切换到宽版
  • 广告投放
  • 稿件投递
  • 繁體中文
    • 1951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
    6425
    光币
    26270
    光券
    0
    只看楼主 倒序阅读 楼主  发表于: 2021-10-22
    简介 LZ&CGV"Z-  
    L?KEe>;r  
    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。 3)0*hq&83  
    6xz&Qi7w  
    模型 l`$f@'k  
    Pn7oQA\  
    模型的定义如表1种所示,由半径、圆锥常数、折射率、阿贝数、到下一面的距离等一系列表面组成。一些参数由屈光度(A)来决定。 qLYv=h$,  
    2b|vb}|t{  
    Table 1. AZ眼睛模型的定义
    wm2Q(l*HH  
    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. %t+V8A  
    }aX).u  
    光源 Kq!n `@  
    0TA/ExJ-LT  
    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。 5-u=ZB%p  
    &2?kD{  
    JI\u -+BE  
    图1. 光源和提示信息使用
    _\o +9X!  
    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。 j1d#\  
    |Ca$>]?  
    在往下看是内置的脚本用来修改屈光度,使其为4(250mm),光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 }3[ [ONA  
    v/yk T9@;  
    图2. 字母F光源的设定方法光 ^Gs!"Y  
    a+]=3o  
    图3. 字母F在视网膜上位置点列图
    NmtBn^ t  
    视网膜的散射 :syR4A WM  
    >{GC@Cw  
    在散射文件中,有一个名为“Retina surface”的72%的反射型朗伯散射,它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射,改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 u4+VG5.rhT  
    W=)}=^N0  
    'inWV* P*g  
    图4. 视网膜朗伯散射设定
    `VBjH]$  
    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。 @RaMO#  
    ?+Qbr$]  
    T,?^J-h^  
    图5. 视网膜重点采样规格设定
    c yN_Sg  
    脚本 kP;Rts8JD  
    5gJQr%pS  
    内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框,如下图所示: PVtQ&m$y  
    .-Ao%A W  
    图6. 用户对话框的创建与编辑
    CB|z{(&N  
    图7. 用户对话框编辑器
    >Xb]n_`  
    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。 _bMs~%?~/  
    余下的脚本计算与屈光度有关的所有参数。 >/'WU79TYE  
    4L5Wa~5\  
    分析 ![Jxh,f  
    QCtG #/  
    屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 -@#AQ\  
    lXz<jt@5  
    图7. 字母F在视网膜上颜色分析
    bt j\v[D  
    脚本代码 }:hdAZ+z  
    {ZfTUt)-P  
    Option Explicit     'Remove this to enable non-dimensioned variables to be used. V@Po}  
    yr;oq(&N  
    Dim entity As T_ENTITY @ObsW!g  
    Dim op As T_OPERATION @8_K^3-~e  
    Dim mat As T_MODELMATERIAL iWtWT1n8n  
    Dim A As Double 7x1jpQ -  
    Dim pupilDiam As Double 14^t{  
    Dim eID As Long V25u'.'v  
    Dim parID As Long IPT}JX'  
    Dim count As Integer OK2wxf  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double x3M`l|  
    Dim tlens As Double, nlens As Double 74Kl!A  
    Dim curv As Double, conic As Double beIEy(rA  
    Dim ok As Long ?SQT;C3j(  
    fitm*  
    Sub Main da 2BQ;  
    bo@1c0  
        '用户输入对话框 {(aJrSE<z  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 Crey}A/N  
            TextBox 220,21,40,21,.TextBox1 'default: 0 )T2Sw z/  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 N:&Gv'`  
            OKButton 40,91,90,21 8`*`4m  
            CancelButton 190,91,90,21 u|w[ b9^r  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 E7jv  
            TextBox 220,49,40,21,.TextBox2 'default: 4  kU#$  
        End Dialog &i!.6M2  
        Dim dlg As UserDialog AalyEn&>  
    I/'jRM  
        ok = Dialog (dlg) KD#ip3  
    rN>f"/J |  
        If ok=0 Then    'cancel button was pressed fC81(5   
            Print "Execution cancelled." h7%<  
            End @h$7C<  
        End If jdoI)J@9H  
    ,':?3| $c  
        'Assign accommodation and pupil diameter & use defaults if field left empty pRYt.}/K  
        If dlg.TextBox1 = "" Then ^LnCxA&QH  
            A = 0           'Default accommodation Wk$%0xZ7  
        Else &{7%Vs TB  
            A = CDbl(dlg.TextBox1) y|1-,u.$  
        End If Ejn19{  
    L%=u&9DmU  
        If dlg.TextBox2 = "" Then DuCq16'0T  
            pupilDiam = 4   'Default pupil diameter 1o.]"~0:  
        Else /)v X|qtIY  
            pupilDiam = CDbl(dlg.TextBox2) RJSNniYr7  
        End If JZai{0se  
    |qZ4h7wL  
        Print " " <.:B .k  
