切换到宽版
  • 广告投放
  • 稿件投递
  • 繁體中文
    • 1457阅读
    • 0回复

    [分享]Arizona眼睛模型 [复制链接]

    上一主题 下一主题
    离线infotek
     
    发帖
    6401
    光币
    26150
    光券
    0
    只看楼主 倒序阅读 楼主  发表于: 2020-12-09
    简介 #N?EPV$  
    ika/ GG  
    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。 yT<yy>J9l#  
    vlAYKtl3]  
    模型 VQO6!ToKY  
    6u`E{$  
    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。 TpLlbsd  
    ^<#08L;  
    Table 1. AZ眼睛模型的定义
    =l TV2C<  
    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. :4PK4D s7  
    j()<.h;'  
    光源 't:|>;Wx  
    9pD=E>4?#  
    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。 445}Yw5;9  
    FWv-_  
     &y/  
    图1. 光源和提示信息使用
    8r7~ >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。 \Jr ta  
    Nh7+Vl  
    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。 y-qbK0=X4  
    RfVVAaI  
    图2. 字母F光源的设定方法光 i>w'$ {  
    K r9 P#Y  
    图3. 字母F在视网膜上位置点列图
    C~Fdo0D  
    视网膜的散射 B>}=x4-8  
    ;ZMm6o  
    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。 B:om61Dn  
    47b=>D8  
    _,Wb`P  
    图4. 视网膜朗伯散射设定
    Z&gM7Zo8  
    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。 :|3n`,  
    G j[`r  
    kGsd3t!'  
    图5. 视网膜重点采样规格设定
    F3$@6J8<[z  
    脚本 ]5X=u(}  
    3[plwe  
    内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框,如下图所示: E?1"&D m  
    IKx]?0sS  
    图6. 用户对话框的创建与编辑
    zWYm* c"n\  
    图7. 用户对话框编辑器
    >6ul\xMU  
    如果“OK”按钮按下,将会核对对话框下面的代码行,如果点击取消则脚本终止。然后输入的参数赋予变量,如果此处是保留为空白,则使用默认值。因此,如果没有值输入并点击“OK”按钮,则脚本是以屈光度为0,光瞳直径为4mm来运行的。 8.4 1EKr2  
    余下的脚本计算与屈光度有关的所有参数。 t{n|!T&  
    ]]~tFdh  
    分析 Y;ytm #=  
    SXfuPM  
    屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 K]4XD1n7  
    bkfwsYZx  
    图7. 字母F在视网膜上颜色分析
    C'mYR3?m;  
    脚本代码 ;fLYO6  
    i`-,=RJ  
    Option Explicit     'Remove this to enable non-dimensioned variables to be used. #p@8m_g  
    "L'0"  
    Dim entity As T_ENTITY VPG+]> *  
    Dim op As T_OPERATION dLb9p"EE#  
    Dim mat As T_MODELMATERIAL 0'T*l 2Z`2  
    Dim A As Double  AnK-\4  
    Dim pupilDiam As Double >*#clf;@p  
    Dim eID As Long jiS|ara"  
    Dim parID As Long * 7: )k  
    Dim count As Integer |_q:0qo  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double bqjj6bf'o  
    Dim tlens As Double, nlens As Double 5ve4u  
    Dim curv As Double, conic As Double 6(1xU\x  
    Dim ok As Long f>$Ld1  
    [C)JI;\  
    Sub Main ^B[%|{cO  
    !vNZ- }  
        '用户输入对话框 *~b3FLzq  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 2n}nRv/'  
            TextBox 220,21,40,21,.TextBox1 'default: 0 t Dx!m~[  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 HZ$q`e  
            OKButton 40,91,90,21 F0,-7<G  
            CancelButton 190,91,90,21 72oiO[>N'  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 L`E^BuP/  
            TextBox 220,49,40,21,.TextBox2 'default: 4 H]v"_!(\  
        End Dialog &^WJ:BvA|^  
        Dim dlg As UserDialog iwb]mJUA  
    @Y2"=QVt  
        ok = Dialog (dlg) n^O Wz4  
    B{IYVviiP  
        If ok=0 Then    'cancel button was pressed 1 o5DQ'~n  
            Print "Execution cancelled." CS[[TzC=5  
            End 'M"JF;*r  
        End If e~7h8?\.q  
