[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 M~Ttb29{  
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。 (la[KqqCO  
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模型 q`NXJf=sc  
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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。 A]0:8@k5  
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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\wn?f  
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光源 j
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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。 PxS4,`#~  
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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。 Sq\(pfvo  
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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。 Vwk#qgnX  
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视网膜的散射 HB+|WW t>  
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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。 ]?O2:X  
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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。 css64WX^0c  
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脚本 bXUy9-L  
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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： 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。 bVP"(H]  
余下的脚本计算与屈光度有关的所有参数。 n  -(  
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分析 6T 8!xyi-+  
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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。 I>L-1o|^  
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脚本代码 {*{Ox[Nh{  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. 6aM*:>C"  
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Dim entity As T_ENTITY @gY)8xMbA  
Dim op As T_OPERATION PkI:*\R  
Dim mat As T_MODELMATERIAL dy_:-2S  
Dim A As Double MSf;ZB  
Dim pupilDiam As Double 8@so"d2e  
Dim eID As Long {s.=)0V  
Dim parID As Long H":oNpfb  
Dim count As Integer 2eMTxwt*S  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double J:V?EE,\-  
Dim tlens As Double, nlens As Double cnTaJ/o  
Dim curv As Double, conic As Double lNSLs"x^  
Dim ok As Long ~69&6C1Ch  
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Sub Main j?'GZ d"B  
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    '用户输入对话框 7uzkp&+:  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1  SdD6 ~LS  
        TextBox 220,21,40,21,.TextBox1 'default: 0 ,v"YqD+GC5  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 0_88V  
        OKButton 40,91,90,21 Gz.|]:1  
        CancelButton 190,91,90,21 4?B\O`sy.  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 |\pbir  
        TextBox 220,49,40,21,.TextBox2 'default: 4 %c4Hse#Y  
    End Dialog 82l~G;.n3  
    Dim dlg As UserDialog Jv^h\~*jH  
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    ok = Dialog (dlg) d3xmtG {i  
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    If ok=0 Then    'cancel button was pressed zCk^B/j sM  
        Print "Execution cancelled." %7|9sQ:  
        End &Xf}8^T<V  
    End If YPxM<Gfa8  
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    'Assign accommodation and pupil diameter & use defaults if field left empty {;2PL^i  
    If dlg.TextBox1 = "" Then _bNzX
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        A = 0           'Default accommodation a|X a3E  
    Else i{`:(F5*  
        A = CDbl(dlg.TextBox1) wRVUu)  
    End If !z>6Uf!{  
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    If dlg.TextBox2 = "" Then +U3DG$  
        pupilDiam = 4   'Default pupil diameter }~L.qG  
    Else x7Yu I  
        pupilDiam = CDbl(dlg.TextBox2) ,y#Kv|R  
    End If > ;*b|Ik  
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    Print " " y gz6C  
    Print "Accommodation = " & A & " Diopters" .6Pw|xu`Pw  
    Print "Pupil Diameter = " & pupilDiam & " mm" vw9@v`k  
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    ' Calculate new parameters with accommodation 6
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    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness #"G]ke1l$  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens .:F%_dS D  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens 8A})V8  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens r97pOs#5:  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens )AvN\sC  
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    tlens = 3.767 + 0.04*A                  'Lens thickness fumm<:<CLO  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction J| w>a  
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    'Adjust parameters to account for accommodation GBPo8L"9  
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    '************************************************************************* .(cw>7e3D  
    'Aqueous thickness (Position of Lens) Li4zTR|U  
    '************************************************************************* b0Ps5G\ u  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) ,?^ p(w  
    GetCustomElement eID, entity VAHh~Q6 ;e  
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    parID = FindFullName( "Geometry.Arizona Eye" ) yPb"V  
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    ' Delete any shift(s) in z \!.B+7t=I  
    count = 0 R{SF(g3  
    While GetOperationCount(eID)>count 4O^xY 6m  
        GetOperation eID, count, op !Wntd\w  
        If op.Type="ShiftZ" Then gCB |DY  
            DeleteOperation eID,count I;wp':  
            count=count-1 AP?R"%  
        End If 8p 'L#Q.  
