[技术]Arizona眼睛模型 [复制链接]

简介 >`|uc  
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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。 y8S6ZtA}2  
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模型 vEp8
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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。 ']Xx#U N  
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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. ,:4w$!;  
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光源 CPeK0(7Zh  
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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。 wSyu^KDz  
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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。 
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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。 L [M8[~Hy  
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视网膜的散射 1AV1W_"  
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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。 A3pQ?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。 Ud*[2Oi|R  
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脚本 O;?~#E<6w  
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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： mXaUWgO  
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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。 DP]|}8~L  
余下的脚本计算与屈光度有关的所有参数。 Bys|i0tb-  
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分析 [KJL%u|8/  
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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。 6D(m8  
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脚本代码 FQ)Ekss~C  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. }TvAjLIS6  
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Dim entity As T_ENTITY !:{_<C"D  
Dim op As T_OPERATION "iG
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Dim mat As T_MODELMATERIAL .utL/1Ej  
Dim A As Double nCB3d[/B  
Dim pupilDiam As Double vy?YA-  
Dim eID As Long ,[#f}|s_  
Dim parID As Long iNSJO
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Dim count As Integer Mv=;+?z!  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double jQ}|]pj+  
Dim tlens As Double, nlens As Double c'R|Wyf  
Dim curv As Double, conic As Double xII!2.  
Dim ok As Long tH(#nx8  
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Sub Main ;A!i V|  
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    '用户输入对话框 nQ~L.V  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 U$bM:d  
        TextBox 220,21,40,21,.TextBox1 'default: 0 cn:VEF:l  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 Y,~]ecI  
        OKButton 40,91,90,21 N2J!7uoQ  
        CancelButton 190,91,90,21 `,[c??h  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 +Ti@M1A&  
        TextBox 220,49,40,21,.TextBox2 'default: 4 u*`GIRfWT  
    End Dialog d*HAKXd&:j  
    Dim dlg As UserDialog +Wc[$,vk  
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    ok = Dialog (dlg) ^)~M,rW8c  
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    If ok=0 Then    'cancel button was pressed m=V2xoMw6  
        Print "Execution cancelled." e: tp7w 4  
        End S(l^TF  
    End If BW 7[JD  
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    'Assign accommodation and pupil diameter & use defaults if field left empty g*M3;G  
    If dlg.TextBox1 = "" Then ;@hP*7Lm  
        A = 0           'Default accommodation i,T{SV  
    Else Rw`s O:eZ  
        A = CDbl(dlg.TextBox1) &YNhKm@"  
    End If 'C<=bUM  
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    If dlg.TextBox2 = "" Then >2/zL.O  
        pupilDiam = 4   'Default pupil diameter d+'+z %s%  
    Else l1S1CS  
        pupilDiam = CDbl(dlg.TextBox2) ',pPs=  
    End If u 36;;z  
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    Print " " +qec>ALAg  
    Print "Accommodation = " & A & " Diopters" x;Q2/YZ#  
    Print "Pupil Diameter = " & pupilDiam & " mm" ~@;7}Aag  
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    ' Calculate new parameters with accommodation /'&LM\  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness { L5m`-x  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens [geY:v_B  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens Jo0x/+?,+  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens V*~5*OwB  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens we9AB_y  
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    tlens = 3.767 + 0.04*A                  'Lens thickness K]l)z* I  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction j3><J  
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    'Adjust parameters to account for accommodation ;D:v@I$I  
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    '************************************************************************* AXCJFqk;  
    'Aqueous thickness (Position of Lens) Z"jo xZ  
    '************************************************************************* )j]RFt  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) uu>g(q?4II  
    GetCustomElement eID, entity `*a,8M%  
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    parID = FindFullName( "Geometry.Arizona Eye" ) T"jl;,gr]J  
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    ' Delete any shift(s) in z oS4ag  
    count = 0 BG"6jQh  
    While GetOperationCount(eID)>count __M}50^  
        GetOperation eID, count, op Z6p>R;9n  
        If op.Type="ShiftZ" Then ^&}Y>O,  
            DeleteOperation eID,count Xqy{=:0  
            count=count-1 Evc 9k  
        End If 3]i1M%'i  
        count=count+1 ,x/j&S9!  
