[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 x[0hY0 ?[M  
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。 BO7HJF)a  
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模型 y$]<m+1  
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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。 ^@RvCJ+  
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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. g`S;xs  
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光源 *->*p35  
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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<L{e~{!7f  
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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。 b/ \EN)  
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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。 MJ?t{=  
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视网膜的散射 k &J;,)V  
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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。 'vVWUK956  
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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。 HYGd :SeH  
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脚本 n8;p]{  
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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： ?<3 d Fb  
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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。 Xzg >/w 8J  
余下的脚本计算与屈光度有关的所有参数。 d;l%XZe  
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分析 ^SG>VfgC  
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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。 5Z; 5?\g  
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脚本代码 Bh=t%#y|`  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. =l/Dc=[  
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Dim entity As T_ENTITY |}:}14ty  
Dim op As T_OPERATION Oo;]j)z  
Dim mat As T_MODELMATERIAL X[dfms;H  
Dim A As Double _";w*lg}  
Dim pupilDiam As Double & tT6.@kH  
Dim eID As Long _ncBq;j{  
Dim parID As Long <lIm==U<-  
Dim count As Integer i*:QbMb  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double )r{Wj*u  
Dim tlens As Double, nlens As Double e`={_R{N  
Dim curv As Double, conic As Double 1T|")D  
Dim ok As Long DVhBZ!u9  
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Sub Main m85ZcyW1T  
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    '用户输入对话框 ZK
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    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 V;SV0~&  
        TextBox 220,21,40,21,.TextBox1 'default: 0 MF'Z?M  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 E3j`e>Yz  
        OKButton 40,91,90,21 :$K=LV#Iru  
        CancelButton 190,91,90,21 3>7{Q_5  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 2c[HA  
        TextBox 220,49,40,21,.TextBox2 'default: 4 )-5eIy  
    End Dialog _J,rql@nG<  
    Dim dlg As UserDialog <t(H+ykh  
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    ok = Dialog (dlg) %XukiA+  
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    If ok=0 Then    'cancel button was pressed 7Ji'7$  
        Print "Execution cancelled." e.MyJ:eL  
        End !5De?OXe   
    End If ;5X~"#%U_  
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    'Assign accommodation and pupil diameter & use defaults if field left empty !Ltx2CB2]  
    If dlg.TextBox1 = "" Then =dNE1rdzNa  
        A = 0           'Default accommodation p:nl4O/  
    Else SPlt=*C#_  
        A = CDbl(dlg.TextBox1) v=G*K11@  
    End If ``g  
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    If dlg.TextBox2 = "" Then Brs6RkRf  
        pupilDiam = 4   'Default pupil diameter (kO(R#M  
    Else sS{Co8EJn  
        pupilDiam = CDbl(dlg.TextBox2) 9O&gR46.  
    End If 0/DO"pnL@  
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    Print " " s'N<  
    Print "Accommodation = " & A & " Diopters" REU&8J@k&?  
    Print "Pupil Diameter = " & pupilDiam & " mm" ;\A_-a_(#  
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    ' Calculate new parameters with accommodation C;:=r:bth  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness e?;c9]XO,o  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens )=gU~UV  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens y7h^_D+Ce  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens -?#iPvk6  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens w+')wyB  
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    tlens = 3.767 + 0.04*A                  'Lens thickness HTiLA%%6  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction  $LuU  
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    'Adjust parameters to account for accommodation :!t4.ko  
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    '************************************************************************* k*2khh-  
    'Aqueous thickness (Position of Lens) M __S)  
    '************************************************************************* w3 vZ}1|  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) cX1?4e8  
    GetCustomElement eID, entity Q'=7#_  
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    parID = FindFullName( "Geometry.Arizona Eye" ) |
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    ' Delete any shift(s) in z _nz_.w0H9  
    count = 0 v9@_DlV\  
    While GetOperationCount(eID)>count yR{rje*  
        GetOperation eID, count, op tR9iFv_  
        If op.Type="ShiftZ" Then E71H=C 4  
            DeleteOperation eID,count 'W9[Vm  
            count=count-1 }sqFvab<  
        End If hunlKIg  
        count=count+1 E83$(6z  
    Wend ]vR Ol.  
