切换到宽版
  • 广告投放
  • 稿件投递
  • 繁體中文
    • 2263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
    6634
    光币
    27319
    光券
    0
    只看楼主 倒序阅读 楼主  发表于: 2021-10-22
    简介 h2&y<Eg>  
    t&pGQ  
    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。 q2Rf@nt  
    I7bi@t  
    模型 ?360SQ<  
    E!dp~RwZu  
    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。 qL>v&Rd<  
    ".M:`BoW4  
    Table 1. AZ眼睛模型的定义
    YE_6OLW  
    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. x:C@)CAr  
    D2?S,9+E_  
    光源 0x4l5x$8  
    #W^_]Q=5R'  
    多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 2$DSBQEx  
    s[Gswd  
    HSql)iT  
    图1. 光源和提示信息使用
    H` Lu"EK  
    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。 :3gFHBFDj  
    }JGq1  
    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。 /xf.\Z7<  
    bQpoXs0w;  
    图2. 字母F光源的设定方法光 6>lW5U^yA\  
     2+Vp'5>&  
    图3. 字母F在视网膜上位置点列图
    rxArTpS{.#  
    视网膜的散射 Y)v%  
    aLHrl6"  
    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。 K_FBy  
    d~,n_E$q;  
    R{ 4u|A?9  
    图4. 视网膜朗伯散射设定
    _Ua PwJ  
    注意在视网膜的表面有散射重点采样规格定义,在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳,半角度10度。 LiF.w:}  
    6<+8}`@B>G  
    gvK"*aIj  
    图5. 视网膜重点采样规格设定
    ',%5mF3j  
    脚本 >["Kd.ye  
    xNx`J@xt$  
    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: ~"\P~cg0J  
    LsnXS9_  
    图6. 用户对话框的创建与编辑
    E8 \\X  
    图7. 用户对话框编辑器
    F-i&M1 \_  
    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。 nT)~w s  
    余下的脚本计算与屈光度有关的所有参数。 {6DpPw^"  
    7%X+O8  
    分析 o` 2 5  
    ruWye1X;  
    屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 HN^w'I'bp  
    pM,#wYL  
    图7. 字母F在视网膜上颜色分析
    &9k"9  
    脚本代码 z[%[bs2{  
    DU(X,hDBF  
    Option Explicit     'Remove this to enable non-dimensioned variables to be used. 9.jG\i  
    2Sv>C `FMU  
    Dim entity As T_ENTITY 1ME|G"$;  
    Dim op As T_OPERATION @RQ+JYQi  
    Dim mat As T_MODELMATERIAL @i\7k(9:A  
    Dim A As Double 0;'j!`l9  
    Dim pupilDiam As Double +)% ,G@-`  
    Dim eID As Long *:k~g].Iz  
    Dim parID As Long ;k-g _{M  
    Dim count As Integer [ +yGDMLs  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double T$f:[ye]Z  
    Dim tlens As Double, nlens As Double JHHb|  
    Dim curv As Double, conic As Double Bc5YW-QD  
    Dim ok As Long $]xE$dzJ  
    6Uch 0xha!  
    Sub Main -i2D#i'  
    oM-b96  
        '用户输入对话框 e?|d9;BO  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 o$*bm6o  
            TextBox 220,21,40,21,.TextBox1 'default: 0 USH@:c#t  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 !>?4[|?n<  
            OKButton 40,91,90,21 ccIDMJ=2  
            CancelButton 190,91,90,21 `4se7{'UK`  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 jo]m1 2ps  
            TextBox 220,49,40,21,.TextBox2 'default: 4 Zjw!In|vC  
        End Dialog 3}v0{c  
        Dim dlg As UserDialog ': 5Trx  
     >cC Gx  
        ok = Dialog (dlg) ]:[)KZ~  
    X L{{7%j  
        If ok=0 Then    'cancel button was pressed [P(rY  
            Print "Execution cancelled." L.R"~3  
            End 8ct+?-3g  
        End If ~5x4?2  
    sDW"j\  
        'Assign accommodation and pupil diameter & use defaults if field left empty Cb4d|yiS8  
        If dlg.TextBox1 = "" Then i7Y s_8A"9  
            A = 0           'Default accommodation j=`y  @~  
        Else J r=REa0  
            A = CDbl(dlg.TextBox1) 7O;BS}Lv=  
        End If =ip~J<sw&  
    9/@FADh  
        If dlg.TextBox2 = "" Then GLbc/qs  
            pupilDiam = 4   'Default pupil diameter ,AGM?&A  
        Else {o Q(<&Aw  
            pupilDiam = CDbl(dlg.TextBox2) tg4LE?nv  
        End If u&hDjE  
     m^W*[ ^p  
        Print " " !Qj)tS#Az  
        Print "Accommodation = " & A & " Diopters" }[XB]Xf  
        Print "Pupil Diameter = " & pupilDiam & " mm" G~b`O20N  
    `</=AY>  
        ' Calculate new parameters with accommodation Qivf|H619  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness 7C,<iY  
    s8`}x_k=  
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens v Ie=wf~D`  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens 1Xk{(G<\  
    9&|12x$  
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens [qO5~E`;  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens AQJ|^'%  
    ,)B~cic'u  
        tlens = 3.767 + 0.04*A                  'Lens thickness C}M0XW  
    ox i a}  
        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction o>/uW8  
    r_!{!i3B  
        'Adjust parameters to account for accommodation e>ZbZy?  
