[技术]Arizona眼睛模型 [复制链接]

简介 &hZwZgV+3  
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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。 A{,n;;  
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模型 "/%89 HMD  
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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。 Yx?aC!5M  
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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. zQuM !.  
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光源 `6w#8}  
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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。 -Wo15O"  
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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。 H7IW"UkBR  
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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。 ()|3  
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视网膜的散射 5:gj&jt;)7  
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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。 YF[$Q=7.
 
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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。 ToU.mM?f^  
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脚本 5+L8\V9;  
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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： ( pD7  
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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。 QMb^&?;s  
余下的脚本计算与屈光度有关的所有参数。 TG]}X\c+V|  
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分析 /.ZaE+  
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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。 a|.20w5  
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脚本代码 CKC0{J8g  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. 3ZN>9`  
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Dim entity As T_ENTITY 0BXs&i-TP5  
Dim op As T_OPERATION A\g%  
Dim mat As T_MODELMATERIAL vzy!3Hiw  
Dim A As Double Y
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Dim pupilDiam As Double uQ1jwYK`7  
Dim eID As Long E0jUewG  
Dim parID As Long MCd F!{  
Dim count As Integer d#7]hF
  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double LaT8l?q q  
Dim tlens As Double, nlens As Double =M7PvH'"  
Dim curv As Double, conic As Double z"qv  
Dim ok As Long &CO|Y(+  
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Sub Main D"`[6EN[  
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    '用户输入对话框 I4ctxMVP  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 fO+UHSC  
        TextBox 220,21,40,21,.TextBox1 'default: 0 G{O\)gf  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 /x O{ .dr  
        OKButton 40,91,90,21 We\Y \*!v  
        CancelButton 190,91,90,21 d/4ubf+$k  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 i\vpGlx  
        TextBox 220,49,40,21,.TextBox2 'default: 4 A`Q >h{  
    End Dialog nHVPMi>  
    Dim dlg As UserDialog V0S6M^\DK  
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    ok = Dialog (dlg) !c."   
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    If ok=0 Then    'cancel button was pressed ~K%k 0kT  
        Print "Execution cancelled." ?4MSgu  
        End qkiJHT  
    End If =kF?_KN  
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    'Assign accommodation and pupil diameter & use defaults if field left empty C|9[Al  
    If dlg.TextBox1 = "" Then pqOA/^ar  
        A = 0           'Default accommodation )FV6

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    Else oFb\TiLu  
        A = CDbl(dlg.TextBox1) U-1VnX9m  
    End If A3<^ U  
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    If dlg.TextBox2 = "" Then Q|Nzbmwh  
        pupilDiam = 4   'Default pupil diameter JR!Q,7S2!N  
    Else VZt;P%1;h  
        pupilDiam = CDbl(dlg.TextBox2) T0s35z9  
    End If "wC0eDf  
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    Print " " xSx&79Ez<*  
    Print "Accommodation = " & A & " Diopters" -*r[  
    Print "Pupil Diameter = " & pupilDiam & " mm" cl@kRX<7'  
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    ' Calculate new parameters with accommodation FLK"|*A  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness ?<Z)*CF)  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens K?$9N}+  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens fYb K
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens Av@&hD\  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens t
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    tlens = 3.767 + 0.04*A                  'Lens thickness zoR,RBU6  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction 4u@yJ?U  
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    'Adjust parameters to account for accommodation K3a>^g  
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    '************************************************************************* Xs{/}wc.q;  
    'Aqueous thickness (Position of Lens) 6{cybD`Ef&  
    '************************************************************************* FrgW7`s[A  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) JqL<$mSep  
    GetCustomElement eID, entity 'Na|#tPYI  
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    parID = FindFullName( "Geometry.Arizona Eye" ) %j~9O~-  
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    ' Delete any shift(s) in z ~l;yr @  
    count = 0 We[<BJo4  
    While GetOperationCount(eID)>count kqjxJ5  
        GetOperation eID, count, op cZPbD;e:  
        If op.Type="ShiftZ" Then l :f9Ih  
            DeleteOperation eID,count }K#iCb
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            count=count-1 rd|@*
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        End If }".\ 4B$n  
        count=count+1
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    Wend _bN))9 3  
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    'Set new shift in "
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    op.Type = "ShiftZ" }`+O$0A  
    op.val1 = taq
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    op.parent = parID Y9z:xE  
    AddOperation eID, op dM);LT8@  
    Print "Set aqueous humor thickness = " & taq-0.55 wxdh?sQ  
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    '************************************************************************* ^4n2 -DvG  
    'Radius and conic constant of anterior lens BZ]&uD|f  
    '************************************************************************* m]+X}|  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) ;`X`c  
    GetConic eID, entity, curv, conic jldcvW  
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    SetConic eID, entity, 1/Rant, CCant >=Rd3dgDG  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant X=S}WKu  
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    '************************************************************************* DzX6U[=  
    'Radius and conic constant of posterior lens *@b~f&Lx6  
    '************************************************************************* ~FK+bF?%  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) oT9XJwqnv  
    GetConic eID, entity, curv, conic Mt7X<?GZm  
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    SetConic eID, entity, 1/Rpost, CCpost 8EW`*
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    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost ":(Cpf0  
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    '************************************************************************* "9MX,}X*  
    'Lens thickness (Position of posterior lens surface) J8`1V`$  
    '************************************************************************* m\R@.jkZ
 
