[分享]Arizona眼睛模型 [复制链接]

简介 vXE0%QE'Q  
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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。 xHA0gZf  
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模型 <vV_%uoM  
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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。 3Q^fVn$tk  
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在FRED中使用0屈光度来创建的，光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. bulS&dAX  
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光源 r6Aneg7  
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多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 XvTCK>1  
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除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处，并增加了pre-propagation distance= -8。尽管光线在光瞳处创建，规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射，而不是在光瞳处入射。 zi@]83SS#  
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在往下看是内置的脚本用来修改屈光度，使其为4（250mm），光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 <ABX0U[*  
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视网膜的散射 4GdX/6C.  
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在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 2_^aw[-  
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注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 Pz*_)N}j >  
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脚本 s#~GH6/  
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内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： % 2$/JZ  
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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。 fWfk[(M'9  
余下的脚本计算与屈光度有关的所有参数。 t7n(Qkrv  
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分析 M5nWVK7c  
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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。 f"7O "6  
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脚本代码 ]^':Bmq  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. C2LL|jp*  
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Dim entity As T_ENTITY wO ?+Nh  
Dim op As T_OPERATION _vSn`  
Dim mat As T_MODELMATERIAL k.("3R6v:  
Dim A As Double dm0QcW4  
Dim pupilDiam As Double j 8*ZF  
Dim eID As Long p&+;w  
Dim parID As Long }bY;q-  
Dim count As Integer pyLRgD0 g  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double (py]LBZ  
Dim tlens As Double, nlens As Double &%})wZ+Dj  
Dim curv As Double, conic As Double I2nF-JzD2a  
Dim ok As Long H 0+dV3  
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Sub Main
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    '用户输入对话框 z<H~ItX,n  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 C<KrMRWh^  
        TextBox 220,21,40,21,.TextBox1 'default: 0 8} =JKR^cK  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 'YNT8w/3  
        OKButton 40,91,90,21 nJ~drG}TD  
        CancelButton 190,91,90,21 >2bK
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        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 !Mi;*ZR  
        TextBox 220,49,40,21,.TextBox2 'default: 4 =FE|+!>PA  
    End Dialog tOfg?)h{dc  
    Dim dlg As UserDialog 2M#r]  
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    ok = Dialog (dlg) 0-~\ W(  
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    If ok=0 Then    'cancel button was pressed bh^LIU  
        Print "Execution cancelled." ^i:`ZfA#
 
        End 1
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    End If ()~pY!)1/  
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    'Assign accommodation and pupil diameter & use defaults if field left empty iD<(b`S  
    If dlg.TextBox1 = "" Then +$oF]OO  
        A = 0           'Default accommodation &f&z_WU  
    Else p.LFVFPT  
        A = CDbl(dlg.TextBox1) jDQZQ NS  
    End If H54R8O$  
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    If dlg.TextBox2 = "" Then Z!hafhcX  
        pupilDiam = 4   'Default pupil diameter ABUSTf<  
    Else 5nsq[Q`  
        pupilDiam = CDbl(dlg.TextBox2) kF/9-[]$g,  
    End If ,"B+r6}EF  
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    Print " " &hRv
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    Print "Accommodation = " & A & " Diopters" G "73=8d  
    Print "Pupil Diameter = " & pupilDiam & " mm" OKoan$#sn  
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    ' Calculate new parameters with accommodation >nzdnF_&zW  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness _q~=~nub  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens K_dOq68_  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens O%FPS=  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens M)U{7c$c7  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens 9uGrk^<t  
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    tlens = 3.767 + 0.04*A                  'Lens thickness 'nF2a
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction L'F<ev  
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    'Adjust parameters to account for accommodation u9N 1pZ~  
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    '************************************************************************* b,CaWg  
    'Aqueous thickness (Position of Lens) *hw\35%P`?  
    '************************************************************************* J>\B`E  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) Z,=7Tu bR#  
    GetCustomElement eID, entity -{ H0g]  
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    parID = FindFullName( "Geometry.Arizona Eye" ) B'fb^n<  

