[技术]Arizona眼睛模型 [复制链接]

简介 %QH "x`;  
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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。 7.@$D;L9  
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模型 c]3% wL  
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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。 =g|e-XC  
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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. /3`#ldb%}  
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光源 l,5<g-r V  
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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。 {nTQc2T?;  
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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。 T;!7GW4E ?  
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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。 <5rs~  
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视网膜的散射 `\!oY;jk  
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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。 6b&<5,=d:  
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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。 2E]SKpJ  
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脚本 pZ4]KxX@  
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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： `R:p-"'b  
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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。 n27df9L  
余下的脚本计算与屈光度有关的所有参数。 ch2Qk8  
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分析 eteq Mg}M  
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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。 0sxZa+G0o  
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脚本代码 yL =*yC  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. oy+``W~  
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Dim entity As T_ENTITY 0XwDk$l<  
Dim op As T_OPERATION &n:3n  
Dim mat As T_MODELMATERIAL NyHHK8>  
Dim A As Double iq s  
Dim pupilDiam As Double 8)I,WWj  
Dim eID As Long QiDf,$t|,  
Dim parID As Long MDETAd  
Dim count As Integer c*0pF=3  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double SCbN(OBN!  
Dim tlens As Double, nlens As Double 8NY$Iw  
Dim curv As Double, conic As Double ;Y:_}kN8_  
Dim ok As Long Co e q<  
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Sub Main LR:Qb]|"  
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    '用户输入对话框 n<Vq@=9AE  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 '2`MT-  
        TextBox 220,21,40,21,.TextBox1 'default: 0 K(*QhKX  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 D$k<<dvv
 
        OKButton 40,91,90,21 n,KOQI;  
        CancelButton 190,91,90,21 I'"b3]DXG  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 w h4WII  
        TextBox 220,49,40,21,.TextBox2 'default: 4 \5g7_3,3W  
    End Dialog uc6;%=%+  
    Dim dlg As UserDialog :]?y,e%xu,  
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    ok = Dialog (dlg) WJH)>4M#  
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    If ok=0 Then    'cancel button was pressed hAHZN^x&  
        Print "Execution cancelled." t\[aU\4-7  
        End gO C5  
    End If 1$cX`D`  
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    'Assign accommodation and pupil diameter & use defaults if field left empty 1PwqWg-\\  
    If dlg.TextBox1 = "" Then ppv/A4Kv  
        A = 0           'Default accommodation eUiJl6^x  
    Else +qz"+g  
        A = CDbl(dlg.TextBox1) 9C-!I,  
    End If >s\j/yM  
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    If dlg.TextBox2 = "" Then hdFIriE3  
        pupilDiam = 4   'Default pupil diameter wd4
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    Else WM8 Ce0E  
        pupilDiam = CDbl(dlg.TextBox2) &<{=  
    End If yHvF"4]  
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    Print " " D@[Mk
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    Print "Accommodation = " & A & " Diopters" n}8J-/(|+  
    Print "Pupil Diameter = " & pupilDiam & " mm" y1DP`Ro  
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    ' Calculate new parameters with accommodation zP\n<L
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    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness fX)C8J^=G  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens XqD/~_z;  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens &"bcI7uGT  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens >BC?%|l  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens @=Kuo
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    tlens = 3.767 + 0.04*A                  'Lens thickness E;l|I A/7  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction x"kc:F  
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    'Adjust parameters to account for accommodation RfP>V/jy5  
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    '************************************************************************* R-Y|;  
    'Aqueous thickness (Position of Lens) rDNz<{evj  
    '************************************************************************* Wb!"L`m  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) "zSi9]j  
    GetCustomElement eID, entity y#\jc4F_a  
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    parID = FindFullName( "Geometry.Arizona Eye" ) /I2RU2|B  
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    ' Delete any shift(s) in z OoKzPePWji  
    count = 0 m>4jRr6sF  
    While GetOperationCount(eID)>count B~HA 32  
        GetOperation eID, count, op #NZ\UmA  
        If op.Type="ShiftZ" Then \79KU  
            DeleteOperation eID,count 2#z6=M~A  
            count=count-1 t#s?:  
        End If q'kZ3G   
        count=count+1 _=RA-qZ"  
    Wend x\qS|q\N  
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    'Set new shift in M{Ss?G4H  
    op.Type = "ShiftZ" (yk^%  
    op.val1 = taq Yk',a$.S  
    op.parent = parID w,L PM+  
    AddOperation eID, op [n/'JeG5  
    Print "Set aqueous humor thickness = " & taq-0.55 )zK`*Fa az  
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    '************************************************************************* k%w5V>]1  
    'Radius and conic constant of anterior lens b&.j>=  
    '************************************************************************* sW)C6 #  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) ~.qzQ_O/  
    GetConic eID, entity, curv, conic Lq@pJ)a  
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    SetConic eID, entity, 1/Rant, CCant uWw4l"RK`  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant ajIgL<x  
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    '************************************************************************* (fON\)l  
    'Radius and conic constant of posterior lens T:+%3+;a  
    '************************************************************************* HA%%WSuf  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) mG[S"?C  
    GetConic eID, entity, curv, conic @vWC "W  
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    SetConic eID, entity, 1/Rpost, CCpost M/GQQG;  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost J%']t$AR  
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    '************************************************************************* H!U\;ny  
    'Lens thickness (Position of posterior lens surface) ]_NN,m>z  
    '************************************************************************* l1^/Q~u  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) iq$edq[  
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    ' Delete any z-shift(s) &wRdUIc  
    count = 0 ZN!OM)@:!  
    While GetOperationCount(eID)>count j""I,$t  
        GetOperation eID, count, op P<b.;Oz__-  
        If op.Type="ShiftZ" Then l!f/0Rx5  
            DeleteOperation eID,count $3BCA)5:  
            count=count-1 =ECw'  
        End If ;=X6pK  
        count=count+1 Vm.&JVb  
    Wend j:D@X=|  
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    'Set new z-shift IuDg-M[  
    op.Type = "ShiftZ" 5T,Doxo  
    op.val1 = tlens P;[
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    op.parent = parID {GDMix  
    AddOperation eID, op )@.
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    Print "Set lens thickness = " & tlens 9`}Wp2  
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    '************************************************************************* iMRb` \KH  
    'Lens index of refraction [^r0red  
    '************************************************************************* jR7 , b5  
    eID = FindMaterial( "Lens" ) Izq]nR  
    GetModelMaterial eID, mat rDkAeX0  
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    mat.Nd = nlens HM%n`1ZU  
    SetModelMaterial eID, mat $2E n^  
    Print "Set lens index of refraction = " & nlens $
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    '************************************************************************* Q:Q)-|,  
    'Pupil diameter ~[XDK`B
  
