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    [技术]Arizona眼睛模型 [复制链接]

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    只看楼主 倒序阅读 楼主  发表于: 2021-10-22
    简介 iNcZ)m/  
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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。 B~r}c4R{7  
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    模型 j{#Wn !,  
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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。 5,+\`!g  
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    Table 1. AZ眼睛模型的定义
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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. @^nu #R  
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    光源 M%Ku5X6:/  
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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。 +R$?2  
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    图1. 光源和提示信息使用
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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。 ;##]G=%  
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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。 TZ^LA L'8_  
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    图2. 字母F光源的设定方法光 p(3sgY1  
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    图3. 字母F在视网膜上位置点列图
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    视网膜的散射 y<r}"TAf-  
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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。 X\GM/A  
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    图4. 视网膜朗伯散射设定
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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。 .{dE}2^  
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    图5. 视网膜重点采样规格设定
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    脚本 * UcjQ  
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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: nW;kcS*A  
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    图6. 用户对话框的创建与编辑
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    图7. 用户对话框编辑器
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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。 ;i)KHj'  
    余下的脚本计算与屈光度有关的所有参数。 NXoK@Y  
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    分析 u]vPy ria  
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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。 _'iDF  
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    图7. 字母F在视网膜上颜色分析
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    脚本代码 /5a;_  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. ~ l )t|'6  
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    Dim entity As T_ENTITY A!HK~yk~Q  
    Dim op As T_OPERATION G\rj?%  
    Dim mat As T_MODELMATERIAL ofCVbn  
    Dim A As Double  ]6~k4  
    Dim pupilDiam As Double OhWC}s  
    Dim eID As Long iz x[  
    Dim parID As Long |^5/(16  
    Dim count As Integer `ut)+T V  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double H`|0-`q  
    Dim tlens As Double, nlens As Double c cr" ep  
    Dim curv As Double, conic As Double g5}7y\  
    Dim ok As Long : ^(nj7D  
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    Sub Main `!Ln|_,d  
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        '用户输入对话框 Q]i[.ME  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 U>3 >Ex  
            TextBox 220,21,40,21,.TextBox1 'default: 0 wixD\t59X  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 5Bj77?Z  
            OKButton 40,91,90,21 Ru7L>(Njs  
            CancelButton 190,91,90,21 Uz>Yn&{y6  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 :uR>UDlPX  
            TextBox 220,49,40,21,.TextBox2 'default: 4 Yk7"XP[Y  
        End Dialog -Op@y2+c  
        Dim dlg As UserDialog TNsg pJ?\  
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        ok = Dialog (dlg) !$E~\uT  
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        If ok=0 Then    'cancel button was pressed Q<'@V@H  
            Print "Execution cancelled." "'aqb~j^  
            End KZ\dB;W< |  
        End If S~&\o\"5  
    =tq7z =k  
        'Assign accommodation and pupil diameter & use defaults if field left empty "gg(tp45  
        If dlg.TextBox1 = "" Then N l|^o{#  
            A = 0           'Default accommodation J[+Tj @n'  
        Else E 8^sy*f  
            A = CDbl(dlg.TextBox1) |0DP} `~  
        End If z (#Xca  
    }wG|%Y#+r  
        If dlg.TextBox2 = "" Then VVN # $  
            pupilDiam = 4   'Default pupil diameter Ei~]iZ}  
        Else 0$?qoS  
            pupilDiam = CDbl(dlg.TextBox2) `E%(pjG  
        End If 3Pa3f >}-  
    JchA=n  
        Print " " 1l~.R#WG&  
        Print "Accommodation = " & A & " Diopters" jqqaw  
        Print "Pupil Diameter = " & pupilDiam & " mm" yHtGp%j  
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        ' Calculate new parameters with accommodation 5 2fO)!  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness @|]iSD&T #  
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        Rant = 12.0 - 0.4*A                     'Radius of anterior lens gm}C\q9  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens -MUQ \pZ  
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        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens LNbx3W oC  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens `^`9{@~  
    b/G8M r  
        tlens = 3.767 + 0.04*A                  'Lens thickness d)9PEtI  
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        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction n<+~ zQ  
    zo87^y5?G  
        'Adjust parameters to account for accommodation q>c+bo 6  
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        '************************************************************************* krwf8!bI  
        'Aqueous thickness (Position of Lens) {MA@ A5  
        '************************************************************************* i"KL;t[1  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) pO5v*oONz+  
        GetCustomElement eID, entity e$x4Ux7*"  
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        parID = FindFullName( "Geometry.Arizona Eye" ) 7kOE/>P?  
    *di&%&f  
        ' Delete any shift(s) in z KgL<}=S  
        count = 0 %oMWcgsdJi  
        While GetOperationCount(eID)>count +6wx58.B&  
            GetOperation eID, count, op TIKEg10I  
            If op.Type="ShiftZ" Then u;QH8LK  
                DeleteOperation eID,count <)=3XEcb  
                count=count-1 WNl&v]   
            End If aKa  R  
            count=count+1 t.gq5Y.[  
        Wend G!-7ic_4  
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        'Set new shift in m`[oT\  
        op.Type = "ShiftZ" `\nON  
        op.val1 = taq ^7J~W'hI  
        op.parent = parID k{zs578h2  
        AddOperation eID, op qAnA=/k`  
        Print "Set aqueous humor thickness = " & taq-0.55 #IH<HL)t%e  
    ~r{\WZ.  