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    ' Delete any shift(s) in z e
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    count = 0 ;aw=MV  
    While GetOperationCount(eID)>count VY3&  
        GetOperation eID, count, op ~c&bH]cj  
        If op.Type="ShiftZ" Then cJrmm2.0kD  
            DeleteOperation eID,count vvm0t"|\  
            count=count-1 yxH ( c  
        End If Sv +IS  
        count=count+1 vMS |$L  
    Wend <WcR,d  
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    'Set new shift in h@[R6G|  
    op.Type = "ShiftZ" jrS[f  
    op.val1 = taq wYmM"60  
    op.parent = parID ?O8ViB?2  
    AddOperation eID, op Cvf[/C+  
    Print "Set aqueous humor thickness = " & taq-0.55 PS[+~>%  
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    '************************************************************************* 49vcoHlf  
    'Radius and conic constant of anterior lens -q*i_r:,  
    '************************************************************************* ZSG
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    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) <>8WQn,K  
    GetConic eID, entity, curv, conic GSRVe/[  
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    SetConic eID, entity, 1/Rant, CCant w'm;82V:P-  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant gntxNp[9T  
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    '************************************************************************* @0F3$  
    'Radius and conic constant of posterior lens ;LMJd@  
    '************************************************************************* %oO4|JkJX  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) HB
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    GetConic eID, entity, curv, conic gy_>`16K  
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    SetConic eID, entity, 1/Rpost, CCpost xLC3>>P  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost ]]*7\ :cb  
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    '************************************************************************* 4B^ZnFJ%m  
    'Lens thickness (Position of posterior lens surface) WUh$^5W  
    '************************************************************************* {$wjO7Glp  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) @9lUSk^9  
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    ' Delete any z-shift(s) BDjn !3  
    count = 0 QC9eUYe  
    While GetOperationCount(eID)>count =,UWX3`f  
        GetOperation eID, count, op ,d{"m)r<  
        If op.Type="ShiftZ" Then s[w6FXt  
            DeleteOperation eID,count ~W{2Jd  
            count=count-1 |563D#?cR  
        End If E/%9jDTQ  
        count=count+1 L{8xlx`  
    Wend 28UU60  
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    'Set new z-shift ::
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    op.Type = "ShiftZ" p{j.KI s7  
    op.val1 = tlens c1E'$- K@  
    op.parent = parID id1s3b;  
    AddOperation eID, op Yj6*NZ*  
    Print "Set lens thickness = " & tlens R~S
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    '************************************************************************* #~<0t(3Q  
    'Lens index of refraction _tYx~J2.Q  
    '************************************************************************* 1*@'-mj  
    eID = FindMaterial( "Lens" ) j4^97  
    GetModelMaterial eID, mat "-+\R}q$  
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    mat.Nd = nlens Z)SY.iK.  
    SetModelMaterial eID, mat n6BQk2l  
    Print "Set lens index of refraction = " & nlens xo&]$W8  
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    '************************************************************************* a_'2V;  
    'Pupil diameter hMykf4  
    '************************************************************************* d%V*|0c)  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) N _86t  
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    'Adjust pupil diameter (trimming volume inner hole) qLB)XnQ  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" C<m{*C-`a  
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    ' Adjust pupil location to just in front of the lens =5(>q5Z*  
    parID = FindFullName( "Geometry.Arizona Eye" ) V0P>YQq9s  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) 4\4FolsK  
    count = 0 Cd>WUw  
    While GetOperationCount(eID)>count 2AO~HxF  
        GetOperation eID, count, op $h*L=t(  
        If op.Type="ShiftZ" Then A m>cd;  
            DeleteOperation eID,count T
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            count=count-1 K otrX  
        End If mjKS{  
        count=count+1 r}mbXvn  
    Wend Y]B)'[=h  
    op.Type = "ShiftZ" z$?~Y(EY  
    op.val1 = taq-0.01 "saUai4z  
    op.parent = parID UHTvCc  
    AddOperation eID, op &GB:|I'%7  
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    Print "Set pupil diameter = " & pupilDiam 'U\<IL#U  
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    'Update AZ Eye subassembly Description Y}#J4i0b*  
    eID = FindFullName( "Geometry.Arizona Eye" ) mg$]QnbAnH  
    GetEntity eID, entity Cc%LztP>  
    entity.Description = "Accommodation = " & A & "D" er!DYv  
    SetEntity eID, entity <7j87  
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    Update b-{=s+:  
    Print "DONE!" !AKg m'Nw  
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End Sub ]Zyur`  
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如果屈光度是4，光瞳直径是4，则会输出如下数据： 'VlDh`<W  
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Accommodation = 4 Diopters  ng_^  
Pupil Diameter = 4 mm #py[  
Set aqueous humor thickness = 2.81 o .qf _A  
Set anterior lens radius = 10.4 and conic constant = -2.375869 'Pn3%&O$  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 vA]W|sLF9  
Set lens thickness = 3.927 7 D^gMN%p  
Set lens index of refraction = 1.42672 p%*%n3bw  
Set pupil diameter = 4 r0,:J  
DONE! (tZrw5@  
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