[技术]Arizona眼睛模型 [复制链接]

简介 ;1%-8f:lW  
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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。 _#r+ !e  
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模型 5]AC*2(  
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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。 aqj@Cjk4Z  
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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. )N7Y^CN~  
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光源 X*{2[+<o  
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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。 7ccO93Mz  
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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。 Jl#%uU/sx  
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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 B{'( L|  
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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。 ki?S~'a  
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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。 qz0;p=$8Z  
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脚本 NbgK@eV}+{  
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内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： }\\KYyjY  
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如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 a@@)6FM  
余下的脚本计算与屈光度有关的所有参数。 Yu)NO\3&  
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分析 wr$M$i:  
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屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 C8Qa$._  
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脚本代码 zNxW'?0Z
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. "Zl5<  
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Dim entity As T_ENTITY x:),P-~w  
Dim op As T_OPERATION }<@b=_>S  
Dim mat As T_MODELMATERIAL S- pV_Ff  
Dim A As Double ~<_2WQ/$  
Dim pupilDiam As Double HCyv]LR  
Dim eID As Long D~
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Dim parID As Long >7I15U  
Dim count As Integer &7PG.Ff!r  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double qf!p 9@4F[  
Dim tlens As Double, nlens As Double p"n$!ilbm  
Dim curv As Double, conic As Double $8UUzk  
Dim ok As Long $Tu61zq  
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Sub Main ^l9N48]|?  
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    '用户输入对话框 2NC.Z;  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 CG0 M  
        TextBox 220,21,40,21,.TextBox1 'default: 0 g.BdlVB\  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 Si8p
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        OKButton 40,91,90,21 NidIVbT.A  
        CancelButton 190,91,90,21 _F>CBG  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 K@I D/]PF  
        TextBox 220,49,40,21,.TextBox2 'default: 4 s5CXwM6cx  
    End Dialog {1UQ/_  
    Dim dlg As UserDialog Yw^m  
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    ok = Dialog (dlg) \NgYTZ  
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    If ok=0 Then    'cancel button was pressed lR )
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        Print "Execution cancelled." )bS yB29S  
        End {:6r;TB  
    End If i,>khc  
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    'Assign accommodation and pupil diameter & use defaults if field left empty 7gf05Z'=  
    If dlg.TextBox1 = "" Then %zG;Q@  
        A = 0           'Default accommodation hs^zTZ_  
    Else 11o.c;  
        A = CDbl(dlg.TextBox1) ]^h]t~  
    End If 0z1ifg&  
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    If dlg.TextBox2 = "" Then >V-A;S:  
        pupilDiam = 4   'Default pupil diameter 't:;irLW.  
    Else \k.{-nh  
        pupilDiam = CDbl(dlg.TextBox2) pMw*9sX  
    End If dP3CG8w5  
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    Print " " '@o;-'b  
    Print "Accommodation = " & A & " Diopters" |2O]R s  
    Print "Pupil Diameter = " & pupilDiam & " mm" l4F%VR4KT  
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    ' Calculate new parameters with accommodation tr<Nm6!  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness iW$_zgN  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens ((H^2KJn  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens zZL6z4g  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens I(i}c~R  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens a=J^  
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    tlens = 3.767 + 0.04*A                  'Lens thickness cz >V8  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction /sx@$cvW  
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    'Adjust parameters to account for accommodation mk;&yh  
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    '************************************************************************* 7?#J~.d5  
    'Aqueous thickness (Position of Lens) ?9!6%]2D  
    '************************************************************************* Nv#t:J9f  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) /5S30 |K  
    GetCustomElement eID, entity 9]k @Q_  
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    parID = FindFullName( "Geometry.Arizona Eye" ) h{%nC>m;  
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    ' Delete any shift(s) in z } df
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    count = 0 }q_<_lQ  
    While GetOperationCount(eID)>count PC~Y8,A|.t  
        GetOperation eID, count, op y&6FybIz  
        If op.Type="ShiftZ" Then WffQ:L?  
            DeleteOperation eID,count p*< 0"0  
            count=count-1 H=<S 9M  
        End If 8m-U){r!U^  
        count=count+1 g2BHHL;`  
    Wend _dqzB$JV  
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    'Set new shift in *1uKr9  
    op.Type = "ShiftZ" o)h_H;  
    op.val1 = taq CuFSeRe  
    op.parent = parID '.on)Zd.  
    AddOperation eID, op U_Vs.M.p  
    Print "Set aqueous humor thickness = " & taq-0.55 &q3"g*q  
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    '************************************************************************* @Pm>sY}d<I  
    'Radius and conic constant of anterior lens N@2dA*T,  
    '************************************************************************* 0]'7_vDs|  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) bLB:MW\%  
    GetConic eID, entity, curv, conic D[4u+g?[}>  
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    SetConic eID, entity, 1/Rant, CCant rV2WnAb[H&  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant L9r8BK;  
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    '************************************************************************* <lgYcdJ   
    'Radius and conic constant of posterior lens o m^0}$V  
    '************************************************************************* {o)Lc6T8s  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) QiQ_bB!\  
    GetConic eID, entity, curv, conic ]_Vx{oT7  
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    SetConic eID, entity, 1/Rpost, CCpost 4;w;'3zq  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost LzG%Z1`  
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    '************************************************************************* riUwBiVa?2  
    'Lens thickness (Position of posterior lens surface) ];VA!++  
    '************************************************************************* {ME2ImD  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) lsgh#x  
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    ' Delete any z-shift(s) o1
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    count = 0 KT_!d*  
    While GetOperationCount(eID)>count &4{KV.  
        GetOperation eID, count, op )fF
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        If op.Type="ShiftZ" Then |v`AA?@{8  
            DeleteOperation eID,count Cw iKi^m  
            count=count-1 $~~Jw]   
        End If Ar%%}Gx/  
        count=count+1 <C_jF  
    Wend Lco~,OE  
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    'Set new z-shift ~,d,#)VE2q  
    op.Type = "ShiftZ" cpe+XvBuK  
    op.val1 = tlens &SIq2>QA  
    op.parent = parID tGD6AI1"I  
    AddOperation eID, op tnV/xk#!  
    Print "Set lens thickness = " & tlens 8Ry3`ct  
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    '************************************************************************* L
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    'Lens index of refraction J &o|QG  
    '************************************************************************* ",p;Sd  
    eID = FindMaterial( "Lens" ) |+"<wEKI  
    GetModelMaterial eID, mat 1[mXd  
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    mat.Nd = nlens _- [''(E
  