        Print "Accommodation = " & A & " Diopters" RX#:27:  
        Print "Pupil Diameter = " & pupilDiam & " mm" '{ C=vW  
    R|5w:+=z  
        ' Calculate new parameters with accommodation "|&SC0*  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness m}8c.OJ>K`  
     /pV^w  
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens g9 g &]  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens `@eQL[Z9x  
    mGoUF$9 k  
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens iao_w'tJ  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens 6&h,eQ!  
    ky[FNgQ3n  
        tlens = 3.767 + 0.04*A                  'Lens thickness hXZk$a'  
    >a]{q^0  
        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction <sn^>5Ds  
    +jQW6k#  
        'Adjust parameters to account for accommodation l? 7D0  
    o_jVtEP  
        '************************************************************************* 91[(K'=&  
        'Aqueous thickness (Position of Lens) _AK-AY  
        '************************************************************************* j].XVn,  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) Lw2EA 5  
        GetCustomElement eID, entity 8BBuYY {  
    y1@{(CDp"  
        parID = FindFullName( "Geometry.Arizona Eye" ) _sx]`3/86  
    ~#O nA1)  
        ' Delete any shift(s) in z >~2oQ[ n  
        count = 0 T&cf6soo  
        While GetOperationCount(eID)>count C+jlIT+  
            GetOperation eID, count, op _@SC R%  
            If op.Type="ShiftZ" Then s}X2*o`,  
                DeleteOperation eID,count Pe~[qETv  
                count=count-1 T[q2quXgk  
            End If #sN]6  
            count=count+1 _-^a8F>/19  
        Wend -=@d2LY  
    =`99ez+y  
        'Set new shift in ;MR8E9  
        op.Type = "ShiftZ" 9K~X}]u  
        op.val1 = taq "! m6U#^  
        op.parent = parID GK~uoz:^O  
        AddOperation eID, op G[@RZ~o4  
        Print "Set aqueous humor thickness = " & taq-0.55 S sGb;  
    SwXVa/9a"  
        '************************************************************************* V*}ft@GPD  
        'Radius and conic constant of anterior lens ?sk{(UN]  
        '************************************************************************* /&_$+Iun  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) xo a1='  
        GetConic eID, entity, curv, conic J<yt/V]  
    jH({Qc,97  
        SetConic eID, entity, 1/Rant, CCant I w~R@,  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant Xq@Bzya  
    Kejp7 okb  
        '************************************************************************* "A6m-xE~  
        'Radius and conic constant of posterior lens +Hgil  
        '************************************************************************* h'jc4mu0  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) n 9PYZxy  
        GetConic eID, entity, curv, conic Q V)>+6\  
    41Hv)}Yd  
        SetConic eID, entity, 1/Rpost, CCpost u5;;s@{Ye4  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost ;G.5.q[A  
    ^CO{86V  
        '************************************************************************* X6 *4IE  
        'Lens thickness (Position of posterior lens surface) 9kHVWDf  
        '************************************************************************* ~t^ Umx"Ew  
    ct`j7[  
        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) ,sI<AFI  
    xsu9DzPf&{  
        ' Delete any z-shift(s) Ql"kJ_F!br  
        count = 0 oq${}n<  
        While GetOperationCount(eID)>count 4a}[&zm(5  
            GetOperation eID, count, op KW-GVe%8f  
            If op.Type="ShiftZ" Then  |W_;L6)  
                DeleteOperation eID,count 2,aH1Xbex  
                count=count-1 o=J-Ju  
            End If @GUlw[vi  
            count=count+1 t xE=AOY5  
        Wend DK)T2{:  
    17$'r^t,S  
        'Set new z-shift ,2YZB*6h{  
        op.Type = "ShiftZ" 3{$vN).  
