[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 0o$HC86w  
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。 kr`B
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模型 ([CnYv  
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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。 `vxrC&,As  
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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. j$8|ym^OX  
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光源 +%qSB9_>N{  
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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。 kad;Wa#h  
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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。 +#uNQ`1v  
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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(5@8(>a  
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视网膜的散射 $JhZ'Z  
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在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 ;*-@OLT_K  
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注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 @nx}6?p\,  
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脚本 U+*oI*  
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内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： Z<N&UFw7QJ  
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如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 YBtq0c  
余下的脚本计算与屈光度有关的所有参数。 J+@MzkpK  
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分析 :m*!?QGdL  
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屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 \,l.p_<  
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脚本代码 )l#%.Z9  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. <+T\F;   
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Dim entity As T_ENTITY s%N`  
Dim op As T_OPERATION ~m?74^ i  
Dim mat As T_MODELMATERIAL <78$]Z2we  
Dim A As Double %tzN@  
Dim pupilDiam As Double >'} Y1_S5  
Dim eID As Long qGpP,  
Dim parID As Long ;|>q zx  
Dim count As Integer ?w]"~   
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double {PODisl>\D  
Dim tlens As Double, nlens As Double sf |oNOz  
Dim curv As Double, conic As Double ( zn_8s  
Dim ok As Long I&TTr7  
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Sub Main (s}Rj)V[^  
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    '用户输入对话框 t] r,9df'  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 cBz!U8(  
        TextBox 220,21,40,21,.TextBox1 'default: 0 7
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        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 35Ai;mU'  
        OKButton 40,91,90,21 BIxV|\k  
        CancelButton 190,91,90,21 2BoFyL*  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 :y+B;qw  
        TextBox 220,49,40,21,.TextBox2 'default: 4 IL~]m?'V(  
    End Dialog (3 IZ  
    Dim dlg As UserDialog Ur'9bl{5  
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    ok = Dialog (dlg) 81GQijq  
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    If ok=0 Then    'cancel button was pressed *QbM*oH  
        Print "Execution cancelled." H$z>OS_6U  
        End { 1+Cw?1d  
    End If LP.HS'M~u  
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    'Assign accommodation and pupil diameter & use defaults if field left empty 8weSrm  
    If dlg.TextBox1 = "" Then x96qd%l/  
        A = 0           'Default accommodation B#FHf Z  
    Else _1I K$gb[  
        A = CDbl(dlg.TextBox1) .)LZ`Ge3F  
    End If YV5Yx-+3w$  
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    If dlg.TextBox2 = "" Then J.1O/Pw!.a  
        pupilDiam = 4   'Default pupil diameter kUNj4xp)  
    Else z%OuI 8"'  
        pupilDiam = CDbl(dlg.TextBox2) $Mdbto~<  
    End If R'rTE  
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    Print " " %lN2n,AK  
    Print "Accommodation = " & A & " Diopters" "yg.hK`  
    Print "Pupil Diameter = " & pupilDiam & " mm" 8O,?|c=>  
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    ' Calculate new parameters with accommodation TqIAWbb&  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness ?nQ_w0j  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens j]rXoV>  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens 2zz,(RA  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens js~tKUvg  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens YP
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    tlens = 3.767 + 0.04*A                  'Lens thickness 59.$ULQVMY  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction vB^uxdt|m  
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    'Adjust parameters to account for accommodation f0vJm  
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    '************************************************************************* u^Vh.g]  
    'Aqueous thickness (Position of Lens) cv2]*  
    '************************************************************************* ^EF

