[技术]Arizona眼睛模型 [复制链接]

简介 XMF#l]P  
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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。 =d$m@rc0r  
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模型 pmiC|F83!8  
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模型的定义如表1种所示，由半径、圆锥常数、折射率、阿贝数、到下一面的距离等一系列表面组成。一些参数由屈光度（A）来决定。 HggINMG  
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在FRED中使用0屈光度来创建的，光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. ikb;,Js  
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光源 f3*SIKi  
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多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 D1V^DbUm_  
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除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处，并增加了pre-propagation distance= -8。尽管光线在光瞳处创建，规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射，而不是在光瞳处入射。 F!RP *  
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在往下看是内置的脚本用来修改屈光度，使其为4（250mm），光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 ),@m 3wQ  
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视网膜的散射 W
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在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 r@CbhD  
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注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 #;\tgUQ  
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脚本 ,[
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内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： Gdr7d  
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如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 Zzv,p  
余下的脚本计算与屈光度有关的所有参数。 FD.L{  
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分析 Px`z$~*B:  
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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。 TYedem<$  
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脚本代码
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. &z"yls  
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Dim entity As T_ENTITY 7.B]B,]  
Dim op As T_OPERATION ?Q: KW  
Dim mat As T_MODELMATERIAL 5dhT?/qvc  
Dim A As Double T]?QCf  
Dim pupilDiam As Double 0GnbE2&  
Dim eID As Long k^\>=JTq=  
Dim parID As Long vH vwH  
Dim count As Integer bdr!|WZ  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double \E,Fe:/g  
Dim tlens As Double, nlens As Double "3VMjF\  
Dim curv As Double, conic As Double ysQ8==`38i  
Dim ok As Long !,N),xG}~  
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Sub Main 3EX41)u  
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    '用户输入对话框 TYgn X  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 QfsTUAfR  
        TextBox 220,21,40,21,.TextBox1 'default: 0 D(Yq<%Q  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 H3jb{S b  
        OKButton 40,91,90,21 8(0q,7)y  
        CancelButton 190,91,90,21 ]73BJ  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 3gY4h*|`<  
        TextBox 220,49,40,21,.TextBox2 'default: 4 qEB]Tj e[  
    End Dialog .{LJ  
    Dim dlg As UserDialog {;ur~KE  
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    ok = Dialog (dlg) ){XG%nC  
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    If ok=0 Then    'cancel button was pressed P7kb*
  
        Print "Execution cancelled." .+hM1OF`x  
        End Y7 `i~K;  
    End If ~<w9a]  
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    'Assign accommodation and pupil diameter & use defaults if field left empty Gv zw=~8  
    If dlg.TextBox1 = "" Then 2j7e@p
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        A = 0           'Default accommodation R?$Nl  
    Else Kly`V]XE  
        A = CDbl(dlg.TextBox1) LVp*YOq7  
    End If b<mxf\b  
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    If dlg.TextBox2 = "" Then ok7yFm1\  
        pupilDiam = 4   'Default pupil diameter rocG;$[  
    Else #35@YMF  
        pupilDiam = CDbl(dlg.TextBox2) @AU<'?k  
    End If MPmsW&  
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    Print " " GwaU7[6  
    Print "Accommodation = " & A & " Diopters" _o-D},f*e  
    Print "Pupil Diameter = " & pupilDiam & " mm" ~wsDg[  
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    ' Calculate new parameters with accommodation )Vb_0n=^  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness QR;E>eEq  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens #7~M1/eH=t  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens ;Y>cegG\  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens Ge]2g0  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens jTJ]: EN  
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    tlens = 3.767 + 0.04*A                  'Lens thickness +\a`:QET  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction 4(f4 4' ^  
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    'Adjust parameters to account for accommodation dM1)wkbET  
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    '************************************************************************* :}Tw+S5  
    'Aqueous thickness (Position of Lens) 1wpeYn7>W  
    '************************************************************************* jWd 7>1R?  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) t%n3~i4X:  
    GetCustomElement eID, entity {IW pI *  
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    parID = FindFullName( "Geometry.Arizona Eye" ) IP`;hC  
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    ' Delete any shift(s) in z ^rc!X]C9  
    count = 0 q.OkZI0n  
    While GetOperationCount(eID)>count 8h#/b1\  
        GetOperation eID, count, op U
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        If op.Type="ShiftZ" Then pOn>
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            DeleteOperation eID,count q=5#t~?  
            count=count-1 x-5XOqD{'  
        End If 5CxD ys&<  
        count=count+1 i[~oMwc&  
    Wend K>TdN+Z}=  
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    'Set new shift in u$N2uFc  
    op.Type = "ShiftZ" | 1Fy  
    op.val1 = taq dE+xU(\,w  
    op.parent = parID pNo<:p  
    AddOperation eID, op tVZjtGz=  
    Print "Set aqueous humor thickness = " & taq-0.55 J>P{8Aw  
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    '************************************************************************* .pgTp X  
    'Radius and conic constant of anterior lens .VVY]>bJg@  
    '************************************************************************* =>Vo|LBoe  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) i!jZZj-{  
    GetConic eID, entity, curv, conic Eg?6$[U`8<  
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    SetConic eID, entity, 1/Rant, CCant .,pGW8Js  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant  t]Xdzy  
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    '************************************************************************* e`#c[lbAAM  
    'Radius and conic constant of posterior lens j5ZeYcQ-  
    '************************************************************************* U3 e3  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) ;f7(d\=y  
    GetConic eID, entity, curv, conic ?Ovl(4VG  
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    SetConic eID, entity, 1/Rpost, CCpost *]fBd<(8  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost o[Yxh%T  
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    '************************************************************************* \FSkI0  
    'Lens thickness (Position of posterior lens surface) /a%5!)NE%  
    '************************************************************************* E
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) 5tg  
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    ' Delete any z-shift(s) ?5nF` [rx  
    count = 0 ;CD.8f]N  
    While GetOperationCount(eID)>count KvC`6  
        GetOperation eID, count, op udDh
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        If op.Type="ShiftZ" Then 15_OtK  
            DeleteOperation eID,count mvI[=e*  
            count=count-1 'H2TwSbIXI  
        End If ^c}Z$V  
        count=count+1 RF 4u\ \  
    Wend ^WP`;e  
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    'Set new z-shift o~,dkV
  