        '************************************************************************* |C&%S"*+D  
        'Radius and conic constant of anterior lens z%++\.g_  
        '************************************************************************* s0_-1VU  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) ^mS.HT=X  
        GetConic eID, entity, curv, conic dx k;@Tz  
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        SetConic eID, entity, 1/Rant, CCant -ryDsq  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant myEGibhK  
    &Bj,.dD/a  
        '************************************************************************* ppPG+[cz  
        'Radius and conic constant of posterior lens Xp<A@2wt?  
        '************************************************************************* :|*Gnu  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) 4Z<]4:o  
        GetConic eID, entity, curv, conic p} t{8j >  
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        SetConic eID, entity, 1/Rpost, CCpost V:nMo2'hb  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost +,ZU TG  
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        '************************************************************************* 3ybK6!g`[  
        'Lens thickness (Position of posterior lens surface) ]}UeuF\  
        '************************************************************************* >!:$@!6L  
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        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) M63s(f  
    s BeP;ox  
        ' Delete any z-shift(s) chvrHvByS  
        count = 0 8MYLXW6  
        While GetOperationCount(eID)>count ^&f{beU9  
            GetOperation eID, count, op P5yJO97  
            If op.Type="ShiftZ" Then f}Ne8]U/Hc  
                DeleteOperation eID,count  ?.4yg(  
                count=count-1 Q#yu(  
            End If &hSnB~hi  
            count=count+1 {<''OwQF~+  
        Wend Uxj<x`<1x  
    E|F!S(.:,M  
        'Set new z-shift j]@ x Q,y  
        op.Type = "ShiftZ" a2(D!_dZR  
        op.val1 = tlens D:ql^{~  
        op.parent = parID glOqft&>`  
        AddOperation eID, op 35]j;8N:  
        Print "Set lens thickness = " & tlens IS5.i95m  
    (`q6G d  
        '************************************************************************* m11"i=S"  
        'Lens index of refraction xdFP$Y~ogy  
        '************************************************************************* {UV<=R,E  
        eID = FindMaterial( "Lens" ) m2-fi*Mgg  
        GetModelMaterial eID, mat XudH  
    Y:tW]   
        mat.Nd = nlens mK7^:(<.LO  
        SetModelMaterial eID, mat qb>|n1F_  
        Print "Set lens index of refraction = " & nlens ^cKv JSY  
    Q5`+eQ?_\  
        '************************************************************************* &F<J#cfe8  
        'Pupil diameter 6\)8mK  
        '************************************************************************* jFJW3az@z  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) BM=V,BZy  
    )$9C`d[  
        'Adjust pupil diameter (trimming volume inner hole) OTNZ!U/)j  
    x 1%J1?Fp  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" oneSgJ  
    3H\b N4  
        ' Adjust pupil location to just in front of the lens Sug~FV?k$e  
        parID = FindFullName( "Geometry.Arizona Eye" ) 8vX*SrM  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) ^cPo{xf  
        count = 0 u$Pf.#  
        While GetOperationCount(eID)>count i SAidK,  
            GetOperation eID, count, op l7D4`i<F  
            If op.Type="ShiftZ" Then VAF:Z  
                DeleteOperation eID,count Un8#f+odR  
                count=count-1 NejsI un%  
            End If V!kQuQJ>  
            count=count+1 Us@ {w`T  
        Wend *'`3]!A  
        op.Type = "ShiftZ" y ? {PoNI  
        op.val1 = taq-0.01 vBCZ/F[  
        op.parent = parID &ESR1$)'P  
        AddOperation eID, op ,,C~j`F  
    0%&fUz36E6  
        Print "Set pupil diameter = " & pupilDiam %xbz&'W,  
    2'O!~8U  
        'Update AZ Eye subassembly Description J7 *G/F  
        eID = FindFullName( "Geometry.Arizona Eye" ) 1Hk<_no5  
        GetEntity eID, entity 3' :[i2[  
        entity.Description = "Accommodation = " & A & "D" :+gCO!9Y  
        SetEntity eID, entity 0=(-8vwd  
    ^RF mRn  
        Update u {E^<fW]  
        Print "DONE!" t UAY]BJ*s  
         Ph! KL\  
    End Sub ru6HnLhL  
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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: |V~(mS747:  
    d)17r\*>I  
    Accommodation = 4 Diopters )*$  
    Pupil Diameter = 4 mm qS/71Kv'  
    Set aqueous humor thickness = 2.81  ]5)&36  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 Q'Jpsmwu  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 9(FcA5Y  
    Set lens thickness = 3.927 7PQj7&m  
    Set lens index of refraction = 1.42672 )l!&i?h%  
    Set pupil diameter = 4 xUYN\Pc-  
    DONE! U0|j^.)  
     
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