[技术]Arizona眼睛模型 [复制链接]

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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。 Mf0g)X}1  
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模型 [T', ZLR|  
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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。 >b;fhdd:4  
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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. ~:ddT
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光源 VHX&#vm*  
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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。 ?4=8z8((!  
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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。 0 1[LPN  
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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。 R}4o{l6  
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视网膜的散射 
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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。 =tl[?6  
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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。 +]Of f^s  
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脚本 ~,yHE3B\G  
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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： &9\z!r6mc  
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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。 !o &+  
余下的脚本计算与屈光度有关的所有参数。 VP=(",`  
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分析 BR\%
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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。 vOsd>3"  
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脚本代码 94%gg0azp  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. CFqoD l  
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Dim entity As T_ENTITY (r`+q[  
Dim op As T_OPERATION 49}yw
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Dim mat As T_MODELMATERIAL OlhfBu)~  
Dim A As Double A|tee@H*0  
Dim pupilDiam As Double ` =dD6r  
Dim eID As Long !*u5HVn  
Dim parID As Long )F&@ M;2p'  
Dim count As Integer ?*E Y~'I  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double exV6&bdu  
Dim tlens As Double, nlens As Double i0,{*LD%^  
Dim curv As Double, conic As Double ?UQVmE&  
Dim ok As Long W^0F(9~!(  
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Sub Main W5(t+$L.  
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    '用户输入对话框 j11\t  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 mp0p#8txi  
        TextBox 220,21,40,21,.TextBox1 'default: 0 JU:!lyd  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 zB\g'F/  
        OKButton 40,91,90,21 KgVit+4u/  
        CancelButton 190,91,90,21 ]>/YU*\  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 [y}/QPR  
        TextBox 220,49,40,21,.TextBox2 'default: 4 ]R}#3(]1  
    End Dialog y#HD1SZ  
    Dim dlg As UserDialog
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    ok = Dialog (dlg) WM: ~P$%cx  
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    If ok=0 Then    'cancel button was pressed a*CP1@O  
        Print "Execution cancelled." 9:A>a3KOH  
        End ?+GbPG~  
    End If 93x.b]]"  
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    'Assign accommodation and pupil diameter & use defaults if field left empty ,oIZ5u{#,  
    If dlg.TextBox1 = "" Then |`s}PcV  
        A = 0           'Default accommodation MTb}um.($  
    Else Ol9U^  
        A = CDbl(dlg.TextBox1) FFbMG:>:  
    End If "Na9Xea  
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    If dlg.TextBox2 = "" Then VbM5]UT/  
        pupilDiam = 4   'Default pupil diameter V-A^9AAPm  
    Else yNc>s/  
        pupilDiam = CDbl(dlg.TextBox2) tzi+A;>c(v  
    End If m<8j' [+  
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    Print " " KU-z;}9s  
    Print "Accommodation = " & A & " Diopters" cAyR)Y!I  
    Print "Pupil Diameter = " & pupilDiam & " mm" ro@Zbm;P  
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    ' Calculate new parameters with accommodation (&PamsV*8  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness i0-!!  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens |{PQ0DS  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens >1pD'UZIy7  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens B_hob  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens Qu!\Cx@  
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    tlens = 3.767 + 0.04*A                  'Lens thickness *Vfas|3hZI  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction P)1@HDN==  
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    'Adjust parameters to account for accommodation H4l:L(!D  
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    '************************************************************************* "x\3`Qk  
    'Aqueous thickness (Position of Lens) =e$ #m;  
    '************************************************************************* T~"
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    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) 0
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    GetCustomElement eID, entity (n" )  
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    parID = FindFullName( "Geometry.Arizona Eye" ) OOl{  
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    ' Delete any shift(s) in z t)cG_+rJ  
    count = 0 CSr{MF`]e  
    While GetOperationCount(eID)>count cnLC>_hY  
        GetOperation eID, count, op v^@L?{"}8  
        If op.Type="ShiftZ" Then 1"/V?ArfL  
            DeleteOperation eID,count <$?:|  
