[技术]Arizona眼睛模型 [复制链接]

简介 i;*c|ma1>  
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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。 $1.iMHb  
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模型 REB8_H"  
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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。 lZV]Z3=p'0  
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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. m7z/@b[  
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光源 t*zve,?}  
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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。 |OF<=GGO+  
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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。 5H:NY|  
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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。 +cheLc  
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视网膜的散射 =r3Yt9  
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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。 huWUd)Po%  
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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。 x^8xz5:O  
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脚本 x%k4Lm  
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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： QB#f'X  
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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。 FlOKTY  
余下的脚本计算与屈光度有关的所有参数。 )AXTi4MNp  
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分析 7n,nODbJ  
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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。 J;+tQ8,AP  
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脚本代码  ?Vbe  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. "}*P9-%  
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Dim entity As T_ENTITY ,COSpq]6  
Dim op As T_OPERATION ^TVica  
Dim mat As T_MODELMATERIAL =:P9 $  
Dim A As Double fxI>FhU_  
Dim pupilDiam As Double }(Nb]_H  
Dim eID As Long YgQ_P4B;  
Dim parID As Long !vr">@}K  
Dim count As Integer RSG4A>%!mI  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double Mto3Ryic!  
Dim tlens As Double, nlens As Double pTOS}A[dh  
Dim curv As Double, conic As Double "%D+_Yb'X  
Dim ok As Long (=CV")tF  
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Sub Main q!7z4Cn  
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    '用户输入对话框 $d:/cN 8E  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 ]d9;YVAU  
        TextBox 220,21,40,21,.TextBox1 'default: 0 JiDX|Q<c  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 p!AQ
  
        OKButton 40,91,90,21 !a[ voUS  
        CancelButton 190,91,90,21 N12K*P[!  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 Q6_!I42Y`  
        TextBox 220,49,40,21,.TextBox2 'default: 4 UB|Nx(V s  
    End Dialog (jPN+yQ  
    Dim dlg As UserDialog KG'4;Z5J  
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    ok = Dialog (dlg) 4Yt:PN2  
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    If ok=0 Then    'cancel button was pressed 7{D+\i  
        Print "Execution cancelled." }bIEWho  
        End J}i$ny_3OB  
    End If 5f=e JDo=x  
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    'Assign accommodation and pupil diameter & use defaults if field left empty FnP/NoZa>  
    If dlg.TextBox1 = "" Then b}9K"GT  
        A = 0           'Default accommodation rMTtPuc2  
    Else TA`*]*O(  
        A = CDbl(dlg.TextBox1) pb{'t2kk  
    End If -J:](p  
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    If dlg.TextBox2 = "" Then W`eYd|+C  
        pupilDiam = 4   'Default pupil diameter )qn =  
    Else <gZC78}E  
        pupilDiam = CDbl(dlg.TextBox2) Fng":28o  
    End If I:]s/r7  
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    Print " " A0oC*/  
    Print "Accommodation = " & A & " Diopters" }dAb}0XK.  
    Print "Pupil Diameter = " & pupilDiam & " mm" 5A7!Xd  
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    ' Calculate new parameters with accommodation VaZS_qGe:  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness 6@wnF>'/\  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens [uc;M6o}?  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens Y_p  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens t<|=-  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens ?.v!RdM+  
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    tlens = 3.767 + 0.04*A                  'Lens thickness vo!:uvy;2  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction yf3%g\k  
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    'Adjust parameters to account for accommodation !b rN)b)f  
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    '************************************************************************* 4D$$KSa  
    'Aqueous thickness (Position of Lens) F!|Z_6\tv:  
    '************************************************************************* iWCN2om  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) s]5wzbFO  
    GetCustomElement eID, entity VXn]*Mo  
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    parID = FindFullName( "Geometry.Arizona Eye" ) ^5 F-7R8Q  
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    ' Delete any shift(s) in z x@v,qF$K  
    count = 0 _AI2\e  
    While GetOperationCount(eID)>count vFL3eu#  
        GetOperation eID, count, op E0ud<'3<  
        If op.Type="ShiftZ" Then udp&U+L  
            DeleteOperation eID,count -R~;E[ {%  
            count=count-1 YDi_Gl$  
        End If a}
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        count=count+1 &5(|a"5+G  
    Wend wC
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    'Set new shift in S,G=MI"  
    op.Type = "ShiftZ" U+@yx>!  
    op.val1 = taq Mr2dhSQ!  
    op.parent = parID e>nRJH8pK  
    AddOperation eID, op mC>7l7%  
    Print "Set aqueous humor thickness = " & taq-0.55 L.U [eH  
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    '************************************************************************* C([;JO 11[  
    'Radius and conic constant of anterior lens .g(yTA  
    '************************************************************************* .A\9|sRZ5  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) n@T4z.*~lA  
    GetConic eID, entity, curv, conic u\Fq
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    SetConic eID, entity, 1/Rant, CCant K+ufcct  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant [g=yuVXNZZ  
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    '************************************************************************* Ln[R}qD  
    'Radius and conic constant of posterior lens oF]0o`U&a  
    '************************************************************************* N(t1?R/e
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    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) 3t68cdFlz  
    GetConic eID, entity, curv, conic K`(STvtM  
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    SetConic eID, entity, 1/Rpost, CCpost R/ l1$}  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost ll[U-v{  
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    '************************************************************************* COJqVC(#  
    'Lens thickness (Position of posterior lens surface) Nf-IDK  
    '************************************************************************* qFe|$rVVIl  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) +s1+;VUs3  
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    ' Delete any z-shift(s) ~`T(mh',  
    count = 0 eoTOccb!  
    While GetOperationCount(eID)>count 3|9)A+,#  
        GetOperation eID, count, op Q&`$:h.~  
        If op.Type="ShiftZ" Then 9WtTUk
 
