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infotek 2020-12-09 09:18

Arizona眼睛模型

简介 CcDi65s  
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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。 &IZthJqV  
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模型 2A,iY}R  
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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。 s\Zp/-Q  
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Table 1. AZ眼睛模型的定义
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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. _7k6hVQ  
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光源 [Y%H8}  
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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。 >^U$2P  
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图1. 光源和提示信息使用
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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。 l7p*: :(9  
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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。 ~8htg8CZ`  
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图2. 字母F光源的设定方法光 E+tV7xa~  
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图3. 字母F在视网膜上位置点列图
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视网膜的散射 .&Q'aOg  
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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。 piy_9nk  
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图4. 视网膜朗伯散射设定
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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。 uPvE;E_  
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图5. 视网膜重点采样规格设定
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脚本 EAE\'9T&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: B0&W wa:  
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图6. 用户对话框的创建与编辑
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图7. 用户对话框编辑器
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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。 =Ll:Ba Q  
余下的脚本计算与屈光度有关的所有参数。 /^XGIQ/W  
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分析 P_:~!+W,  
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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。 $vQ#ah/k  
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图7. 字母F在视网膜上颜色分析
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脚本代码 %~$P.Zh  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. o;#9$j7QP!  
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Dim entity As T_ENTITY i`F8kg`_K  
Dim op As T_OPERATION : K#z~#n  
Dim mat As T_MODELMATERIAL @ 7WWoy  
Dim A As Double UmC_C[/n?  
Dim pupilDiam As Double <Y9 L3O`[  
Dim eID As Long %xH2jf  
Dim parID As Long <691pk X  
Dim count As Integer 7"iUyZ(  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double )uJu.foE  
Dim tlens As Double, nlens As Double , (Bo .(]  
Dim curv As Double, conic As Double eOdB<He36  
Dim ok As Long Jh)x_&R&Q  
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Sub Main [ BpZ{Ql  
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    '用户输入对话框 aJmSagr69C  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 $XOs(>~"r  
        TextBox 220,21,40,21,.TextBox1 'default: 0 !i`HjV0wS  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 \*(A1Vk  
        OKButton 40,91,90,21 VPAi[<FzOG  
        CancelButton 190,91,90,21 $}*bZ~  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 ;B,6v P#  
        TextBox 220,49,40,21,.TextBox2 'default: 4 )nI}KQJ<  
    End Dialog 42{\u08Z  
    Dim dlg As UserDialog h:J0d~u  
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    ok = Dialog (dlg) )fRZ}7k:  
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    If ok=0 Then    'cancel button was pressed v*&WxP^Gm  
        Print "Execution cancelled." t04_~e  
        End ev$\Ns^g$3  
    End If ?$>#FKrt  
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    'Assign accommodation and pupil diameter & use defaults if field left empty 3kc.U  
    If dlg.TextBox1 = "" Then q3CcXYY  
        A = 0           'Default accommodation 6BnP"R.  
    Else PqhR^re0.  
        A = CDbl(dlg.TextBox1) |v'_Co0ki  
    End If )$.::[pNA  
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    If dlg.TextBox2 = "" Then ^E)*i#."4  
        pupilDiam = 4   'Default pupil diameter - s}  
    Else ^ |xSU_wa  
        pupilDiam = CDbl(dlg.TextBox2) 19r4J(pV  
    End If 5\?\ |*WT  
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    Print " " &"h 9Awn2  
    Print "Accommodation = " & A & " Diopters" O>h,u[0  
    Print "Pupil Diameter = " & pupilDiam & " mm" X*Qtbm,  
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    ' Calculate new parameters with accommodation 4IT`8n~  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness 4=Wtv/ 3  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens y,.X5#rnX*  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens s.zfiJ  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens hhqSfafUX  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens EGY'a*]cU  
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    tlens = 3.767 + 0.04*A                  'Lens thickness E/OJ}3Rf  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction vq.~8c1  
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    'Adjust parameters to account for accommodation C,;hNg[  
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    '************************************************************************* t=K;/ 1  
    'Aqueous thickness (Position of Lens) >\/H2j  
    '************************************************************************* X:un4B}O  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) <#[_S$54  
    GetCustomElement eID, entity n0nvp@?7bJ  
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    parID = FindFullName( "Geometry.Arizona Eye" ) _>6xU t  
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    ' Delete any shift(s) in z z)Yk&;XC  
    count = 0 Zgw;AY.R>  
    While GetOperationCount(eID)>count wU9H=w^  
        GetOperation eID, count, op a/n KKhXaM  
        If op.Type="ShiftZ" Then sW53g$`v  
            DeleteOperation eID,count 5yh:P3 /  
            count=count-1 hJkSk;^  
        End If R.Plfm06Ue  
        count=count+1 ;T9u$4 <  
    Wend =u*\P!$  
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    'Set new shift in ]d}h`!:  
    op.Type = "ShiftZ" WT-BHB1  
    op.val1 = taq 7lC );  
    op.parent = parID /uh?F  
    AddOperation eID, op L7gZ4Hu=`  
    Print "Set aqueous humor thickness = " & taq-0.55 C9,|G7~*q  
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    '************************************************************************* M_:_(y>l  
    'Radius and conic constant of anterior lens Ve]ufn6  
    '************************************************************************* GH6HdZ  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) 4/z K3%J  
    GetConic eID, entity, curv, conic (P+TOu-y\  
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    SetConic eID, entity, 1/Rant, CCant aB=&XGV9  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant &gP/<!#  
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    '************************************************************************* P0Q]Ds|  
    'Radius and conic constant of posterior lens >q}Ns^ .'  