        op.val1 = tlens (qglD  
        op.parent = parID ' _d4[Olu  
        AddOperation eID, op Yw] 7@  
        Print "Set lens thickness = " & tlens v%:VV*MxF  
    A:y HClmn  
        '************************************************************************* i/j53towe  
        'Lens index of refraction -M/j&<;LW  
        '************************************************************************* wU6sU]P  
        eID = FindMaterial( "Lens" ) Z _Wzm!:  
        GetModelMaterial eID, mat Q2/65$ nW  
    XeX\u3<D  
        mat.Nd = nlens m/z,MT74*J  
        SetModelMaterial eID, mat mG"xo^1_H  
        Print "Set lens index of refraction = " & nlens H2H`7 +I,  
    CYRZ2Yrk?"  
        '************************************************************************* _j+!Fd  
        'Pupil diameter !O,Sq/=.  
        '************************************************************************* K!]a+M]>  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" )  ^M{,{bG  
    sUF9_W5z  
        'Adjust pupil diameter (trimming volume inner hole) `78Bv>[A  
    I`zd:o]  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" {j=`  
    dvZH~mF  
        ' Adjust pupil location to just in front of the lens Xu8I8nAwl  
        parID = FindFullName( "Geometry.Arizona Eye" ) tI1OmhNN  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) ~w a6S?  
        count = 0 *,mI=1  
        While GetOperationCount(eID)>count ~: {05W  
            GetOperation eID, count, op /a'1 W/^2  
            If op.Type="ShiftZ" Then J$Z=`=] t+  
                DeleteOperation eID,count s3HVX'   
                count=count-1 Wl |5EY  
            End If B*N1)J\5  
            count=count+1 [% C,&h5  
        Wend +? h}e  
        op.Type = "ShiftZ" ;h\T7pwwb  
        op.val1 = taq-0.01 =A.$~9P  
        op.parent = parID 8LbwEKl  
        AddOperation eID, op ;eN ^'/4A  
    &'SD1m1P  
        Print "Set pupil diameter = " & pupilDiam &E_a0*)e  
    )V\@N*L`ik  
        'Update AZ Eye subassembly Description Pg%9hejf3  
        eID = FindFullName( "Geometry.Arizona Eye" ) X/yq<_ g  
        GetEntity eID, entity f<NR6],}  
        entity.Description = "Accommodation = " & A & "D" H/c (m|KK  
        SetEntity eID, entity Zz0e4C  
    BH">#&j[  
        Update g w" \pD  
        Print "DONE!" GC{M"q|_  
         |;vQ"8J  
    End Sub gv''A"  
    y3zP`^  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: pFvu,Q"  
    EU$.{C_O(  
    Accommodation = 4 Diopters q`VL i  
    Pupil Diameter = 4 mm "j@\a)a  
    Set aqueous humor thickness = 2.81 Ax;=Zh<DAv  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 l~6K}g?  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 )th[fUC(  
    Set lens thickness = 3.927 "9wD|wsz  
    Set lens index of refraction = 1.42672 5o#JHD  
    Set pupil diameter = 4 1^!SuAA@  
    DONE! T$I_nxh[)L  
     
    分享到