切换到宽版
  • 广告投放
  • 稿件投递
  • 繁體中文
    • 1771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 o%Be0~n'  
    \Y!T>nWn)I  
    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。 N+CXOI=6x  
    HYjMNj0  
    模型 )%iRZ\`f  
    xl+DRPzl  
    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。 :vc[/<  
    [ME}Cv`?<E  
    Table 1. AZ眼睛模型的定义
    "t[M'[ `C  
    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. 6X@mPj[/  
    DR k]{^C~  
    光源 uQGz;F x  
    Q'Jv} 'eK_  
    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。 La"o)L +m_  
     20I4r  
    `6a]|7|f  
    图1. 光源和提示信息使用
    UGhW0X3k  
    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。 PUbaS{J7  
    X}oj_zsy;^  
    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。 nE/=:{~Ws  
    5/& 1Oxo  
    图2. 字母F光源的设定方法光 ss? ]  
    :8p&#M  
    图3. 字母F在视网膜上位置点列图
    v~ ^ks{  
    视网膜的散射 (Ij0AeJ#  
    KxO/]  
    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。 I3Lg?bZ  
    <jbj/Q )"  
    NH'1rt(w  
    图4. 视网膜朗伯散射设定
    NTqo`VWe  
    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。 Zxg1M  
    u-m%=2  
    Y)$52m5rM  
    图5. 视网膜重点采样规格设定
    <"* "1(wN  
    脚本 3c c1EQ9  
    mJ)tHv"7  
    内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框,如下图所示: o_iEkn  
    12idM*  
    图6. 用户对话框的创建与编辑
    h^}_YaT\  
    图7. 用户对话框编辑器
    /&CUspb  
    如果“OK”按钮按下,将会核对对话框下面的代码行,如果点击取消则脚本终止。然后输入的参数赋予变量,如果此处是保留为空白,则使用默认值。因此,如果没有值输入并点击“OK”按钮,则脚本是以屈光度为0,光瞳直径为4mm来运行的。 p3g4p  
    余下的脚本计算与屈光度有关的所有参数。 +'-rTi\  
    D9ANm"#  
    分析 |y.zo cBj  
    {tPnj_|n<  
    屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 TbOJp  
    JW=uK$sO  
    图7. 字母F在视网膜上颜色分析
    i-`,/e~XT  
    脚本代码 nz^nptw  
    ~eDI$IO  
    Option Explicit     'Remove this to enable non-dimensioned variables to be used.  AlO,o[0  
    #C4|@7w%  
    Dim entity As T_ENTITY )AOPiC$jL  
    Dim op As T_OPERATION ;t}'X[U  
    Dim mat As T_MODELMATERIAL &]w#z=5SXi  
    Dim A As Double Bb~5& @M|N  
    Dim pupilDiam As Double M~-h-tG  
    Dim eID As Long Sa Cx)8ul0  
    Dim parID As Long d7E7f  
    Dim count As Integer hHpx?9O+!  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double &`\ep9  
    Dim tlens As Double, nlens As Double [q'eEN G  
    Dim curv As Double, conic As Double @8|Gh]\P  
    Dim ok As Long _ j~4+H  
    $57\u/(  
    Sub Main 3c b[RQf  
    B22b&0  
        '用户输入对话框 ~P/]:=  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 H.:9:I[n  
            TextBox 220,21,40,21,.TextBox1 'default: 0 a2o.a 2  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 3!aEClRtq  
            OKButton 40,91,90,21 GWgd8x*V  
            CancelButton 190,91,90,21 X<Z(]`i  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 Vb2\/e:k  
            TextBox 220,49,40,21,.TextBox2 'default: 4 0 sZwdO  
        End Dialog Tw x{' S  
        Dim dlg As UserDialog Rs2-94$!5  
    q3+I<qsAz  
        ok = Dialog (dlg) EY~7oNfc`R  
    6+iK!&+=  
        If ok=0 Then    'cancel button was pressed Hq?&Qo  
            Print "Execution cancelled." w,Q)@]_  
            End `_GO=QQ  
        End If DcN"=Y  
    e8{^f]5  
        'Assign accommodation and pupil diameter & use defaults if field left empty '*4iqP R;  
        If dlg.TextBox1 = "" Then p5-<P?B  
            A = 0           'Default accommodation y:.?5KsPI  
        Else &U&Zo@ot"x  
            A = CDbl(dlg.TextBox1) 6}ftBmv  
        End If x9%-plP  
    j{)~QD?  
