[技术]Arizona眼睛模型 [复制链接]

简介 /{J4:N'B>  
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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。 ! I:%0
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模型 W+c<2?d:  
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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。 $99n&t$Y  
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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. iq8<ov  
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光源 wU36sCo  
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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。 H2 {+)  
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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。 pU}(@oy  
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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。 \:'/'^=#|  
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视网膜的散射 Fyx|z'4b  
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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。 9&2O9Nz6  
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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。 u%KTNa0  
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脚本 kZ .gO  
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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： KP^V>9q  
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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。 wu!59pL  
余下的脚本计算与屈光度有关的所有参数。 iN\4gQ!  
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分析 6 7.+ .2  
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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。 bdrg(d6  
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脚本代码 6Q@j  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. 'R
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Dim entity As T_ENTITY B\=8
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Dim op As T_OPERATION . B9iLI  
Dim mat As T_MODELMATERIAL yCR?UH;  
Dim A As Double Lc,Pom  
Dim pupilDiam As Double m+R[#GE8#  
Dim eID As Long jl$ece5v  
Dim parID As Long RD
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Dim count As Integer &MQmu,4  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double ?0?#U0(;u  
Dim tlens As Double, nlens As Double M61xPq8y5  
Dim curv As Double, conic As Double Su7?;Oh/yI  
Dim ok As Long _$YkM,  
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Sub Main ZRB)uA)5=  
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    '用户输入对话框 Y|f[bw  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 ,, OW  
        TextBox 220,21,40,21,.TextBox1 'default: 0 4<Utmr  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 c /HHy,  
        OKButton 40,91,90,21 xb~yM%*c  
        CancelButton 190,91,90,21 G
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        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 ^z IW+:  
        TextBox 220,49,40,21,.TextBox2 'default: 4 &\WSQmtto  
    End Dialog [)M%cyQ   
    Dim dlg As UserDialog 2B[X,rL.pX  
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    ok = Dialog (dlg) xd?f2=dd~h  
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    If ok=0 Then    'cancel button was pressed p!7FpxZY  
        Print "Execution cancelled." 2g-j.TM  
        End Oi'5ytsES  
    End If O7m(o:t x3  
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    'Assign accommodation and pupil diameter & use defaults if field left empty {_[N<U:QT&  
    If dlg.TextBox1 = "" Then iDp)FQ$  
        A = 0           'Default accommodation x7&B$.>3  
    Else dO<ERY  
        A = CDbl(dlg.TextBox1) %KlrSo  
    End If 3*"WG O5  
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    If dlg.TextBox2 = "" Then ghG**3xr  
        pupilDiam = 4   'Default pupil diameter rNWw?_H-H(  
    Else %9F([K  
        pupilDiam = CDbl(dlg.TextBox2) u<tbbKM  
    End If q]ku5A\y  
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    Print " " :Uzm  
    Print "Accommodation = " & A & " Diopters" i(%W_d!  
    Print "Pupil Diameter = " & pupilDiam & " mm" #uG%j  
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    ' Calculate new parameters with accommodation ?r "{}%  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness UT~4x|b:O  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens s 8jV(P(O  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens ifMRryN4  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens GX!G>  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens a od-3"7[  
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    tlens = 3.767 + 0.04*A                  'Lens thickness -8ywO"6  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction {0Yf]FQb-a  
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    'Adjust parameters to account for accommodation OhQgF  
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    '************************************************************************* K( c\wr\6  
    'Aqueous thickness (Position of Lens) n`B:;2X,
 
    '************************************************************************* 17%,7P9pg  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) |PCm01NU!  
    GetCustomElement eID, entity p?%y82E  
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    parID = FindFullName( "Geometry.Arizona Eye" ) mA}TJz  
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    ' Delete any shift(s) in z B:yGS*.tu  
    count = 0 hB]Np1('  
    While GetOperationCount(eID)>count .GPT!lDc  
        GetOperation eID, count, op O'p9u@kc  
        If op.Type="ShiftZ" Then ios&n)W&  
            DeleteOperation eID,count $kdB |4C  
            count=count-1 a8e6H30Sm  
        End If ?DS@e@lx  
        count=count+1 5K1)1E/Fu  
    Wend &v/dj@   
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    'Set new shift in }#RakV4  
    op.Type = "ShiftZ"  twHVv  
    op.val1 = taq iJ)_RSFK  
    op.parent = parID kYP#SH/  
    AddOperation eID, op e{'BAj  
    Print "Set aqueous humor thickness = " & taq-0.55 [B*x-R[FI  
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    '************************************************************************* "+R+6<"  
    'Radius and conic constant of anterior lens !I{0 _b
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    '************************************************************************* aB2FC$z  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) g-4
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    GetConic eID, entity, curv, conic 13$%,q
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    SetConic eID, entity, 1/Rant, CCant t9GR69v:?  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant v|_K/|  
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    '************************************************************************* htO+z7  
    'Radius and conic constant of posterior lens .ljnDL/  
    '************************************************************************* *2>&"B09`  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) 8rAg\H3E  
    GetConic eID, entity, curv, conic _P#
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    SetConic eID, entity, 1/Rpost, CCpost A_"w^E{P  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost l?v86k  
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    '************************************************************************* xk9%F?)
 