    '************************************************************************* s>RtCw3,  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) d){o#@  
    GetConic eID, entity, curv, conic 3@t&5UjwQ  
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    SetConic eID, entity, 1/Rpost, CCpost /K@_O\+;Q  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost h^H~q<R[T  
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    '************************************************************************* 'e/= !"T  
    'Lens thickness (Position of posterior lens surface) ,y>%m;jL  
    '************************************************************************* $N}nO:`t  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) xT]|78h$   
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    ' Delete any z-shift(s) cE|Z=}4I7  
    count = 0 (i 3=XfZ!C  
    While GetOperationCount(eID)>count XBmAD!  
        GetOperation eID, count, op J&B>"s,  
        If op.Type="ShiftZ" Then I}Fv4wlZG  
            DeleteOperation eID,count ;cFlZGw   
            count=count-1 6*{sZMG  
        End If {mkD{2)KQ  
        count=count+1 e"){B  
    Wend /OX;3" +1  
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    'Set new z-shift oB$P6   
    op.Type = "ShiftZ" 1-h"1UN2E  
    op.val1 = tlens l2&s4ERqSm  
    op.parent = parID c=^A3[AM  
    AddOperation eID, op /qKO9M5A  
    Print "Set lens thickness = " & tlens (]Pr[xB  
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    '************************************************************************* zL%ruWNG  
    'Lens index of refraction 4P>4d +  
    '************************************************************************* 3YFbT Z  
    eID = FindMaterial( "Lens" ) ;b-d2R  
    GetModelMaterial eID, mat 0+iaO"%  
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    mat.Nd = nlens g5\EVcHkz  
    SetModelMaterial eID, mat \i2S'AblYq  
    Print "Set lens index of refraction = " & nlens k;fy8  
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    '************************************************************************* b: c$EPK  
    'Pupil diameter 3SeM:OYq]s  
    '************************************************************************* G2,9$8qE  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) BJL*Dih m[  
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    'Adjust pupil diameter (trimming volume inner hole) }OJ,<!v2pc  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" pO10L`|  
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    ' Adjust pupil location to just in front of the lens Q!T+Jc9N  
    parID = FindFullName( "Geometry.Arizona Eye" ) Za>0&Fnf  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) O 8\wH  
    count = 0 _[kZ:#  
    While GetOperationCount(eID)>count K,$Ro@!  
        GetOperation eID, count, op _'.YC<;  
        If op.Type="ShiftZ" Then zG|#__=T  
            DeleteOperation eID,count w]& o]VP  
            count=count-1 x,+2k6Wn!  
        End If G|LJOq7QB  
        count=count+1 T+q3]&  
    Wend }[2|86,G;  
    op.Type = "ShiftZ" gE}+`w/X  
    op.val1 = taq-0.01 mjI $z3  
    op.parent = parID ^(:Z*+X~>  
    AddOperation eID, op ;r1.Uz(  
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    Print "Set pupil diameter = " & pupilDiam rDEd MT  
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    'Update AZ Eye subassembly Description B S^P&TR!  
    eID = FindFullName( "Geometry.Arizona Eye" ) /ll2lyS+  
    GetEntity eID, entity UD+r{s/%  
    entity.Description = "Accommodation = " & A & "D" @5)THYAx4  
    SetEntity eID, entity jW< aAd  
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    Update Di^7@}kQS  
    Print "DONE!" 1k:s~m?!  
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End Sub WNa#X]*E)  
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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: >+3tOv3:  
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Accommodation = 4 Diopters Y;B#_}yF  
Pupil Diameter = 4 mm fN-y8  
Set aqueous humor thickness = 2.81 q]}1/JZS  
Set anterior lens radius = 10.4 and conic constant = -2.375869 "x"y3v'  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 N =0R6{'  
Set lens thickness = 3.927 MF}}o0P  
Set lens index of refraction = 1.42672 mKh <M)Bz  
Set pupil diameter = 4 *qN (_  
DONE! @XSxoUF\  
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