            count=count-1 h4?+/jk7  
        End If <g*rTqT'  
        count=count+1 f
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    Wend )V@qH]  
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    'Set new shift in 'Dat.@j  
    op.Type = "ShiftZ" >7;JZuVo  
    op.val1 = taq n:wn(BC3  
    op.parent = parID "3\RJ?eW:S  
    AddOperation eID, op C{!Czz.N  
    Print "Set aqueous humor thickness = " & taq-0.55 <(f4#BP  
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    '************************************************************************* '')G6-c/  
    'Radius and conic constant of anterior lens cYbO)?mC_  
    '************************************************************************* .z[+sy_  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) YvYavd  
    GetConic eID, entity, curv, conic uXhp+q\  
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    SetConic eID, entity, 1/Rant, CCant 7PQedZ<\  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant e. [+xOu`  
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    '************************************************************************* ;euWpE;E\#  
    'Radius and conic constant of posterior lens nn=JM7e\9  
    '************************************************************************* hA@X;Mh^w  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) _I8-0DnOM  
    GetConic eID, entity, curv, conic A%GJ|h,i  

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    SetConic eID, entity, 1/Rpost, CCpost piId5Gx7  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost wZC'BLD  
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    '*************************************************************************
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    'Lens thickness (Position of posterior lens surface) }2\"(_  
    '************************************************************************* <5X@r#Lz  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) [=9R5.)c  
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    ' Delete any z-shift(s) CD[7h  
    count = 0 ^#=L?e  
    While GetOperationCount(eID)>count 7q\c\qL  
        GetOperation eID, count, op p0tv@8C>  
        If op.Type="ShiftZ" Then
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            DeleteOperation eID,count K&X'^|en  
            count=count-1 I}q-J~s  
        End If Gt1Up~\s  
        count=count+1 AH7k|6ku<*  
    Wend )a}5\
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    'Set new z-shift 3jI.!xD`  
    op.Type = "ShiftZ" g@U#Y#b@"  
    op.val1 = tlens H 0h  
    op.parent = parID =CVw0'yZ  
    AddOperation eID, op asF-mf;D  
    Print "Set lens thickness = " & tlens :rj78_
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    '************************************************************************* t/$xzsoJZr  
    'Lens index of refraction O<E0L&4-&  
    '************************************************************************* uqyf3bK  
    eID = FindMaterial( "Lens" ) O-B3@qQ. h  
    GetModelMaterial eID, mat Wp]EaYt2D  
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    mat.Nd = nlens e56#Qb@$\  
    SetModelMaterial eID, mat jG2w(h/"  
    Print "Set lens index of refraction = " & nlens Cn55%:  
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    '************************************************************************* g}D$`Nx:  
    'Pupil diameter J)G3Kq5>:b  
    '************************************************************************* g\l;>  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) xL BG}C  
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    'Adjust pupil diameter (trimming volume inner hole) }ot _k-  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" <oO,CXF  
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    ' Adjust pupil location to just in front of the lens ep?0@5D}]  
    parID = FindFullName( "Geometry.Arizona Eye" ) m7"f6zSo(  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) }-vBRY  
    count = 0 gfYB|VyWo  
    While GetOperationCount(eID)>count Wk|z\OR(  
        GetOperation eID, count, op Zb 2  
        If op.Type="ShiftZ" Then IBqY$K+l  
            DeleteOperation eID,count H6I #Xj  
            count=count-1 |rvrSab)  
        End If LnDj   
        count=count+1 ]Rye AJ3  
    Wend ^55?VQB  
    op.Type = "ShiftZ" /kz&9FM  
    op.val1 = taq-0.01 m\f_u*  
    op.parent = parID A|
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    AddOperation eID, op OeYLL4H  
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    Print "Set pupil diameter = " & pupilDiam R u5&xIQ  
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    'Update AZ Eye subassembly Description @"!SU'*  
    eID = FindFullName( "Geometry.Arizona Eye" ) G|lI=Q3f  
    GetEntity eID, entity K5>:WiY  
    entity.Description = "Accommodation = " & A & "D" `$H  
    SetEntity eID, entity z
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    Update [S:)UvB  
    Print "DONE!" &w0=/G/T=~  
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End Sub fYy.>m+P1  
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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： }L!`K"^O&  
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Accommodation = 4 Diopters zRu`[b3u<  
Pupil Diameter = 4 mm |esjhf}H>v  
Set aqueous humor thickness = 2.81 G 7]wg>*  
Set anterior lens radius = 10.4 and conic constant = -2.375869 )^H9C"7T  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 W~3tQ!  
Set lens thickness = 3.927 6t:c]G'J  
Set lens index of refraction = 1.42672 MuGg z>CV[  
Set pupil diameter = 4 14!J\`rI  
DONE! >e;STU