        If dlg.TextBox2 = "" Then .Vmtx  
            pupilDiam = 4   'Default pupil diameter ;, rnk-  
        Else OF8WDo`  
            pupilDiam = CDbl(dlg.TextBox2) <7^Kt7k  
        End If ?I[h~vr6.  
    _dr*`yXi  
        Print " " \-OC|\{32  
        Print "Accommodation = " & A & " Diopters" D^u\l  
        Print "Pupil Diameter = " & pupilDiam & " mm" .fEw k  
    'irGvex  
        ' Calculate new parameters with accommodation 4 [1k\  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness >$uUuiyL4  
    ^X &)'H  
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens f>niFPW"  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens hO6RQ0Iv@  
     , ]7XMU3  
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens vU}: U)S  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens y"-{$N  
    q`^3ov^</  
        tlens = 3.767 + 0.04*A                  'Lens thickness |{f~Ks%  
    (B:uc_+  
        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction 2h )8Fq_"  
    4fty~0i=z  
        'Adjust parameters to account for accommodation 59i]  
    +_~,86  
        '************************************************************************* o@3B(j;J`  
        'Aqueous thickness (Position of Lens) #ZlM?Q  
        '************************************************************************* :tLbFW[  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) E eB3 }  
        GetCustomElement eID, entity Cw#V`70a  
    2r;GcjezH  
        parID = FindFullName( "Geometry.Arizona Eye" ) fa{@$ppx  
    uN bIX:L,  
        ' Delete any shift(s) in z &SmXI5>Bo0  
        count = 0 EwQae(PpA  
        While GetOperationCount(eID)>count .&iN(Bd  
            GetOperation eID, count, op ltSh'w0  
            If op.Type="ShiftZ" Then h<% U["   
                DeleteOperation eID,count .S_QQM}Q  
                count=count-1 L/x(RCD  
            End If Dtt-|_EMS  
            count=count+1 yW("G-Nm  
        Wend <d"Gg/@a  
    -:S IS`0s  
        'Set new shift in TQJF+;%  
        op.Type = "ShiftZ" hnzNP\$U]  
        op.val1 = taq $XGtS$  
        op.parent = parID 3dG4pl~  
        AddOperation eID, op jdM=SBy7q  
        Print "Set aqueous humor thickness = " & taq-0.55 Dm%%e o  
    GNU;jSh5  
        '************************************************************************* m7m \`;  
        'Radius and conic constant of anterior lens J3B.-XJ+n  
        '************************************************************************* CH;;V3  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) XLb0 9;  
        GetConic eID, entity, curv, conic <%KUdkzEP  
    _z8;lt   
        SetConic eID, entity, 1/Rant, CCant ~`R1sSr"  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant 7'OPjt M  
    Rd%0\ B  
        '************************************************************************* (Es{la G  
        'Radius and conic constant of posterior lens Ttv'k*$cP  
        '************************************************************************* WZ?!!   
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) H]Wp%"L  
        GetConic eID, entity, curv, conic #ElejQ|?  
