[技术]Arizona眼睛模型 [复制链接]

简介 YY!6/5*/]  
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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。 mB9r3[  
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模型 y2vUthRwo  
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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。 Ii_ojQP-z  
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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. 5~WGZc  
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光源 e0@Y#7N62  
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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。 :2-pjkhiwY  
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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。 )R  2.  
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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。 Xo*%/0q'  
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视网膜的散射 i?:_:"^x  
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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。 mL`5uf  

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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。 1YJC{bO  
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脚本 @L:>!<  
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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： SdwS= (e6  
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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。 n?urE-
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余下的脚本计算与屈光度有关的所有参数。 fb:j%1WF  
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分析 8Bq!4uq\5|  
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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。 m&iH2|  
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脚本代码 d@G}~&.|  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. k` (jkbEZ  
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Dim entity As T_ENTITY D^;*U[F?  
Dim op As T_OPERATION rJInj>
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Dim mat As T_MODELMATERIAL %9#gB  
Dim A As Double .pvV1JA'  
Dim pupilDiam As Double c9nH}/I_  
Dim eID As Long ~|AwN [  
Dim parID As Long 7 +@qB]Bi<  
Dim count As Integer A?T<",bO
 
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double \S)2  
Dim tlens As Double, nlens As Double I;?X f  
Dim curv As Double, conic As Double h<\_XJJ  
Dim ok As Long zn@N'R/  
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Sub Main o!r8{L  
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    '用户输入对话框
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    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 C}*cx$.  
        TextBox 220,21,40,21,.TextBox1 'default: 0 b]JI@=s?  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 W Qc>  
        OKButton 40,91,90,21 LR,7,DH$9'  
        CancelButton 190,91,90,21 EIf~dOgH  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 hwDbs[:  
        TextBox 220,49,40,21,.TextBox2 'default: 4 N9rBW
 
    End Dialog Lh-`OmO0>F  
    Dim dlg As UserDialog %,*G[#*&  
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    ok = Dialog (dlg) 9r2IuS0  
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    If ok=0 Then    'cancel button was pressed x)_@9ldYv  
        Print "Execution cancelled." -sMytHH.  
        End iYbX  
    End If @E53JKYhY  
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    'Assign accommodation and pupil diameter & use defaults if field left empty ='E$-_  
    If dlg.TextBox1 = "" Then =)OC|?9C\  
        A = 0           'Default accommodation l#wdpD a{  
    Else D8# on!  
        A = CDbl(dlg.TextBox1) 1SV^){5I  
    End If <[/%{sUNC  
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    If dlg.TextBox2 = "" Then ]fI/(e_U  
        pupilDiam = 4   'Default pupil diameter 7a$G@  
    Else ksjUr1o  
        pupilDiam = CDbl(dlg.TextBox2) 9><mp]E4  
    End If -6
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    Print " " jRpdft  
    Print "Accommodation = " & A & " Diopters" ,A5)<}  
    Print "Pupil Diameter = " & pupilDiam & " mm" <39!G7ny  
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    ' Calculate new parameters with accommodation EC?Efc+O  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness 2PSTGG8JV  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens :'r6TVDW  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens ~mN%(w!^  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens HpexH{.u)  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens fj'j
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    tlens = 3.767 + 0.04*A                  'Lens thickness +TRy:e  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction O hR1Jaed  
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    'Adjust parameters to account for accommodation P l{QOR  
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    '************************************************************************* a1MFjmq  
    'Aqueous thickness (Position of Lens) 5QWNZJ&}d  
    '************************************************************************* BZF,=v  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) #cwCocw  
    GetCustomElement eID, entity u=qPzmywt  
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    parID = FindFullName( "Geometry.Arizona Eye" ) /axTh  
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    ' Delete any shift(s) in z 3,.% s  
    count = 0 p#_[  
    While GetOperationCount(eID)>count M'1HA  
        GetOperation eID, count, op ".2A9]
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        If op.Type="ShiftZ" Then G"S5ki`o  
            DeleteOperation eID,count C 7nKk/r
 
