[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 3~ZtAgih%  
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。 4wBCs0NIm  
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模型 5jsnE )  
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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。 TY88PXW  
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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. \dfq&oyU\  
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光源 -|3U0:'m  
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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。 UIu'x_qc  
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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。 yDyq. -Q  
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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。 j$L<9(DoR  
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视网膜的散射 
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在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 4$|G$h  
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注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 2`Pk@,:_  
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脚本 .&[nS<~`  
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内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示：
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如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 V3`*LU  
余下的脚本计算与屈光度有关的所有参数。 PD$'xY|1=  
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分析 Dnp^yqz*  
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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。 'kC$R;#\7  
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脚本代码 6=kd4'yV  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. HK-?<$Yc  
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Dim entity As T_ENTITY 6#K_Rg>.  
Dim op As T_OPERATION SMhT>dB  
Dim mat As T_MODELMATERIAL .CYq+^  
Dim A As Double Q7SS<'(  
Dim pupilDiam As Double x7*}4>|W,I  
Dim eID As Long QHQj6]
 
Dim parID As Long g=%W"v  
Dim count As Integer '2 )d9_ w  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double Jrffb=+b  
Dim tlens As Double, nlens As Double 'Gc6ZSLM  
Dim curv As Double, conic As Double wHY;Y-(ZT  
Dim ok As Long j[z\p~^  
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Sub Main fkI<RgM  
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    '用户输入对话框 T|}HK]QOX  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 bWyXDsr+  
        TextBox 220,21,40,21,.TextBox1 'default: 0 !sLn;1l  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 S\f^y8*<  
        OKButton 40,91,90,21 JRNyvG>j  
        CancelButton 190,91,90,21 b&e? 6h^G  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 p1&d@PF&&  
        TextBox 220,49,40,21,.TextBox2 'default: 4 F>}).qx  
    End Dialog oZ=e/\[K  
    Dim dlg As UserDialog p"X\]g^jA>  
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    ok = Dialog (dlg) QvqBT  
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    If ok=0 Then    'cancel button was pressed
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        Print "Execution cancelled." Npu;f>g0_  
        End 1'd "O @  
    End If 7.=u:PK7kM  
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    'Assign accommodation and pupil diameter & use defaults if field left empty g3qtWS  
    If dlg.TextBox1 = "" Then c"QI`;D_c  
        A = 0           'Default accommodation v` B_xEl  
    Else 2AlLcfAW  
        A = CDbl(dlg.TextBox1) xqG` _S l  
    End If k!%HcU%J  
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    If dlg.TextBox2 = "" Then qD9B[s8  
        pupilDiam = 4   'Default pupil diameter B8P%4@T  
    Else zL_X?UmV  
        pupilDiam = CDbl(dlg.TextBox2) wF&\@H  
    End If
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    Print " " L@+j8[3BX  
    Print "Accommodation = " & A & " Diopters" S-L6KA{  
    Print "Pupil Diameter = " & pupilDiam & " mm" $]hf2Yr(  
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    ' Calculate new parameters with accommodation H)4Rs~;{'g  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness bLUn0)c  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens u}$U|Cw-;T  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens 9np<r82  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens G3e%~  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens 8pk5[=3Z  
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    tlens = 3.767 + 0.04*A                  'Lens thickness Mc\lzq8\ 1  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction fW\u*dMMZE  
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    'Adjust parameters to account for accommodation q6,xsO,+  
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    '************************************************************************* M0]fh5O  
    'Aqueous thickness (Position of Lens) %ZxKN;  
    '************************************************************************* w68qyG|wM  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) H;Bj\-Pa  
    GetCustomElement eID, entity +6>Pp[%  
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    parID = FindFullName( "Geometry.Arizona Eye" ) 9R E;50h  
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    ' Delete any shift(s) in z ;3-ssF}k*  
    count = 0 G/D{K$=t~  
    While GetOperationCount(eID)>count Mu:H'$"'H  
        GetOperation eID, count, op B 51LZP  
        If op.Type="ShiftZ" Then _}\&;  
            DeleteOperation eID,count T<ua0;7  
            count=count-1
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        End If )/=J=xw2  
