[技术]Arizona眼睛模型 [复制链接]

简介 f(~N+2}  
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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。 U$& '>%#  
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模型 83t/\x,Q  
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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。 /:(A9b-B  
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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. 'o#oRK{#  
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光源 jga\Ry=nw  
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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。 mY4pvpZw8  
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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。 !W@mW 5J|  
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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。 PRaVe,5a  
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视网膜的散射 D^US2B  
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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。 8TeOh1\  
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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。 2WFZ6  
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脚本 zH}3J}  
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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： P7XZ|Td4*
 
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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。 -?)^ hbr  
余下的脚本计算与屈光度有关的所有参数。 {jB>]7  
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分析 /h+ W L  
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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。 3u/JcU-<  
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脚本代码 P|$n   
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. g&xj(SMj-$  
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Dim entity As T_ENTITY %%s)D4sW  
Dim op As T_OPERATION h2Nt@  
Dim mat As T_MODELMATERIAL y%i9 b&gDd  
Dim A As Double EyA ny\"  
Dim pupilDiam As Double H@1'El\9  
Dim eID As Long 3&^hf^yg  
Dim parID As Long 8Re[]bE  
Dim count As Integer \+R%KA/F  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double Q
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Dim tlens As Double, nlens As Double >S7t  
Dim curv As Double, conic As Double cj>UxU][eS  
Dim ok As Long QX<n^W  
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Sub Main . fja;aG  
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    '用户输入对话框 A r]*?:4y[  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 ]{6/6jl  
        TextBox 220,21,40,21,.TextBox1 'default: 0 1DB{"8ov  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 ):G%o  
        OKButton 40,91,90,21 =\%
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        CancelButton 190,91,90,21 mxgT}L0i  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 6 H P66B  
        TextBox 220,49,40,21,.TextBox2 'default: 4 (NLw#)?  
    End Dialog `&D#P%  
    Dim dlg As UserDialog r89AX{:  
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    ok = Dialog (dlg) Z8$BgP  
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    If ok=0 Then    'cancel button was pressed 47Z3nl?  
        Print "Execution cancelled." ]!{S2x&"  
        End 0 MK}  
    End If u?`{s88_mF  
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    'Assign accommodation and pupil diameter & use defaults if field left empty %jjPs.  
    If dlg.TextBox1 = "" Then u4~+Bc_GL  
        A = 0           'Default accommodation )\Q(=:  
    Else tC'E#2  
        A = CDbl(dlg.TextBox1) S<i1t[E@W  
    End If 6AJk6W^Z  
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    If dlg.TextBox2 = "" Then IrL%0&*hS  
        pupilDiam = 4   'Default pupil diameter 6NX#=A  
    Else (BLxK)0<"  
        pupilDiam = CDbl(dlg.TextBox2) / rc[HbNg.  
    End If %cSx`^`6j  
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    Print " " ?0t^7HMP  
    Print "Accommodation = " & A & " Diopters" c},pu[nL  
    Print "Pupil Diameter = " & pupilDiam & " mm" (Y)2[j  
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    ' Calculate new parameters with accommodation Wz'!stcp  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness {jO+N+Ez9  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens <rE>?zvm  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens ]_h3  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens VH]}{i"`  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens kAEq+{h  
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    tlens = 3.767 + 0.04*A                  'Lens thickness %N-aLw\  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction CO`)XB6W  
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    'Adjust parameters to account for accommodation $97O7j@  
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    '************************************************************************* LXo$\~M8G8  
    'Aqueous thickness (Position of Lens) S&}7XjY  
    '************************************************************************* R)66qRf  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" )
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    GetCustomElement eID, entity T$lV+[7  
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    parID = FindFullName( "Geometry.Arizona Eye" ) N-upNuv  
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    ' Delete any shift(s) in z G~5pMyOR  
    count = 0 Sh!c]r>\Q  
    While GetOperationCount(eID)>count !=:>yWQ  
        GetOperation eID, count, op Ts !g=
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        If op.Type="ShiftZ" Then 44*#qLN  
            DeleteOperation eID,count }%Mdf6LS64  
            count=count-1 !s-A`} s+  
        End If eP]y\S*
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        count=count+1 #S?^?3d  
    Wend by>%}#M  
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    'Set new shift in /GGyM
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    op.Type = "ShiftZ" O z0-cM8t  
    op.val1 = taq u
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    op.parent = parID X6 BIZ  
    AddOperation eID, op vSnVq>-q&  
    Print "Set aqueous humor thickness = " & taq-0.55 A.r7 ks  
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    '************************************************************************* U*a#{C7"  
    'Radius and conic constant of anterior lens h7+"*fN  
    '************************************************************************* ura&9~  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) F[}#7}xjA  
    GetConic eID, entity, curv, conic s-rc0:I  
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    SetConic eID, entity, 1/Rant, CCant 73X*|g  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant n0l|7:Mk  
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    '************************************************************************* xK6`|/e  
    'Radius and conic constant of posterior lens + -Rf@  
    '************************************************************************* P{)D_Bi  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) )(G<(eiD  
    GetConic eID, entity, curv, conic @]n8*n  
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    SetConic eID, entity, 1/Rpost, CCpost #[M^Q h  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost n3$=&  
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    '************************************************************************* }SWfP5D@  
    'Lens thickness (Position of posterior lens surface) vy~6]hH  
    '************************************************************************* 5Yv*f:  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) ZOfv\(iJ;  
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    ' Delete any z-shift(s) 4|_xz;i  
    count = 0 HVA:|Z19  
    While GetOperationCount(eID)>count p'LLzc##  
        GetOperation eID, count, op 3q4Zwv0z20  
        If op.Type="ShiftZ" Then Xd:{.AXW  
            DeleteOperation eID,count &C MBTY#u  
            count=count-1 ,5zY1C==Ut  
        End If Cl3vp_  
        count=count+1 R7rM$|n=o  
    Wend Y[L,rc/j  
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    'Set new z-shift BaIpX<$T  
    op.Type = "ShiftZ" 2T*kmDp  
    op.val1 = tlens kI`HD
 
