&Ak_I2G  
    'Lens thickness (Position of posterior lens surface) '|Dm\cy  
    '************************************************************************* JTB
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) ?XO$9J  
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    ' Delete any z-shift(s) =o]V!MW  
    count = 0 {` Bgxejf  
    While GetOperationCount(eID)>count Z'p7I}-qr  
        GetOperation eID, count, op 7c$;-O  
        If op.Type="ShiftZ" Then JVE]Qb_  
            DeleteOperation eID,count 7@al)G;~  
            count=count-1 9Y&,dBj+  
        End If i~:FlW]  
        count=count+1 g &~T X  
    Wend i3g;B?54  
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    'Set new z-shift f@lRa>Z(Fm  
    op.Type = "ShiftZ" |9.`qv  
    op.val1 = tlens .6S]\dp7~  
    op.parent = parID m@  b~  
    AddOperation eID, op 6N[XWyS  
    Print "Set lens thickness = " & tlens P[-2^1P
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    '************************************************************************* ];bB7+  
    'Lens index of refraction gn"_()8cT  
    '************************************************************************* o mstJ9  
    eID = FindMaterial( "Lens" ) 99
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    GetModelMaterial eID, mat so_  
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    mat.Nd = nlens Cc^`M9dP  
    SetModelMaterial eID, mat v&oE!s#  
    Print "Set lens index of refraction = " & nlens C(7
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    '************************************************************************* NFTEp0eP  
    'Pupil diameter ^pA|ubZ  
    '************************************************************************* -~T?xs0_  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) OV ~|@{6T  
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    'Adjust pupil diameter (trimming volume inner hole) &A>Hq/Y  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" RbUBKMZU  
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    ' Adjust pupil location to just in front of the lens #UGm/4C  
    parID = FindFullName( "Geometry.Arizona Eye" ) Q-78B'!=  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) =\H.C@r  
    count = 0 ,W"Q)cL  
    While GetOperationCount(eID)>count
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        GetOperation eID, count, op %IGcn48J  
        If op.Type="ShiftZ" Then @4dB$QF`&  
            DeleteOperation eID,count _
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            count=count-1 * Zb-
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        End If KrN#>do&<  
        count=count+1 H: q(T >/w  
    Wend l?E7'OEF:  
    op.Type = "ShiftZ" Qe<DX"  
    op.val1 = taq-0.01 FaO=<jYi  
    op.parent = parID Fa78y
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    AddOperation eID, op 16=tHo8|  
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    Print "Set pupil diameter = " & pupilDiam @WVpDhG  
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    'Update AZ Eye subassembly Description qD:3;85  
    eID = FindFullName( "Geometry.Arizona Eye" ) )HWf`;VQ  
    GetEntity eID, entity "1P8[  
    entity.Description = "Accommodation = " & A & "D" bm9@A]yP  
    SetEntity eID, entity <wV?B9j  
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    Update n|5+HE4@  
    Print "DONE!" `[x`#irD  
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End Sub 8+m;zvDSU  
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如果屈光度是4，光瞳直径是4，则会输出如下数据： GQ~wx1jj1  
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Accommodation = 4 Diopters I_xvg >i  
Pupil Diameter = 4 mm .T0w2Dv/  
Set aqueous humor thickness = 2.81 N3 qtq9{  
Set anterior lens radius = 10.4 and conic constant = -2.375869 *k$&U3=  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 xu[6h?u(h8  
Set lens thickness = 3.927 4kZX$ct}  
Set lens index of refraction = 1.42672 mk#xbvvG  
Set pupil diameter = 4 u'}SaX]0  
DONE! ?.66B9Lld