    'Lens thickness (Position of posterior lens surface) 0mYXv4 <  
    '************************************************************************* M!siK2  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) +[6G5
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    ' Delete any z-shift(s) B{n,t}
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    count = 0 TNT4<5Ol6  
    While GetOperationCount(eID)>count 1sy[@Q2b  
        GetOperation eID, count, op nSDMOyj+  
        If op.Type="ShiftZ" Then 
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            DeleteOperation eID,count >jDDQ@  
            count=count-1 ch*8B(:  
        End If Co9^OF-k  
        count=count+1 P1.[  
    Wend \i>?q  
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    'Set new z-shift {LI=:xJJv  
    op.Type = "ShiftZ" 5ORo3T%  
    op.val1 = tlens h]5(].  
    op.parent = parID JMCKcZ%N  
    AddOperation eID, op 
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    Print "Set lens thickness = " & tlens )rIwqUgp6\  
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    '************************************************************************* }`@vF|2L  
    'Lens index of refraction L8@f-Kk  
    '************************************************************************* ^x]r`b  
    eID = FindMaterial( "Lens" )  C#.->\  
    GetModelMaterial eID, mat ~p6 V,Q  
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    mat.Nd = nlens F@D`N0Pte  
    SetModelMaterial eID, mat +zqn<<9  
    Print "Set lens index of refraction = " & nlens ~f2z]JLr:  
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    '************************************************************************* ZuzEg*lb  
    'Pupil diameter RXMISt3+{y  
    '************************************************************************* Gm&Za,4%4  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) l ~"^7H?4e  
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    'Adjust pupil diameter (trimming volume inner hole) zEX  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" (Bb5?fw  
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    ' Adjust pupil location to just in front of the lens a@K%06A;'
 
    parID = FindFullName( "Geometry.Arizona Eye" ) E:_ZA  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) Bpo4?nCl}  
    count = 0 V;VHv=9`o  
    While GetOperationCount(eID)>count *uRBzO}  
        GetOperation eID, count, op ]"As1"  
        If op.Type="ShiftZ" Then 20h} [Q(  
            DeleteOperation eID,count q4h]o^+  
            count=count-1 Ys9[5@7  
        End If ,$L4dF3  
        count=count+1 |)th1 UH  
    Wend S/hQZHZHg,  
    op.Type = "ShiftZ" :wyno#8`-
 
    op.val1 = taq-0.01 #6aW9GO  
    op.parent = parID 23eX;gL  
    AddOperation eID, op %bn jgy  
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    Print "Set pupil diameter = " & pupilDiam ITXa&5D  
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    'Update AZ Eye subassembly Description [ZwjOi:)  
    eID = FindFullName( "Geometry.Arizona Eye" ) A/$QaB,x  
    GetEntity eID, entity V*;(kEqj  
    entity.Description = "Accommodation = " & A & "D" ha<[bue  
    SetEntity eID, entity MTh<|$   
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    Update @Sn(lnlB  
    Print "DONE!" %)8}X>xq  
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End Sub *!t/"b
  
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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： U[-o> W#  
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Accommodation = 4 Diopters E?f-wQF  
Pupil Diameter = 4 mm &vMb_;~B  
Set aqueous humor thickness = 2.81 Y;M|D'y+  
Set anterior lens radius = 10.4 and conic constant = -2.375869 !;v|'I  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 hpX9[3  
Set lens thickness = 3.927 ^ig' bw+WS  
Set lens index of refraction = 1.42672 `UyG_;  
Set pupil diameter = 4 `:K
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DONE! Tn e4