    ofe SGx  
        'Assign accommodation and pupil diameter & use defaults if field left empty BzFD_A>j;_  
        If dlg.TextBox1 = "" Then YDEUiZ~  
            A = 0           'Default accommodation jn+NX)9  
        Else }T!2IaAB  
            A = CDbl(dlg.TextBox1) z:PH _N~  
        End If /+pPcK  
    wFr}]<=Mi  
        If dlg.TextBox2 = "" Then zPwU'TbF  
            pupilDiam = 4   'Default pupil diameter W`zY\]  
        Else I{Pny/d`  
            pupilDiam = CDbl(dlg.TextBox2) 4fe$0mye  
        End If JI1O(  
    5fGUJ[F=  
        Print " " z?C;z7eT  
        Print "Accommodation = " & A & " Diopters" MZ_+doN  
        Print "Pupil Diameter = " & pupilDiam & " mm" F_Q,j]0  
    F12tOSfu*  
        ' Calculate new parameters with accommodation qK ,mG {  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness 0>D:  
    # L\t)W  
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens l@}BWSx&ms  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens C9oF*{  
    Kgi| 7w  
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens !*8x>,/>  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens U'i L|JRF  
    o!Vs{RRu}  
        tlens = 3.767 + 0.04*A                  'Lens thickness ,Mwyk1:xix  
     *,9.Bx*  
        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction Ln;jB&t  
    <&'Ye[k  
        'Adjust parameters to account for accommodation x~."P*5  
    ns.[PJ"8  
        '************************************************************************* !x9j~D'C`  
        'Aqueous thickness (Position of Lens) %]9 <a  
        '************************************************************************* y%T5"p$,  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) HLMEB0zh^  
        GetCustomElement eID, entity yVPkJ  
    "i$uV3d  
        parID = FindFullName( "Geometry.Arizona Eye" ) tMaJ; 4  
    WWF#&)ti  
        ' Delete any shift(s) in z S fE^'G\  
        count = 0 UV>^[/^O  
        While GetOperationCount(eID)>count k fx<T  
            GetOperation eID, count, op qL^}t_>  
            If op.Type="ShiftZ" Then SM:SxhrGt  
                DeleteOperation eID,count ZIAiVq2)  
                count=count-1 mY9u/; dK  
            End If 8uME6]m i  
            count=count+1 F<q3{}1zR  
        Wend R6 w K'  
    Y^gK^ ?K  
        'Set new shift in \\jB@O  
        op.Type = "ShiftZ" WG 9f>kE  
        op.val1 = taq ak50]KYo  
        op.parent = parID l79jd%/m  
        AddOperation eID, op qx5X2@-;:  
        Print "Set aqueous humor thickness = " & taq-0.55 qQR> z  
    :>lica_  
        '************************************************************************* >vg!<%]W]  
        'Radius and conic constant of anterior lens :V2j'R,  
        '************************************************************************* /2oTqEqaV  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) 3OHP-oa.  
        GetConic eID, entity, curv, conic x+5Q}ux'G  
    *qg9~/  
        SetConic eID, entity, 1/Rant, CCant RVfRGc^lK  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant z]>aWH}$  
    3Z'{#<1>^;  
        '*************************************************************************  >p!d(J?  
