[技术]Arizona眼睛模型 [复制链接]

简介 rmoEc]kt]  
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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。 [cs8/Q8+  
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模型 /Loe y   
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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。 p5BcDYOw`  
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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. tC~itU=V  
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光源 \./2Qc,  
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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。 py4_hj\v  
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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。 4w[ta?&6B  
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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。 ,Ou)F;r  
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视网膜的散射 aoX$,~oI5  
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在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 (#`o>G(  
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注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 9$i`B>C
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脚本 1jVcL)szU  
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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： H0 t1& :  
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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。 Bw[VK7  
余下的脚本计算与屈光度有关的所有参数。 PN=yf@<V3F  
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分析 {\I\4P  
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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。 I^=M>_s4  
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脚本代码 Gx($q;8  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. GYO"1PM  
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Dim entity As T_ENTITY ?Fu.,srt  
Dim op As T_OPERATION AaVlNjB  
Dim mat As T_MODELMATERIAL "H8N,eb2  
Dim A As Double XlPy(>  
Dim pupilDiam As Double T8LwDqio  
Dim eID As Long ,H8Pmn?  
Dim parID As Long Dlp::U*N'  
Dim count As Integer aL}_j#m{  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double ~MF. M8  
Dim tlens As Double, nlens As Double !WXSrICX[  
Dim curv As Double, conic As Double fsoS!6h0k  
Dim ok As Long qS>el3G  
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Sub Main gO%3~f!vY#  
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    '用户输入对话框 wvD|c%   
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 T=vI'"w  
        TextBox 220,21,40,21,.TextBox1 'default: 0
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        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 `KN{0<Ne  
        OKButton 40,91,90,21 PQ" Dl=,  
        CancelButton 190,91,90,21 fy5)Tih%.*  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 nm..$QL  
        TextBox 220,49,40,21,.TextBox2 'default: 4 O#g31?TO  
    End Dialog 1ARIZ;H  
    Dim dlg As UserDialog utv.uwfat  
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    ok = Dialog (dlg) f|!
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    If ok=0 Then    'cancel button was pressed o
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        Print "Execution cancelled." G6FknYj  
        End rnUe/HjH  
    End If x\WKsc  
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    'Assign accommodation and pupil diameter & use defaults if field left empty L,$9)`j  
    If dlg.TextBox1 = "" Then ? T9-FGW  
        A = 0           'Default accommodation _F3:j9^  
    Else j1)w1WY0@  
        A = CDbl(dlg.TextBox1) Ktoxl+I?  
    End If %5b2vrg~*  
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    If dlg.TextBox2 = "" Then R/=yS7@{)  
        pupilDiam = 4   'Default pupil diameter 1jR<H$aS  
    Else w5p+Yx=q  
        pupilDiam = CDbl(dlg.TextBox2) /n_N`VJ7H  
    End If ] '..G-  
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    Print " " x(A.^Yz  
    Print "Accommodation = " & A & " Diopters" R"jX9~3Ln  
    Print "Pupil Diameter = " & pupilDiam & " mm" d4/ZOj+%  
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    ' Calculate new parameters with accommodation se&:Y&vrc~  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness o4xZaF4+  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens Q/':<QY  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens ` 6PdMvF  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens U.&=b<f(0r  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens -g~$HTsGm  
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    tlens = 3.767 + 0.04*A                  'Lens thickness )l^w _;  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction uv,t(a.^  
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    'Adjust parameters to account for accommodation }JS?42CTaV  
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    '************************************************************************* WlU5`NJl]2  
    'Aqueous thickness (Position of Lens) <S<(wFE@4  
    '************************************************************************* ."dmL=  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) CQS34&G$a  
    GetCustomElement eID, entity o}<}zTU  
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    parID = FindFullName( "Geometry.Arizona Eye" ) @X:P`?("^  
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    ' Delete any shift(s) in z %A04'dj`zQ  
    count = 0 
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    While GetOperationCount(eID)>count I_4'9  
        GetOperation eID, count, op ^b'[81%  
        If op.Type="ShiftZ" Then }{s<!b  
            DeleteOperation eID,count 7^=O^!sa  
            count=count-1 6#v"+V  
        End If t68h$u  
        count=count+1 &q>=6sQvf  
    Wend BDpeA
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    'Set new shift in ~nw]q<7r  
    op.Type = "ShiftZ" $5l8V  
    op.val1 = taq lCDXFy(E  
    op.parent = parID X2~>Z^, U  
    AddOperation eID, op kP3'BBd,  
    Print "Set aqueous humor thickness = " & taq-0.55 U
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    '************************************************************************* sJ,:[  
    'Radius and conic constant of anterior lens i!9yN:m0  
    '************************************************************************* a
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    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) #7GbG\  
    GetConic eID, entity, curv, conic ~]3y667  
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    SetConic eID, entity, 1/Rant, CCant l:%4@t`  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant j"hfsA<_I  
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    '************************************************************************* mJ
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    'Radius and conic constant of posterior lens d?S7E q9`  
    '************************************************************************* 6p])2]N>p  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) 7EO/T,{a  
    GetConic eID, entity, curv, conic C[gy{40}  
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    SetConic eID, entity, 1/Rpost, CCpost +Ccj@#M;  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost P >HEV a  
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    '************************************************************************* f 0D9Mp  
    'Lens thickness (Position of posterior lens surface) l*rli[No  
    '************************************************************************* dX?8@uzu  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) Z7lv|m&  
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    ' Delete any z-shift(s)
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    count = 0 1--_E,Su>  
    While GetOperationCount(eID)>count \L Gj]mb1  
        GetOperation eID, count, op Ey4%N`H-^  
        If op.Type="ShiftZ" Then Ksr.'  
