[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 H[hJUR+#  
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。 D=^&?@k<  
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模型 i975)_X(  
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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。 4 *}H3-`  
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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. _fS\p|W(E  
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光源 I-^sJ@V;  
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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。 XnP?hw%  
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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。 BX$<5S@  
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在往下看是内置的脚本用来修改屈光度，使其为4（250mm），光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 ~T;:Tg*  
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视网膜的散射 68
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在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 l1T`[2  
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注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 {v
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脚本 bXJ(QXHd%  
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内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： 'a0M.*f}G  
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如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 iA{q$>{8  
余下的脚本计算与屈光度有关的所有参数。 t#(=$  
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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。 a0)w/A&  
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脚本代码 &S xF"pYV  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. X~&8^?  
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Dim entity As T_ENTITY Fy\q>(v.  
Dim op As T_OPERATION q`PA~C];  
Dim mat As T_MODELMATERIAL jR}EBaI}  
Dim A As Double pNd`fV#jX  
Dim pupilDiam As Double W#!AZ!  
Dim eID As Long )U|V|yem'  
Dim parID As Long H0&wn#);6R  
Dim count As Integer GXm#\)  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double  ;@k=9o]A  
Dim tlens As Double, nlens As Double kntY2FM  
Dim curv As Double, conic As Double 5ph CEKt;  
Dim ok As Long {HY3E}YJL  
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Sub Main t0fgG/f'  
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    '用户输入对话框 c`x4."m  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 ?ch?q~e)  
        TextBox 220,21,40,21,.TextBox1 'default: 0 oUsfO-dET^  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 MR,I`9Pe  
        OKButton 40,91,90,21 L/Kb\\f  
        CancelButton 190,91,90,21 cQ<|Of  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1
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        TextBox 220,49,40,21,.TextBox2 'default: 4 SrNc  
    End Dialog UH0l8ixc  
    Dim dlg As UserDialog @{RhO|UR  
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    ok = Dialog (dlg) -q9m@!L  
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    If ok=0 Then    'cancel button was pressed sg-^ oy*^  
        Print "Execution cancelled." T^]]z}k  
        End 4jDi3MMU9  
    End If ~Y f8,m  
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    'Assign accommodation and pupil diameter & use defaults if field left empty W=EcbH9/.)  
    If dlg.TextBox1 = "" Then Tv'1IE  
        A = 0           'Default accommodation 3pML+Y|ij  
    Else ;;i419  
        A = CDbl(dlg.TextBox1) c nv%J}wq  
    End If clyp0`,7  
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    If dlg.TextBox2 = "" Then v+xrnz  
        pupilDiam = 4   'Default pupil diameter * G*VY#L  
    Else >{(c\oMD  
        pupilDiam = CDbl(dlg.TextBox2) du}HTrsC  
    End If CR.d3!&28  
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    Print " " 6oQ7u90z*  
    Print "Accommodation = " & A & " Diopters" /L2ZI1v  
    Print "Pupil Diameter = " & pupilDiam & " mm" }@6yROy.  
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    ' Calculate new parameters with accommodation -*[)CR-{  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness >pZ_  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens yqK_|7I+  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens &S
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens ~X2# z|  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens e`][zx  
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    tlens = 3.767 + 0.04*A                  'Lens thickness L-U4 8 i  

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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction K!(WcoA&2i  
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    'Adjust parameters to account for accommodation c]VK%zl  
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    '************************************************************************* BQUYT/$(  
    'Aqueous thickness (Position of Lens) Pl|I{l*o(`  
    '************************************************************************* SF:{
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    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) %r6_['T  
    GetCustomElement eID, entity q2|z \  
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    parID = FindFullName( "Geometry.Arizona Eye" ) jX'pUO  
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    ' Delete any shift(s) in z NR&a er  
    count = 0 Z>w@3$\z  
    While GetOperationCount(eID)>count aVVE2:M  
        GetOperation eID, count, op SK/}bZ;f  
        If op.Type="ShiftZ" Then Bk.`G)t  
            DeleteOperation eID,count |9 *$6Y  
            count=count-1 dUn]aS  
        End If 7 v3%dCvf  
        count=count+1 ML$#&Z@ *7  
    Wend SmyJ@.L"  
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    'Set new shift in N{RHbSa(  
    op.Type = "ShiftZ" v{lDEF@2^N  
    op.val1 = taq *2pE39  
    op.parent = parID "/^kFsvp  
    AddOperation eID, op t':*~b{V@7  
    Print "Set aqueous humor thickness = " & taq-0.55 N8r+Q
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    '************************************************************************* \(f82kv  
    'Radius and conic constant of anterior lens vcy+p]6KE-  
    '************************************************************************* <;b  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" )  wN0?~  
    GetConic eID, entity, curv, conic WV|9d}5  
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    SetConic eID, entity, 1/Rant, CCant $1Z3yb^  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant )086u8w )y  
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    '************************************************************************* [sPLu)q2  
    'Radius and conic constant of posterior lens S +73 /Vs  
    '************************************************************************* |SJ%Myy  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) Y'6P ~C;v  
    GetConic eID, entity, curv, conic ONcS
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    SetConic eID, entity, 1/Rpost, CCpost JKXIxw>q  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost sh<JB`^$(?  
