[技术]Arizona眼睛模型 [复制链接]

简介 shzG Eb  
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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。 )qd={  
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模型 x`L+7,&n  
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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。 uY]T:UVk
 
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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. WGMb8 /{$P  
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光源 o3\
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多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 }AJ L,Q7q  
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除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处，并增加了pre-propagation distance= -8。尽管光线在光瞳处创建，规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射，而不是在光瞳处入射。 v#F-<?Vv  
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在往下看是内置的脚本用来修改屈光度，使其为4（250mm），光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 Man^<T%F  
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视网膜的散射 qy&\Xgn;GA  
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在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 q0g1EJar  
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注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 C]Q>*=r  
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脚本 k:mlt:  
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内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： ;:?*t{r4#  
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如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 nzWQQra|?  
余下的脚本计算与屈光度有关的所有参数。 L^)qe^%3  
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分析 )vQNiik#  
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屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 mYzcVhV  
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脚本代码 %z2oDAjX  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. #w;;D7{@m  
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Dim entity As T_ENTITY ,# eO&  
Dim op As T_OPERATION ET3,9+Gj  
Dim mat As T_MODELMATERIAL 2^J/6R$  
Dim A As Double d=F)y~&'  
Dim pupilDiam As Double GZS{
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Dim eID As Long [WYJrk.  
Dim parID As Long wR(ttwxK3  
Dim count As Integer <ZV7|'^  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double f}%sO  
Dim tlens As Double, nlens As Double a}w&dE$!-  
Dim curv As Double, conic As Double F=:c5z  
Dim ok As Long pLPd[a  
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Sub Main &*jixqzvn
 
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    '用户输入对话框 4L!e=>as"1  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 -CwWs~!  
        TextBox 220,21,40,21,.TextBox1 'default: 0 tpE3|5dZF  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 *5^ze+:  
        OKButton 40,91,90,21 sI$:V7/!  
        CancelButton 190,91,90,21 ^>eFm8`N  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 v >NTh  
        TextBox 220,49,40,21,.TextBox2 'default: 4 IQ#So]9~Y  
    End Dialog F; 0Dp
 
    Dim dlg As UserDialog pIL`WE1'  
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    ok = Dialog (dlg) u$\Tg3du2  
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    If ok=0 Then    'cancel button was pressed ^,>}%1\  
        Print "Execution cancelled." ,d5ia4\K  
        End bnIf}ut-G  
    End If 95VqaR,  
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    'Assign accommodation and pupil diameter & use defaults if field left empty RBPYGu'6B  
    If dlg.TextBox1 = "" Then u"e
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        A = 0           'Default accommodation L-SdQTx_  
    Else E|\3f(aF  
        A = CDbl(dlg.TextBox1) WGluZhRuT3  
    End If Xp.|.)Od  
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    If dlg.TextBox2 = "" Then rC=f#YjR  
        pupilDiam = 4   'Default pupil diameter =y`-sU Hx  
    Else :LG}yq^  
        pupilDiam = CDbl(dlg.TextBox2) Gl=@>Dc%  
    End If m79m{!q$-  
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    Print " " ~rp.jd 0l  
    Print "Accommodation = " & A & " Diopters" ">03~:oA  
    Print "Pupil Diameter = " & pupilDiam & " mm" U. NeK{  
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    ' Calculate new parameters with accommodation `;R|V  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness u)wu=z8  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens tPQ2kEW  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens N.kuE=X  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens jp"XS  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens Ey 0>L  
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    tlens = 3.767 + 0.04*A                  'Lens thickness hrUm}@d  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction x A@|I#  
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    'Adjust parameters to account for accommodation \>&@lA  
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    '************************************************************************* H!Fr("6}  
    'Aqueous thickness (Position of Lens) EY=\C$3J:  
    '************************************************************************* sqgD?:@J  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) 9CgXc5  
    GetCustomElement eID, entity =P@M&Yy'  
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    parID = FindFullName( "Geometry.Arizona Eye" ) o;HdW  
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    ' Delete any shift(s) in z .N'%hh  
    count = 0 k 2 mkOb  
    While GetOperationCount(eID)>count zzDNWPzsA  
        GetOperation eID, count, op 11^ {WF  
        If op.Type="ShiftZ" Then ljaAB+  
            DeleteOperation eID,count *rujdQ
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            count=count-1 ^Y1AeJ$L  
        End If !;BZ#tF&  
        count=count+1 &z{dr~  
    Wend 8,Q.t7v  
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    'Set new shift in -;W\f<q]  
    op.Type = "ShiftZ" oRtY?6^$  
    op.val1 = taq sYW1T @  
    op.parent = parID +?J_6Mo@X  
    AddOperation eID, op t6! p\Y}}  
    Print "Set aqueous humor thickness = " & taq-0.55 _ d(Ks9  
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    '************************************************************************* `Lb _J  
    'Radius and conic constant of anterior lens =PeW$q+  
    '************************************************************************* ,_e/a
  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) ~7)rKHau  
    GetConic eID, entity, curv, conic f6(9wz$Trt  
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    SetConic eID, entity, 1/Rant, CCant z[$9B#P  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant 8xeun~e"vS  
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    '************************************************************************* ZipK;!9by  
    'Radius and conic constant of posterior lens 4`EvEv$i  
    '************************************************************************* &})4?5  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) O#uaGziFf  
    GetConic eID, entity, curv, conic eX]9mQ]E  
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    SetConic eID, entity, 1/Rpost, CCpost 80R=r  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost )KT
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    '************************************************************************* ux/[d6To  
    'Lens thickness (Position of posterior lens surface) 9 up*g  
    '************************************************************************* t"!8
 
