切换到宽版
  • 广告投放
  • 稿件投递
  • 繁體中文
    • 1801阅读
    • 0回复

    [技术]Arizona眼睛模型 [复制链接]

    上一主题 下一主题
    离线infotek
     
    发帖
    6374
    光币
    26015
    光券
    0
    只看楼主 倒序阅读 楼主  发表于: 2021-10-22
    简介 viJP6fh  
    y&V'GhW!dd  
    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。 K)^8 :nt  
    bq9/ d4  
    模型 f`iDF+h<6  
    _M^^0kf  
    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。 z0%tBgqY(  
    X|aD>CT  
    Table 1. AZ眼睛模型的定义
    y#= j{  
    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. ZZ T 9t#~  
    dkeMiL m  
    光源 Cu_-QE  
    FF;Fo}no-  
    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。 o$Y#C{wC%  
    06?d#{?M1o  
    Er - rm  
    图1. 光源和提示信息使用
    k9;t3-P  
    除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处,并增加了pre-propagation distance= -8。尽管光线在光瞳处创建,规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射,而不是在光瞳处入射。 R\<d&+q@  
    W0}FOfL9  
    在往下看是内置的脚本用来修改屈光度,使其为4(250mm),光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 de;CEm<n  
    "x nULQK  
    图2. 字母F光源的设定方法光 LnM$@  
    13*S<\  
    图3. 字母F在视网膜上位置点列图
    TF80WMt  
    视网膜的散射 <AK9HPxP  
    IVVX3RI  
    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。 h6}rOchj  
    O<ybiPR  
    6J">@+  
    图4. 视网膜朗伯散射设定
    <\ eRa{ef  
    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。 ~,Yd.?.TI  
    a!f71k r  
    ~Orz<%k.  
    图5. 视网膜重点采样规格设定
    m/;fY>}3  
    脚本 itg"dGDk  
    `5"3Cj"M  
    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: GB;_!69I  
    x&"P^gh)  
    图6. 用户对话框的创建与编辑
    wEN[o18{  
    图7. 用户对话框编辑器
    suYbD!`(  
    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。 g9=_^^Tg  
    余下的脚本计算与屈光度有关的所有参数。 ddbQFAQQQ  
    NNwGRoDco  
    分析 F)Z9Qlo  
    oKH+Q6S:  
    屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 Z$B%V t  
    PIdGis5G  
    图7. 字母F在视网膜上颜色分析
    H/Rzs$pnv  
    脚本代码 8'NT_NPNb  
    OJhMM-  
    Option Explicit     'Remove this to enable non-dimensioned variables to be used. 9p1@Lfbj  
    '&2-{Y [!  
    Dim entity As T_ENTITY <_]W1V:0  
    Dim op As T_OPERATION ~N7;. 3 7  
    Dim mat As T_MODELMATERIAL _^`V0>Mh:  
    Dim A As Double zbGZ\pz  
    Dim pupilDiam As Double o wI:Qs_/4  
    Dim eID As Long V-E 77u6{0  
    Dim parID As Long >;R7r|^k  
    Dim count As Integer ((<\VQ,>(  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double Rf2mBjJ(z  
    Dim tlens As Double, nlens As Double b|;h$otC  
    Dim curv As Double, conic As Double mIPDF1= )  
    Dim ok As Long Mz86bb^J  
    k+J63+obd  
    Sub Main  Mz+vT0  
    =-&h@mB;G  
        '用户输入对话框 >YsM'.EFD  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 Pc7p2  
            TextBox 220,21,40,21,.TextBox1 'default: 0 cYXL3)p*Q  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 I?Z"YR+MQ  
            OKButton 40,91,90,21 TP~1-(M)}  