            count=count-1 }&G]0hCT!  
        End If mT_GrIl[  
        count=count+1 U 0ZB^`  
    Wend |tG+iF@4  
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    'Set new shift in <4D%v"zRP  
    op.Type = "ShiftZ" nJVp.*S  
    op.val1 = taq *PM}"s  
    op.parent = parID PX3  
    AddOperation eID, op  ?B4#f!X  
    Print "Set aqueous humor thickness = " & taq-0.55 =p\Xy*  
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    '************************************************************************* Rk<%r k  
    'Radius and conic constant of anterior lens P&t;WPZ  
    '************************************************************************* GFR!n1Hv  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) =[(1my7  
    GetConic eID, entity, curv, conic H,>#|F  
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    SetConic eID, entity, 1/Rant, CCant
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    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant &jJckT  
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    '************************************************************************* {of]/3=  
    'Radius and conic constant of posterior lens pVOI5>f\  
    '************************************************************************* v>WB FvyD  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) +?e}<#vd'?  
    GetConic eID, entity, curv, conic ,z66bnjO  
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    SetConic eID, entity, 1/Rpost, CCpost IH3FK!>6  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost `45d"B I  
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    '************************************************************************* VC=6uB  
    'Lens thickness (Position of posterior lens surface) <PD|_nZ
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    '************************************************************************* q$^<zY  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) )Z:m)k>r;  
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    ' Delete any z-shift(s) kGD|c=K}  
    count = 0 !3KPwI,  
    While GetOperationCount(eID)>count *o|p)lH  
        GetOperation eID, count, op @9_)On9hZ  
        If op.Type="ShiftZ" Then tQ0=p| T]  
            DeleteOperation eID,count )@c3##Zp)  
            count=count-1 )_O.{$ to  
        End If Mw|SH;nM  
        count=count+1 \DyKtrnm%  
    Wend ;qT5faKB3J  
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    'Set new z-shift i;HH ! TaN  
    op.Type = "ShiftZ" 4(iS-8{J  
    op.val1 = tlens u<q)SQ1  
    op.parent = parID g*r/u;  
    AddOperation eID, op Isp_U5M  
    Print "Set lens thickness = " & tlens ]n1D1  
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    '************************************************************************* WH;xq^  
    'Lens index of refraction GG>Y/;^  
    '************************************************************************* 0nT
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    eID = FindMaterial( "Lens" ) dp< auA  
    GetModelMaterial eID, mat &U0WkW  
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    mat.Nd = nlens L)G">T;  
    SetModelMaterial eID, mat wL'C1Vr  
    Print "Set lens index of refraction = " & nlens *lY+Yy(  
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    '************************************************************************* d'q;+jnP  
    'Pupil diameter "DzGBu\  
    '************************************************************************* [Z% l.  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) :28@J?jjO  
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    'Adjust pupil diameter (trimming volume inner hole) Qq>ElQ@  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" Xi
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    ' Adjust pupil location to just in front of the lens I &cX8Tw  
    parID = FindFullName( "Geometry.Arizona Eye" ) 9$EHK  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) 1+FYjh!2t  
    count = 0 eFes+i(35  
    While GetOperationCount(eID)>count e)br`CD%  
        GetOperation eID, count, op 7~lB}$L  
        If op.Type="ShiftZ" Then v6KL93  
            DeleteOperation eID,count 0 c,bet{m  
            count=count-1 s/\XH&KR3V  
        End If MXh^dOWR  
        count=count+1 /;b.-
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    Wend )e#fj+>x)  
    op.Type = "ShiftZ" Fv;u1Atiw  
    op.val1 = taq-0.01 _4~k3%w\`l  
    op.parent = parID H.)fOctbO  
    AddOperation eID, op a'm!M:w  
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    Print "Set pupil diameter = " & pupilDiam UVnrDhd!0  
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    'Update AZ Eye subassembly Description # e$\~cPd  
    eID = FindFullName( "Geometry.Arizona Eye" ) IZ|c<#r6  
    GetEntity eID, entity s%FP6u7[i  
    entity.Description = "Accommodation = " & A & "D" Lq3(Z%  
    SetEntity eID, entity
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    Update |F3vRt@  
    Print "DONE!" R<_mK33hd  
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End Sub Z<w,UvJa  
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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： 9#s,K! !3{  
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Accommodation = 4 Diopters q`h7H]
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Pupil Diameter = 4 mm mMn2(  
Set aqueous humor thickness = 2.81 }FuVY><l  
Set anterior lens radius = 10.4 and conic constant = -2.375869 =H L9Z  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 D[+|^,^>  
Set lens thickness = 3.927 #!(Zn:[  
Set lens index of refraction = 1.42672 X9p+a,  
Set pupil diameter = 4 gCjH%=s  
DONE! L;L2j&i%v)