    op.Type = "ShiftZ" +?n81|7`  
    op.val1 = tlens Lc6Wj'G G  
    op.parent = parID zCT Wi  
    AddOperation eID, op 7_taqcj  
    Print "Set lens thickness = " & tlens h8oG5|Y  
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    '************************************************************************* 3hr&p{/  
    'Lens index of refraction ]S4kWq{Y  
    '************************************************************************* A^2VH$j]+  
    eID = FindMaterial( "Lens" ) L,| 60*  
    GetModelMaterial eID, mat }s=D,_}m  
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    mat.Nd = nlens }<o.VY&;.  
    SetModelMaterial eID, mat 4mJ4)  
    Print "Set lens index of refraction = " & nlens &a%
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    '************************************************************************* {wRsV=*  
    'Pupil diameter 7.$0LN/a!Z  
    '************************************************************************* );V6YE  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) 2J =K\ L  
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    'Adjust pupil diameter (trimming volume inner hole) o ^L3Xiv  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" ,qV8(`y_  
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    ' Adjust pupil location to just in front of the lens jKZJ0`06q  
    parID = FindFullName( "Geometry.Arizona Eye" ) uPc}a3'?  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) b[Sd$ACd  
    count = 0 Vu0jNKUV  
    While GetOperationCount(eID)>count >4`("#  
        GetOperation eID, count, op b;#3X)  
        If op.Type="ShiftZ" Then bsy\L|wd  
            DeleteOperation eID,count [ps5;  
            count=count-1 TaeN?jc5  
        End If 6Y0k}+j|>E  
        count=count+1 {^2``NYM_  
    Wend Mfe/(tlI  
    op.Type = "ShiftZ" fEE[huG  
    op.val1 = taq-0.01 R9nW5f Nf  
    op.parent = parID 3JM0 m (  
    AddOperation eID, op !`L%wS  
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    Print "Set pupil diameter = " & pupilDiam >&3M #s(w  
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    'Update AZ Eye subassembly Description -jdS8n4  
    eID = FindFullName( "Geometry.Arizona Eye" ) X&fM36o7  
    GetEntity eID, entity St9W{  
    entity.Description = "Accommodation = " & A & "D" K>X#,lE-  
    SetEntity eID, entity Fg<$;p  
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    Update ]3]I`e{  
    Print "DONE!" yEIM58
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End Sub awh<CmcZ  
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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： kx0(v1y3gT  
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Accommodation = 4 Diopters 8)HUo?/3  
Pupil Diameter = 4 mm ste0:.*qb  
Set aqueous humor thickness = 2.81 :,%~R2  
Set anterior lens radius = 10.4 and conic constant = -2.375869 [E<NEl*  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 ZN#mu]jC?  
Set lens thickness = 3.927 T#kPn#|  
Set lens index of refraction = 1.42672 .1<QB{4~v  
Set pupil diameter = 4 >Lj0B%^EvM  
DONE! ")m0{