[技术]Arizona眼睛模型 [复制链接]

简介 @pz2}Hd|  
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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。 |Gi/=[Tp  
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模型 2]wh1)  
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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。 %94"e7Hy  
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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. =Ju}{ bX  

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光源 9Wn0YIc  
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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。 [cq>QMW  
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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。 )U` c9*.  
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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。 (WC<XKf  
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视网膜的散射 w&H7S{
 
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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。 tq[C"| dH  
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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。 23PSv8;EM  
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脚本 RN0Rk 8AC  
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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： s*;~CH-[  
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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。 v|e>zm<  
余下的脚本计算与屈光度有关的所有参数。 b\?`721BG  
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分析 u4Sa4o  
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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。 S$Wd}2>  
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脚本代码 G} p~VLf  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. *+G K?Ga  
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Dim entity As T_ENTITY tU(6%zvR  
Dim op As T_OPERATION D4G{= Y}G  
Dim mat As T_MODELMATERIAL m$kmoY/  
Dim A As Double WrV|<%EQh  
Dim pupilDiam As Double Rj8l]m6U9  
Dim eID As Long V1+IqOXAIp  
Dim parID As Long =J:~AD#  
Dim count As Integer TS-[
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Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double :=/DF  
Dim tlens As Double, nlens As Double `f(!i mN  
Dim curv As Double, conic As Double @{bf]Oc  
Dim ok As Long F>&8b^v bn  
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Sub Main
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    '用户输入对话框 f~53:;L/  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 KS%,N _F<  
        TextBox 220,21,40,21,.TextBox1 'default: 0 Uc/%4Gx  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 |i|O9^*%  
        OKButton 40,91,90,21 __a9}m4i7x  
        CancelButton 190,91,90,21 @?t)UE  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 =[P||  
        TextBox 220,49,40,21,.TextBox2 'default: 4 GK)hK-  
    End Dialog hfY2pG9N  
    Dim dlg As UserDialog ;;2s{{(R  
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    ok = Dialog (dlg) p4/
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    If ok=0 Then    'cancel button was pressed J[^-k!9M  
        Print "Execution cancelled." CkOd>Kn  
        End
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    End If m$U2|5un&  
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    'Assign accommodation and pupil diameter & use defaults if field left empty RSp=If+4  
    If dlg.TextBox1 = "" Then S-im o  
        A = 0           'Default accommodation gG#M-2P  
    Else DCHU=r  
        A = CDbl(dlg.TextBox1) \=w|Zeu{l  
    End If V%"aU}   
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    If dlg.TextBox2 = "" Then AH;h#dT  
        pupilDiam = 4   'Default pupil diameter [z/OY&kF  
    Else ,Q^.SHP8  
        pupilDiam = CDbl(dlg.TextBox2) i`X/d
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    End If -?j'<g0  
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    Print " " $[H3O(B0*  
    Print "Accommodation = " & A & " Diopters" R+P1 +5  
    Print "Pupil Diameter = " & pupilDiam & " mm" 0PZpE "$X  
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    ' Calculate new parameters with accommodation Qv#]T,  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness gVb;sk^  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens p2\@E} z  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens ?v6xaVg:  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens ,XR1N$LN8_  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens f`T#=6C4|  
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    tlens = 3.767 + 0.04*A                  'Lens thickness iOw'NxmY  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction 4v Ug:'DM  
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    'Adjust parameters to account for accommodation J#MUtpPdQ  
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    '************************************************************************* uq'T:
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    'Aqueous thickness (Position of Lens) H}`}qu #~V  
    '************************************************************************* qEE V
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    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) 6,| !zaeS  
    GetCustomElement eID, entity Z!DGCw  
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    parID = FindFullName( "Geometry.Arizona Eye" ) X$)<>e]!>  
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    ' Delete any shift(s) in z 2{(_{9<>z  
    count = 0 h<JV6h:8  
    While GetOperationCount(eID)>count x= X"4Mj0)  
        GetOperation eID, count, op "|`euxYV  