            CancelButton 190,91,90,21 IGi9YpI&K  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 "@|rU4Y  
            TextBox 220,49,40,21,.TextBox2 'default: 4 t OxH9  
        End Dialog *B84Y.df  
        Dim dlg As UserDialog d @ l  
    ^FVmP d*1  
        ok = Dialog (dlg) #{^qBP[  
    uBn35%  
        If ok=0 Then    'cancel button was pressed M{jq6c  
            Print "Execution cancelled." \=`jo$S  
            End ,oPxt  
        End If pf+VYZ#)  
    4sW~7:vU  
        'Assign accommodation and pupil diameter & use defaults if field left empty bI_MF/r''  
        If dlg.TextBox1 = "" Then ]0[ot$Da6  
            A = 0           'Default accommodation g!o2vTt5  
        Else euW   
            A = CDbl(dlg.TextBox1) ^HtB!Xc  
        End If `e?~c'a@  
    ^4'!B +}F  
        If dlg.TextBox2 = "" Then Qw }1mRv  
            pupilDiam = 4   'Default pupil diameter y$_]}<b  
        Else g}uSIv^  
            pupilDiam = CDbl(dlg.TextBox2) LR\8M(rtvH  
        End If 5tzO=gO[  
    i[ws%GfEv  
        Print " " 8OO[Le]1  
        Print "Accommodation = " & A & " Diopters" fO .=i1 E}  
        Print "Pupil Diameter = " & pupilDiam & " mm" m6]6 !_  
    ll- KK`Ka  
        ' Calculate new parameters with accommodation 7s!rer>  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness ' I!/I  
    eT]*c?"  
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens 412E7   
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens zMBGpqdP  
    z|Yt|W  
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens ; sqxFF@  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens bR~5 :A^  
    [9:";JSl"Y  
        tlens = 3.767 + 0.04*A                  'Lens thickness q">}3`k  
    o~q.j_Sa  
        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction yF%e)6  
    )0"T?Ivp]  
        'Adjust parameters to account for accommodation }UQ,B  
    K[ S>EITr  
        '************************************************************************* 0vBQzM Q  
        'Aqueous thickness (Position of Lens) pG"h ZB3)  
        '************************************************************************* ;ceg:-Zqo  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) t)g %9 k^  
        GetCustomElement eID, entity T!HAE#xC  
    /=A@O !l  
        parID = FindFullName( "Geometry.Arizona Eye" ) C>mFylN  
    W- nS{v(  
        ' Delete any shift(s) in z R rYNtc  
        count = 0 s0/m qZ]s  
        While GetOperationCount(eID)>count jp@X,HES  
            GetOperation eID, count, op csxn" Dz\  
            If op.Type="ShiftZ" Then ,dw\y/dn  
                DeleteOperation eID,count Q~k|lTf  
                count=count-1 ^tWSu?9  
            End If W1t_P&i  
            count=count+1 m}zXy\  
        Wend qt/6o|V  
    Wa.!eAe}  
        'Set new shift in *yo'Nqu  
        op.Type = "ShiftZ" a|#pl!  
