[技术]Arizona眼睛模型 [复制链接]

简介 9,|{N(N<!  
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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。 UwOZBF<  
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模型 `s#0/t  
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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。 x*td nor&  
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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. t"M&Yy  
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光源 nEu,1  
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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。 %UZ_wsY\  
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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。 {<0=y#@u  
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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。 X`bN/sI  
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视网膜的散射 's]I:06A  
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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。 OZ 4uk.)  
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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。 I^|6gaP|6  
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脚本 YEfa8'7R  
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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： =^ur@E  
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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。 5bU[uT,`6  
余下的脚本计算与屈光度有关的所有参数。  d(PS  
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分析 P5 GM s  
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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。 ={&}8VA  
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脚本代码 r #H(kJu,  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. iW.4'9  
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Dim entity As T_ENTITY hE
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Dim op As T_OPERATION ["l1\YCi  
Dim mat As T_MODELMATERIAL g+>$_s  
Dim A As Double 3^p<Wx  
Dim pupilDiam As Double L"|4 v  
Dim eID As Long 9MfBsp}c  
Dim parID As Long &"!s+_  
Dim count As Integer 'r`#u@TTZ  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double p H&Tb4  
Dim tlens As Double, nlens As Double GFM$1}  
Dim curv As Double, conic As Double r&F(VF0 6  
Dim ok As Long G#{ Xd6L  
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Sub Main Fkgnc{NI  
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    '用户输入对话框 AKWM7fI  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 vrVb/hhG  
        TextBox 220,21,40,21,.TextBox1 'default: 0 :N!Fe7H,  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 *n9t~t6GHg  
        OKButton 40,91,90,21 q2Xm~uN`)  
        CancelButton 190,91,90,21 $
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        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 .h
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        TextBox 220,49,40,21,.TextBox2 'default: 4 [UO?L2$&  
    End Dialog 5I#L|+  
    Dim dlg As UserDialog RmXC ^VQ  
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    ok = Dialog (dlg) Z}#,E;  
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    If ok=0 Then    'cancel button was pressed qs\O(K
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        Print "Execution cancelled." {Rc!S? 8  
        End 02g!mJW>}y  
    End If 5Ym/'eT  
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    'Assign accommodation and pupil diameter & use defaults if field left empty vZEeb j  
    If dlg.TextBox1 = "" Then [x}]sT`#a  
        A = 0           'Default accommodation w!$|IC  
    Else S $wx>715  
        A = CDbl(dlg.TextBox1) 5sbMp;ZM  
    End If #$!(8>YJ  
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    If dlg.TextBox2 = "" Then ]Z/<HP$#  
        pupilDiam = 4   'Default pupil diameter Mm7l!  
    Else #vk-zx*v7=  
        pupilDiam = CDbl(dlg.TextBox2) B>kx$_~  
    End If eWjLP{W  
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    Print " " om$x;L6  
    Print "Accommodation = " & A & " Diopters" 5DgfrX  
    Print "Pupil Diameter = " & pupilDiam & " mm" qU!*QZ^y&  
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    ' Calculate new parameters with accommodation IN
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    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness |\g=ua+h  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens ~jK'n4  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens o*5<Cxg  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens i:ar{ q  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens }6#lE,\lM  
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    tlens = 3.767 + 0.04*A                  'Lens thickness sGx"ja+  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction oj.f uJD  
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    'Adjust parameters to account for accommodation Rv9oK-S  
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    '************************************************************************* Jb'l.xN  
    'Aqueous thickness (Position of Lens) F@e9Dz|  
    '************************************************************************* <0my,hAK  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) 0@w8,x  
    GetCustomElement eID, entity }UwDHq=  
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    parID = FindFullName( "Geometry.Arizona Eye" ) dZnAdlJ  
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    ' Delete any shift(s) in z x1['+!01  
    count = 0 e1'<;;; L  
    While GetOperationCount(eID)>count 7P}&<;5zD  
        GetOperation eID, count, op B+:'Ld](  
        If op.Type="ShiftZ" Then x5q5<-#  
            DeleteOperation eID,count c(@V t&gE  
            count=count-1 Kyy CS>  
        End If _yje"  
        count=count+1 }S{#DgZ@X  
    Wend u<`CkYT  
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    'Set new shift in WLr\ l29  
    op.Type = "ShiftZ" JTu^p]os?  