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) )=SYJ-ta<  
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    ' Delete any z-shift(s) rwV u?W  
    count = 0 l,FG:"`Z@  
    While GetOperationCount(eID)>count
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        GetOperation eID, count, op QBBJ1U  
        If op.Type="ShiftZ" Then r)Mx.`d!  
            DeleteOperation eID,count 5D02%U2N)G  
            count=count-1 >> 8KL`l  
        End If b$$L]$q2  
        count=count+1 j)lM:vXR  
    Wend Y;I(6`,Y  
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    'Set new z-shift -$!Pf$l@  
    op.Type = "ShiftZ" %]= 'Uv^x  
    op.val1 = tlens 3vvFF]D5k  
    op.parent = parID +XaO?F[c  
    AddOperation eID, op UdM5R [  
    Print "Set lens thickness = " & tlens [7Kj$PB3  
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    '************************************************************************* #D*J5k>2  
    'Lens index of refraction JwG5#CFu^  
    '************************************************************************* L^ jC& dF  
    eID = FindMaterial( "Lens" ) {u[K ^G  
    GetModelMaterial eID, mat JXa%TpI: E  
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    mat.Nd = nlens `'k's]Y  
    SetModelMaterial eID, mat iTBhLg,  
    Print "Set lens index of refraction = " & nlens
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    '************************************************************************* <xh'@592  
    'Pupil diameter 0T{Y_IG  
    '************************************************************************* Zv7$epDUz  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) kHIQ/\3?Q  
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    'Adjust pupil diameter (trimming volume inner hole) '/"M02a  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" H fmMf^c  
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    ' Adjust pupil location to just in front of the lens *]UEF_  
    parID = FindFullName( "Geometry.Arizona Eye" ) 1X:whS5S  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) <?va) ou  
    count = 0 p-03V"^&  
    While GetOperationCount(eID)>count (j8,n<o  
        GetOperation eID, count, op v(nQd6;T  
        If op.Type="ShiftZ" Then 7J_f/st  
            DeleteOperation eID,count O=?X%m #  
            count=count-1 l$_+WC*wp  
        End If ^DCv-R+p  
        count=count+1 co%_~xO  
    Wend ZCF-*nm  
    op.Type = "ShiftZ" Dp |FyP_w  
    op.val1 = taq-0.01 25@j2K(  
    op.parent = parID {zN_l!  
    AddOperation eID, op /W
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    Print "Set pupil diameter = " & pupilDiam />I8nS}T  
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    'Update AZ Eye subassembly Description qN,FX#DP  
    eID = FindFullName( "Geometry.Arizona Eye" ) %+W >+xRb  
    GetEntity eID, entity -/{}^QWB  
    entity.Description = "Accommodation = " & A & "D" jHw2Q8s|R  
    SetEntity eID, entity N'BctKL  
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    Update B91PlM.  
    Print "DONE!" `Q^Sm`R  
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End Sub e;u
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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： Qi]Z)v{^  
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Accommodation = 4 Diopters ?Pw\&q  
Pupil Diameter = 4 mm ' 1]bjW*!  
Set aqueous humor thickness = 2.81 9F1stT0G%  
Set anterior lens radius = 10.4 and conic constant = -2.375869 oi4Wxcj  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 O!+5As  
Set lens thickness = 3.927 ffd3QQ  
Set lens index of refraction = 1.42672 Yf`.Cq_:  
Set pupil diameter = 4 '*Mb .s"  
DONE! G6bg ~V5Q: