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    [分享]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: 2020-12-09
    简介 3H#/u! W  
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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。 DPQGh`J  
    F%Umau*1  
    模型 wx%nTf/Oa  
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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。 ?J@qg20z  
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    Table 1. AZ眼睛模型的定义
    i2a"J&,6O  
    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. dIa(</ }  
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    光源 W$Q)aA7  
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    多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 C1B3VG  
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    图1. 光源和提示信息使用
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    除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处,并增加了pre-propagation distance= -8。尽管光线在光瞳处创建,规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射,而不是在光瞳处入射。 #C;zS9(]B  
    :Mu8W_  
    在往下看是内置的脚本用来修改屈光度,使其为4(250mm),光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 4B8Se  
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    图2. 字母F光源的设定方法光 a$zm/  
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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 @S"pJeP/f  
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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。 #"p1Qea$  
    )Z8"uRTb0  
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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。 EOPS? @  
    SeNF!k% Y  
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    图5. 视网膜重点采样规格设定
    ,KhMzE8_a  
    脚本 3Da,] w<  
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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: ,;cel^.b  
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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。 *0&4mi8  
    余下的脚本计算与屈光度有关的所有参数。 h%1~v$W`  
    ]o[X+;Tj|  
    分析 tf7v5iGe  
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    屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 #7~tL23}]  
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    图7. 字母F在视网膜上颜色分析
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    脚本代码 pqH( Tbjq  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. )+w/\~@  
    qb-2QPEB  
    Dim entity As T_ENTITY Iu-'o  
    Dim op As T_OPERATION ,a9D~i 9R  
    Dim mat As T_MODELMATERIAL esh$*)1  
    Dim A As Double zr3q>]oma  
    Dim pupilDiam As Double k_K,J 6_)  
    Dim eID As Long qu<B%v  
    Dim parID As Long 'Vm5Cs$  
    Dim count As Integer zM_DE  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double 2Ft8dfdm`  
    Dim tlens As Double, nlens As Double H b A3*2  
    Dim curv As Double, conic As Double @~$F;M=.*  
    Dim ok As Long `i t+D  
    462!;/ y  
    Sub Main ;# R3k  
    ~@-QbkC  
        '用户输入对话框 pYLY;qkG"  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 .K|P&  
            TextBox 220,21,40,21,.TextBox1 'default: 0 dysX  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 ^ o $W  
            OKButton 40,91,90,21 ERfd7V<c>  
            CancelButton 190,91,90,21 FE8+E\ U?  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 MtZt8s  
            TextBox 220,49,40,21,.TextBox2 'default: 4 u}-d7-=  
        End Dialog zdLVxL>87  
        Dim dlg As UserDialog 8^<c,!DM  
    X"hOHx5P  
        ok = Dialog (dlg) *Nv y+V  
    &\[Qm{lN  
        If ok=0 Then    'cancel button was pressed C 'B4 mmC  
            Print "Execution cancelled." 2!{_/@I\Y  
            End 5E]UI YAkV  
        End If !y>lOw})Q  
    _l#3]#  
        'Assign accommodation and pupil diameter & use defaults if field left empty |`_ <@b  
        If dlg.TextBox1 = "" Then kf+JM/  
            A = 0           'Default accommodation }yx=(+jP  
        Else xHEVR!&c4  
            A = CDbl(dlg.TextBox1) ]PR|d\O  
        End If `"xk,fVYd  
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        If dlg.TextBox2 = "" Then QO5OnYh  
            pupilDiam = 4   'Default pupil diameter I;Al? &uw  
        Else #joF{ M{  
            pupilDiam = CDbl(dlg.TextBox2) }': EJ~H  
        End If *C4~}4WT\  
    ?)!SmN/  
        Print " " ?@Z7O.u  
        Print "Accommodation = " & A & " Diopters" :0M' =~[  
        Print "Pupil Diameter = " & pupilDiam & " mm" ]{K5zSK  
    (g%JK3  
        ' Calculate new parameters with accommodation 8s QQK.N(  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness ltNuLZ  
    McT\ R{/  
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens Rz`@N`U  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens beJZ pg  
    ..??O^   
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens <8iYL`3  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens H,(F1+~d  
    6b%`^B\  
        tlens = 3.767 + 0.04*A                  'Lens thickness !?BW_vY  
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        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction xh{mca>?G  
    bHO7* E  
        'Adjust parameters to account for accommodation fkW3~b  
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        '************************************************************************* ~J%R-{U9  
        'Aqueous thickness (Position of Lens) rQ=xcn[A  
        '************************************************************************* OF-E6bc  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) ~@%(RMJm&  
        GetCustomElement eID, entity sk#9x`Rw  
    H!Wis3S3G  
        parID = FindFullName( "Geometry.Arizona Eye" ) I_:t}3s  
    "w;08TX8  
        ' Delete any shift(s) in z f8^"E $"  
        count = 0 J=@hk@Nq#  
        While GetOperationCount(eID)>count /r>IV`n{  
            GetOperation eID, count, op kX igX-  
            If op.Type="ShiftZ" Then M,&tA1CH  
                DeleteOperation eID,count grGhN q  
                count=count-1 HpW" lYW4  
            End If c L?\^K)  
            count=count+1 d?JAUbqy  
        Wend !K!)S^^Po?  
    IZ+ *`E  
        'Set new shift in D=2~37CzQ1  
        op.Type = "ShiftZ" !{ $qMhT  
        op.val1 = taq :}^Rs9 '  
        op.parent = parID b([:,T7  
        AddOperation eID, op 3b#L17D3_  
        Print "Set aqueous humor thickness = " & taq-0.55 +IvNyj|  
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        '************************************************************************* 1d`cTaQ-  
        'Radius and conic constant of anterior lens z|uOJ0uK  
        '************************************************************************* 5xhM0 (  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) KCE=|*6::|  
        GetConic eID, entity, curv, conic 2>g^4(  
    Og +)J9#  
        SetConic eID, entity, 1/Rant, CCant S3ErH,XB.  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant : -E,   
    c2/"KT  
        '************************************************************************* n4Vwao/9x  
        'Radius and conic constant of posterior lens (m6EQoW^s+  
        '************************************************************************* 6Ux[,]G K  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) >xZ5 ac I  
        GetConic eID, entity, curv, conic b,9@P&=:2  
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        SetConic eID, entity, 1/Rpost, CCpost i)=m7i  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost Xj%,xm>}!u  
    cbfD B^_  
        '************************************************************************* L"4]Tm>zq  
        'Lens thickness (Position of posterior lens surface) 5~QhX22  
        '************************************************************************* V5~fMsse  
    B`#*o<eb  
        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) H*GlWgfG  
    { yTpRQN~  
        ' Delete any z-shift(s) xg?auje  
        count = 0 { E^U6@  
        While GetOperationCount(eID)>count 3+ e4e  
            GetOperation eID, count, op ,'=hjIel  
            If op.Type="ShiftZ" Then MBlBMUJk  
                DeleteOperation eID,count |4 Qx=x>  
                count=count-1 fSbS(a  
            End If ,'u*ZB;  
            count=count+1 v_.HGG S  
        Wend "3wv:BL  
    Zd$JW=KR]l  
        'Set new z-shift z4bN)W )p  
        op.Type = "ShiftZ" eIsT!V" 7  
        op.val1 = tlens Y|_O8[  
        op.parent = parID X PA 0m  
        AddOperation eID, op B@"J]S  
        Print "Set lens thickness = " & tlens 02(h={  
    ) y`i@S}J  
        '************************************************************************* rmsQt  
        'Lens index of refraction g &*mozs  
        '************************************************************************* (#If1[L  
        eID = FindMaterial( "Lens" ) b;*c:{W)  
        GetModelMaterial eID, mat ##v`(#fu  
    vTHq)C.7G  
        mat.Nd = nlens Yh$fQ:yi\&  
        SetModelMaterial eID, mat 9)Ly}Kzx  
        Print "Set lens index of refraction = " & nlens XC2FF&B&  
    fgmSgG"b  
        '************************************************************************* NZ+7p{&AN  
        'Pupil diameter NCn`}QP  
        '************************************************************************* 68p R:  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) ] opto  
    $~G@   
        'Adjust pupil diameter (trimming volume inner hole) 0yaMe@&,  
    D#ZPq,f  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" sBU_Ft  
    V 9Hl1\j^  
        ' Adjust pupil location to just in front of the lens "W5rx8a  
        parID = FindFullName( "Geometry.Arizona Eye" ) !9D1 Fa  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) SB/3jH  
        count = 0 z0 \N{rP&  
        While GetOperationCount(eID)>count lH6fvz  
            GetOperation eID, count, op cJ2PI  
            If op.Type="ShiftZ" Then (0R2T"/  
                DeleteOperation eID,count +(&|uq^  
                count=count-1 l|q%%W0  
            End If BPewc9RxV  
            count=count+1 ceG&,a$\  
        Wend Bzw19S6y  
        op.Type = "ShiftZ" KUFz:&wK  
        op.val1 = taq-0.01 SO_>c+Dw  
        op.parent = parID tF%QH[  
        AddOperation eID, op +{e`]t>_  
    #1gO?N(<=  
        Print "Set pupil diameter = " & pupilDiam G\ex^&M  
    , D"]y~~I5  
        'Update AZ Eye subassembly Description #kci=2q_  
        eID = FindFullName( "Geometry.Arizona Eye" ) iZ "y7s  
        GetEntity eID, entity }LQC.!  
        entity.Description = "Accommodation = " & A & "D" Cfv]VQQE  
        SetEntity eID, entity |vz9Hs$@l  
    0X>T+A[E  
        Update =) }nLS3t  
        Print "DONE!" $@.jZ_G  
         pV=@sz,G  
    End Sub `*k@4.J{  
    SY T$3|a  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: !^?qU;|  
    V{ |[oIp  
    Accommodation = 4 Diopters " #v%36U  
    Pupil Diameter = 4 mm x*q35K^PE  
    Set aqueous humor thickness = 2.81 ,H{={aln  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 i*CnoQH  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 ^{[[Z.&R?  
    Set lens thickness = 3.927 ~},W8\C>  
    Set lens index of refraction = 1.42672 7&|6KN}c  
    Set pupil diameter = 4 yWY|]Pp  
    DONE! 2y%R:Mu  
    niz'b]] +  
    $r15gfne>  
    QQ:2987619807 ShGp^xVj  
     
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