    '************************************************************************* ($*bwqp]}  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) Q&:%
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    'Adjust pupil diameter (trimming volume inner hole) @O+yxGA  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" "UVqkw,vt  
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    ' Adjust pupil location to just in front of the lens 0-"ps]X  
    parID = FindFullName( "Geometry.Arizona Eye" ) B`OggdE  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) NGB%fJ  
    count = 0 v :]y#y  
    While GetOperationCount(eID)>count a?6 r4u0  
        GetOperation eID, count, op ]d?`3{h9LD  
        If op.Type="ShiftZ" Then :~loy'  
            DeleteOperation eID,count T/G1v;]  
            count=count-1 E :*!an  
        End If 8'J>@ uW  
        count=count+1 =zXpeo&|m  
    Wend FT73P0!8.  
    op.Type = "ShiftZ" +U&aK dQs  
    op.val1 = taq-0.01 <lZyUd  
    op.parent = parID (:E_m|00;  
    AddOperation eID, op e:{v.C0ez  
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    Print "Set pupil diameter = " & pupilDiam Py\xN  
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    'Update AZ Eye subassembly Description 2D`@$)KL  
    eID = FindFullName( "Geometry.Arizona Eye" ) SQ5SvYH  
    GetEntity eID, entity @PuJre4!;L  
    entity.Description = "Accommodation = " & A & "D" RL |.y~  
    SetEntity eID, entity )0`;leli  
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    Update qC?J`   
    Print "DONE!" W3*BdpTw  
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End Sub [CBA Lj5  
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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： iZ#dS}VlJ  
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Accommodation = 4 Diopters a#FkoA~M  
Pupil Diameter = 4 mm E-_)w  
Set aqueous humor thickness = 2.81 Da1BxbDeI  
Set anterior lens radius = 10.4 and conic constant = -2.375869 o%X_V!B{V  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 7CYu"+Ea  
Set lens thickness = 3.927 R'qB-v.  
Set lens index of refraction = 1.42672 %1SA!1>j  
Set pupil diameter = 4 1i#uKKwE  
DONE! NUiZ!&