[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 5<Xq7|Jt  
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。 WdnCRFO?l  
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模型 iKs/8n  
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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。 +}J2\!Jw  
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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. 1wi{lJaz  
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光源 eICk}gfun  
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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。 d/j$_NQ&!  
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除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处，并增加了pre-propagation distance= -8。尽管光线在光瞳处创建，规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射，而不是在光瞳处入射。 K\`L>B. 1  
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在往下看是内置的脚本用来修改屈光度，使其为4（250mm），光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 rH8w||S2U  
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视网膜的散射 1aS[e%9Mg  
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在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 {r#2X1  
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注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 Wt"fn&R}  
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脚本 D ?1$I0=  
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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： c6:"5};_  
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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。 [k ZvBd  
余下的脚本计算与屈光度有关的所有参数。 4=9To|U*  
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分析 %K@D{)r_^  
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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。  (f,D$mX  
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脚本代码 6kK\nZ$o$  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. <.s=)}'`P  
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Dim entity As T_ENTITY {w$1_GU  
Dim op As T_OPERATION _
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Dim mat As T_MODELMATERIAL $?YRy_SI  
Dim A As Double w4H3($ K  
Dim pupilDiam As Double L1D{LzlBti  
Dim eID As Long f^@`[MJj1C  
Dim parID As Long (D]l/akP  
Dim count As Integer yd2v_  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double 6q RZ#MC  
Dim tlens As Double, nlens As Double rj&  
Dim curv As Double, conic As Double
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Dim ok As Long
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Sub Main 3P-qLbJ  
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    '用户输入对话框 =/&ob%J)9]  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 J?&lpsB3_l  
        TextBox 220,21,40,21,.TextBox1 'default: 0 Y0:y72mK  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 4h\MSTF*  
        OKButton 40,91,90,21 oqH811  
        CancelButton 190,91,90,21 F2WUG  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1
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        TextBox 220,49,40,21,.TextBox2 'default: 4 qRT1Wre 3  
    End Dialog :[z=u  
    Dim dlg As UserDialog Gnop  
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    ok = Dialog (dlg) O?/\hZ"&c  
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    If ok=0 Then    'cancel button was pressed -(V]knIF  
        Print "Execution cancelled." Me;@/;c(  
        End :uy8$g*;TE  
    End If rs2G{a  
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    'Assign accommodation and pupil diameter & use defaults if field left empty
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    If dlg.TextBox1 = "" Then i,=greA]"  
        A = 0           'Default accommodation 4:RL[;  
    Else M/C7<?&  
        A = CDbl(dlg.TextBox1) gq~>S1  
    End If - ?_aYJ  
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    If dlg.TextBox2 = "" Then 0Aw.aQ~E8i  
        pupilDiam = 4   'Default pupil diameter Vui5ZK  
    Else L!s/0kBg  
        pupilDiam = CDbl(dlg.TextBox2) Bh$hgf.C  
    End If 9AK<<Mge.  
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    Print " " cf)2GoV>e  
    Print "Accommodation = " & A & " Diopters" 6C@,&2<yK  
    Print "Pupil Diameter = " & pupilDiam & " mm" P -0  
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    ' Calculate new parameters with accommodation 12BTZ  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness j3jf:7 /\  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens l&2A]5C  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens <;<_f U  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens . #`lW7  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens F!OVx<  
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    tlens = 3.767 + 0.04*A                  'Lens thickness >fRI^Q,  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction -jy-KC  
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    'Adjust parameters to account for accommodation EEFM1asJf  
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    '************************************************************************* M&o@~z0  
    'Aqueous thickness (Position of Lens) qDZ?iTHQq  
    '************************************************************************* ?n<b:oO  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) d7s? c  
    GetCustomElement eID, entity p.^glz>B  
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    parID = FindFullName( "Geometry.Arizona Eye" ) S~fURn  
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    ' Delete any shift(s) in z ; mnV)8:F  
    count = 0 'X&sH/>r  
    While GetOperationCount(eID)>count lj0"2@z3"E  
        GetOperation eID, count, op rUvjc4O}  
        If op.Type="ShiftZ" Then q8%T)$!  
            DeleteOperation eID,count )7@f{E#w  
            count=count-1 ?RL[#d+y  
        End If Si#I^aF`%  
        count=count+1 /.{4 KW5  
    Wend m`luMt9  
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    'Set new shift in ??eSGQ|  
    op.Type = "ShiftZ" pJ35M  
    op.val1 = taq <y#-I%ed  
    op.parent = parID (n:d {bKV  
    AddOperation eID, op <>JN&#3?  