    *o:B oP=S  
        '************************************************************************* @'k,\$/  
        'Aqueous thickness (Position of Lens) ;W$w=j: O{  
        '************************************************************************* Pl>nd)i`  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) iMOPD}`IX  
        GetCustomElement eID, entity jWO&SWso  
    t(uB66(_F  
        parID = FindFullName( "Geometry.Arizona Eye" ) ue^?/{OuT  
    V{ a}#J  
        ' Delete any shift(s) in z z<3}TD  
        count = 0 ]*kP>  
        While GetOperationCount(eID)>count =DmPPl{  
            GetOperation eID, count, op /Gh x2B  
            If op.Type="ShiftZ" Then EA%#/n  
                DeleteOperation eID,count b7>-aem@I  
                count=count-1 ^-c si   
            End If !"o1ve`{  
            count=count+1 ^>vO5Ho.  
        Wend it/C y\f  
    )|59FOWg  
        'Set new shift in :3E8`q~c1  
        op.Type = "ShiftZ" 0IT20.~  
        op.val1 = taq dZ;~b(CA  
        op.parent = parID $z`cMQ r  
        AddOperation eID, op z</XnN  
        Print "Set aqueous humor thickness = " & taq-0.55 ATXx? b8h  
    Wj  
        '************************************************************************* L&3Ar'  
        'Radius and conic constant of anterior lens n'x`oI)-  
        '************************************************************************* g O\f:Pg  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) ;k63RNT,M&  
        GetConic eID, entity, curv, conic e5"-4udCn  
    Js^r]=\F'  
        SetConic eID, entity, 1/Rant, CCant f4aD0.K.g|  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant t<EX#_i,  
    7Da^Jv k  
        '************************************************************************* gl(6m`a>  
        'Radius and conic constant of posterior lens ,pGCgOG#}c  
        '************************************************************************* -V<=`e  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) dTU.XgX)1^  
        GetConic eID, entity, curv, conic Fm[?@Z&wP  
    ek0;8Ds9  
        SetConic eID, entity, 1/Rpost, CCpost l66ipgw_^I  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost !z4Hj{A_  
    0F;(_2V-  
        '************************************************************************* 40l#'< y;  
        'Lens thickness (Position of posterior lens surface) MRl*r K  
        '************************************************************************* At^DY!3vx  
    d= T9mj.@  
        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) )lngef /D_  
    >/OXC+=^4  
        ' Delete any z-shift(s) DT7-v4Zd  
        count = 0 ?`[ uh%  
        While GetOperationCount(eID)>count RGPU~L  
            GetOperation eID, count, op (1r>50Ge  
            If op.Type="ShiftZ" Then PUFW^"LV  
                DeleteOperation eID,count exrt|A] _[  
                count=count-1 @T~#Gwv  
            End If GWkJ/EX  
            count=count+1 C{I8Pio{b  
        Wend 7+Jma!o  
    PB3!;  
        'Set new z-shift *IO;`k q,;  
        op.Type = "ShiftZ" %N_S/V0`  
        op.val1 = tlens C_khd"  
        op.parent = parID 5\*wX.wp  
        AddOperation eID, op 0.+Z;j  
        Print "Set lens thickness = " & tlens $nd-[xV  
    wGQhr="  
        '************************************************************************* B6!<@* BI  
        'Lens index of refraction |~" A:gf  
        '************************************************************************* u>i+R"hi"  
        eID = FindMaterial( "Lens" ) p~zTRnm  
        GetModelMaterial eID, mat 0 f#a_  
    jiB>.te  
        mat.Nd = nlens (9[C0eS  
        SetModelMaterial eID, mat :M?')  
        Print "Set lens index of refraction = " & nlens $^+KR]\q  
    i\R\bv[9  
        '************************************************************************* D(ntVR  
        'Pupil diameter ,DUQto  
        '************************************************************************* M0IqQM57N  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) Vi -!E  
    !m O] zn  
        'Adjust pupil diameter (trimming volume inner hole) +mQC:B7>  
    . eag84_  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" VEYKrZA  
    n YMf[kW  
        ' Adjust pupil location to just in front of the lens kE(-vE9  
        parID = FindFullName( "Geometry.Arizona Eye" ) i^V4N4ux]  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) YHv,Z|.w  
        count = 0 PNxO \Rc  
        While GetOperationCount(eID)>count f!kdcr=/"  
            GetOperation eID, count, op mt6uW+t/  
            If op.Type="ShiftZ" Then xA1pDrfC/  
                DeleteOperation eID,count DBrzw+;e3  
                count=count-1 mbG^fy'  
            End If AeQ&V d|  
            count=count+1 B46H@]d#7K  
        Wend y42T.oK8c  
        op.Type = "ShiftZ" ~Wd8>a{w  
        op.val1 = taq-0.01 5}^08Xl  
        op.parent = parID !";$Zu  
        AddOperation eID, op ?;7>`F6ld  
    bzL;)H4Eo  
        Print "Set pupil diameter = " & pupilDiam iW%0pLn  
    *wZV*)}  
        'Update AZ Eye subassembly Description ?|rw=%  
        eID = FindFullName( "Geometry.Arizona Eye" ) -+2xdLa63  
        GetEntity eID, entity M]zNW{Xt  
        entity.Description = "Accommodation = " & A & "D" -OGy-"  
        SetEntity eID, entity Evgq}3  
    7(iRz  
        Update .8xacVyK2  
        Print "DONE!" I8wVvs;k  
         1UWgOCc  
    End Sub n{NgtH\V  
    )s[S.`S Tz  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: mztq7[&-  
    %iFIY=W  
    Accommodation = 4 Diopters 4!W?z2ly~R  
    Pupil Diameter = 4 mm MBrVh6z>  
    Set aqueous humor thickness = 2.81 DMpd(ws  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 \B +SzW  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 !/9Sb1_~  
    Set lens thickness = 3.927 D_kz R  
    Set lens index of refraction = 1.42672 (w  
    Set pupil diameter = 4 ,'DrFlI  
    DONE! nk.E q[08  
     
    分享到