[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 Ort\J~O  
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。 y8L:nnSj  
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模型 k@2gw]y"  
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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。 @MM|.# ~T  
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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. iqU}t2vFrj  
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光源 Y/+ D4^L  
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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。 ,9rT|:N  
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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。 +bSv-i-  
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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。 f 6q@  
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视网膜的散射 rYLNV!_  
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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。 HGKm?'['  
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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。 '!0CwZ 7  
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脚本 0I k@d'7  
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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： nQ+{1 C  
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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。 )uaB^L1  
余下的脚本计算与屈光度有关的所有参数。 Bm?Ku7}.  
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分析 *iR`mZb  
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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。 t_N `e(V  
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脚本代码 OJK/>  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. 7KEGTKfW  
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Dim entity As T_ENTITY |N
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Dim op As T_OPERATION D^u{zZy@e  
Dim mat As T_MODELMATERIAL $D89|sy  
Dim A As Double tEeMl =u  
Dim pupilDiam As Double DXiD>1(q  
Dim eID As Long 8}0 D?  
Dim parID As Long cnj_tC=zt  
Dim count As Integer gV7o eZ5  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double :Y'nye3:  
Dim tlens As Double, nlens As Double D9Z5g3s7R  
Dim curv As Double, conic As Double qvscf_%FM  
Dim ok As Long w.3R1}R  
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Sub Main Grqs*V &|g  
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    '用户输入对话框 >!2'|y^  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 Z`%
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        TextBox 220,21,40,21,.TextBox1 'default: 0 f6#H@ X  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 Pv'x|
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        OKButton 40,91,90,21 gu/Yc`S[  
        CancelButton 190,91,90,21 J0K"WmW  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 `MD/CFl4  
        TextBox 220,49,40,21,.TextBox2 'default: 4 v!uLd.(  
    End Dialog 9f@)
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    Dim dlg As UserDialog <uvshZv  
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    ok = Dialog (dlg) 0jmlsC>  
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    If ok=0 Then    'cancel button was pressed H~@h #6  
        Print "Execution cancelled." usA!MMH4  
        End f[RnL#*xJU  
    End If {)y4Qp  
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    'Assign accommodation and pupil diameter & use defaults if field left empty Wama>dy%  
    If dlg.TextBox1 = "" Then c1^3lgPv  
        A = 0           'Default accommodation Yem
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    Else pIXQ/(h31  
        A = CDbl(dlg.TextBox1) "duJl-  
    End If A
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    If dlg.TextBox2 = "" Then ;1%
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        pupilDiam = 4   'Default pupil diameter #cs!`Ngb+  
    Else nAzr!$qbNv  
        pupilDiam = CDbl(dlg.TextBox2) cG?266{g  
    End If 8vo} .JIl  
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    Print " " NO$Nl/XM  
    Print "Accommodation = " & A & " Diopters" RBXoU'.  
    Print "Pupil Diameter = " & pupilDiam & " mm" ]Oy<zU  
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    ' Calculate new parameters with accommodation -AE/,@\P  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness <'-me09C*  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens R32d(2%5K  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens H]e 2d|  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens lg1D>=(mY  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens | QA8"&r  
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    tlens = 3.767 + 0.04*A                  'Lens thickness zvD5i,I  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction +[ zo2lBx  
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    'Adjust parameters to account for accommodation 9:>K!@  
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    '************************************************************************* m5Kx}H~  
    'Aqueous thickness (Position of Lens) [7V]=] p  
    '************************************************************************* 3[0:,^a  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) N,|oV|i  
    GetCustomElement eID, entity gISs+g  
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    parID = FindFullName( "Geometry.Arizona Eye" ) n&]w* (,  
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    ' Delete any shift(s) in z jH1~Ve+q9  
    count = 0 [w f12P  
    While GetOperationCount(eID)>count \4k*Zk  
        GetOperation eID, count, op qE}YVKV*  
        If op.Type="ShiftZ" Then 4lCm(#T{,  
            DeleteOperation eID,count .Q@"];wH  
            count=count-1 _u$K Lqt/,  
        End If =&b[V"  
        count=count+1 =HHg:"  
    Wend
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    'Set new shift in 3)Y:c2  
    op.Type = "ShiftZ" ;\+0H$  
    op.val1 = taq >gJWp@6V  
    op.parent = parID 7w,FA  
    AddOperation eID, op OB22P%  
    Print "Set aqueous humor thickness = " & taq-0.55 LS'=>s"  
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    '************************************************************************* Y=Qf!Cq]  
    'Radius and conic constant of anterior lens OWsYE?  
