[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 ^l=!JP=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。 b TM{l.Aq3  
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模型 e .2ib?8  
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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。 ^O<&fD  
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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. 4@n1Uk  
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光源 f~y%%+{p  
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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。 ~yfNxH~k  
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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。 !GLz)#SBl  
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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。 M/ni6%x  
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视网膜的散射 m-*i>4;  
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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。 D 38$`j  
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注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 %Bn?n{/  
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脚本 <2|O:G  
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内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： rI>aAW'  
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如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 C>$E%=h+_  
余下的脚本计算与屈光度有关的所有参数。 , GY h9  
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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。 a1.Ptf eW|  
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脚本代码 U{z9>  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. VUYmz)m5  
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Dim entity As T_ENTITY bKQ"ax>6p  
Dim op As T_OPERATION <]4i`6{v  
Dim mat As T_MODELMATERIAL CkD#/  
Dim A As Double Xn,v]$M!  
Dim pupilDiam As Double k
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Dim eID As Long {>,V\J0p  
Dim parID As Long g'=B%eO$j:  
Dim count As Integer $
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Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double ;._7jFj.  
Dim tlens As Double, nlens As Double WxJf{=-  
Dim curv As Double, conic As Double X 9%'|(tL  
Dim ok As Long 80&.JP.
 
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Sub Main t|<NI+H(e  
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    '用户输入对话框 &jczO-R^  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 0=q;@OIf  
        TextBox 220,21,40,21,.TextBox1 'default: 0 9D}/\jM  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 DUe&r,(4O  
        OKButton 40,91,90,21 Sh,&{z!  
        CancelButton 190,91,90,21 }gMDXy}  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 $w0lrh[+  
        TextBox 220,49,40,21,.TextBox2 'default: 4 'GoZqiYT  
    End Dialog X*Dj[TD]  
    Dim dlg As UserDialog I,VH=Yn5,  
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    ok = Dialog (dlg) b0A1hb[|  
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    If ok=0 Then    'cancel button was pressed J}@z_^|"mJ  
        Print "Execution cancelled." ~$f;U  
        End .8uz 6~  
    End If
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    'Assign accommodation and pupil diameter & use defaults if field left empty mVsIAC$}8  
    If dlg.TextBox1 = "" Then "zY](P  
        A = 0           'Default accommodation wwoweztER  
    Else npyAJp  
        A = CDbl(dlg.TextBox1) k({\/t3i  
    End If E)-r+ <l  
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    If dlg.TextBox2 = "" Then }%`~T>/  
        pupilDiam = 4   'Default pupil diameter zrv#Xa!O\  
    Else ww{_c]My  
        pupilDiam = CDbl(dlg.TextBox2) l?DJJ|>O  
    End If 7Irau_  
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    Print " "
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    Print "Accommodation = " & A & " Diopters" JwRF(1_sM  
    Print "Pupil Diameter = " & pupilDiam & " mm" ?D)<,  
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    ' Calculate new parameters with accommodation M9f?q.Bv  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness pdb1GDl0q  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens ^*= 85iyo  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens 0hn-FH-XE  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens <0.$'M~E  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens %q322->
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    tlens = 3.767 + 0.04*A                  'Lens thickness A[dvEb;r  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction ph|ZG6:
  
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    'Adjust parameters to account for accommodation ,chf~-d  
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    '************************************************************************* !epgTN  
    'Aqueous thickness (Position of Lens) o{kbc5_  
    '************************************************************************* asgF1?r  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) tPyyZ#,  
    GetCustomElement eID, entity zT* .jv  
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    parID = FindFullName( "Geometry.Arizona Eye" ) =AEz9d ciS  
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    ' Delete any shift(s) in z h2;z4  
    count = 0 &&<9p;E  
    While GetOperationCount(eID)>count )g@S%Yu  
        GetOperation eID, count, op 5;TuVU.8Q  
        If op.Type="ShiftZ" Then geefnb  
            DeleteOperation eID,count p(m1O70C  
            count=count-1 _0 snAt^iC  
        End If hc$@J}`  
        count=count+1 aSYs_?&.  
    Wend i_LF`JhEQT  
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    'Set new shift in LDy<k=;o  
    op.Type = "ShiftZ" 68'>Zbelb  
    op.val1 = taq DV]7.Bm  
    op.parent = parID +f;CyMEp  
    AddOperation eID, op HT_TP q  
    Print "Set aqueous humor thickness = " & taq-0.55 N(3R|Ii  
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    '************************************************************************* z&$/EP-  
    'Radius and conic constant of anterior lens @gBE{)Fj  
    '************************************************************************* ;}.Kb
 