    SetModelMaterial eID, mat 2n,*Nd`  
    Print "Set lens index of refraction = " & nlens ^Xuvy{TkPH  
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    '************************************************************************* wa(8Hl|Y  
    'Pupil diameter r  [9x  
    '************************************************************************* &X`C%h  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) $CxKuB(  
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    'Adjust pupil diameter (trimming volume inner hole) ?# Mr  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder"  jPC[_g  
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    ' Adjust pupil location to just in front of the lens Av @b!iw+  
    parID = FindFullName( "Geometry.Arizona Eye" ) CWf /H)~  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) 5uGqX"  
    count = 0 #c!*</  
    While GetOperationCount(eID)>count
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        GetOperation eID, count, op NWP5If|'X  
        If op.Type="ShiftZ" Then +y,T4^{  
            DeleteOperation eID,count E_gD:PPU5  
            count=count-1 LZ\q37UV  
        End If HvUxsdT  
        count=count+1 Q;MT"=RW  
    Wend `0rd26Qro  
    op.Type = "ShiftZ" Jx_cf9{  
    op.val1 = taq-0.01 c4!^nk]  
    op.parent = parID g(nPQOs$u  
    AddOperation eID, op TSA,WP\  
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    Print "Set pupil diameter = " & pupilDiam <i
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    'Update AZ Eye subassembly Description Y4%:7mw~=  
    eID = FindFullName( "Geometry.Arizona Eye" ) Pih tf4
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    GetEntity eID, entity m9)p-1y@5  
    entity.Description = "Accommodation = " & A & "D" 7;u e
 
    SetEntity eID, entity `+`Z7  
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    Update .\K_@M  
    Print "DONE!" Twh!X*uQ  
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End Sub OL5v).Bb  
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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： < |e,05aM  
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Accommodation = 4 Diopters W"724fwu&  
Pupil Diameter = 4 mm .R`5Qds*l  
Set aqueous humor thickness = 2.81 ai}mOyJs  
Set anterior lens radius = 10.4 and conic constant = -2.375869 1h(0IjG8  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 ?=>+LqP  
Set lens thickness = 3.927 d^/3('H6  
Set lens index of refraction = 1.42672 so^lb?g  
Set pupil diameter = 4 ,?PTcQF  
DONE! B! rTD5a