[技术]Arizona眼睛模型 [复制链接]

简介 (h>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。 DEwtP  
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模型 53+rpU_  
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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。 qpwh #^2  
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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. |KrG3-i3X  
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光源 `0G.Y  
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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。 jUR#  
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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[[  
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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。 Yg,WdVI&@  
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视网膜的散射 %iS]+Sa.K  
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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。 <^q"31f  
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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。 g!Yh=kA'N  
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脚本 c@#zjJhW]  
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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： YB1DL^:  
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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。 ]9< 9F ?  
余下的脚本计算与屈光度有关的所有参数。 fX$4TPy(h  
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分析 WJ8vHPSM  
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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。 F20-!b  
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脚本代码  mFoK76  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. WJ4UJdf'  
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Dim entity As T_ENTITY rZQHB[^3  
Dim op As T_OPERATION )[X!/KR90  
Dim mat As T_MODELMATERIAL mf_'| WDs  
Dim A As Double Wy>\KrA1  
Dim pupilDiam As Double IeI%X\G  
Dim eID As Long ]sP9!hup  
Dim parID As Long '"\Mjz)/  
Dim count As Integer /~huTKA}  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double il%tu<E#J~  
Dim tlens As Double, nlens As Double "57G@NC{n  
Dim curv As Double, conic As Double n]c,0N  
Dim ok As Long %
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Sub Main HFWm}vA:  
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    '用户输入对话框 f_2^PF>?  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 /_\W*@ E  
        TextBox 220,21,40,21,.TextBox1 'default: 0 uOqDJM'RM  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 j=%-b]  
        OKButton 40,91,90,21 C\@YH]  
        CancelButton 190,91,90,21 }M@Jrq+7  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 aMg f6veM  
        TextBox 220,49,40,21,.TextBox2 'default: 4 G6mM6(Sr  
    End Dialog >,vW  
    Dim dlg As UserDialog @@mW+16  
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    ok = Dialog (dlg) jV&W[xKa  
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    If ok=0 Then    'cancel button was pressed Jd6Q9~z#  
        Print "Execution cancelled." @7 HBXP
 