        'Radius and conic constant of posterior lens HSx~Fs^J  
        '************************************************************************* my")/e  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) s<qSelj  
        GetConic eID, entity, curv, conic CGg:e:4  
    =!xeki]|9  
        SetConic eID, entity, 1/Rpost, CCpost <9bQAyL9  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost xtjTU;T  
    :5?ti  
        '************************************************************************* > c7/E  
        'Lens thickness (Position of posterior lens surface) t; n6Q0  
        '************************************************************************* # RJy  
    sXTt )J  
        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) i`r,B`V`08  
    "}K/ b  
        ' Delete any z-shift(s) k`js~/Xv  
        count = 0 +nd'Uf   
        While GetOperationCount(eID)>count d8M"vd  
            GetOperation eID, count, op I(Nsm3L  
            If op.Type="ShiftZ" Then W<2%J)N<  
                DeleteOperation eID,count ]T^m>v)X  
                count=count-1 GMU<$x8o  
            End If (W+9 u0Zq  
            count=count+1  -/  
        Wend QAi(uL5   
    W _b $E =  
        'Set new z-shift D4'? V Iz  
        op.Type = "ShiftZ" ao{>.b  
        op.val1 = tlens 8)rv.'A((E  
        op.parent = parID t@.gmUUA  
        AddOperation eID, op EyNI]XEj  
        Print "Set lens thickness = " & tlens NOx&`OU+  
    G !1- 20  
        '************************************************************************* &t%CuU]/@  
        'Lens index of refraction { r&M  
        '************************************************************************* w^|,[G ^}H  
        eID = FindMaterial( "Lens" ) /N%f78 Z  
        GetModelMaterial eID, mat 3N+P~v)T'  
    =La}^  
        mat.Nd = nlens d?N"NqaN  
        SetModelMaterial eID, mat Pms3X  
        Print "Set lens index of refraction = " & nlens v/+dx/  
    ?%Y?z ]L#  
        '************************************************************************* q'(WIv@  
        'Pupil diameter `8FC&%X_  
        '************************************************************************* )SA$hwR  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) &K>]!yn   
    9^a>U(,  
        'Adjust pupil diameter (trimming volume inner hole) YfMe69/0I  
    F5 LQgK-z  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" V2VsJ  
    8@h zw~>  
        ' Adjust pupil location to just in front of the lens o95O!5 hl  
        parID = FindFullName( "Geometry.Arizona Eye" ) 2zFdKs,  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) ]nX.zE|F  
        count = 0 R8'yQ#FVy  
        While GetOperationCount(eID)>count k 5"3*  
            GetOperation eID, count, op 3]N}k|lb%  
            If op.Type="ShiftZ" Then h*MR5qa  
                DeleteOperation eID,count (X>y)V  
                count=count-1 W$'pUhq\H  
            End If klf<=V  
            count=count+1 Z}NAH`V`:+  
        Wend W77JXD93  
        op.Type = "ShiftZ" H&03>.b  
        op.val1 = taq-0.01 Q`vyDoF  
        op.parent = parID EW5S%Y  
        AddOperation eID, op A^K,[8VX  
    k2t?e:)3zr  
        Print "Set pupil diameter = " & pupilDiam 3$Is==>7  
    NPoXz  
        'Update AZ Eye subassembly Description B4|`Z'U#;  
        eID = FindFullName( "Geometry.Arizona Eye" ) EPa3Yb?BGb  
        GetEntity eID, entity Y43#];  
        entity.Description = "Accommodation = " & A & "D" B8_l+dXO  
        SetEntity eID, entity fwq|8^S@  
    (|[3/_!;v  
        Update vj^U F(X  
        Print "DONE!" 5z]dA~;*2  
         ("lcL2Bq  
    End Sub %x927I>  
    dX$])b_Uw  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: Bw_Ih|y,w  
    25ayYO%PTc  
    Accommodation = 4 Diopters -:~`g*3#  
    Pupil Diameter = 4 mm 8m1zL[.8g  
    Set aqueous humor thickness = 2.81 x.^vWka(  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 6VE >$`m  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 ,gOQI S56  
    Set lens thickness = 3.927 }oN(nPxv9  
    Set lens index of refraction = 1.42672 q~w;C([k_  
    Set pupil diameter = 4 gMGg9U$@  
    DONE! v PGuEfz  
    N)!v-z,k  
    <>e<Xd:77{  
    QQ:2987619807 D/:)rj14b  
     
    分享到