切换到宽版
  • 广告投放
  • 稿件投递
  • 繁體中文
    • 1396阅读
    • 0回复

    [分享]Arizona眼睛模型 [复制链接]

    上一主题 下一主题
    在线infotek
     
    发帖
    6358
    光币
    25935
    光券
    0
    只看楼主 倒序阅读 楼主  发表于: 2020-12-09
    简介 vXE0%QE'Q  
    F@YKFk+a  
    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。 xHA0gZf  
    6%Mt  
    模型 <vV_%uo M  
    8LzBh_J?  
    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。 3Q^fVn$tk  
    JRaq!/[(  
    Table 1. AZ眼睛模型的定义
    N2C7[z+l`  
    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. bulS&dAX  
    i3$$,W!  
    光源 r6Aneg7  
    W?woNt'n  
    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。 XvTCK>1  
    Z4b||  
    }H> ^o9  
    图1. 光源和提示信息使用
    [iP#VM-N  
    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。 zi@]83SS#  
    V)ig)(CT  
    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。 <ABX0U[*  
    sgUud_r)4  
    图2. 字母F光源的设定方法光 W/$Zvl  
    yLE7>48  
    图3. 字母F在视网膜上位置点列图
    "R>FqX6FB  
    视网膜的散射 4GdX/6C.  
    ').}Nz  
    在散射文件中,有一个名为“Retina surface”的72%的反射型朗伯散射,它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射,改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 2_^aw[-  
    (t+;O;  
    %QmxA 7fW  
    图4. 视网膜朗伯散射设定
    ED>prE0  
    注意在视网膜的表面有散射重点采样规格定义,在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳,半角度10度。 Pz*_)N}j >  
    4`m~FNVS   
    B%CTOi  
    图5. 视网膜重点采样规格设定
    #G" xNl  
    脚本 s#~GH6/  
     ^zzP.   
    内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框,如下图所示: % 2$/JZ  
    "5R~(+~<@  
    图6. 用户对话框的创建与编辑
    D"(L5jR8m@  
    图7. 用户对话框编辑器
    K_)eWf0a  
    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。 fWfk[(M'9  
    余下的脚本计算与屈光度有关的所有参数。 t7 n(Qkrv  
    9vUO *D  
    分析 M5nWVK7c  
    o8/ ;;*  
    屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 f"7O  "6  
    >(uZtYM\j  
    图7. 字母F在视网膜上颜色分析
    vE@!{*  
    脚本代码 ]^':Bmq  
    *_a@z1  
    Option Explicit     'Remove this to enable non-dimensioned variables to be used. C2LL|jp*  
    gb ^?l~SS  
    Dim entity As T_ENTITY wO ?+Nh  
    Dim op As T_OPERATION _v Sn`  
    Dim mat As T_MODELMATERIAL k.("3R6v:  
    Dim A As Double dm0QcW4  
    Dim pupilDiam As Double j 8*ZF  
    Dim eID As Long p&+;w  
    Dim parID As Long }bY; q-  
    Dim count As Integer pyLRgD0 g  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double (py]LBZ  
    Dim tlens As Double, nlens As Double &%})wZ+Dj  
    Dim curv As Double, conic As Double I2nF-JzD2a  
    Dim ok As Long H 0+dV3  
    R\o<7g-|  
    Sub Main j83p)ido  
    =mA: ctu~v  
        '用户输入对话框 z<H~ItX,n  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 C<KrMRWh^  
            TextBox 220,21,40,21,.TextBox1 'default: 0 8} =JKR^cK  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 'YNT8w/3  
            OKButton 40,91,90,21 nJ~drG}TD  
            CancelButton 190,91,90,21 >2bKSh  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 !Mi;*ZR  
            TextBox 220,49,40,21,.TextBox2 'default: 4 =FE|+!>PA  
        End Dialog tOfg?)h{dc  
        Dim dlg As UserDialog 2M# r]  
    /|xra8?H[  
        ok = Dialog (dlg) 0-~\ W(  
    D8 hr?:I9  
        If ok=0 Then    'cancel button was pressed bh^LIU  
            Print "Execution cancelled." ^i:`ZfA#  
            End 1V8-^  
        End If ()~pY!)1/  
    TMY d47  
        'Assign accommodation and pupil diameter & use defaults if field left empty iD<(b`S  
        If dlg.TextBox1 = "" Then +$oF]OO  
            A = 0           'Default accommodation &f&z_WU  
        Else p.LFVFPT  
            A = CDbl(dlg.TextBox1) jDQZQ NS  