            DeleteOperation eID,count )5Mf,  
            count=count-1 ]lV\D8#  
        End If  E|P  
        count=count+1 3=SIIMp7=  
    Wend }&M$  
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    'Set new z-shift ,'N8Ivt  
    op.Type = "ShiftZ" b;A(6^V  
    op.val1 = tlens .Lbu[  
    op.parent = parID 7#wdBB%  
    AddOperation eID, op D',[M)  
    Print "Set lens thickness = " & tlens KsZd.Rf=@  
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    '************************************************************************* wC{?@h  
    'Lens index of refraction (r78AZ  
    '************************************************************************* w_4/::K*  
    eID = FindMaterial( "Lens" ) ]#x!mZ!  
    GetModelMaterial eID, mat ?Zu2=<DU  
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    mat.Nd = nlens !(QDhnx}9c  
    SetModelMaterial eID, mat av~dH=&=  
    Print "Set lens index of refraction = " & nlens V}_M\Y^^;  
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    '************************************************************************* M`{~AIqd(  
    'Pupil diameter |:Q`9;  
    '*************************************************************************
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    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) Y_S>S(0  
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    'Adjust pupil diameter (trimming volume inner hole) !A@Ft}
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" ]N<:6+  
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    ' Adjust pupil location to just in front of the lens w=Cqv~  
    parID = FindFullName( "Geometry.Arizona Eye" ) /1O
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    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) !5FZxmUup  
    count = 0 +OM`c7M:  
    While GetOperationCount(eID)>count ]m&cVy&  
        GetOperation eID, count, op 1FC' iGI  
        If op.Type="ShiftZ" Then TX/Ng+v S  
            DeleteOperation eID,count gN./u   
            count=count-1 %z9eVkPI~  
        End If EkWipF(  
        count=count+1 (4ueO~jb$  
    Wend \l$gcFXb  
    op.Type = "ShiftZ" 5ctH=t0  
    op.val1 = taq-0.01 \r4QS  
    op.parent = parID YhpNeP{A  
    AddOperation eID, op L&*/s&>b  
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    Print "Set pupil diameter = " & pupilDiam Y5rR  
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    'Update AZ Eye subassembly Description F^knlv'  
    eID = FindFullName( "Geometry.Arizona Eye" ) O:K={#Xj  
    GetEntity eID, entity <Vu/6"DP  
    entity.Description = "Accommodation = " & A & "D" /1s|FI$-L  
    SetEntity eID, entity _@-D/g  
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    Update tp4/c'w;)J  
    Print "DONE!" 8Df(|>mK  
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End Sub )+!~xL  
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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： IYb%f T  
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Accommodation = 4 Diopters $]H^?  
Pupil Diameter = 4 mm aVI%FycYo  
Set aqueous humor thickness = 2.81 #:C?:RMS  
Set anterior lens radius = 10.4 and conic constant = -2.375869 kZ^}  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 ">?ocJ\9  
Set lens thickness = 3.927 3>jL7sh%|  
Set lens index of refraction = 1.42672 -5v2E-  
Set pupil diameter = 4 ~KtA0BtC  
DONE!
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