    op.val1 = taq +bwSu)k  
    op.parent = parID Hm=!;xAFX  
    AddOperation eID, op 0pP;[7k\  
    Print "Set aqueous humor thickness = " & taq-0.55 83,ATQg  
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    '************************************************************************* HorFQ?8  
    'Radius and conic constant of anterior lens =,B
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    '************************************************************************* T;(k  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) Wi3:;`>G<p  
    GetConic eID, entity, curv, conic >;Er[Rywr  
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    SetConic eID, entity, 1/Rant, CCant v]CH L# |  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant Y*
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    '************************************************************************* FX QUj&9  
    'Radius and conic constant of posterior lens vu^ '+ky  
    '************************************************************************* }:UNL^
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    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) I f9t^T#  
    GetConic eID, entity, curv, conic )l}Gwd]h  
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    SetConic eID, entity, 1/Rpost, CCpost T%kr&XsQX  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost ZTV|rzE   

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    '************************************************************************* ^J
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    'Lens thickness (Position of posterior lens surface) rt+%&%wt  
    '************************************************************************* XV"8R"u%Q  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) k&-SB -  
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    ' Delete any z-shift(s) G}B)bM2  
    count = 0 P@Oq'y[  
    While GetOperationCount(eID)>count 92|\`\LP%  
        GetOperation eID, count, op Y%AVC9(  
        If op.Type="ShiftZ" Then ,DUD4 [3  
            DeleteOperation eID,count fi*@m,-  
            count=count-1 ,tt]C~\u  
        End If 8PQKB*<dB"  
        count=count+1 "
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    Wend L+s3@C;b  
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    'Set new z-shift 9ohaU  
    op.Type = "ShiftZ" 3o=R_%r  
    op.val1 = tlens -%8*>%  
    op.parent = parID  4[=vt  
    AddOperation eID, op /"w%?Ea  
    Print "Set lens thickness = " & tlens 15NeC7GAh  
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    '************************************************************************* {C6,h#|pg  
    'Lens index of refraction kXw&*B-/  
    '************************************************************************* b4o`eR  
    eID = FindMaterial( "Lens" ) i,5mH$a&u:  
    GetModelMaterial eID, mat V\U,PNkZQ  
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    mat.Nd = nlens ^Ec);Z  
    SetModelMaterial eID, mat +6dq+8msF  
    Print "Set lens index of refraction = " & nlens 0s>ozAJ  
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    '************************************************************************* VKI`@rY4  
    'Pupil diameter J]|Zh  
    '************************************************************************* 0E[&:6#Y  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) Tw^b!74gq  
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    'Adjust pupil diameter (trimming volume inner hole) rVo0H.+N)`  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" :Fe}.* t  
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    ' Adjust pupil location to just in front of the lens WX@a2c.'  
    parID = FindFullName( "Geometry.Arizona Eye" ) zQpF,N<b  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) *^|.bBG  
    count = 0 >93I|C|  
    While GetOperationCount(eID)>count (MfPu8j  
        GetOperation eID, count, op Yz6+ x]  
        If op.Type="ShiftZ" Then g9N_s,3jC  
            DeleteOperation eID,count a!iG;:K   
            count=count-1 fa~4+jx>S  
        End If }:6$5/?  
        count=count+1 <d&9`e1Hc  
    Wend P
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    op.Type = "ShiftZ" J.%%]-f=&  
    op.val1 = taq-0.01 V4~`yT?*"  
    op.parent = parID  D`Tx,^E  
    AddOperation eID, op (c^ZFh2]  
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    Print "Set pupil diameter = " & pupilDiam ((Jiv=%  
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    'Update AZ Eye subassembly Description 2<"kfan  
    eID = FindFullName( "Geometry.Arizona Eye" ) jv<C#0E^  
    GetEntity eID, entity (P=q&]l[  
    entity.Description = "Accommodation = " & A & "D" 1?!z<<  
    SetEntity eID, entity
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    Update $G $147z  
    Print "DONE!" {`X O3  
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End Sub 57nSyd]PR  
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如果屈光度是4，光瞳直径是4，则会输出如下数据： eyUhMjd  
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Accommodation = 4 Diopters nqnVFkGd9  
Pupil Diameter = 4 mm OE{PP9eh  
Set aqueous humor thickness = 2.81 at(oepq  
Set anterior lens radius = 10.4 and conic constant = -2.375869 HutwgPvy  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 /*$B  
Set lens thickness = 3.927 wO>P<KBU  
Set lens index of refraction = 1.42672 p bR
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Set pupil diameter = 4 e#R'_}\yj  
DONE! xzI?'?duC