    '************************************************************************* gN~y6c:N  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) mC`! \"w  
    GetConic eID, entity, curv, conic ]?{lQ0vw'w  
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    SetConic eID, entity, 1/Rant, CCant UmX[=D|  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant (N4(r<o;  
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    '************************************************************************* xQap44KPZ  
    'Radius and conic constant of posterior lens >N-%  
    '************************************************************************* QE2^.|d{  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) L0tK
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    GetConic eID, entity, curv, conic 8[;oUVb
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    SetConic eID, entity, 1/Rpost, CCpost D5u"4\g<&  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost PqLqF5`S  
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    '************************************************************************* X>7]g670@  
    'Lens thickness (Position of posterior lens surface) 9'g{<(R]  
    '************************************************************************* 7"ps#)O  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) ~79Qg{+]N  
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    ' Delete any z-shift(s) +z0}{,HX  
    count = 0 .+}o'rU  
    While GetOperationCount(eID)>count )Cvzj<Q0  
        GetOperation eID, count, op =pyZ^/}P  
        If op.Type="ShiftZ" Then 9t.yP;j\Y  
            DeleteOperation eID,count 4!vUksM  
            count=count-1 _x6E_i-(  
        End If es+_]:7B9  
        count=count+1 fMPq  
    Wend cE5Zxcn  
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    'Set new z-shift v9lBk]c  
    op.Type = "ShiftZ" E:=KH\2f  
    op.val1 = tlens AO$PuzlLh  
    op.parent = parID zN/~a
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    AddOperation eID, op #UCQiQfP  
    Print "Set lens thickness = " & tlens
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    '************************************************************************* r5fkt>HZ  
    'Lens index of refraction ZHECcPhz  
    '************************************************************************* fhIj+/{_O  
    eID = FindMaterial( "Lens" ) GtJ*&=(  
    GetModelMaterial eID, mat I@Z*Nu1L  
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    mat.Nd = nlens 8t:&#h  
    SetModelMaterial eID, mat oEoJa:h  
    Print "Set lens index of refraction = " & nlens 'oZn<c`  
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    '************************************************************************* ?En| _E_C  
    'Pupil diameter <`j[;>O  
    '************************************************************************* [2 w<F[  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) m4U+,|Fa  
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    'Adjust pupil diameter (trimming volume inner hole) 9'#.>Q>0=j  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" <&s)k  
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    ' Adjust pupil location to just in front of the lens |;u%JW$4  
    parID = FindFullName( "Geometry.Arizona Eye" ) A='+tJa  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) ->2wrOH|H  
    count = 0 (<R\  
    While GetOperationCount(eID)>count 4Re@QOZ  
        GetOperation eID, count, op 4B8Se  
        If op.Type="ShiftZ" Then wQ=yY$VP  
            DeleteOperation eID,count K*U=;*p)  
            count=count-1 N' $DE  
        End If LH/&\k  
        count=count+1 vgA!?P3  
    Wend 'Rkvsch  
    op.Type = "ShiftZ" oz0n$`O$/  
    op.val1 = taq-0.01 xe gL!  
    op.parent = parID g[wP!y%V  
    AddOperation eID, op YUVc9PV)Ws  
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    Print "Set pupil diameter = " & pupilDiam iPY vePQ  
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    'Update AZ Eye subassembly Description ;Ma/b=Y  
    eID = FindFullName( "Geometry.Arizona Eye" ) Pm#x?1rAj  
    GetEntity eID, entity 3Da,]w<  
    entity.Description = "Accommodation = " & A & "D" $dZ>bXUw:  
    SetEntity eID, entity 3aE[F f[  
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    Update ()nKug`.@  
    Print "DONE!" VU`z|nBW@  
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End Sub FJd8s*  
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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： >1a\%G  
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Accommodation = 4 Diopters I*:qGr+ WJ  
Pupil Diameter = 4 mm I`"-$99|t1  
Set aqueous humor thickness = 2.81 +\k9w.[:/  
Set anterior lens radius = 10.4 and conic constant = -2.375869 3Zaq#uA  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 ]D?# \|  
Set lens thickness = 3.927 qJX+[PJ  
Set lens index of refraction = 1.42672 6R-C0_'h  
Set pupil diameter = 4 t(j_eq}J  
DONE! 8_<&f%
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