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    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) zJ;Rt9<7-  
    GetCustomElement eID, entity FKC\VF  
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    parID = FindFullName( "Geometry.Arizona Eye" ) xOythvO  
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    ' Delete any shift(s) in z
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    count = 0 E!zX)|Z<  
    While GetOperationCount(eID)>count 3)3Hck  
        GetOperation eID, count, op %<ic%gt`#  
        If op.Type="ShiftZ" Then D|l,08n"?  
            DeleteOperation eID,count )>\4ULR83  
            count=count-1 zN%97q_  
        End If Y6
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        count=count+1 @xS]!1-  
    Wend ND5$bq Nu?  
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    'Set new shift in 3H
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    op.Type = "ShiftZ" +TH3&H5I_A  
    op.val1 = taq ?n.)&ZIx0  
    op.parent = parID >.e+S?o  
    AddOperation eID, op 6W&_2a7*  
    Print "Set aqueous humor thickness = " & taq-0.55 -p`L%xj\  
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    '************************************************************************* ,X68xk.'  
    'Radius and conic constant of anterior lens OUI6 ax\[  
    '************************************************************************* iCP~
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    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) Ow@v"L;jF!  
    GetConic eID, entity, curv, conic F)SPaC4  
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    SetConic eID, entity, 1/Rant, CCant je%ldY]/@  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant :HRT 
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    '************************************************************************* )6-9)pH@)  
    'Radius and conic constant of posterior lens W\8Ln>  
    '************************************************************************* oh~:,  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) +Rwx%=  
    GetConic eID, entity, curv, conic x GH1epf  
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    SetConic eID, entity, 1/Rpost, CCpost 6S1m<aH6  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost 8AL\ST51x"  
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    '************************************************************************* d(;4`kd*N  
    'Lens thickness (Position of posterior lens surface) M:n6BC>t"  
    '************************************************************************* Zgamd1DJ[l  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) NmpnJu|8  
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    ' Delete any z-shift(s) z wk.bf>m  
    count = 0 =:=/Gz1  
    While GetOperationCount(eID)>count o&SSvW  
        GetOperation eID, count, op <jA105U"m>  
        If op.Type="ShiftZ" Then [syj#  
            DeleteOperation eID,count j}f[W [2  
            count=count-1 5MF#&v  
        End If H'DVwnn>ik  
        count=count+1 )OP){/   
    Wend S,{tV=&m]  
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    'Set new z-shift xZ.!d.rn  
    op.Type = "ShiftZ" wTc)S6%7  
    op.val1 = tlens ' cIEc1y  
    op.parent = parID h8{(KRa6  
    AddOperation eID, op O_~7Glu  
    Print "Set lens thickness = " & tlens n3KI+I%nQ  
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    '************************************************************************* ~h$wH{-U#  
    'Lens index of refraction 5(m(xo6  
    '************************************************************************* l\OLyQ  
    eID = FindMaterial( "Lens" ) `A@w7J'  
    GetModelMaterial eID, mat BuOgOYh9  
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    mat.Nd = nlens 'b&yrBFD  
    SetModelMaterial eID, mat m Y,|J\w@  
    Print "Set lens index of refraction = " & nlens K> g[k_  
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    '************************************************************************* L2UsqVU  
    'Pupil diameter x;s0j"`Jb  
    '************************************************************************* % Zjdl  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) j<<3Pr  
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    'Adjust pupil diameter (trimming volume inner hole) tc+WWDP#"
 
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" 88s/Q0l  
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    ' Adjust pupil location to just in front of the lens p4!:]0c  
    parID = FindFullName( "Geometry.Arizona Eye" ) _}xd}QW  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) OHv!  
    count = 0 ^D%Za'  
    While GetOperationCount(eID)>count =c.5874A`  
        GetOperation eID, count, op 2,q}Nq  
        If op.Type="ShiftZ" Then }_9,w;M$  
            DeleteOperation eID,count
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            count=count-1 co8"sz0(U  
        End If
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        count=count+1 ia
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    Wend >Gml4vGK  
    op.Type = "ShiftZ" i%m"@7.kk  
    op.val1 = taq-0.01 8,P- 7^  
    op.parent = parID b;sVls  
    AddOperation eID, op \_V-A f{6  
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    Print "Set pupil diameter = " & pupilDiam w'MGA  
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    'Update AZ Eye subassembly Description aT!'}GjL  
    eID = FindFullName( "Geometry.Arizona Eye" ) OJ
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    GetEntity eID, entity x+8_4>,>Y7  
    entity.Description = "Accommodation = " & A & "D" yZr M.%V  
    SetEntity eID, entity ^&@w$  
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    Update K_)eWf0a  
    Print "DONE!" l/TjQ*
 
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End Sub TxjYrzC  
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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： m7a#qs;,  
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Accommodation = 4 Diopters KqBk~-G  
Pupil Diameter = 4 mm xsd_Uu*  
Set aqueous humor thickness = 2.81 y&}E~5O  
Set anterior lens radius = 10.4 and conic constant = -2.375869 {vUN+We  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 u0
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Set lens thickness = 3.927 %~L>1ShtU  
Set lens index of refraction = 1.42672 ;c~cet4  
Set pupil diameter = 4 m8'C_U^89  
DONE! :I -V_4b  
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