[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 t(-noy)  
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。 Pk7Yq:avL  
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模型 3<1Uq3Pa  
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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。 V{p*N*  
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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. 57Q^"sl  
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光源 x1W<r)A )r  

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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。 \C5YVl#  
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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。 DnS# cs~  
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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。 'due'|#^  
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视网膜的散射 t&T0E.kh*X  
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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。 OW-[#r  
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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。 m!3b.2/h  
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脚本 8Eyi`~cAiH  
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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： l5F>v!NA  
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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。 ]pp
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余下的脚本计算与屈光度有关的所有参数。 (xf_  
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分析 Y u\
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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。 YhYcqE8  
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脚本代码 e>vV8a\  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. SIv8EMGo  
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Dim entity As T_ENTITY d0ThhO  
Dim op As T_OPERATION -.-je"E  
Dim mat As T_MODELMATERIAL WJbdsPs  
Dim A As Double /` 891(f,  
Dim pupilDiam As Double <`,pyvR Kv  
Dim eID As Long DFKFsu8s  
Dim parID As Long Dnn$-W|NC  
Dim count As Integer .|[ZEXq  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double @FVan  
Dim tlens As Double, nlens As Double px;5X4U  
Dim curv As Double, conic As Double hfT HP  
Dim ok As Long D%GB2-j R  
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Sub Main }1E'a>^|  
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    '用户输入对话框 /cHd&i,>  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 gdkl,z3N3  
        TextBox 220,21,40,21,.TextBox1 'default: 0 wv0d"PKTS  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 [~03Z[_"/  
        OKButton 40,91,90,21 BayO+,>K
 
        CancelButton 190,91,90,21 i
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        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 r2A%.bL#  
        TextBox 220,49,40,21,.TextBox2 'default: 4 37GJ}%Qs  
    End Dialog rI34K~ P  
    Dim dlg As UserDialog 1cPm $=B  
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    ok = Dialog (dlg) V^fSrW]  
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    If ok=0 Then    'cancel button was pressed gI8r SmH  
        Print "Execution cancelled." V ;Kzh$^rk  
        End vJ5`:4n"  
    End If "{>I5<:t  
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    'Assign accommodation and pupil diameter & use defaults if field left empty lg` Qi&  
    If dlg.TextBox1 = "" Then &2IrST{d:V  
        A = 0           'Default accommodation ^9*FYV  
    Else %zj;~W;qPH  
        A = CDbl(dlg.TextBox1) mUW|4zl i}  
    End If `L p3snS  
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    If dlg.TextBox2 = "" Then E^uau=F  
        pupilDiam = 4   'Default pupil diameter .w5#V|  
    Else fy|ycWW>8  
        pupilDiam = CDbl(dlg.TextBox2) L4Ep7=  
    End If l%"[857  
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    Print " " 3=o^Vv  
    Print "Accommodation = " & A & " Diopters" `H+~LVH  
    Print "Pupil Diameter = " & pupilDiam & " mm" S~jl%]  
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    ' Calculate new parameters with accommodation ,Q|[Yr  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness ;#c|ZnX  