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    '************************************************************************* 1*@Q~f:Uk  
    'Lens thickness (Position of posterior lens surface) k8.,id  
    '************************************************************************* [.G~5%974  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) jI}{0LW&F&  
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    ' Delete any z-shift(s) 5FNf)F   
    count = 0 V3pn@'pr  
    While GetOperationCount(eID)>count ON_GD"  
        GetOperation eID, count, op sD XJXJZ  
        If op.Type="ShiftZ" Then <l9qhqHv&  
            DeleteOperation eID,count 'aZAWY d  
            count=count-1 Ce3  
        End If W9SEYkg  
        count=count+1 ybm&g( -\  
    Wend |-AR)Smt  
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    'Set new z-shift a)L=+Z  
    op.Type = "ShiftZ" ==7=1QfP  
    op.val1 = tlens WgV[,(  
    op.parent = parID %}Ob~m>P  
    AddOperation eID, op 0jefV*3qpB  
    Print "Set lens thickness = " & tlens vr>Rd{dm  
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    '************************************************************************* Q#$dp  
    'Lens index of refraction }xzb
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    '************************************************************************* (e{pAm  
    eID = FindMaterial( "Lens" ) PmE2T\{s!  
    GetModelMaterial eID, mat o{QPW  
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    mat.Nd = nlens F a'2i<  
    SetModelMaterial eID, mat w.0]>/C  
    Print "Set lens index of refraction = " & nlens t3$+;K(  
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    '************************************************************************* lhV'Q]s@6  
    'Pupil diameter aib)ItNb  
    '************************************************************************* ~dqEUu!C  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) V$ss[fX  
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    'Adjust pupil diameter (trimming volume inner hole) m&#a M8:\  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" "Q@ZS2;A  
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    ' Adjust pupil location to just in front of the lens vo DTU]pf  
    parID = FindFullName( "Geometry.Arizona Eye" ) =i)k@w_(x  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) NCysYmt  
    count = 0 ~v<,6BS<$Z  
    While GetOperationCount(eID)>count nM)H2'%kL&  
        GetOperation eID, count, op U~8 oE_+  
        If op.Type="ShiftZ" Then sh"\ kk9  
            DeleteOperation eID,count !23#Bz7  
            count=count-1 )TcW.d6  
        End If A,qWg0A]nt  
        count=count+1 a<X<hxW:  
    Wend @v,qfT*k7  
    op.Type = "ShiftZ" G?6[K&w  
    op.val1 = taq-0.01 rx#\Dc}  
    op.parent = parID ^m:?6y_uw  
    AddOperation eID, op VXAgp6  
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    Print "Set pupil diameter = " & pupilDiam uB:utg  
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    'Update AZ Eye subassembly Description u
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    eID = FindFullName( "Geometry.Arizona Eye" ) v2Bks2  
    GetEntity eID, entity &H{KXX"X  
    entity.Description = "Accommodation = " & A & "D" obE_`u l#  
    SetEntity eID, entity 8V(#S:G35  
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    Update n300kp
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    Print "DONE!" ,Mwj`fgh
 
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End Sub RSY{I
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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： @`ttyI^1f  
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Accommodation = 4 Diopters U>^-Db
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Pupil Diameter = 4 mm (k..ll p~  
Set aqueous humor thickness = 2.81 Z\y@rp\l  
Set anterior lens radius = 10.4 and conic constant = -2.375869 E:&ga}h  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 toEmIa~o6  
Set lens thickness = 3.927 d\V\,%&.  
Set lens index of refraction = 1.42672 `1
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Set pupil diameter = 4 ,g$N  
DONE! KPUc+`cN%  
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