[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 Y"r728T`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。 g oyQ',+  
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模型 <%`Rku  
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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。 ]NI CQ9  
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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. om9'A=ZU  
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光源 WHOX<YJs  
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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。 cDzb}W*UM  
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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。 q8-hbWNm4  
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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。 8O(L;
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视网膜的散射 K/*"U*9Kv  
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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。 /V`SJ"  
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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。 S w%6-  
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脚本 -K(d]-yv  
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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： kaiK1/W0;  
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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。 $F9w0kz:,*  
余下的脚本计算与屈光度有关的所有参数。 BBGub?(dR  
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分析 j[FB*L1!D  
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屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 0vX6n6G}  
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脚本代码 `GY3H3B  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. 0*tnJB  
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Dim entity As T_ENTITY _e;bB?S  
Dim op As T_OPERATION w+)wrJTtm  
Dim mat As T_MODELMATERIAL -64;P9:A>  
Dim A As Double \lQI;b;$  
Dim pupilDiam As Double EW vhT]<0  
Dim eID As Long #a~BigZ[G  
Dim parID As Long 7UGc2J  
Dim count As Integer ?wv3HN  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double X[H.t$w5A  
Dim tlens As Double, nlens As Double .d[^&<^  
Dim curv As Double, conic As Double 6^V( C;5!  
Dim ok As Long dY0W=,X$7T  
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Sub Main YQFz6#Ew  
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    '用户输入对话框 ZsXw]Wa  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 QRKP
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        TextBox 220,21,40,21,.TextBox1 'default: 0  4q7H  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 1!;~Y#  
        OKButton 40,91,90,21 ^c(r4#}$"  
        CancelButton 190,91,90,21 $6J22m!S4n  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 "eOl(TSu/  
        TextBox 220,49,40,21,.TextBox2 'default: 4 hEZo{0:b"  
    End Dialog NF4(+E9g  
    Dim dlg As UserDialog cZF|oZ6<  
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    ok = Dialog (dlg) qzA_ ~=g
 
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    If ok=0 Then    'cancel button was pressed _z%~m2SP  
        Print "Execution cancelled." 4guR8 elM  
        End N}NKQ]=  
    End If MaD|X_g  
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    'Assign accommodation and pupil diameter & use defaults if field left empty cr]b
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    If dlg.TextBox1 = "" Then A-3^~aEgx  
        A = 0           'Default accommodation :=+YZ|&j  
    Else .57Fh)Y  
        A = CDbl(dlg.TextBox1) ):Z#!O<  
    End If v?6*n>R  
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    If dlg.TextBox2 = "" Then YU+P+m2X  
        pupilDiam = 4   'Default pupil diameter 1,$"'lKwt  
    Else
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        pupilDiam = CDbl(dlg.TextBox2) nsXG@CS:  
    End If 8rlf9m  
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    Print " " IgwHC0W  
    Print "Accommodation = " & A & " Diopters" ;8K>]T)  
    Print "Pupil Diameter = " & pupilDiam & " mm" ,ZrR*W?iF  
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    ' Calculate new parameters with accommodation Akc |E!V  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness V6_":L"!  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens _w%:PnO  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens 3dbaCusT$  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens Hhk`yX c_  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens ]3='TN8aQF  
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    tlens = 3.767 + 0.04*A                  'Lens thickness eg?p)|  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction {` bX*]  
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    'Adjust parameters to account for accommodation 0[<'ygu  
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    '************************************************************************* '-n Iy$>  
    'Aqueous thickness (Position of Lens) AX6:*aZB  
    '************************************************************************* <3N\OV2  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) ZBx,'ph}4  
    GetCustomElement eID, entity iR{@~JN=)  
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    parID = FindFullName( "Geometry.Arizona Eye" ) /y
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    ' Delete any shift(s) in z ?6ssSjR}  
    count = 0 NYg&8s.  
    While GetOperationCount(eID)>count nm%qm  
        GetOperation eID, count, op lf KV%  
        If op.Type="ShiftZ" Then _7;G$\^&.  
