[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 C[<}eD4bV  
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。 9gcW;  
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模型 A{ ~D_q  
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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。 3"7Q[9Oj  
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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. lG\uJxV  
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光源 Vo@7G@7K(  
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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。 K2
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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。 ZKXE7
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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。 SYYx>1;8`  
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视网膜的散射 {P8d^=#q  
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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。 <=">2WP{  
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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。 9jTBLp-i#N  
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脚本 @&}}tALi  
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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： 5v)^4( )  
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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。 /aI@2]|~  
余下的脚本计算与屈光度有关的所有参数。 [=>=5'-  
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分析 PY5&Fwjc  
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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。 ]o<]A[<  
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脚本代码 F0<)8{s  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. [<#jK}g  
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Dim entity As T_ENTITY 9>~pA]j%  
Dim op As T_OPERATION X<L=*r^C,=  
Dim mat As T_MODELMATERIAL =\O#F88ui  
Dim A As Double %
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Dim pupilDiam As Double  g{Hgs  
Dim eID As Long iwK.*0
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Dim parID As Long Z\nDR
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Dim count As Integer 5bLNQz\WJ  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double 7[1L
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Dim tlens As Double, nlens As Double M@cFcykK  
Dim curv As Double, conic As Double .^wpfS  
Dim ok As Long `9^tuR,  
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Sub Main +Uq|Yh'Q  
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    '用户输入对话框 RsZj  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 FH=2,"A  
        TextBox 220,21,40,21,.TextBox1 'default: 0 z%D7x5!,R  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 FgH7YkKrD  
        OKButton 40,91,90,21 9^}&PEl  
        CancelButton 190,91,90,21 H>CbMz1u  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 j$)ogG
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        TextBox 220,49,40,21,.TextBox2 'default: 4 B]
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    End Dialog [Z$H<m{c-  
    Dim dlg As UserDialog iJzB
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    ok = Dialog (dlg) VE+H! ob A  
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    If ok=0 Then    'cancel button was pressed izl6L  
        Print "Execution cancelled." \l59/ZFan  
        End >jI.$%L$  
    End If 7zG r+Px  
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    'Assign accommodation and pupil diameter & use defaults if field left empty N9w"Lb  
    If dlg.TextBox1 = "" Then j.q}OK  
        A = 0           'Default accommodation 1$&@wG  
    Else q/ljH_-  
        A = CDbl(dlg.TextBox1) X!]v4ma`  
    End If u}5CzV`  
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    If dlg.TextBox2 = "" Then U ]<l-~|  
        pupilDiam = 4   'Default pupil diameter qfDG.Zee#  
    Else oXm !  
        pupilDiam = CDbl(dlg.TextBox2) {M**a  
    End If &r1(1<  
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    Print " " fmW{c mr|  
    Print "Accommodation = " & A & " Diopters" Jy(G A  
    Print "Pupil Diameter = " & pupilDiam & " mm" yx]9rD1cz  
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    ' Calculate new parameters with accommodation 3]*Kz*i  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness G8av5zR  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens es)^^kGj6f  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens Pe_O(  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens \FsA-W\X  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens N68mvBe  
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    tlens = 3.767 + 0.04*A                  'Lens thickness $*0-+h  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction H,(vTthd  
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    'Adjust parameters to account for accommodation c""&He4zp  
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    '************************************************************************* ~Zr}QO}G  
    'Aqueous thickness (Position of Lens) FOk&z!xYKd  
    '************************************************************************* m'"r<]pB*4  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) Y9^l|,bm5  
    GetCustomElement eID, entity G&*P*f1S  
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    parID = FindFullName( "Geometry.Arizona Eye" ) q/b+V)V  
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    ' Delete any shift(s) in z B7f<XBU6
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    count = 0  vD#U+  
    While GetOperationCount(eID)>count G0 )[(s  
        GetOperation eID, count, op a`'>VCg  
        If op.Type="ShiftZ" Then t.( `$  
            DeleteOperation eID,count Rt#QW*h\|i  
            count=count-1 LSC[
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        End If  t;o\"H  
        count=count+1 }B-$}  
    Wend "-&K!Vfs  
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    'Set new shift in MH.+pqIv^  
    op.Type = "ShiftZ" uRb48Qy2  
    op.val1 = taq "u6pl);G  
    op.parent = parID H,%bKl#  
    AddOperation eID, op (%B{=w}8  
    Print "Set aqueous humor thickness = " & taq-0.55 _pTcSp3  
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    '************************************************************************* j=O+U_w  
    'Radius and conic constant of anterior lens uY5|Nmiu  
    '************************************************************************* p7|I>8ur.  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) Jx+6Kq(  
    GetConic eID, entity, curv, conic 9)VAEyv  
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    SetConic eID, entity, 1/Rant, CCant pq) =  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant }h^ fX  
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    '************************************************************************* dEk#"cvg  
    'Radius and conic constant of posterior lens jF?0,g  
    '************************************************************************* 3= =["hO  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) 8!2)=8|f  
    GetConic eID, entity, curv, conic fJ*^4
  

