[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 jOT/|k  
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;)U4__!  
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模型 x'0_lf</#  
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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。 ho$}#o  
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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. 6hj[/O)E  
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光源 (-$5YKm  
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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。 ?;o0~][!  
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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。 S(CkA\[rz  
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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。 v@]SddP,?  
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视网膜的散射 hY!ek;/Gc  
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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。 iT:i '\~  
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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。 w2xD1oK~o  
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脚本 qqo#H O  
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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： omg#[  
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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。 C9?mxa*z  
余下的脚本计算与屈光度有关的所有参数。 I'BHNZO5tf  
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分析 ilQ}{p6I  
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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。 .`~?w+ ~  
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脚本代码 I4%kYp]  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. b>QdP$>  
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Dim entity As T_ENTITY 2]?=\_T  
Dim op As T_OPERATION QY4;qA  
Dim mat As T_MODELMATERIAL qE2V
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Dim A As Double \"$P :Uv  
Dim pupilDiam As Double bK!h{Rr  
Dim eID As Long .'A1Eoo0d  
Dim parID As Long 5qH*"i+|s  
Dim count As Integer c_ncx|dUs  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double d)V8FX,t  
Dim tlens As Double, nlens As Double 4v/MZ:%C`  
Dim curv As Double, conic As Double T8Mqu`$r  
Dim ok As Long )EB+(c~E  
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Sub Main ~b
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    '用户输入对话框 pt"9zkPj  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 k L6s49  
        TextBox 220,21,40,21,.TextBox1 'default: 0 2DPv7\fW  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 MG=8`J-`  
        OKButton 40,91,90,21 d'Bxi"K  
        CancelButton 190,91,90,21 i,^3aZwJ'  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 sM MtU@<x  
        TextBox 220,49,40,21,.TextBox2 'default: 4 9vyf9QE;  
    End Dialog @Q,Q"c2  
    Dim dlg As UserDialog { rLgyrj$  
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    ok = Dialog (dlg) *GoTN  
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    If ok=0 Then    'cancel button was pressed XX/s@C  
        Print "Execution cancelled." 
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        End iii|;v]+  
    End If 4@{?4k-cq  
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    'Assign accommodation and pupil diameter & use defaults if field left empty L$3lsu!4n  
    If dlg.TextBox1 = "" Then nl 'MWP  
        A = 0           'Default accommodation 8cOft ;|qB  
    Else fWq*Op.]c  
        A = CDbl(dlg.TextBox1) 9h6Oq(0b8  
    End If -_Z4)"k  
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    If dlg.TextBox2 = "" Then \mh #MMp  
        pupilDiam = 4   'Default pupil diameter CnL=s6XD'  
    Else `WXlq#:K  
        pupilDiam = CDbl(dlg.TextBox2) .\_RavW23  
    End If tXtNK2-1  
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    Print " " '

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    Print "Accommodation = " & A & " Diopters" DNq(\@x[!  
    Print "Pupil Diameter = " & pupilDiam & " mm" t?G6|3
  