        If op.Type="ShiftZ" Then ogtl UCUD  
            DeleteOperation eID,count 'Y`or14E  
            count=count-1 w6aq/m"'  
        End If bu$YW'  
        count=count+1 E&9BeU a#  
    Wend yJNQO'wcv  
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    'Set new shift in "&W80,O3  
    op.Type = "ShiftZ" l]C#bL>i  
    op.val1 = taq 0w)Gb}o$  
    op.parent = parID },+ &y^  
    AddOperation eID, op b"iPuN!p  
    Print "Set aqueous humor thickness = " & taq-0.55 ^zn&"@  
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    '************************************************************************* R.^ Y'TLyc  
    'Radius and conic constant of anterior lens Qq+$ea?>  
    '************************************************************************* ~lib~Y'-  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) bi~1d"j  
    GetConic eID, entity, curv, conic opqY@>Vh&  
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    SetConic eID, entity, 1/Rant, CCant 05hjC  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant X;'H@GU0  
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    '************************************************************************* pr-=<[ d  
    'Radius and conic constant of posterior lens 9X/]O<i,Es  
    '************************************************************************* t\S=u y  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) -aPRLHR  
    GetConic eID, entity, curv, conic K,j'!VQA4g  
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    SetConic eID, entity, 1/Rpost, CCpost owQSy9Az  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost *!NxtB!LC  
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    '************************************************************************* <<w*_GM  
    'Lens thickness (Position of posterior lens surface) _xY dnTEl  
    '************************************************************************* }ff+RGxLIG  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) [3D*DyQt  
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    ' Delete any z-shift(s) 4]G J
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    count = 0 l$Y*ii  
    While GetOperationCount(eID)>count p?-qlPl  
        GetOperation eID, count, op _TntZv.?  
        If op.Type="ShiftZ" Then zCji]:  
            DeleteOperation eID,count N2 4J!L  
            count=count-1 y~Z7sx0  
        End If WIKSz {"=/  
        count=count+1 \?tE,\Ln  
    Wend i+90##4<?  
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    'Set new z-shift WYJH+"@%j  
    op.Type = "ShiftZ" )sN}ClgJ  
    op.val1 = tlens V9Pw\K!w#\  
    op.parent = parID WA((>Daf]  
    AddOperation eID, op g286 P_a`*  
    Print "Set lens thickness = " & tlens DrK@y8  
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    '************************************************************************* ;&c9!LfP  
    'Lens index of refraction (h"-#q8$  
    '************************************************************************* UMUG~P&@  
    eID = FindMaterial( "Lens" ) ?k`UQi]Q  
    GetModelMaterial eID, mat .fAHP 5-  
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    mat.Nd = nlens F1*xY%Jv^M  
    SetModelMaterial eID, mat #$X _,+<HZ  
    Print "Set lens index of refraction = " & nlens U0=: `G2l  
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    '************************************************************************* R0~w F>  
    'Pupil diameter mor[AJ  
    '************************************************************************* &yRR!1n)H  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) BdrYc^?JL]  
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    'Adjust pupil diameter (trimming volume inner hole) J4%"38l  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" `{%ImXQF  
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    ' Adjust pupil location to just in front of the lens ;;S9kNp^v  
    parID = FindFullName( "Geometry.Arizona Eye" ) V3Ep&<=/  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) ,Cd4Q7T  
    count = 0 ?{L5=X@$$  
    While GetOperationCount(eID)>count 9zl-C*9vj  
        GetOperation eID, count, op '""s%C+  
        If op.Type="ShiftZ" Then L"RE[" m  
            DeleteOperation eID,count 1}R\L"  
            count=count-1 6zIK%<  
        End If V%'' GF   
        count=count+1 h<G7ocu!  
    Wend 9^7z"*@#  
    op.Type = "ShiftZ" B[~Q0lPih  
    op.val1 = taq-0.01 G/ H>M%M  
    op.parent = parID 2y IDyo  
    AddOperation eID, op 5,|of{8  
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    Print "Set pupil diameter = " & pupilDiam iD.p KG  
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    'Update AZ Eye subassembly Description 97dF  
    eID = FindFullName( "Geometry.Arizona Eye" ) }{}?mQ  
    GetEntity eID, entity WMS~Bk+!  
    entity.Description = "Accommodation = " & A & "D" z))rk vL%  
    SetEntity eID, entity %Z8wUG  
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    Update F. I\?b  
    Print "DONE!" BCO (,k  
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End Sub BoXPX2:  
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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： YZAQt*x
 
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Accommodation = 4 Diopters \!"3yd  
Pupil Diameter = 4 mm &oE'|^G  
Set aqueous humor thickness = 2.81 \E6 0  
Set anterior lens radius = 10.4 and conic constant = -2.375869 Y.q$"lm7k  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 *x_e] /}  
Set lens thickness = 3.927 #r,!-;^'p  
Set lens index of refraction = 1.42672 fZ(k"*\MZ  
Set pupil diameter = 4 7Y)i>[u3  
DONE! MO? }$j