        op.val1 = taq P4c3kO0  
        op.parent = parID #o9CC)q5G  
        AddOperation eID, op :(tKc3z  
        Print "Set aqueous humor thickness = " & taq-0.55 OYn5k6  
    7!FiPH~kM  
        '************************************************************************* l @@pXg3  
        'Radius and conic constant of anterior lens F M YcZ+4  
        '************************************************************************* @PhAg  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) 6Yt3Oq<U  
        GetConic eID, entity, curv, conic :,j^ei  
    JP {`^c  
        SetConic eID, entity, 1/Rant, CCant @\xEK5SG  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant 8x7TK2r  
    f~TkU\Rh  
        '************************************************************************* :,R>e}lM  
        'Radius and conic constant of posterior lens .h4Z\R`  
        '************************************************************************* E?|NYu#I6  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) b&1hj[`)  
        GetConic eID, entity, curv, conic u|u)8;'9(  
    ~| ZAS]  
        SetConic eID, entity, 1/Rpost, CCpost H1KXAy`&  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost Gv }  
    :eB+t`M  
        '************************************************************************* O&~ @ior  
        'Lens thickness (Position of posterior lens surface) 7Q~W}`Qv'  
        '************************************************************************* hb/Z{T'   
    f;l}Z|dok6  
        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) |E||e10wR  
    <mTo54g  
        ' Delete any z-shift(s) >c5   
        count = 0 b].U/=Hs  
        While GetOperationCount(eID)>count [eTEK W]  
            GetOperation eID, count, op 7M5H vG#w%  
            If op.Type="ShiftZ" Then p} eO  
                DeleteOperation eID,count US-f<Wq  
                count=count-1 +>[zn  
            End If *`/4KMrq  
            count=count+1 -ik((qx_  
        Wend D(dV{^} 9  
    g}a+%Obb  
        'Set new z-shift [C~N#S[]  
        op.Type = "ShiftZ" BC1smSlJ  
        op.val1 = tlens lU&2K$`  
        op.parent = parID +u\w4byl  
        AddOperation eID, op ~HT:BO$  
        Print "Set lens thickness = " & tlens n-qle5sj  
    cd=H4:<T5  
        '************************************************************************* US9@/V*2  
        'Lens index of refraction R3)ccom  
        '************************************************************************* v~._]f$:  
        eID = FindMaterial( "Lens" ) aYHs35  
        GetModelMaterial eID, mat ^"vmIC.h  
     :fy,%su  
        mat.Nd = nlens VAyAXN~  
        SetModelMaterial eID, mat j>v8i bS(  
        Print "Set lens index of refraction = " & nlens .N\t3\9}  
    T xpj#JD  
        '************************************************************************* mYXL  
        'Pupil diameter qvhG ^b0h  
        '*************************************************************************  z{V#_(  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) YWV)C?5x&  
    ?@Tsd@s~r  
        'Adjust pupil diameter (trimming volume inner hole) fmUrwI1 %  
    ?hIDyM  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" 9Q\B1Q  
    gS]  
        ' Adjust pupil location to just in front of the lens \X]I: 0^j  
        parID = FindFullName( "Geometry.Arizona Eye" ) Pmr'W\aIR  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) q1r-xsjV=  
        count = 0 F%%mcmHD#  
        While GetOperationCount(eID)>count ,5 3`t  
            GetOperation eID, count, op ('d,Sh  
            If op.Type="ShiftZ" Then ,MHF  
                DeleteOperation eID,count /!/Pk'p=/  
                count=count-1 B/hQvA;(  
            End If gssEdJ  
            count=count+1 ;9J6)zg !n  
        Wend G-]_ d  
        op.Type = "ShiftZ" b0se-#+  
        op.val1 = taq-0.01 G[OJ <px  
        op.parent = parID Eb29tq  
        AddOperation eID, op 9~K+h/  
    7W&XcF  
        Print "Set pupil diameter = " & pupilDiam ^HI2Vp  
    Gs04)KJm<  
        'Update AZ Eye subassembly Description ']OT7)_  
        eID = FindFullName( "Geometry.Arizona Eye" ) :inVwc  
        GetEntity eID, entity j[t2Bp  
        entity.Description = "Accommodation = " & A & "D" hW;n^\lF#e  
        SetEntity eID, entity EgzdRB\Cf  
    < 5ULu(b&$  
        Update ;LKYA?=/V  
        Print "DONE!" F^}d>2W(  
         lC d\nE8G  
    End Sub ,&Zk63V  
    cN\_1  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: 2:yXeSeA  
    [w+1<ou;j  
    Accommodation = 4 Diopters O\%0D.HEz  
    Pupil Diameter = 4 mm v`6vc)>8  
    Set aqueous humor thickness = 2.81 OsYZ a`$,  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 @x *,fk  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 &{q'$oF  
    Set lens thickness = 3.927 yaHkWkl =  
    Set lens index of refraction = 1.42672 '?X?'_3  
    Set pupil diameter = 4 C}9|e?R[Rz  
    DONE! \3F)M`g  
     
    分享到