[技术]Arizona眼睛模型 [复制链接]

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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。 $@<qaR{t\  
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模型 X YO09#>&  
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模型的定义如表1种所示，由半径、圆锥常数、折射率、阿贝数、到下一面的距离等一系列表面组成。一些参数由屈光度（A）来决定。 Mn7nS:  
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在FRED中使用0屈光度来创建的，光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. .]}kOw:(#  
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光源 {h5 S=b  
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多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 !_P;4E  
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除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处，并增加了pre-propagation distance= -8。尽管光线在光瞳处创建，规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射，而不是在光瞳处入射。 WX$mAQDV  
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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。 WlVp|s{TYP  
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视网膜的散射
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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。 9N5ptdP.d  
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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。 `\LhEnIwu  
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脚本 v3SH+Ej4  
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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： /Ud<4j-  
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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。 mNS7/I\  
余下的脚本计算与屈光度有关的所有参数。 Y Y4"r\V  
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分析 _q*4+x  
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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。 rF C6"_  
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脚本代码 "J:~Aa%
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. H{Tt>k  
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Dim entity As T_ENTITY V?"X0>]0  
Dim op As T_OPERATION g}HB|$P7  
Dim mat As T_MODELMATERIAL oL?(; `"&  
Dim A As Double tj:3R$a  
Dim pupilDiam As Double "[(&$I  
Dim eID As Long xszGao'  
Dim parID As Long 7d&_5Tj:  
Dim count As Integer wcGI2aflD  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double jSa9UD  
Dim tlens As Double, nlens As Double Cw`8[)=}o  
Dim curv As Double, conic As Double 3k)W0]:|<  
Dim ok As Long sjh>i>t  
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Sub Main -<rQOPH%  
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    '用户输入对话框 VA4>!t)  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 m# #( uSh  
        TextBox 220,21,40,21,.TextBox1 'default: 0 x:'M\c7  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 cI}
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        OKButton 40,91,90,21 `m
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        CancelButton 190,91,90,21 .XPcH(q  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 m\a_0!K
 
        TextBox 220,49,40,21,.TextBox2 'default: 4 1,cd[^`.  
    End Dialog %ux%=@%  
    Dim dlg As UserDialog !e~Yp0gX#  
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    ok = Dialog (dlg) ?v-Y1j  
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    If ok=0 Then    'cancel button was pressed GdZ_  
        Print "Execution cancelled." z{h#l!Edh  
        End 4o,%}bo&  
    End If +$]eA'Bh@  
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    'Assign accommodation and pupil diameter & use defaults if field left empty a*4"j2j v  
    If dlg.TextBox1 = "" Then qyXx`'e  
        A = 0           'Default accommodation t;BvKH77  
    Else q^{Z"ifL  
        A = CDbl(dlg.TextBox1) ?f1PQ
  
    End If |ocIp/$  
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    If dlg.TextBox2 = "" Then \BB(0Ah+t  
        pupilDiam = 4   'Default pupil diameter ,:yv T6)p  
    Else :uM2cc^  
        pupilDiam = CDbl(dlg.TextBox2) eIVCg-l}  
    End If ) V}q7\G~  
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    Print " " /Mq]WXq[V  
    Print "Accommodation = " & A & " Diopters" *We.?"X'].  
    Print "Pupil Diameter = " & pupilDiam & " mm" 3/sKRU  
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    ' Calculate new parameters with accommodation p#vZYwe=L  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness a`}b'X:  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens i!zh9,i>M  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens \EH:FM}l,  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens c*nH=  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens ?h`Ned0P  
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    tlens = 3.767 + 0.04*A                  'Lens thickness gI^);JrTE  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction ^{<x*/nK  
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    'Adjust parameters to account for accommodation _Q<wb8+/  
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    '************************************************************************* 7?6?`no~JJ  
    'Aqueous thickness (Position of Lens) ]h (TZu  
    '************************************************************************* ^+Ez[S{8  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) /'|'3J]HP  
    GetCustomElement eID, entity jF}zv  
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    parID = FindFullName( "Geometry.Arizona Eye" ) |_l\.  
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    ' Delete any shift(s) in z 6T6 S9A*nT  
    count = 0 AYHfe#!  
    While GetOperationCount(eID)>count i<D}"h|  
        GetOperation eID, count, op QZufQRfr{  
        If op.Type="ShiftZ" Then Uo{h. .7?  
            DeleteOperation eID,count yjvH)t/!.  
            count=count-1 l ' ]d&  
        End If 9GnNL I{  
        count=count+1 l*[.  
    Wend b6D}GuW  
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    'Set new shift in OwIW;8Z  
    op.Type = "ShiftZ" %UJ!(_  
    op.val1 = taq G'XlsyaWrb  
    op.parent = parID W5-p0,?[6  
    AddOperation eID, op 3j.Ft*SV  
    Print "Set aqueous humor thickness = " & taq-0.55 ~CRr)(M  
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    '************************************************************************* 8F0+\40  
    'Radius and conic constant of anterior lens qF6
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    '************************************************************************* :W5*fE(i  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) yWIM,2x}  
    GetConic eID, entity, curv, conic $Aww5G5e  
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    SetConic eID, entity, 1/Rant, CCant GY4:9Lub7  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant puS'9Lpp  
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    '************************************************************************* ToJV.AdfT  
    'Radius and conic constant of posterior lens L>{E8qv>w  
    '************************************************************************* JJ56d)37.  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) BQf}S +  
    GetConic eID, entity, curv, conic Kp"mV=RG2T  
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    SetConic eID, entity, 1/Rpost, CCpost ~\hA-l36  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost Ns9cx  
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    '************************************************************************* !mpRLBH  
    'Lens thickness (Position of posterior lens surface) wP1dPl_j:0  
    '************************************************************************* 9QJ=?bIC#  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) <
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    ' Delete any z-shift(s) D0PP   
    count = 0 ) 0$7{3  
    While GetOperationCount(eID)>count AW6]S*rh  
        GetOperation eID, count, op ^BjwPh4Z#  
        If op.Type="ShiftZ" Then fl~k')s  
            DeleteOperation eID,count 6+IOJtj  
            count=count-1 !.L%kw7z  
        End If +IVVsVp
 