    Wend ;k0*@c*  
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    'Set new shift in *uIHa"  
    op.Type = "ShiftZ" };*5+XY^  
    op.val1 = taq 19S,>  
    op.parent = parID <+a\'Xc  
    AddOperation eID, op -l",!sV  
    Print "Set aqueous humor thickness = " & taq-0.55 = 4If7  
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    '************************************************************************* ?2M15Q  
    'Radius and conic constant of anterior lens qv:WC TAn  
    '************************************************************************* .jCdJ =z  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) l},%g%}iMU  
    GetConic eID, entity, curv, conic ll#PCgIm  
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    SetConic eID, entity, 1/Rant, CCant Q|>y2g!  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant F~B8XUa3  
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    '************************************************************************* &zZSWNW  
    'Radius and conic constant of posterior lens [;(|^0  
    '************************************************************************* SG~R!kN}Q  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) iG;6e
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    GetConic eID, entity, curv, conic Q_dFZ  
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    SetConic eID, entity, 1/Rpost, CCpost pO^ 6p%  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost vq{:=:5'P  
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    '************************************************************************* tFGLqR%/  
    'Lens thickness (Position of posterior lens surface) qRUz;M4  
    '************************************************************************* %63<Iz"  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) CB~&!MdMr  
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    ' Delete any z-shift(s) G -;Yua2\  
    count = 0 SbB5J> >7J  
    While GetOperationCount(eID)>count 0iYe>u  
        GetOperation eID, count, op K46\Rm_:B;  
        If op.Type="ShiftZ" Then =Ru
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            DeleteOperation eID,count = *sP, 6  
            count=count-1 MG~^>  
        End If )b =$!  
        count=count+1 h\1_$ac  
    Wend @g{=f55  
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    'Set new z-shift gAE}3//  
    op.Type = "ShiftZ" htaB!Q?V  
    op.val1 = tlens Q>.-u6(&  
    op.parent = parID 39OZZaWL  
    AddOperation eID, op NE(6`Wq`  
    Print "Set lens thickness = " & tlens #i~.wQ$1  
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    '************************************************************************* U $+rlw}  
    'Lens index of refraction
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    '************************************************************************* y"7?]#$9/  
    eID = FindMaterial( "Lens" ) H}:apRb  
    GetModelMaterial eID, mat t+vn.X+&  
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    mat.Nd = nlens %3q@\:s  
    SetModelMaterial eID, mat ~<|xS  
    Print "Set lens index of refraction = " & nlens *u-
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    '************************************************************************* m86w{b$8  
    'Pupil diameter s|qB;  
    '************************************************************************* bzZEwMc6  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) 8Uc#>Ae'_  
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    'Adjust pupil diameter (trimming volume inner hole) Chjth"  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" G $?VYC8;  
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    ' Adjust pupil location to just in front of the lens q
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    parID = FindFullName( "Geometry.Arizona Eye" ) qgu.c`GmW  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) 6N]v9uXZ  
    count = 0 sB /*gO  
    While GetOperationCount(eID)>count z7J#1q~:yY  
        GetOperation eID, count, op '*22j ]  
        If op.Type="ShiftZ" Then bj7v<G|Y  
            DeleteOperation eID,count /VJ[1o^  
            count=count-1 1MOQ/N2BR  
        End If 7XdLZ4ub  
        count=count+1 u+S
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    Wend f4uK_{  
    op.Type = "ShiftZ" ]` 3;8,  
    op.val1 = taq-0.01 \p.ku%{  
    op.parent = parID Q~uj:A]n<  
    AddOperation eID, op 514;!Q4K  
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    Print "Set pupil diameter = " & pupilDiam KO:o GUR  
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    'Update AZ Eye subassembly Description #Jg)HU9  
    eID = FindFullName( "Geometry.Arizona Eye" ) 6N6d[t"  
    GetEntity eID, entity yay{lP}b"  
    entity.Description = "Accommodation = " & A & "D" 5&6S["lt  
    SetEntity eID, entity 2TiUo(MK  
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    Update Dk8" H>*  
    Print "DONE!" ?/NxZ\  
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End Sub ~^Gk7
 
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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： Q;SMwCB0M  
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Accommodation = 4 Diopters ]M>mwnt+  
Pupil Diameter = 4 mm ,D>$N3;  
Set aqueous humor thickness = 2.81 Hb IRE  
Set anterior lens radius = 10.4 and conic constant = -2.375869 7 zK%CJ  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 <T<?7SE+  
Set lens thickness = 3.927 H<g- Bhv  
Set lens index of refraction = 1.42672 T[L  
Set pupil diameter = 4 u9QvcD^'z  
DONE! b?qtTce