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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens MQ;c'?!5[!  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens p&1IK8i"  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens qh}M!p2  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens |lH~nU.*  
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    tlens = 3.767 + 0.04*A                  'Lens thickness V9xZH5T8^  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction BLxtS  
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    'Adjust parameters to account for accommodation ,arFR'u>  
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    '************************************************************************* [@D+kL*>  
    'Aqueous thickness (Position of Lens) L \0nO i  
    '************************************************************************* ?^iX%   
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) sO7$
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    GetCustomElement eID, entity \(UEjlo  
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    parID = FindFullName( "Geometry.Arizona Eye" ) b_88
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    ' Delete any shift(s) in z \ZdV|23  
    count = 0 6itp Mck  
    While GetOperationCount(eID)>count S0.  
        GetOperation eID, count, op )@DT^#zR  
        If op.Type="ShiftZ" Then @l3L_;6a  
            DeleteOperation eID,count 0gNwC~IA8  
            count=count-1  _Y@'<S.  
        End If mo%9UL,#W  
        count=count+1 .<JD'%?"  
    Wend W]|;ZzZ=m  
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    'Set new shift in ahgm*Cpc  
    op.Type = "ShiftZ" }>:v  
    op.val1 = taq zo66=vE!  
    op.parent = parID +gb2>fei&  
    AddOperation eID, op @W3fKF9*R  
    Print "Set aqueous humor thickness = " & taq-0.55 $I(2}u?1+d  
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    '************************************************************************* 1G/bqIMg63  
    'Radius and conic constant of anterior lens $^R[t;  
    '************************************************************************* 42:~oKiQ$"  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) Mt
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    GetConic eID, entity, curv, conic Te?UQX7Z}M  
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    SetConic eID, entity, 1/Rant, CCant @ ?y(\>  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant s+?r4t3H!  
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    '************************************************************************* 4)Y=)#=  
    'Radius and conic constant of posterior lens eN]0]9JO  
    '************************************************************************* $x;wnXXXM  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) _$/(l4\T[  
    GetConic eID, entity, curv, conic +) 2c\1  
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    SetConic eID, entity, 1/Rpost, CCpost ?}^e,.M0?s  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost d|Wpub  
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    '************************************************************************* #tG/{R  
    'Lens thickness (Position of posterior lens surface) 2&fIF}vk>m  
    '************************************************************************* E@QsuS2&  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) pLMki=.Ld  
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    ' Delete any z-shift(s) 8YFfnk  
    count = 0 UMUr"-l =  
    While GetOperationCount(eID)>count ewB&PR  
        GetOperation eID, count, op reLYtv  
        If op.Type="ShiftZ" Then 0+IJ, ;Wx  
            DeleteOperation eID,count SFKW"cP  
            count=count-1 !$hrK6o  
        End If :av6*&+  
        count=count+1 ;<0Q<0G  
    Wend y]eH@:MJ;A  
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    'Set new z-shift m *8[I  
    op.Type = "ShiftZ" 1R9hA7y&,/  
    op.val1 = tlens e#IED!U  
    op.parent = parID ->&AJI0  
    AddOperation eID, op pgT{#[=>  
    Print "Set lens thickness = " & tlens q{Hk27kt  
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    '************************************************************************* ?,NZ/n  
    'Lens index of refraction
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    '************************************************************************* 4W}8?&T  
    eID = FindMaterial( "Lens" ) X<ZIeZBn  
    GetModelMaterial eID, mat Y[Us"K`  
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    mat.Nd = nlens a^i`DrX  
    SetModelMaterial eID, mat YMLo~j4J  
    Print "Set lens index of refraction = " & nlens "?lirOD  
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    '************************************************************************* Hk8:7"4Q  
    'Pupil diameter VcIsAK".4[  
    '************************************************************************* `ysPEwA|  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) =K{$?%"  
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    'Adjust pupil diameter (trimming volume inner hole) K,%H*1YKK  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" 9I=J#Hi|+  
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    ' Adjust pupil location to just in front of the lens kvv-f9/-  
    parID = FindFullName( "Geometry.Arizona Eye" ) P (jlWr$$  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) d6,%P6  
    count = 0 pmB}a7  
    While GetOperationCount(eID)>count K+Al8L?K_  
        GetOperation eID, count, op U*,8,C  
        If op.Type="ShiftZ" Then cH'*J/  
            DeleteOperation eID,count :h0as!2@dp  
            count=count-1 Xj"/6|X  
        End If o+
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        count=count+1 l/[@1(F  
    Wend CjORL'3  
    op.Type = "ShiftZ" 
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    op.val1 = taq-0.01 akgXI^K  
    op.parent = parID r vVU5zA4H  
    AddOperation eID, op |~hSK  
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    Print "Set pupil diameter = " & pupilDiam =#n05*^  
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    'Update AZ Eye subassembly Description 8^&)A b  
    eID = FindFullName( "Geometry.Arizona Eye" ) f!e8xDfA  
    GetEntity eID, entity p9XHYf72  
    entity.Description = "Accommodation = " & A & "D" )QaI{ z  
    SetEntity eID, entity UF=5k~7<b  

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    Update s ,\w00-:  
    Print "DONE!" !0c7nzjm  
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End Sub BqP:]  
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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： gl:vJD  
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Accommodation = 4 Diopters 6Bmv1n[X^h  
Pupil Diameter = 4 mm \% !]qv  
Set aqueous humor thickness = 2.81 X<K[` =I  
Set anterior lens radius = 10.4 and conic constant = -2.375869 +cheLc  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 wd~e3%JM  
Set lens thickness = 3.927 2W|4
 
Set lens index of refraction = 1.42672 c%>t(ce`Tl  
Set pupil diameter = 4 lg&"=VXx51  
DONE! FoWE<  
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