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    ' Calculate new parameters with accommodation 1}a4AGAp  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness jG7PT66>;  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens 3<W
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    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens mTI`^e  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens an"~n`g  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens O_1[KiZ  
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    tlens = 3.767 + 0.04*A                  'Lens thickness dWQs
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction A/<u>cCW  
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    'Adjust parameters to account for accommodation '+_>PBOc  
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    '************************************************************************* `5@F'tKQ  
    'Aqueous thickness (Position of Lens) 5_'lu  
    '************************************************************************* J;obh.}u"{  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) Z,#H\1v3lB  
    GetCustomElement eID, entity ;9k>;g3m  
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    parID = FindFullName( "Geometry.Arizona Eye" ) ia'z9  
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    ' Delete any shift(s) in z >E+g.5 ,:W  
    count = 0 JnsJ]_<  
    While GetOperationCount(eID)>count HGGq;Nbm  
        GetOperation eID, count, op .^{%hc*w4  
        If op.Type="ShiftZ" Then :Mu*E5  
            DeleteOperation eID,count S/5QK(XLC)  
            count=count-1 l@B9}Icq  
        End If NV4g5)D&L  
        count=count+1 nf /*n  
    Wend G@H!D[wd  
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    'Set new shift in iwJ_~  
    op.Type = "ShiftZ" d>hv-nD  
    op.val1 = taq geR+v+B,  
    op.parent = parID .}!.4J%q2  
    AddOperation eID, op Gc|)4c  
    Print "Set aqueous humor thickness = " & taq-0.55 *z0d~j*W;  
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    '************************************************************************* uMg\s\Z  
    'Radius and conic constant of anterior lens Gk
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    '************************************************************************* [Iks8ZWr_  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) 1.!U{>$  
    GetConic eID, entity, curv, conic >-A@6Qe_  
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    SetConic eID, entity, 1/Rant, CCant U7s$';y"%  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant 4qie&:4j  
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    '************************************************************************* -)}s{[]d6m  
    'Radius and conic constant of posterior lens nzflUR{`-  
    '************************************************************************* )Zr9 `3[  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) '}_r/l]K  
    GetConic eID, entity, curv, conic -x//@8"   
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    SetConic eID, entity, 1/Rpost, CCpost 1]7gYNzV"  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost _B^zm-}8|B  
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    '************************************************************************* [%.v;+L  
    'Lens thickness (Position of posterior lens surface) \~5|~|9<  
    '************************************************************************* jfuHZ^YA  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) .Fn|Okn^gr  
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    ' Delete any z-shift(s) Ha@;Sz<R  
    count = 0 _>- D*l  
    While GetOperationCount(eID)>count ;/K2h_=3z  
        GetOperation eID, count, op cszvt2BIg  
        If op.Type="ShiftZ" Then P3_.U8g$r  
            DeleteOperation eID,count <sH}X$/  
            count=count-1 \Rny*px  
        End If L80(9Y^xn  
        count=count+1 ?"d$SK"6Z  
    Wend e,U:H~+]  
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    'Set new z-shift &~,4$&_  
    op.Type = "ShiftZ" UD.bb  
    op.val1 = tlens Jxe+LG  
    op.parent = parID W$c@C02<  
    AddOperation eID, op x}] 56f  
    Print "Set lens thickness = " & tlens W7>2&$
  
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    '************************************************************************* Zl
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    'Lens index of refraction w_(3{P[Iz  
    '************************************************************************* HxG8'G  
    eID = FindMaterial( "Lens" ) isZ5s\  
    GetModelMaterial eID, mat %nZ
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    mat.Nd = nlens bNea5u##  
    SetModelMaterial eID, mat Y?0/f[Ax,y  
    Print "Set lens index of refraction = " & nlens JVE\{ e)  
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    '************************************************************************* j_Szw w-  
    'Pupil diameter %**f`L%jN  
    '************************************************************************* P-@MLIC{  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) [^5\Ww  
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    'Adjust pupil diameter (trimming volume inner hole) fj_23{,/"g  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" tb3VqFx  
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    ' Adjust pupil location to just in front of the lens g68p9#G  
    parID = FindFullName( "Geometry.Arizona Eye" ) nr!N%Hi  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) Ed9Uw7  
    count = 0 "s+4!,k  
    While GetOperationCount(eID)>count U&5*>fd=  
        GetOperation eID, count, op .G0 N+)  
        If op.Type="ShiftZ" Then 5~*)3z^V  
            DeleteOperation eID,count /(N/DMl[  
            count=count-1 Wlj&
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        End If / ;]5X  
        count=count+1 *3GV9'-P  
    Wend uw)7N(os\`  
    op.Type = "ShiftZ" [0H0%z#tU&  
    op.val1 = taq-0.01 .Mt3ec<  
    op.parent = parID f[^f/jGm  
    AddOperation eID, op M;(,0dk  
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    Print "Set pupil diameter = " & pupilDiam ,?fJ0n:!%  
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    'Update AZ Eye subassembly Description m~=~DMj  
    eID = FindFullName( "Geometry.Arizona Eye" ) G95,J/w  
    GetEntity eID, entity +#W94s~0V  
    entity.Description = "Accommodation = " & A & "D" 6 63o  
    SetEntity eID, entity W'lqNOX[v  
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    Update }Mcb\+[  
    Print "DONE!" }r:
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End Sub \/A.j|by,>  
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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： JAPr[O&  
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Accommodation = 4 Diopters ZCiCZ)oc  
Pupil Diameter = 4 mm ]MbPivM  
Set aqueous humor thickness = 2.81 mgs(n5V
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Set anterior lens radius = 10.4 and conic constant = -2.375869 V~J5x >O  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 &d#R'Z  
Set lens thickness = 3.927 :+rGBkw1m  
Set lens index of refraction = 1.42672 #(8|9  
Set pupil diameter = 4 bDI%}k9#  
DONE! 7N.b-}$(  
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