    Print "Set aqueous humor thickness = " & taq-0.55 _)s<E9t2N  
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    '************************************************************************* J60XUxf  
    'Radius and conic constant of anterior lens 70bI}/u  
    '************************************************************************* ~ED8]*H|`  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) .%)FK#s-  
    GetConic eID, entity, curv, conic Y+5nn  
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    SetConic eID, entity, 1/Rant, CCant /
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    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant {(;dHF%{  
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    '************************************************************************* $D{KXkrd  
    'Radius and conic constant of posterior lens 1OB,UU"S$  
    '************************************************************************* 8xs}neDg*  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) !$&k@#v:  
    GetConic eID, entity, curv, conic  u!I Es  
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    SetConic eID, entity, 1/Rpost, CCpost &)`xlIw}  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost 7u[U%yd  
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    '************************************************************************* '&/ 35d9|*  
    'Lens thickness (Position of posterior lens surface) A9Cq(L_H  
    '************************************************************************* y+b4sFf  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) xs+pCK|  
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    ' Delete any z-shift(s) h^_Sd"l3  
    count = 0 g}>Sc=e<  
    While GetOperationCount(eID)>count  2fZVBj  
        GetOperation eID, count, op WAr;g?Q8  
        If op.Type="ShiftZ" Then GJ YXCi  
            DeleteOperation eID,count n0|oV
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            count=count-1 h| q!Qsnj'  
        End If 6*yt^[W  
        count=count+1 GIXxOea1  
    Wend =eG?O7z&  
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    'Set new z-shift &o{=  
    op.Type = "ShiftZ" ;',hwo_LBf  
    op.val1 = tlens cp D=9k!*K  
    op.parent = parID 9 0PF)U  
    AddOperation eID, op dkT
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    Print "Set lens thickness = " & tlens ['9awgkr/  
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    '************************************************************************* ,/{(8hn  
    'Lens index of refraction mqw5\7s?  
    '************************************************************************* \:>GF-Z(  
    eID = FindMaterial( "Lens" ) +um Ua  
    GetModelMaterial eID, mat E=N44[`.G  
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    mat.Nd = nlens :r5DR`Rfm  
    SetModelMaterial eID, mat TNwBnMe  
    Print "Set lens index of refraction = " & nlens M0Eq 7:Ba  
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    '************************************************************************* o1jDQ+  
    'Pupil diameter Fh2$,$ 2  
    '************************************************************************* k^A17Nf`2  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) S b0p?  
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    'Adjust pupil diameter (trimming volume inner hole) -1\*}m%1e  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" luA k$Es  
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    ' Adjust pupil location to just in front of the lens Af*e:}}  
    parID = FindFullName( "Geometry.Arizona Eye" ) B 4s^X`?z  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" )
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    count = 0 ^]nnvvp  
    While GetOperationCount(eID)>count eK<X7m^  
        GetOperation eID, count, op &yu3nA:7D  
        If op.Type="ShiftZ" Then $U3|.4  
            DeleteOperation eID,count 7Jm&z/  
            count=count-1 $bf&ct*$h  
        End If U[l7n3Y=  
        count=count+1 ~3]ZN'b\  
    Wend q. i2BoOd  
    op.Type = "ShiftZ" '.Ww*N  
    op.val1 = taq-0.01 U`{'-L.  
    op.parent = parID Cxn<#Kf\-<  
    AddOperation eID, op ~|W0+&):  
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    Print "Set pupil diameter = " & pupilDiam YH_m
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    'Update AZ Eye subassembly Description
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    eID = FindFullName( "Geometry.Arizona Eye" ) {VBn@^'s  
    GetEntity eID, entity N)F&c!anh  
    entity.Description = "Accommodation = " & A & "D" pKSn 3-A  
    SetEntity eID, entity ;3 N0)  
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    Update f9+J}  
    Print "DONE!" i=m5M
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End Sub A`|Z2  
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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： wR7Ja cKv  
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Accommodation = 4 Diopters ny(`An  
Pupil Diameter = 4 mm H2f!c{t$p  
Set aqueous humor thickness = 2.81 n*'i{P]  
Set anterior lens radius = 10.4 and conic constant = -2.375869 &m=GkK  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 y.xt7 F1  
Set lens thickness = 3.927 =rw60B  
Set lens index of refraction = 1.42672 Qs38VlR_m  
Set pupil diameter = 4 h8nJt>h  
DONE! JbV\eE#KrC  
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