    5pJ*1pfeo  
        SetConic eID, entity, 1/Rpost, CCpost J]fS({(\I  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost 1;Xgc@  
    $]*d#`Sy{%  
        '************************************************************************* A5XR3$5P  
        'Lens thickness (Position of posterior lens surface) c7qwNs*f  
        '************************************************************************* tcA;#^jc  
    K@r*;T  
        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) Y6ben7j%-  
    *#2Rvt*Ox  
        ' Delete any z-shift(s) @^? XaU  
        count = 0 |Q!4GeQL[  
        While GetOperationCount(eID)>count ``9 GY  
            GetOperation eID, count, op $bGD%9 z  
            If op.Type="ShiftZ" Then ow.j+ <M  
                DeleteOperation eID,count ,%hj cGX11  
                count=count-1 %&<W(|U1<  
            End If >Z\BfH  
            count=count+1 DB@EVH  
        Wend >}SRSqJu  
    X/+OF'po  
        'Set new z-shift nbxR"UH  
        op.Type = "ShiftZ" n93zD*;5  
        op.val1 = tlens XP;x@I#l  
        op.parent = parID (vQ+e  
        AddOperation eID, op yVS\Q,:J9  
        Print "Set lens thickness = " & tlens A1A3~9HuK  
    o~C('1Fdb  
        '************************************************************************* 70Ka!  
        'Lens index of refraction E*|tOj9`1n  
        '************************************************************************* VJ{pN~_1  
        eID = FindMaterial( "Lens" ) HFS+QwHW  
        GetModelMaterial eID, mat onl>54M^  
    ~m`!;rE  
        mat.Nd = nlens FC}oL"kk  
        SetModelMaterial eID, mat n}J^6:1  
        Print "Set lens index of refraction = " & nlens Np)aS[9W  
    0H:dv:#WAI  
        '************************************************************************* @2e2^8X7f  
        'Pupil diameter l`gTU?<xd  
        '************************************************************************* 5I,$EGG  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) ;[6&0! N\  
    _e'Y3:  
        'Adjust pupil diameter (trimming volume inner hole) ^l!L)iw  
    \0AiCMX[  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" {L0;{  
    G|9B )`S  
        ' Adjust pupil location to just in front of the lens a$}mWPp+f  
        parID = FindFullName( "Geometry.Arizona Eye" ) _P 5P(^/  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) 2k1aX~?  
        count = 0 .nZ3kT`  
        While GetOperationCount(eID)>count vWY(%Q,  
            GetOperation eID, count, op tWD|qg_  
            If op.Type="ShiftZ" Then g%\L&}Jd  
                DeleteOperation eID,count X+ f9q0  
                count=count-1 yFM>T\@  
            End If km\%BD~  
            count=count+1 77Q}=80GU;  
        Wend Oif,|:  
        op.Type = "ShiftZ" I/p]DT  
        op.val1 = taq-0.01 zvf3b!}  
        op.parent = parID h&'=F)5  
        AddOperation eID, op F2>%KuM  
    {}\CL#~y  
        Print "Set pupil diameter = " & pupilDiam `Q%NSU?  
    ,Y!zORv<7  
        'Update AZ Eye subassembly Description n Ga1a  
        eID = FindFullName( "Geometry.Arizona Eye" ) t26ij`V  
        GetEntity eID, entity nl@E[yA9[  
        entity.Description = "Accommodation = " & A & "D" ')o0O9/;  
        SetEntity eID, entity P s#>y&  
    FH\CK  
        Update BGqa-d  
        Print "DONE!" y\[r(4h  
         b5 Q NEi  
    End Sub nj2gs,k  
    ULl_\5s2  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: iBvOJs  
    I; j3*lV_  
    Accommodation = 4 Diopters Z?1OdoT-  
    Pupil Diameter = 4 mm ?q Xs-  
    Set aqueous humor thickness = 2.81 ;~/4d-  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 !N~*EI$  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 E`xU m9F  
    Set lens thickness = 3.927 Y';>O`  
    Set lens index of refraction = 1.42672 ,")F[%v  
    Set pupil diameter = 4 nW5K[/1D  
    DONE! <lo`q<q  
     
    分享到