    op.parent = parID SHYekX  
    AddOperation eID, op g"sb0d9  
    Print "Set lens thickness = " & tlens #tZ!D^GQHq  
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    '************************************************************************* qGag{E5!  
    'Lens index of refraction tiGH#~?  
    '************************************************************************* LNJK
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    eID = FindMaterial( "Lens" ) 7a9">:~  
    GetModelMaterial eID, mat 9K}DmS  
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    mat.Nd = nlens ,9G'1%z,  
    SetModelMaterial eID, mat Ydsnu  
    Print "Set lens index of refraction = " & nlens Bs0~P 4^  
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    '************************************************************************* }2LG9B%  
    'Pupil diameter H%n
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    '************************************************************************* 0>j0L8#^p  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) C4E}.``Hm  
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    'Adjust pupil diameter (trimming volume inner hole) DA=LR  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" NUiv"tAY  

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    ' Adjust pupil location to just in front of the lens ^4WZ%J#g  
    parID = FindFullName( "Geometry.Arizona Eye" ) Q-h< av9  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) IrRy1][Qr  
    count = 0 ISZEP8w  
    While GetOperationCount(eID)>count J",Cwk\  
        GetOperation eID, count, op /b{@']  
        If op.Type="ShiftZ" Then rYPuo  
            DeleteOperation eID,count |7|'JTy  
            count=count-1 GKg #nXS  
        End If 9Q(Lnu  
        count=count+1 _Rjbm'kC  
    Wend
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    op.Type = "ShiftZ" Y_$!XIJ4  
    op.val1 = taq-0.01 IH*G
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    op.parent = parID g#{7qmM  
    AddOperation eID, op ~yN>9fU  
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    Print "Set pupil diameter = " & pupilDiam 1h(n}u  
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    'Update AZ Eye subassembly Description [D|Uwq  
    eID = FindFullName( "Geometry.Arizona Eye" ) # .&t'"u  
    GetEntity eID, entity )sIzBC  
    entity.Description = "Accommodation = " & A & "D" .gNJY7
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    SetEntity eID, entity c;b<z|}z  
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    Update 4Vj]bm  
    Print "DONE!" kazgI>"Q8  
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End Sub sn[<Lq  
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如果屈光度是4，光瞳直径是4，则会输出如下数据： 3KD:JKn^  
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Accommodation = 4 Diopters @(/$;I,  
Pupil Diameter = 4 mm 1(aib^!B  
Set aqueous humor thickness = 2.81 ,!AYeVq  
Set anterior lens radius = 10.4 and conic constant = -2.375869 e'|P^G>g  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 }+NlYD:qF  
Set lens thickness = 3.927 _B4N2t$  
Set lens index of refraction = 1.42672 ?)qm=mebY  
Set pupil diameter = 4 B_c-@kl   
DONE! L!5="s[}