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    'Set new shift in JP"#9f  
    op.Type = "ShiftZ" $D65&R  
    op.val1 = taq 8M
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    op.parent = parID D,p2MBr  
    AddOperation eID, op  s=:LS  
    Print "Set aqueous humor thickness = " & taq-0.55 73!NoDxb  
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    '************************************************************************* z"z$.c  
    'Radius and conic constant of anterior lens -0;{  
    '************************************************************************* >mvE[iXRG?  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) lz>.mXdx  
    GetConic eID, entity, curv, conic 9-{.WZ  
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    SetConic eID, entity, 1/Rant, CCant $Sy}im
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    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant N@Ap|`Ei  
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    '************************************************************************* "UY34a^I  
    'Radius and conic constant of posterior lens 8f~*T  
    '************************************************************************* # ^,8JRA  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) =s:kC`O  
    GetConic eID, entity, curv, conic r&v!2A]:  
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    SetConic eID, entity, 1/Rpost, CCpost e 5(|9*t  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost Zd-QZ<c";t  
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    '************************************************************************* oMM@{Jp  
    'Lens thickness (Position of posterior lens surface) /'VuMMJ2  
    '************************************************************************* >#S}J 
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) ,=@WE>ip  
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    ' Delete any z-shift(s) T$FKn  
    count = 0 <ldArZ4C4  
    While GetOperationCount(eID)>count \zA3H$Df~  
        GetOperation eID, count, op -; d{}F  
        If op.Type="ShiftZ" Then *<{hLf  
            DeleteOperation eID,count 0#8lg@e8  
            count=count-1
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        End If 3h o'\Ysu/  
        count=count+1 xjxX4_  
    Wend 9}K K]m6u}  
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    'Set new z-shift WqCER^~'>  
    op.Type = "ShiftZ" f@Ve,i  
    op.val1 = tlens Z
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    op.parent = parID vgNrHq&2q  
    AddOperation eID, op :c}PW"0v  
    Print "Set lens thickness = " & tlens !qH)ttW  
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    '************************************************************************* Bbb":c6w0  
    'Lens index of refraction ]E.FBGT  
    '************************************************************************* X,8Zn06
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    eID = FindMaterial( "Lens" ) nhm#_3!6A  
    GetModelMaterial eID, mat uE,TEa9;  
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    mat.Nd = nlens TEK#AR  
    SetModelMaterial eID, mat %vG;'_gMB  
    Print "Set lens index of refraction = " & nlens YWANBM(v+  
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    '************************************************************************* }LWrtmc  
    'Pupil diameter Vd) %qw  
    '************************************************************************* "x:-#2+h  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) 5ry[Lgg  
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    'Adjust pupil diameter (trimming volume inner hole) JV2[jo}0N  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" sG|,#XQ  
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    ' Adjust pupil location to just in front of the lens !;k ^  
    parID = FindFullName( "Geometry.Arizona Eye" ) 1iM(13jW  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) hJ8B&u(  
    count = 0 8l?@ o  
    While GetOperationCount(eID)>count NfCo)C-t  
        GetOperation eID, count, op [H`5mY@  
        If op.Type="ShiftZ" Then 94rx4"AN8;  
            DeleteOperation eID,count r6:nYyF$)v  
            count=count-1 KWw?W1H  
        End If #g Rns  
        count=count+1 Zc9S[ivq  
    Wend M?ElD1#Z  
    op.Type = "ShiftZ" RHt~:D3*  
    op.val1 = taq-0.01 AX{yfL  
    op.parent = parID r
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    AddOperation eID, op &y2DI"Ff  
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    Print "Set pupil diameter = " & pupilDiam lR]SGdY  
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    'Update AZ Eye subassembly Description ).r04)/  
    eID = FindFullName( "Geometry.Arizona Eye" ) *&F~<HC2+  
    GetEntity eID, entity .YIb ny1  
    entity.Description = "Accommodation = " & A & "D" rf2-owWN  
    SetEntity eID, entity #X<s_.7DJ  
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    Update l]P3oB}Yo  
    Print "DONE!" pH.&OW%  
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End Sub Snas:#B!  
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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： tp+H]H3  
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Accommodation = 4 Diopters R<8!lQ4s  
Pupil Diameter = 4 mm -<n]Sv;V  
Set aqueous humor thickness = 2.81 qH*Fv:qnM  
Set anterior lens radius = 10.4 and conic constant = -2.375869 iD!]I$  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 ljO t~@Ea  
Set lens thickness = 3.927 q6N6QI8/  
Set lens index of refraction = 1.42672 E`UEl$($  
Set pupil diameter = 4 \&X*-T[]j  
DONE! Y[alOJ  
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