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    [分享]Arizona眼睛模型 [复制链接]

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    离线infotek
     
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    只看楼主 倒序阅读 楼主  发表于: 2020-12-09
    简介 MxIa,M <  
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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。 <ukBAux,D  
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    模型 -SrZ^  
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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。 j ) 6  
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    Table 1. AZ眼睛模型的定义
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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. I4X9RYB6c  
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    光源 l4oyF|oJTH  
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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。 No'?8+i  
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    图1. 光源和提示信息使用
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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。 J +u}uN@  
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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。 v 3I^81  
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    图2. 字母F光源的设定方法光 147QB+cE  
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    图3. 字母F在视网膜上位置点列图
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    视网膜的散射 T }}2J/sj  
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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。 N T`S)P*?  
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    图4. 视网膜朗伯散射设定
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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。 l#'V SFm&  
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    图5. 视网膜重点采样规格设定
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    脚本 Y^eN}@]?&  
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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: @Jzk2,rI  
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    图6. 用户对话框的创建与编辑
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    图7. 用户对话框编辑器
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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。 ?h= n5}Y  
    余下的脚本计算与屈光度有关的所有参数。 4ba*Nc*Yc  
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    分析 uzy5rA==  
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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。 @r TB&>`  
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    图7. 字母F在视网膜上颜色分析
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    脚本代码 `^bP9X_a  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. Yj/afn(Jt  
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    Dim entity As T_ENTITY uE-(^u  
    Dim op As T_OPERATION )6OD@<r{  
    Dim mat As T_MODELMATERIAL u"[f\l  
    Dim A As Double zJe KB8  
    Dim pupilDiam As Double IOy0WHl|  
    Dim eID As Long x'GB#svi  
    Dim parID As Long `q^#u  
    Dim count As Integer mci> MEb  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double tn]nl!_@  
    Dim tlens As Double, nlens As Double v"USD<   
    Dim curv As Double, conic As Double $|N6I  
    Dim ok As Long j#l=%H  
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    Sub Main U"PcNQy  
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        '用户输入对话框 2HE@!*z9H  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 BI1M(d#1L"  
            TextBox 220,21,40,21,.TextBox1 'default: 0 k^J8 p#`6  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 IPQRdBQ  
            OKButton 40,91,90,21 *WwM"NFHDd  
            CancelButton 190,91,90,21 mMAN* }`O  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 ?:(y  
            TextBox 220,49,40,21,.TextBox2 'default: 4 y>I2}P  
        End Dialog 4Uy%wB  
        Dim dlg As UserDialog yPN'@{ 5#  
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        ok = Dialog (dlg) uO%0rKW  
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        If ok=0 Then    'cancel button was pressed ^P) f]GQx  
            Print "Execution cancelled." "-~ 7lY%  
            End +jm,nM9  
        End If B `(jTL  
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        'Assign accommodation and pupil diameter & use defaults if field left empty [&)]-2w2  
        If dlg.TextBox1 = "" Then LgqQr6y"  
            A = 0           'Default accommodation pgU [di  
        Else /0s1;?  
            A = CDbl(dlg.TextBox1) 3BFOZV+  
        End If UcRP/LR%C  
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        If dlg.TextBox2 = "" Then %w;qu1j  
            pupilDiam = 4   'Default pupil diameter g`Z=Y7jLH  
        Else CMt<oT6.?  
            pupilDiam = CDbl(dlg.TextBox2) iC"iR\Qu  
        End If c+Q'4E0 |  
    }w0pi  
        Print " " lx)^wAO4  
        Print "Accommodation = " & A & " Diopters" Iy<>-e"|  
        Print "Pupil Diameter = " & pupilDiam & " mm" UP~28%>X  
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        ' Calculate new parameters with accommodation >)>f~>  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness &f*o rM:  
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        Rant = 12.0 - 0.4*A                     'Radius of anterior lens +|A`~\@N  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens b1&tk~D  
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        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens +QChD*  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens 7'0Vb !(  
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        tlens = 3.767 + 0.04*A                  'Lens thickness _$~>O7  
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        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction N /4E ~^2  
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        'Adjust parameters to account for accommodation '&IGdB I  
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        '************************************************************************* {6i|"5_j  
        'Aqueous thickness (Position of Lens) `#""JTA"  
