[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 C hQ] d  
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。 Ma'#5)D  
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模型 m68>`  
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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。 M&jlUr&l  
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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. ?@z/#3b  
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光源 !>"fDz<w`  
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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。 _s+G02/q1  
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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。 0K6My4d{  
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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。 .hM t:BMf*  
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视网膜的散射 Y]=k"]:%  
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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。 jU kxA7 }}  
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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。 W"*2,R[}%  
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脚本 mo3A*|U  
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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： BG8/  
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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。 w[D]\>QHa  
余下的脚本计算与屈光度有关的所有参数。 Mvue>)g~>  
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分析 ~#4FL<W  
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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。 9pPLOXr ,  
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脚本代码 L&y"oAp<  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. \EU^`o+  
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Dim entity As T_ENTITY #
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Dim op As T_OPERATION ~ +>ehU  
Dim mat As T_MODELMATERIAL \K~wsu/?`  
Dim A As Double dHTx^1  
Dim pupilDiam As Double ;2\6U;  
Dim eID As Long J^ewG  
Dim parID As Long SASLeGaV  
Dim count As Integer TTFs|T6`q  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double 5y 5Dn!`  
Dim tlens As Double, nlens As Double *Ow2,{Nn  
Dim curv As Double, conic As Double :F@Uq<~(  
Dim ok As Long W1M322]>L  
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Sub Main 0MroHFh9`  
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    '用户输入对话框 xp'Q>%v  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 !zx8I7e4  
        TextBox 220,21,40,21,.TextBox1 'default: 0 mNacLkh[  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 0^dYu/i5  
        OKButton 40,91,90,21 \>pm (gF  
        CancelButton 190,91,90,21 oQ,<Yx%E3  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 H8[A*uYL  
        TextBox 220,49,40,21,.TextBox2 'default: 4 'Etq;^H  
    End Dialog 7n.Oem  
    Dim dlg As UserDialog <qpzs@  
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    ok = Dialog (dlg) Eyjsbj8  
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    If ok=0 Then    'cancel button was pressed GM'yOJo  
        Print "Execution cancelled." K)wWqC.  
        End T]Ai{@i  
    End If !&hqj
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    'Assign accommodation and pupil diameter & use defaults if field left empty <$zhNu~  
    If dlg.TextBox1 = "" Then !OY}`a(z  
        A = 0           'Default accommodation ![_0GF
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    Else MjQju@  
        A = CDbl(dlg.TextBox1) pvUV5^B(M  
    End If w(aHB8T  
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    If dlg.TextBox2 = "" Then h*C!b?:
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        pupilDiam = 4   'Default pupil diameter Vc;[0iB  
    Else :o{,F7(P  
        pupilDiam = CDbl(dlg.TextBox2) isd-b]@:Lc  
    End If ^}p##7t[  
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    Print " " 'UWkJ2:!  
    Print "Accommodation = " & A & " Diopters" c+e?xXCEAz  
    Print "Pupil Diameter = " & pupilDiam & " mm" 5!fYTo|G>  
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    ' Calculate new parameters with accommodation oV0 45G  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness .
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens -ycYQ~
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    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens QwWd"Of  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens UAhWJ$(C  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens 6{]F#ig=  
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    tlens = 3.767 + 0.04*A                  'Lens thickness fxPg"R!1i  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction 4xmJQ>/  
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    'Adjust parameters to account for accommodation ,P`NtTN-  
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    '************************************************************************* wCNn/%C  
    'Aqueous thickness (Position of Lens) 2I}pX9  
    '************************************************************************* v{ >3)$1  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) mLZ1u\7W  
    GetCustomElement eID, entity ga%\n!S  
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    parID = FindFullName( "Geometry.Arizona Eye" )  )^{}ov  
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    ' Delete any shift(s) in z xt?-X%oY8  
    count = 0 X'PZCg W  
    While GetOperationCount(eID)>count zvdut ,6<  
        GetOperation eID, count, op 4-x<^ ev=  
        If op.Type="ShiftZ" Then d2#
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            DeleteOperation eID,count cZ:jht  