        End :Zo2@8@7  
    End If
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    'Assign accommodation and pupil diameter & use defaults if field left empty l<_mag/j9o  
    If dlg.TextBox1 = "" Then _?LI0iIFx  
        A = 0           'Default accommodation IVODR   
    Else K
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        A = CDbl(dlg.TextBox1) Dq4
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    End If Jn&>Z? @  
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    If dlg.TextBox2 = "" Then t1g%o5?;  
        pupilDiam = 4   'Default pupil diameter ui0(#2'h%  
    Else z4:09!o_  
        pupilDiam = CDbl(dlg.TextBox2) BTtYlpN6  
    End If 8@ gD03  
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    Print " " LgKEg90w(  
    Print "Accommodation = " & A & " Diopters" #wuE30d  
    Print "Pupil Diameter = " & pupilDiam & " mm" ~2ei+#d!^  
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    ' Calculate new parameters with accommodation cNCBbOMr  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness c4W"CD;D  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens j'cCX[i  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens 8GQs
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens PMZzzZ  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens o7B+f  
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    tlens = 3.767 + 0.04*A                  'Lens thickness I65GUX#DV  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction rVmO/Y#Hx$  
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    'Adjust parameters to account for accommodation CMUphS-KE  
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    '************************************************************************* #]^`BQ>  
    'Aqueous thickness (Position of Lens) J1MnkxJmpQ  
    '************************************************************************* 'o9V0#$!  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) h8;"B  
    GetCustomElement eID, entity 36UWoo  
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    parID = FindFullName( "Geometry.Arizona Eye" ) ,aL"Wy(  
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    ' Delete any shift(s) in z Pfy;/}u^c  
    count = 0 @Q5^Q'!  
    While GetOperationCount(eID)>count -ZJ:<  
        GetOperation eID, count, op Gl9
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        If op.Type="ShiftZ" Then aW5
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            DeleteOperation eID,count B)*%d7=x  
            count=count-1 N?:S?p9R@  
        End If I!~Omr@P  
        count=count+1 AP@d2{"m}  
    Wend )~kb7rfl  
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    'Set new shift in dq&d>f1  
    op.Type = "ShiftZ" 2Ta F7Jn  
    op.val1 = taq ]ORat.*0[T  
    op.parent = parID VNPdL  
    AddOperation eID, op #xB%v  
    Print "Set aqueous humor thickness = " & taq-0.55 ttrp|(  
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    '************************************************************************* S?$T=[yY)  
    'Radius and conic constant of anterior lens .quc i(D  
    '************************************************************************* PX'%)5:q;i  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) so?1lG  
    GetConic eID, entity, curv, conic nK$m:=  
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    SetConic eID, entity, 1/Rant, CCant hG]20n2  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant 4mg&H0 !  
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    '************************************************************************* 2{\Y<%.  
    'Radius and conic constant of posterior lens 5E8PbV-l  
    '************************************************************************* ^&%?Q_]  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) 4
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    GetConic eID, entity, curv, conic dl4.jLY  
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    SetConic eID, entity, 1/Rpost, CCpost lQjq6Fl2  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost DJ.C
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    '************************************************************************* *lSIT]1  
    'Lens thickness (Position of posterior lens surface) 8wd2\J,]  
    '************************************************************************* s+11) ~  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) \I=:,cz*,  
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    ' Delete any z-shift(s) @lI/g  
    count = 0 9S^-qQH3}  
    While GetOperationCount(eID)>count tz{]H9  
        GetOperation eID, count, op ?{V[b
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        If op.Type="ShiftZ" Then F=H=[pSe  
            DeleteOperation eID,count s_N!6$tS   
            count=count-1 qeYr=%)c  
        End If [+GG Wo  
        count=count+1 *V/SI E*8  
    Wend sAxn ; `  
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    'Set new z-shift 6Jm4?ex  
    op.Type = "ShiftZ" {*m?t 7  
    op.val1 = tlens Q=[&~^Y)  
    op.parent = parID mAMKCxz,  
    AddOperation eID, op lF<(yF5  
    Print "Set lens thickness = " & tlens j:
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    '************************************************************************* wU3Q  
    'Lens index of refraction wJ}8y4O!N  
    '************************************************************************* UcZ3v]$I  
    eID = FindMaterial( "Lens" ) G7yxCU(I\  
    GetModelMaterial eID, mat :;EzvRy  
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    mat.Nd = nlens
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    SetModelMaterial eID, mat VybiuP  
    Print "Set lens index of refraction = " & nlens b4Z#]o  
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    '************************************************************************* 3yQ(,k#  
    'Pupil diameter ,SBL~JJ  
    '************************************************************************* E5rNC/Ul$$  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) {5*5tCIt  
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    'Adjust pupil diameter (trimming volume inner hole) ,70|I{,Km  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" k~H-:@  
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    ' Adjust pupil location to just in front of the lens QeK~A@|F&  
    parID = FindFullName( "Geometry.Arizona Eye" ) JS4pJe\q  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) 6^~&sA  
    count = 0 tY7u\Y;^  
    While GetOperationCount(eID)>count vi'K|[!?  
        GetOperation eID, count, op :Q%&:[2  
        If op.Type="ShiftZ" Then X(8]9  
            DeleteOperation eID,count Qtk'^Fc  
            count=count-1 Qr/?tMALc  
        End If V!oyC$eV  
        count=count+1 7BC9cS(0w9  
    Wend Y$N|p{Z  
    op.Type = "ShiftZ" 1{A4_/R
 
    op.val1 = taq-0.01 te1
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    op.parent = parID pDu~84!])  
    AddOperation eID, op 5K8\hoW{  
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    Print "Set pupil diameter = " & pupilDiam CxO)d7c  
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    'Update AZ Eye subassembly Description I%%$O'S  
    eID = FindFullName( "Geometry.Arizona Eye" ) <4Ak$E%"  
    GetEntity eID, entity XVY^m}pMe  
    entity.Description = "Accommodation = " & A & "D" i22R3&C  
    SetEntity eID, entity Ouj5NL  
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    Update __zsrIUJ  
    Print "DONE!" R (6Jvub"I  
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End Sub {|a' =I#2  
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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： l9n8v\8,o  
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Accommodation = 4 Diopters *G=n${'  
Pupil Diameter = 4 mm wTOB'  
Set aqueous humor thickness = 2.81 Bs^W0K$uBO  
Set anterior lens radius = 10.4 and conic constant = -2.375869 E;%{hAD{  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 WC`<N4g|  
Set lens thickness = 3.927 $?
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Set lens index of refraction = 1.42672 ak<?Eu9rV  
Set pupil diameter = 4 6MZfoR  
DONE! Xc'yz 2B