        End If H54 R8O$  
    2W4qBaG$=  
        If dlg.TextBox2 = "" Then Z!hafhcX  
            pupilDiam = 4   'Default pupil diameter ABUSTf<  
        Else 5nsq[Q`  
            pupilDiam = CDbl(dlg.TextBox2) kF/9-[]$g,  
        End If ,"B+r6}EF  
    ]Kr `9r),  
        Print " " &hRvol\J  
        Print "Accommodation = " & A & " Diopters" G "73=8d  
        Print "Pupil Diameter = " & pupilDiam & " mm" OKoan$#sn  
    liXdNk8  
        ' Calculate new parameters with accommodation >nzdnF_&zW  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness _q~=~nub  
    "HPB!)C8(  
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens K_dOq68_  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens O%FPS=  
    J>/w5$h5  
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens M)U{7c$c7  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens 9uGrk^<t  
    =jN *P?  
        tlens = 3.767 + 0.04*A                  'Lens thickness 'nF2aD%A  
    )E~ 79!  
        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction L'F<ev  
    U\Z?taXB  
        'Adjust parameters to account for accommodation u9N 1pZ~  
    ^Vpq$'!  
        '************************************************************************* b,C aWg  
        'Aqueous thickness (Position of Lens) *hw\35%P`?  
        '************************************************************************* J>\B`E  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) Z,=7Tu bR#  
        GetCustomElement eID, entity -{ H0g]  
    ~$~5qwl  
        parID = FindFullName( "Geometry.Arizona Eye" ) B'fb^n<  
    dH-s2r%s  
        ' Delete any shift(s) in z e d<n9R  
        count = 0 ;aw=MV  
        While GetOperationCount(eID)>count VY3&  
            GetOperation eID, count, op ~c&bH]cj  
            If op.Type="ShiftZ" Then cJrmm2.0kD  
                DeleteOperation eID,count vvm0t"|\  
                count=count-1 yxH ( c  
            End If Sv +IS  
            count=count+1 vMS |$L  
        Wend <WcR,d  
    7k rUKYVo  
        'Set new shift in h@[R6G|  
        op.Type = "ShiftZ"  jrS[f  
        op.val1 = taq wYmM"60  
        op.parent = parID ?O8ViB?2  
        AddOperation eID, op Cvf[/C+  
        Print "Set aqueous humor thickness = " & taq-0.55 PS[+~>%  
    t]YC"%[S  
        '************************************************************************* 49vcoHlf  
        'Radius and conic constant of anterior lens -q*i_r:,  
        '************************************************************************* ZSG9t2qlv  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) <>8WQn,K  
        GetConic eID, entity, curv, conic GSRVe/ [  
    4y+< dw  
        SetConic eID, entity, 1/Rant, CCant w'm;82V:P-  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant gntxNp[9T  
    @w?P7P<O`  
        '************************************************************************* @0F3$  
        'Radius and conic constant of posterior lens ;LMJd@  
        '************************************************************************* %oO4|JkJX  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) HBMhtfWW  
        GetConic eID, entity, curv, conic gy_>`16K  
    `tn{ei  
        SetConic eID, entity, 1/Rpost, CCpost xLC3>>P  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost ]]*7\ :cb  
    rsy'q(N[  
        '************************************************************************* 4B^ZnFJ%m  
        'Lens thickness (Position of posterior lens surface) WUh$^5W  