        count=count+1 /exV6D r  
    Wend ;: Hfkyy]  
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    'Set new z-shift -w 2!k  
    op.Type = "ShiftZ" RrLQM!~  
    op.val1 = tlens :RHNV  
    op.parent = parID .eXIbd<C  
    AddOperation eID, op HeGGAjc  
    Print "Set lens thickness = " & tlens L3nHvKA]  
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    '************************************************************************* !`,6E`Y#  
    'Lens index of refraction UuT>qWxQ8  
    '************************************************************************* dT,X8 "  
    eID = FindMaterial( "Lens" ) 
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    GetModelMaterial eID, mat ?C.C?h6F5B  
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    mat.Nd = nlens P%pB]d.qpi  
    SetModelMaterial eID, mat 'm}~  
    Print "Set lens index of refraction = " & nlens 
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    '************************************************************************* 3w{4G<I  
    'Pupil diameter 8c+i+g
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    '************************************************************************* S3hJL:3c  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" )  2b1LC!'U  
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    'Adjust pupil diameter (trimming volume inner hole) o'myo.k{  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" 3`#sXt9C  
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    ' Adjust pupil location to just in front of the lens 4OCz:t  
    parID = FindFullName( "Geometry.Arizona Eye" ) Ca+d ?IS  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) 6$SsdT|8B  
    count = 0 z2!NBOv  
    While GetOperationCount(eID)>count &#.XLe\y  
        GetOperation eID, count, op w \0=L=J  
        If op.Type="ShiftZ" Then nImRU.;P  
            DeleteOperation eID,count Fxv~;o#  
            count=count-1 k6[t$|lMy  
        End If :+]6SC0ql  
        count=count+1 rVQ:7\=Z  
    Wend {+ [rJ_  
    op.Type = "ShiftZ" `{F8#    
    op.val1 = taq-0.01 a+\Gz  
    op.parent = parID M%&`&{  
    AddOperation eID, op "793R^Tz  
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    Print "Set pupil diameter = " & pupilDiam 'y-IE#!5  
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    'Update AZ Eye subassembly Description 'r1&zw(  
    eID = FindFullName( "Geometry.Arizona Eye" ) Vl^jTX5N  
    GetEntity eID, entity 8Mws?]\/q  
    entity.Description = "Accommodation = " & A & "D" %PlPXoG=  
    SetEntity eID, entity .RJvu$U2j  
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    Update ?/#HTg)!B  
    Print "DONE!"
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End Sub \iowAo$  
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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： ^Po\:x%o  
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Accommodation = 4 Diopters s)/i_Oe$\  
Pupil Diameter = 4 mm
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Set aqueous humor thickness = 2.81 \,p)  
Set anterior lens radius = 10.4 and conic constant = -2.375869  Kn\Oj=4  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 rQisk8%  
Set lens thickness = 3.927  PJkMn  
Set lens index of refraction = 1.42672  J|6aa  
Set pupil diameter = 4 A.WJ#1i}E  
DONE! 9Eg'=YJ