            DeleteOperation eID,count lFcHE c  
            count=count-1 @gf <%>  
        End If
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        count=count+1 !blGc$kC  
    Wend S5F5Tr;TN  
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    'Set new shift in *KiY+_8>  
    op.Type = "ShiftZ" :@E^oNKa0  
    op.val1 = taq HfP<hQmN'  
    op.parent = parID Yc~lYz+b  
    AddOperation eID, op 2sG1Hox  
    Print "Set aqueous humor thickness = " & taq-0.55 )g $T%  
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    '************************************************************************* =s'H o  
    'Radius and conic constant of anterior lens 3xP<J)S0  
    '************************************************************************* ?y>v"1+  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) ?5lO1(  
    GetConic eID, entity, curv, conic 5"!K8 N  
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    SetConic eID, entity, 1/Rant, CCant ;"EDFH#W  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant N.E{6_{S  
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    '************************************************************************* /FW$)w2{j  
    'Radius and conic constant of posterior lens H>]*<2(=-  
    '************************************************************************* O5+Ah%  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) zT/woiyB`  
    GetConic eID, entity, curv, conic Kc1w[EQ  
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    SetConic eID, entity, 1/Rpost, CCpost jY/(kA]}  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost mKV31wvK}  
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    '************************************************************************* 7oUo[  
    'Lens thickness (Position of posterior lens surface) j1+I_  
    '************************************************************************* V8o, e  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) 9<P%?Q  
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    ' Delete any z-shift(s) ]0%{IgB  
    count = 0 }lJ|nl`
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    While GetOperationCount(eID)>count Q($@{[lT  
        GetOperation eID, count, op A93(} V7I  
        If op.Type="ShiftZ" Then > 9z-/e  
            DeleteOperation eID,count |rhB@k  
            count=count-1 @V Tw>=94  
        End If k@n L(2  
        count=count+1 3w[uc~f  
    Wend 3qNuv];2  
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    'Set new z-shift } MP_  
    op.Type = "ShiftZ" g}9heR  
    op.val1 = tlens 94*MRn1E  
    op.parent = parID k!+v*+R+V  
    AddOperation eID, op N5cC!K  
    Print "Set lens thickness = " & tlens aGE} EK}  
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    '************************************************************************* q %tq9%  
    'Lens index of refraction Sw[*1C8  
    '************************************************************************* $mf6!p4  
    eID = FindMaterial( "Lens" ) Dp^=%F{t  
    GetModelMaterial eID, mat Y1qbu~!  
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    mat.Nd = nlens es+ZPX>Y  
    SetModelMaterial eID, mat |-GbHfz  
    Print "Set lens index of refraction = " & nlens o(3OChH  
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    '************************************************************************* MfFmJ7>Bg  
    'Pupil diameter d]E.F64{  
    '************************************************************************* 2U+Fat@  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) y=SpIbn{  
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    'Adjust pupil diameter (trimming volume inner hole) =G'J@[d{d  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder"
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    ' Adjust pupil location to just in front of the lens iZ ;562Mo  
    parID = FindFullName( "Geometry.Arizona Eye" ) !g~u'r'1  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) &oK&vgcj  
    count = 0 8<EU|/O  
    While GetOperationCount(eID)>count poqNiOm4%  
        GetOperation eID, count, op sN1I
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        If op.Type="ShiftZ" Then 2Aa  
            DeleteOperation eID,count YQO9$g0% ~  
            count=count-1 V`feUFw3  
        End If |hu9)0P  
        count=count+1 scd}{Y  
    Wend =}SC .E\  
    op.Type = "ShiftZ" LN'})CI8m  
    op.val1 = taq-0.01 T^Xum2Ec  
    op.parent = parID c+1<3)Q<  
    AddOperation eID, op :pP l|"
 
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    Print "Set pupil diameter = " & pupilDiam *zX^Sg-[  
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    'Update AZ Eye subassembly Description ;,B $lgF  
    eID = FindFullName( "Geometry.Arizona Eye" ) vFgnbWxG  
    GetEntity eID, entity x$b
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    entity.Description = "Accommodation = " & A & "D" !T]bz+  
    SetEntity eID, entity M>jk"*hA|  
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    Update xw1n;IO4  
    Print "DONE!" p;2NO&  
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End Sub %#lJn.o  
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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： $n<X'7@0  
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Accommodation = 4 Diopters 0VI[6t@  
Pupil Diameter = 4 mm a ,
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Set aqueous humor thickness = 2.81 r5!Sps3B  
Set anterior lens radius = 10.4 and conic constant = -2.375869 =G1 5eZW  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 %h=cwT6  
Set lens thickness = 3.927 nrz2f7d$  
Set lens index of refraction = 1.42672 sYyya:ykxT  
Set pupil diameter = 4 >=L<3W1  
DONE! p=f8A71  
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