        '************************************************************************* 9`in r.:  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) 56V|=MzX]  
        GetCustomElement eID, entity ?qh-#,O9B  
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        parID = FindFullName( "Geometry.Arizona Eye" )  a"Qf  
    ?UnQ?F(+G<  
        ' Delete any shift(s) in z `7 "="T~ *  
        count = 0 4G&`&fff]  
        While GetOperationCount(eID)>count a4Q@sn;]  
            GetOperation eID, count, op GVY7`k"km  
            If op.Type="ShiftZ" Then >eJ <-3L;  
                DeleteOperation eID,count zsL@0]e&  
                count=count-1 HC iRk1  
            End If fz'qB-F Y  
            count=count+1 c_8&4  
        Wend 0ho;L0Nr'  
    [WwoGg*)mn  
        'Set new shift in o[Iu9.zJpy  
        op.Type = "ShiftZ" @G5T8qwN  
        op.val1 = taq VAPeMO ck  
        op.parent = parID 1%Xh[  
        AddOperation eID, op q*I*B1p[m  
        Print "Set aqueous humor thickness = " & taq-0.55 l\<.*6r  
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        '************************************************************************* /\mtCa.O  
        'Radius and conic constant of anterior lens nrac )W  
        '************************************************************************* 1lw%RM  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) zdN[Uc+1Bd  
        GetConic eID, entity, curv, conic `v*HH}aDO  
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        SetConic eID, entity, 1/Rant, CCant YT(N][V  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant 0|&@)`  
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        '************************************************************************* ,!orD1,'  
        'Radius and conic constant of posterior lens br I;}m  
        '************************************************************************* C`5'5/-.  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) 3H2~?CaJ  
        GetConic eID, entity, curv, conic fU>l:BzJ K  
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        SetConic eID, entity, 1/Rpost, CCpost ee {ToK  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost H|% J"  
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        '************************************************************************* [ZWAXl $  
        'Lens thickness (Position of posterior lens surface) B+W7zv  
        '************************************************************************* P6+ B!pY  
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        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) ^Jp T8B}  
    4'QX1p  
        ' Delete any z-shift(s) jTa\I&s,A  
        count = 0 hGtz[u#p  
        While GetOperationCount(eID)>count Giyh( DL  
            GetOperation eID, count, op \^)i!@v  
            If op.Type="ShiftZ" Then *b{IWOSe^  
                DeleteOperation eID,count ';C'9k<P:  
                count=count-1 sfF~k-  
            End If Ht[$s40P  
            count=count+1 )vW'g3u_  
        Wend h;V 4|jM  
    .a4,Lr#q.  
        'Set new z-shift (`(D $%  
        op.Type = "ShiftZ"  "J(M.Y  
        op.val1 = tlens $d<NN2  
        op.parent = parID OZ&/&?!XE  
        AddOperation eID, op 4=Th<,<  
        Print "Set lens thickness = " & tlens Sn nfU  
    gUklP(T=u  
        '************************************************************************* +?J  N_aR  
        'Lens index of refraction m23"xnRB  
        '************************************************************************* 4*XNk;Dx  
        eID = FindMaterial( "Lens" ) ?fxM 1<8  
        GetModelMaterial eID, mat ]?6wU-a  
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        mat.Nd = nlens Tg{5%~L]   
        SetModelMaterial eID, mat &5W;E+Pub  
        Print "Set lens index of refraction = " & nlens Pe<VPf9+  
    D Q.4b  
        '************************************************************************* Q(& @ra!{  
        'Pupil diameter j_<qnBeQ  
        '************************************************************************* 5r5on#O&  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) lHM+<Z  
    Spn[:u@  
        'Adjust pupil diameter (trimming volume inner hole) $1.-m{Bd  
    Z9vMz3^N  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" C.?^] Y  
    m.D8@[y  
        ' Adjust pupil location to just in front of the lens ~4 fE`-O  
        parID = FindFullName( "Geometry.Arizona Eye" ) H_&to3b(  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) w)7y{ya$  
        count = 0 7 yE\,  
        While GetOperationCount(eID)>count 6kAAdy}ck  
            GetOperation eID, count, op a2P)@R  
            If op.Type="ShiftZ" Then UFj H8jSBx  
                DeleteOperation eID,count +La2-I  
                count=count-1 2Qe&FeT  
            End If 3Q,&D'];[  
            count=count+1 aM~IRLmK  
        Wend T=PqA)Ym  
        op.Type = "ShiftZ" wO]e%BTO  
        op.val1 = taq-0.01 R+HX'W  
        op.parent = parID 4X^$"lM  
        AddOperation eID, op 8H7#[?F  
     \ ca<L  
        Print "Set pupil diameter = " & pupilDiam ny KfM5s_  
    +u|"q+p  
        'Update AZ Eye subassembly Description r D@*xMW  
        eID = FindFullName( "Geometry.Arizona Eye" ) 6Z|h>H5 a  
        GetEntity eID, entity ]N 9N][n  
        entity.Description = "Accommodation = " & A & "D" "qgwuWbM  
        SetEntity eID, entity |%|03}Q  
    ,:mL\ZED  
        Update e]VW\ 6J&  
        Print "DONE!" t+v %%N_  
         ==Egy:<:Q  
    End Sub G2|jS@L#  
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    如果屈光度是4,光瞳直径是4,则会输出如下数据: B@*b 9  
    ]W;6gmV  
    Accommodation = 4 Diopters YrnC'o`  
    Pupil Diameter = 4 mm !q+ #JW  
    Set aqueous humor thickness = 2.81 Erw1y,mF  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 ;`oK5  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 #G#gc`S-,  
    Set lens thickness = 3.927 cF 5|Pf  
    Set lens index of refraction = 1.42672 e,|gr"$/  
    Set pupil diameter = 4 o8X_uKEI  
    DONE! sJZ2e6?n  
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    j!agD_J  
    QQ:2987619807 i D9 */  
     
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