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) D9@<#2-  
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    ' Delete any z-shift(s) AR[M8RA  
    count = 0 qB`0^V  
    While GetOperationCount(eID)>count 6 ^6uK  
        GetOperation eID, count, op <+mO$0h"r  
        If op.Type="ShiftZ" Then )nbyV a  
            DeleteOperation eID,count MO(5-R`  
            count=count-1 6i?kkULBS  
        End If 0X}w[^f  
        count=count+1 l")o!N?  
    Wend Bt`r6v;\  
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    'Set new z-shift *I;Mp  
    op.Type = "ShiftZ" ;Kq<',u~  
    op.val1 = tlens i >/@]2  
    op.parent = parID ":ws~
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    AddOperation eID, op ,M9hb<:m  
    Print "Set lens thickness = " & tlens 4=#QN  
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    '************************************************************************* @)M.u3{\  
    'Lens index of refraction YRT}fd>R&  
    '************************************************************************* 8)2u@sx%  
    eID = FindMaterial( "Lens" ) vr]dRStr  
    GetModelMaterial eID, mat v2dSC(hRZ  
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    mat.Nd = nlens 7zOvoQ}  
    SetModelMaterial eID, mat fjeE.  
    Print "Set lens index of refraction = " & nlens ROI$;B(  
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    '************************************************************************* 5E!|on  
    'Pupil diameter h11bK'TIv  
    '************************************************************************* &b#NF1Q.  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) rt4|GVa  
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    'Adjust pupil diameter (trimming volume inner hole) 3k
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" k?_$h<Y  
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    ' Adjust pupil location to just in front of the lens ^gVbVz[17  
    parID = FindFullName( "Geometry.Arizona Eye" ) 8B
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    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) (j\UoKLRt  
    count = 0 Xwn|.  
    While GetOperationCount(eID)>count O
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        GetOperation eID, count, op r;s3(@[,@  
        If op.Type="ShiftZ" Then i_Q4bhVj  
            DeleteOperation eID,count b9!J}hto,  
            count=count-1 pz z`4VS:  
        End If EC&19  
        count=count+1 '"NdT7*+  
    Wend Hwi7oXP  
    op.Type = "ShiftZ" Zi'8~iEH  
    op.val1 = taq-0.01 @C6DOB  
    op.parent = parID d(cYtM,P  
    AddOperation eID, op LB 5EGw  
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    Print "Set pupil diameter = " & pupilDiam r_2VExk  
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    'Update AZ Eye subassembly Description w+ )GM  
    eID = FindFullName( "Geometry.Arizona Eye" ) zK]%qv]  
    GetEntity eID, entity 7*W$GCd8  
    entity.Description = "Accommodation = " & A & "D" 'Rf#1ls#  
    SetEntity eID, entity (inwKRH  
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    Update ~<Qxw>S#  
    Print "DONE!" E~U|v'GCd  
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End Sub MkIO0&0O  
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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<3b+Sg  
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Accommodation = 4 Diopters -cC(d$y  
Pupil Diameter = 4 mm #SOj4W  
Set aqueous humor thickness = 2.81 )qQg n]  
Set anterior lens radius = 10.4 and conic constant = -2.375869 h.0&)t\q"  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 dtXJ<1:  
Set lens thickness = 3.927 <i@j
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Set lens index of refraction = 1.42672 fXR_)d  
Set pupil diameter = 4 Ge
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DONE! ~]s"PV:|