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) *sfD#Bi]  
    GetConic eID, entity, curv, conic ^yKY'>T#d  
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    SetConic eID, entity, 1/Rant, CCant qturd7  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant 6a>H|"PNE  
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    '************************************************************************* h:Ndzp{  
    'Radius and conic constant of posterior lens "!Rw)=7O  
    '************************************************************************* x@cN3
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    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) #G,XDW2"w  
    GetConic eID, entity, curv, conic mf|pNiQ,  
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    SetConic eID, entity, 1/Rpost, CCpost re,.@${H  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost *R`MMm  
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    '************************************************************************* ; a/cty0Ch  
    'Lens thickness (Position of posterior lens surface) 'CS.p!Z\  
    '************************************************************************* kJ: 2;t=  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) "t&{yBQ0u  
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    ' Delete any z-shift(s) ?9u
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    count = 0 0%)5.=6  
    While GetOperationCount(eID)>count !Zwf 397  
        GetOperation eID, count, op CYB=Uq,  
        If op.Type="ShiftZ" Then ?Nl"sVCo  
            DeleteOperation eID,count RyRqH:p)3  
            count=count-1 Zy wK/D  
        End If %N~CvN@T  
        count=count+1 jgvh[@uB?  
    Wend {=At#*=A  
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    'Set new z-shift fEu9Jk  
    op.Type = "ShiftZ" u5gZxO1J5  
    op.val1 = tlens !J.rM5K  
    op.parent = parID ,p,Du F  
    AddOperation eID, op A"/aGCG0z  
    Print "Set lens thickness = " & tlens WhUa^  
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    '************************************************************************* .9\Cy4_qSd  
    'Lens index of refraction D$_8rHc\A  
    '************************************************************************* q?VVYZXP  
    eID = FindMaterial( "Lens" ) .{N\<01  
    GetModelMaterial eID, mat iA
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    mat.Nd = nlens uU+s!C9r  
    SetModelMaterial eID, mat $ WFhBak8  
    Print "Set lens index of refraction = " & nlens o?R,0 -  
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    '************************************************************************* L+Nsi~YVq  
    'Pupil diameter jCWu\Oe  
    '************************************************************************* c=t*I0-OVS  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) @bQ!zCI  
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    'Adjust pupil diameter (trimming volume inner hole) pB'x_z  

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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" '{D%\w5{  
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    ' Adjust pupil location to just in front of the lens m0iV m|  
    parID = FindFullName( "Geometry.Arizona Eye" ) ~iT{8  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) @dhH;gt.I  
    count = 0 ECdfLn*c  
    While GetOperationCount(eID)>count u@"o[e':  
        GetOperation eID, count, op OX,F09.C  
        If op.Type="ShiftZ" Then vadM1c*z  
            DeleteOperation eID,count Gt.*_E  
            count=count-1 CI1m5g [P  
        End If V9$-twhu  
        count=count+1 )9pBu B  
    Wend `hF;$  
    op.Type = "ShiftZ" 7+]F^ 6  
    op.val1 = taq-0.01 & 3I7]Wm  
    op.parent = parID ZmO'IT=Ye  
    AddOperation eID, op ;G$)MS'nB  
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    Print "Set pupil diameter = " & pupilDiam &.*T\3UO  
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    'Update AZ Eye subassembly Description fsb=8>}63}  
    eID = FindFullName( "Geometry.Arizona Eye" ) Gm*Uv6?H?  
    GetEntity eID, entity 7#/|VQX<A  
    entity.Description = "Accommodation = " & A & "D" [b pwg&Oo  
    SetEntity eID, entity W)  
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    Update .hnF]_QQ  
    Print "DONE!" Kk56/(_S  
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End Sub {
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如果屈光度是4，光瞳直径是4，则会输出如下数据： <e^6.!;W  
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Accommodation = 4 Diopters YmA) @1@U  
Pupil Diameter = 4 mm ees^O{ 8  
Set aqueous humor thickness = 2.81 A&?WP\_z  
Set anterior lens radius = 10.4 and conic constant = -2.375869 t)`+d=P  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 BfEx'C  
Set lens thickness = 3.927 v,@E}F~-f1  
Set lens index of refraction = 1.42672 EXH!glR[$  
Set pupil diameter = 4 j!"iYtgV  
DONE! >fhSaeN  
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