        count=count+1 286jI7T  
    Wend vApIHI?-  
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    'Set new shift in _-K2/6zy  
    op.Type = "ShiftZ" TNe l/  
    op.val1 = taq )q8pk2  
    op.parent = parID 0ypNUG}   
    AddOperation eID, op X^wt3<Kbf  
    Print "Set aqueous humor thickness = " & taq-0.55 65J
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    '************************************************************************* ];[}:
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    'Radius and conic constant of anterior lens 7x|9n  
    '************************************************************************* Ot_]3:`J~  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) E Nhl&J  
    GetConic eID, entity, curv, conic vc;$-v$&  
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    SetConic eID, entity, 1/Rant, CCant l<58A7   
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant spH7 /5}  
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    '************************************************************************* k8&;lgO'  
    'Radius and conic constant of posterior lens gwuI-d^  
    '************************************************************************* $w`xvX  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) Tztu}t]N  
    GetConic eID, entity, curv, conic U)]oO  
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    SetConic eID, entity, 1/Rpost, CCpost @<hb6bo,N
 
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost N2^=E1|_  
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    '************************************************************************* _7Ju  
    'Lens thickness (Position of posterior lens surface) /|6N*>l)y  
    '************************************************************************* S6Q  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) 24 'J  
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    ' Delete any z-shift(s) r= `Jn6@  
    count = 0 _Eo[7V{NY  
    While GetOperationCount(eID)>count {T$9?`h~M  
        GetOperation eID, count, op $f <(NM6?  
        If op.Type="ShiftZ" Then
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            DeleteOperation eID,count RLjc&WhzXu  
            count=count-1 iy.p n  
        End If i+ ?^8#  
        count=count+1 gV's=c
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    Wend HmGWht6R  
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    'Set new z-shift C2kPMB=Xo  
    op.Type = "ShiftZ" t\dN DS  
    op.val1 = tlens @Md/Q~>  
    op.parent = parID w3ResQ   
    AddOperation eID, op ~g]Vw4pv  
    Print "Set lens thickness = " & tlens &-)N'  
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    '************************************************************************* SwGx?U  
    'Lens index of refraction Woym/[i  
    '************************************************************************* Q~ w|#  
    eID = FindMaterial( "Lens" ) W' VslZG  
    GetModelMaterial eID, mat -$ls(oot  
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    mat.Nd = nlens W:2( .?  
    SetModelMaterial eID, mat 6@5+m 0`u3  
    Print "Set lens index of refraction = " & nlens `Y$4 H,8L  
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    '************************************************************************* L,/%f<wd  
    'Pupil diameter z43M]P<
 
    '************************************************************************* eu-*?]&Di  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) d7;um<%zn  
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    'Adjust pupil diameter (trimming volume inner hole) IFL*kB   
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" lTgjq:mn  
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    ' Adjust pupil location to just in front of the lens U?Zq6_M&  
    parID = FindFullName( "Geometry.Arizona Eye" ) $7ZX]%<s  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) JX;G
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    count = 0 $Ds2>G4c  
    While GetOperationCount(eID)>count j</: WRA`]  
        GetOperation eID, count, op rq].UCj  
        If op.Type="ShiftZ" Then 83_h J  
            DeleteOperation eID,count Xl#ggub?  
            count=count-1 zTSTEOP}%Y  
        End If AQvudx
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        count=count+1 R 'zWYQ  
    Wend 7Ovi{xd@  
    op.Type = "ShiftZ" \
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    op.val1 = taq-0.01 [RhO$c$[\  
    op.parent = parID LU%E:i|  
    AddOperation eID, op Bj;'qB
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    Print "Set pupil diameter = " & pupilDiam qo bc<-  
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    'Update AZ Eye subassembly Description $%#!bV  
    eID = FindFullName( "Geometry.Arizona Eye" ) *^ZV8c}  
    GetEntity eID, entity VY4yS*y  
    entity.Description = "Accommodation = " & A & "D" ( Erc3Ac8  
    SetEntity eID, entity p_%Rt"!  
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    Update hRhe& ,v  
    Print "DONE!" @I?=<Riu  
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End Sub `M8i92V\qY  
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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： w<(pl%  
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Accommodation = 4 Diopters vA8nvoi  
Pupil Diameter = 4 mm OQJ6e:BGt  
Set aqueous humor thickness = 2.81 j A%u 5V  
Set anterior lens radius = 10.4 and conic constant = -2.375869 2c*GuF9(0  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 |@d\S[~^G  
Set lens thickness = 3.927 lt8|9"9<  
Set lens index of refraction = 1.42672 4|DWOQ':  
Set pupil diameter = 4 k5pN  
DONE! D'Q\za  
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