            DeleteOperation eID,count &IXr*I  
            count=count-1 z[z'.{;D  
        End If ^4B6IF*  
        count=count+1 j#-ZL-N  
    Wend c!{.BgGN  
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    'Set new z-shift \&@Tq-o  
    op.Type = "ShiftZ"  EvTdwX.H  
    op.val1 = tlens fJc,KZy  
    op.parent = parID s67$tlV  
    AddOperation eID, op A){kitx-i)  
    Print "Set lens thickness = " & tlens dE/Vl/:  
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    '************************************************************************* si3i#l&.b_  
    'Lens index of refraction WAqR70{KM  
    '************************************************************************* p_B,7@Jl  
    eID = FindMaterial( "Lens" ) c)iQ3_&=  
    GetModelMaterial eID, mat 7lR(6ka&/  
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    mat.Nd = nlens t8]u#bx"?  
    SetModelMaterial eID, mat fm&l0  
    Print "Set lens index of refraction = " & nlens OaU} 9&  
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    '************************************************************************* 8Nci1o  
    'Pupil diameter I[tU}ojP  
    '************************************************************************* g@B9i=  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) )ckx&e  
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    'Adjust pupil diameter (trimming volume inner hole) ,dZ 9=]  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" XRP/E_4  
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    ' Adjust pupil location to just in front of the lens wnt^WW=a[  
    parID = FindFullName( "Geometry.Arizona Eye" ) hl6al:Y  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) |06J4H~k  
    count = 0 8ru@ 8|r  
    While GetOperationCount(eID)>count rLh490
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        GetOperation eID, count, op Dih~5  
        If op.Type="ShiftZ" Then PM%./  
            DeleteOperation eID,count gJvc<]W8!  
            count=count-1 *DDfdn  
        End If D!qtb6<.  
        count=count+1 5>h2WL  
    Wend '["Y;/>  
    op.Type = "ShiftZ" 5'+g'9  
    op.val1 = taq-0.01 oDKgW?x  
    op.parent = parID mc!
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    AddOperation eID, op 9Ki86  
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    Print "Set pupil diameter = " & pupilDiam <KHB/7  
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    'Update AZ Eye subassembly Description GbB&kE3KP  
    eID = FindFullName( "Geometry.Arizona Eye" ) ~X`vRSrH  
    GetEntity eID, entity .Ddl.9p5  
    entity.Description = "Accommodation = " & A & "D" Gp32\^H|<  
    SetEntity eID, entity ',juZ[]_{  
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    Update V!]e#QH;  
    Print "DONE!" prIq9U|@  
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End Sub 3bE^[V8/  
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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： xu& v(C9  
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Accommodation = 4 Diopters l9P~,Ec4''  
Pupil Diameter = 4 mm $t}L|"=8X  
Set aqueous humor thickness = 2.81 ~jF5%Gu  
Set anterior lens radius = 10.4 and conic constant = -2.375869 DrMcE31  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 T3M 4r|  
Set lens thickness = 3.927 @jwUH8g1  
Set lens index of refraction = 1.42672 (qohb0  
Set pupil diameter = 4 tb0s+rb  
DONE! d*q_DV