            count=count-1 %5gdLm!p  
        End If j@z IJ  
        count=count+1 Mww^  
    Wend /Rq\Mgb  
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    'Set new shift in K9k!P8Rd  
    op.Type = "ShiftZ" ~h3G}EH  
    op.val1 = taq {V QGfN  
    op.parent = parID ]A=\P,D  
    AddOperation eID, op OA3J(4!"W  
    Print "Set aqueous humor thickness = " & taq-0.55 CZ3oX#b  
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    '************************************************************************* T[|#DMg$F  
    'Radius and conic constant of anterior lens tjx8UgSi  
    '************************************************************************* WDIin6u-  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) k9rws  
    GetConic eID, entity, curv, conic .u&xo{$'dS  
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    SetConic eID, entity, 1/Rant, CCant )C8^'*!  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant c}qpmWF  
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    '************************************************************************* iX+8!>Q  
    'Radius and conic constant of posterior lens bzNnEH`^]  
    '************************************************************************* Z2$_9.  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) <x^$Fu
 
    GetConic eID, entity, curv, conic jDY B*Y^
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    SetConic eID, entity, 1/Rpost, CCpost F0U %m   
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost TI7$
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    '************************************************************************* KNAvLc
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    'Lens thickness (Position of posterior lens surface) N3L$"g5^  
    '************************************************************************* @ar%`+_  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) c6xr[tc%  
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    ' Delete any z-shift(s) kuH%aM<R  
    count = 0 ML12&E>  
    While GetOperationCount(eID)>count 3$!QP N  
        GetOperation eID, count, op ,IPt4EH$  
        If op.Type="ShiftZ" Then Ww-x+U\l  
            DeleteOperation eID,count g9pKoi|\E  
            count=count-1 F6q=W#~  
        End If I3nE]OcW@  
        count=count+1 >j=ZB3yZ  
    Wend ]%6%rq%9C  
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    'Set new z-shift oDA'$]UL  
    op.Type = "ShiftZ" 3HrG^/  
    op.val1 = tlens l7VO8p]y[R  
    op.parent = parID !.j{vvQ/  
    AddOperation eID, op F|F0#HC ?  
    Print "Set lens thickness = " & tlens s9wzN6re  
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    '************************************************************************* %HG+|)b  
    'Lens index of refraction e#;43=/Ia  
    '************************************************************************* gtuSJ+up  
    eID = FindMaterial( "Lens" ) -w"I  
    GetModelMaterial eID, mat LLTr+@lj  
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    mat.Nd = nlens Dr.eos4 ~  
    SetModelMaterial eID, mat @o0HD
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    Print "Set lens index of refraction = " & nlens 1!1JT;gG^9  
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    '************************************************************************* ExO#V9DaW  
    'Pupil diameter |-=-/u1  
    '************************************************************************* jI8`trD  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) mx}5":}  
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    'Adjust pupil diameter (trimming volume inner hole) P}Ig6^[m\  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" viG=Ap.Th  
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    ' Adjust pupil location to just in front of the lens h/\v+xiF  
    parID = FindFullName( "Geometry.Arizona Eye" ) VjWJx^ZL#  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) ^N<aHFF  
    count = 0 [s^pP2  
    While GetOperationCount(eID)>count eW8cI)wU  
        GetOperation eID, count, op .$-;`&0cZ  
        If op.Type="ShiftZ" Then 9mDdX
 
            DeleteOperation eID,count @M\JzV4 A[  
            count=count-1 ]#M"|iTR  
        End If GcRH$
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        count=count+1 DL,R~  
    Wend z!6_u@^-  
    op.Type = "ShiftZ" I '0
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    op.val1 = taq-0.01 X{#^O/  
    op.parent = parID \/1~5mQ+  
    AddOperation eID, op oX)a6FXK>  
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    Print "Set pupil diameter = " & pupilDiam 2Di~}*9&  
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    'Update AZ Eye subassembly Description |i
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    eID = FindFullName( "Geometry.Arizona Eye" ) Q)aoc.f!v  
    GetEntity eID, entity ^iEf"r  
    entity.Description = "Accommodation = " & A & "D" !=21K0~t#  
    SetEntity eID, entity +iN!$zF5]  
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    Update {@KLN<  
    Print "DONE!" qsp3G7\'=  
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End Sub A
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如果屈光度是4，光瞳直径是4，则会输出如下数据： FiQ&g*=|  
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Accommodation = 4 Diopters @GAj%MK$  
Pupil Diameter = 4 mm JL_(%._J  
Set aqueous humor thickness = 2.81 T|\sN*}\8J  
Set anterior lens radius = 10.4 and conic constant = -2.375869 1N _"Mm{  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 d >L8SL  
Set lens thickness = 3.927 ,Z|O y|+'  
Set lens index of refraction = 1.42672 0*:n<T9  
Set pupil diameter = 4 &S.p%Qe"  
DONE! {!( htg;  
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