        '************************************************************************* {$wjO7Glp  
    o:_Xv.HRZo  
        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) @9lUSk^9  
    N9v1[~ bv_  
        ' Delete any z-shift(s) BDjn !3  
        count = 0 QC9eUYe  
        While GetOperationCount(eID)>count =,UWX3`f  
            GetOperation eID, count, op ,d{"m)r<  
            If op.Type="ShiftZ" Then s[w6FXt  
                DeleteOperation eID,count ~W{2Jd  
                count=count-1 |563D#?cR  
            End If E/%9jDTQ  
            count=count+1 L{8xlx`  
        Wend 28UU60  
    o !vE~  
        'Set new z-shift ::}{_ Z  
        op.Type = "ShiftZ" p{j.KI s7  
        op.val1 = tlens c1E'$- K@  
        op.parent = parID id1s3b;  
        AddOperation eID, op Yj6*NZ*  
        Print "Set lens thickness = " & tlens R~S;sJ& c  
    Z7=`VNHc  
        '************************************************************************* #~<0t(3Q  
        'Lens index of refraction _t Yx~J2.Q  
        '************************************************************************* 1*@'-mj  
        eID = FindMaterial( "Lens" ) j 4^97  
        GetModelMaterial eID, mat "-+\R}q$  
    T-U}QM_e  
        mat.Nd = nlens Z )SY.iK.  
        SetModelMaterial eID, mat n6BQk 2l  
        Print "Set lens index of refraction = " & nlens xo&]$W8  
    i}B2R$Z3  
        '************************************************************************* a_'2V;  
        'Pupil diameter hMykf4  
        '************************************************************************* d%V*|0c)  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) N _86t  
    E.Jkf\  
        'Adjust pupil diameter (trimming volume inner hole) qLB) XnQ  
    Ljp%CI[i  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" C<m{*C-`a  
    V{:A3C41  
        ' Adjust pupil location to just in front of the lens =5(>q5Z*  
        parID = FindFullName( "Geometry.Arizona Eye" ) V0P>YQq9s  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) 4\4FolsK  
        count = 0 Cd>WUw  
        While GetOperationCount(eID)>count 2AO~HxF  
            GetOperation eID, count, op $h*L=t(  
            If op.Type="ShiftZ" Then A m>cd;  
                DeleteOperation eID,count T^Ze3L]  
                count=count-1 K otrX  
            End If mjKS{  
            count=count+1 r}mbXvn  
        Wend Y]B)'[=h  
        op.Type = "ShiftZ" z$?~Y(EY  
        op.val1 = taq-0.01 "saUai4z  
        op.parent = parID UHTvCc  
        AddOperation eID, op &GB:|I'%7  
    u (em&M  
        Print "Set pupil diameter = " & pupilDiam 'U\<IL#U  
    hNH'XQxO  
        'Update AZ Eye subassembly Description Y}#J4i0b*  
        eID = FindFullName( "Geometry.Arizona Eye" ) mg$]QnbAnH  
        GetEntity eID, entity Cc%LztP>  
        entity.Description = "Accommodation = " & A & "D" er!DYv  
        SetEntity eID, entity <7j87  
     D0% Ug>  
        Update b-{=s +:  
        Print "DONE!" !AKg m'Nw  
         ~e+\k>^eN  
    End Sub ]Zyur`  
    lna}@]oR  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: 'VlDh`<W  
    Z(ACc9k6:'  
    Accommodation = 4 Diopters  ng_^  
    Pupil Diameter = 4 mm #py[  
    Set aqueous humor thickness = 2.81 o .qf _A  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 'Pn3%&O$  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 vA]W|sLF9  
    Set lens thickness = 3.927 7 D^gMN%p  
    Set lens index of refraction = 1.42672 p%*%n3bw  
    Set pupil diameter = 4 r0,:J   
    DONE! (tZrw5 @  
    p4-o/8rO  
    9/ibWa\.  
    QQ:2987619807 9&_<f}ou  
     
    分享到