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    SetConic eID, entity, 1/Rpost, CCpost `Q*`\-8J  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost 4FaO+Eo,8  
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    '************************************************************************* RW&o3_Ua  
    'Lens thickness (Position of posterior lens surface) 6u"wgX]H  
    '************************************************************************* 8w:ay,=  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) cP?GRMX@}  
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    ' Delete any z-shift(s) ]H/,Q6Q  
    count = 0 AOg'4  
    While GetOperationCount(eID)>count *y4g\#o.  
        GetOperation eID, count, op VZqCFE3  
        If op.Type="ShiftZ" Then ={BC0,  
            DeleteOperation eID,count YhH3fVM  
            count=count-1 nFlN{_/  
        End If *)Pm  
        count=count+1 W
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    Wend EGD{nE  
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    'Set new z-shift c^w^'<  
    op.Type = "ShiftZ" 7g*!6-W[  
    op.val1 = tlens FsqH:I4O  
    op.parent = parID Zz} o t  
    AddOperation eID, op r%;|gIky  
    Print "Set lens thickness = " & tlens (A?>U_@  
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    '************************************************************************* 9Z-2MF  
    'Lens index of refraction 0o8`Y  
    '************************************************************************* CG%bZco((  
    eID = FindMaterial( "Lens" ) nT|WJ%  
    GetModelMaterial eID, mat CNRSc4Le  
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    mat.Nd = nlens QDxs+<#  
    SetModelMaterial eID, mat G+=Gc(J  
    Print "Set lens index of refraction = " & nlens ;SXkPs3q  
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    '************************************************************************* T}!9T!(HdF  
    'Pupil diameter L!JC)p.  
    '************************************************************************* `RY}g;  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) 76T7<.S  
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    'Adjust pupil diameter (trimming volume inner hole) #btz94/~O  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" B6F!"  
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    ' Adjust pupil location to just in front of the lens }h1BAKg  
    parID = FindFullName( "Geometry.Arizona Eye" ) fOMaTnm'  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) p{oz}}  
    count = 0 vs8[352  
    While GetOperationCount(eID)>count -Jd

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        GetOperation eID, count, op |gV~U~A]  
        If op.Type="ShiftZ" Then 6`2i'flv  
            DeleteOperation eID,count OX.5olb  
            count=count-1 yPmo1|'X>d  
        End If \2u7>fU!  
        count=count+1 J
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    Wend `u3kP  
    op.Type = "ShiftZ" 8T"L'{ggWB  
    op.val1 = taq-0.01 qdQ4%,E[  
    op.parent = parID y={ k7  
    AddOperation eID, op UZ/LR  
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    Print "Set pupil diameter = " & pupilDiam JRBz/ j  
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    'Update AZ Eye subassembly Description 8/2Wq~&  
    eID = FindFullName( "Geometry.Arizona Eye" ) y:\<FLR}j  
    GetEntity eID, entity dZ"}wKbO  
    entity.Description = "Accommodation = " & A & "D" u"5/QB{  
    SetEntity eID, entity #U0| j?!D  
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    Update 3T(ft^~  
    Print "DONE!" >? o5AdZ  
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End Sub At>e4t2@  
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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： u9:sj
 
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Accommodation = 4 Diopters 4qDa:D"5  
Pupil Diameter = 4 mm fBTNI`#  
Set aqueous humor thickness = 2.81 .z CkB86  
Set anterior lens radius = 10.4 and conic constant = -2.375869 $ ^)g,  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 @/aJi6d"^E  
Set lens thickness = 3.927 9Cd=^Im5  
Set lens index of refraction = 1.42672 no\G >#  
Set pupil diameter = 4 y-@`3hYM
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DONE! KdiJ'K.  
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