        count=count+1 2ru6bIb;  
    Wend nd?m+C&W  
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    'Set new shift in s}A]lY  
    op.Type = "ShiftZ" HY42G#^  
    op.val1 = taq 00Rk%QV  
    op.parent = parID ?@u &3/&  
    AddOperation eID, op mHhm~u  
    Print "Set aqueous humor thickness = " & taq-0.55 v|e\o~2D`  
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    '************************************************************************* I?:V EN:  
    'Radius and conic constant of anterior lens >y=%o~  
    '************************************************************************* iUO5hdOM  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) kj[[78  
    GetConic eID, entity, curv, conic ~q9RZ#g13J  
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    SetConic eID, entity, 1/Rant, CCant H4pjtVBr  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant 0q3:"X  
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    '************************************************************************* ^.4<#Qs  
    'Radius and conic constant of posterior lens u|Ai<2b$  
    '************************************************************************* Z`f _e?  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) k82'gJ;MC=  
    GetConic eID, entity, curv, conic E^qKkl  
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    SetConic eID, entity, 1/Rpost, CCpost 4bKZ@r%  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost O=mJ8W@  
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    '************************************************************************* ~:0h o  
    'Lens thickness (Position of posterior lens surface) Xak~He  
    '************************************************************************* yWs/~5[F  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) .h6h&[TEU  
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    ' Delete any z-shift(s) \gzNM
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    count = 0 $;">/"7m  
    While GetOperationCount(eID)>count #a0 (Wh7  
        GetOperation eID, count, op |Gs
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        If op.Type="ShiftZ" Then C2VZE~U+  
            DeleteOperation eID,count 4]g^aaQFd>  
            count=count-1 4f1*?HX&  
        End If aJfW75C  
        count=count+1 6tJM*{$$H  
    Wend ~vt8|OOo0  
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    'Set new z-shift yb]a p  
    op.Type = "ShiftZ"  [g/g(RL  
    op.val1 = tlens 4v{gc/g  
    op.parent = parID "kL5HD]TC  
    AddOperation eID, op r9QNE>UG  
    Print "Set lens thickness = " & tlens 4R
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    '************************************************************************* xOt|j4  
    'Lens index of refraction m/{rm
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    '************************************************************************* Axcm~!uf  
    eID = FindMaterial( "Lens" ) :xA'X+d/'  
    GetModelMaterial eID, mat lKa}Bcd  
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    mat.Nd = nlens 08twcY;&k  
    SetModelMaterial eID, mat LsmC/+7r$1  
    Print "Set lens index of refraction = " & nlens YlYTH_L>E  
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    '************************************************************************* S2Wxf>bt2  
    'Pupil diameter *v&g>Ni  
    '************************************************************************* :JOF!Q  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) m=#2u4H4  
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    'Adjust pupil diameter (trimming volume inner hole) #]Cr zLe  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" e06r5%|.%  
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    ' Adjust pupil location to just in front of the lens *f,EDSN1@d  
    parID = FindFullName( "Geometry.Arizona Eye" ) Bp b_y;E  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) GB{%4)%6  
    count = 0 F&uU ,);  
    While GetOperationCount(eID)>count zIlQqyOQ8  
        GetOperation eID, count, op tewC *%3V  
        If op.Type="ShiftZ" Then 6.k2,C4dT<  
            DeleteOperation eID,count x&7!m  
            count=count-1 1|Fukx<@J<  
        End If 1c\$ziB  
        count=count+1 khyVuWN  
    Wend -ERDWY  
    op.Type = "ShiftZ" tW 9vo-{+  
    op.val1 = taq-0.01 jirxzj
  
    op.parent = parID :V >Z|?[*H  
    AddOperation eID, op uRp-yu[nt%  

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    Print "Set pupil diameter = " & pupilDiam uv Z!3UH.  
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    'Update AZ Eye subassembly Description }PoB`H'K5  
    eID = FindFullName( "Geometry.Arizona Eye" ) ] @IzJz"R  
    GetEntity eID, entity Of-l<Ks\  
    entity.Description = "Accommodation = " & A & "D" p6sXftk  
    SetEntity eID, entity \`x
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    Update teET nz_L  
    Print "DONE!" uN'e~X6  
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End Sub g"F vD_  
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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： VBy=X\w]  
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Accommodation = 4 Diopters 1*#64Y5F  
Pupil Diameter = 4 mm C?X^h{Tp  
Set aqueous humor thickness = 2.81 l+RBe<Mq  
Set anterior lens radius = 10.4 and conic constant = -2.375869 f7\$rx  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 pYH#Vh  
Set lens thickness = 3.927 `n$pR8TZ_  
Set lens index of refraction = 1.42672 )]?sCNb  
Set pupil diameter = 4 r 5:DIA!  
DONE! IL&Mf9m  
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