切换到宽版
  • 广告投放
  • 稿件投递
  • 繁體中文
    • 2117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
    6535
    光币
    26824
    光券
    0
    只看楼主 倒序阅读 楼主  发表于: 2021-10-22
    简介 |y20Hi':  
    dz>;<&2Z  
    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。 <}6{{&mT4  
    ,<DB&&EV8  
    模型  '8j$';&`  
    a(]`F(L  
    模型的定义如表1种所示,由半径、圆锥常数、折射率、阿贝数、到下一面的距离等一系列表面组成。一些参数由屈光度(A)来决定。 .Wi{lt  
    c"!lwm3b  
    Table 1. AZ眼睛模型的定义
    q2:K 4  
    在FRED中使用0屈光度来创建的,光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. 1y^K/.5-  
    {A|TowBN  
    光源 P6,7]6bp  
    /J)l/oI  
    多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 Hqh6:RuL  
    qNyzU@  
    80M;4nH^5  
    图1. 光源和提示信息使用
    ^w~23g.  
    除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处,并增加了pre-propagation distance= -8。尽管光线在光瞳处创建,规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射,而不是在光瞳处入射。 vILy>QS)  
    ,7,g%?_P  
    在往下看是内置的脚本用来修改屈光度,使其为4(250mm),光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 |lH;Fq{\  
    drwgjLC+  
    图2. 字母F光源的设定方法光 >\ST-7[^L  
    :ug4g6;#H0  
    图3. 字母F在视网膜上位置点列图
    27ckdyQx  
    视网膜的散射 hC_Vts[v/  
    fQ+VT|jzx  
    在散射文件中,有一个名为“Retina surface”的72%的反射型朗伯散射,它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射,改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 V Cy5JH  
    NvjJ b-u  
    PN+G:Qv  
    图4. 视网膜朗伯散射设定
    VE2tq k%  
    注意在视网膜的表面有散射重点采样规格定义,在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳,半角度10度。 (yo;NKq,@  
    7 1W5.!  
    d +iR/Ssc  
    图5. 视网膜重点采样规格设定
    Pag63njg?  
    脚本 C}IbxKl  
    uR6w|e`  
    内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框,如下图所示: 6{d6s#|%  
    @+U,Nzd  
    图6. 用户对话框的创建与编辑
    ^5=UK7e5KY  
    图7. 用户对话框编辑器
    h  x6;YV  
    如果“OK”按钮按下,将会核对对话框下面的代码行,如果点击取消则脚本终止。然后输入的参数赋予变量,如果此处是保留为空白,则使用默认值。因此,如果没有值输入并点击“OK”按钮,则脚本是以屈光度为0,光瞳直径为4mm来运行的。 !A8^Xmz"  
    余下的脚本计算与屈光度有关的所有参数。 C9S@v D+  
    Vv$HR  
    分析 b4Y8N"hL%  
    Bqws!RM'&@  
    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&hc m  
    "HM{b?N  
    图7. 字母F在视网膜上颜色分析
    y%]8'q$  
    脚本代码 .'[/|4H  
    8|twV35  
    Option Explicit     'Remove this to enable non-dimensioned variables to be used. ~fz[x9\  
    {mE! Vf  
    Dim entity As T_ENTITY ?(KvQK|d4  
    Dim op As T_OPERATION (\puf+  
    Dim mat As T_MODELMATERIAL RaSz>-3d  
    Dim A As Double #iSFf  
    Dim pupilDiam As Double .DJDpP)M  
    Dim eID As Long A CNfS9M_w  
    Dim parID As Long ;@ WV-bLe  
    Dim count As Integer +?RGta'%k  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double @D`zKYwX1  
    Dim tlens As Double, nlens As Double Mu_i$j$vvP  
    Dim curv As Double, conic As Double j&6 jRX  
    Dim ok As Long ]Gc3Ea;4  
    -'rj&x{Q)U  
    Sub Main dTEJ=d40  
    B'>*[!A  
        '用户输入对话框 Oi:JiD=  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 *.y'(tj[  
            TextBox 220,21,40,21,.TextBox1 'default: 0 IKvBf'%-  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 \9)[ #Ld  
            OKButton 40,91,90,21 U6 82 Th  
            CancelButton 190,91,90,21 w5]"ga>Y  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 #`GbHxd  
            TextBox 220,49,40,21,.TextBox2 'default: 4 w#PZu+  
        End Dialog Q882B1H  
        Dim dlg As UserDialog {j(4m  
    !>;w!^U  
        ok = Dialog (dlg) o%(bQV-T  
    HOYq?40.R  
        If ok=0 Then    'cancel button was pressed 6X+}>qy  
            Print "Execution cancelled." <Mgf]v.QS  
            End m^!Sv?hV  
        End If MM#cLw  
    vW.%[]  
        'Assign accommodation and pupil diameter & use defaults if field left empty eVnbRT2y&  
        If dlg.TextBox1 = "" Then o0;7b>Tv  
            A = 0           'Default accommodation {K aN,td9  
        Else l^ 4OC  
            A = CDbl(dlg.TextBox1) }(i(Ar-  
        End If c]Unbm^w  
    vrcE]5(:s  
        If dlg.TextBox2 = "" Then FuP}Kec  
            pupilDiam = 4   'Default pupil diameter M1=_^f=&.  
        Else |paP<$  
            pupilDiam = CDbl(dlg.TextBox2) xcSR{IZ  
        End If R lg#z4m  
    LZWS^77  
        Print " " {Qtq7q.  
        Print "Accommodation = " & A & " Diopters" oW'PO Ar  
        Print "Pupil Diameter = " & pupilDiam & " mm" D?u`  
    l=Wd,$\  
        ' Calculate new parameters with accommodation A|vP$zy  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness *m_93J  
    yuNfhK/#r  
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens hYvNcOSks  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens cb+y9wA  
    F/<qE!(  
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens (L#%!bd  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens \.>.c g  
    8$ DwpJ  
        tlens = 3.767 + 0.04*A                  'Lens thickness *C_[jk@6  
    ^pcRW44K  
        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction ^@_).:oX7  
    atnQC  
        'Adjust parameters to account for accommodation :GL7J6  
    npj/7nZj  
        '************************************************************************* #\b ;2>  
        'Aqueous thickness (Position of Lens) jfSg){  
        '************************************************************************* e{t=>vry  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) gB+ G'I  
        GetCustomElement eID, entity P3$,ca'  
    ;:_(7|  
        parID = FindFullName( "Geometry.Arizona Eye" ) 9-- dRTG  
    3i(Jon/p  
        ' Delete any shift(s) in z ~L){O*Z  
        count = 0 PPgW ^gj  
        While GetOperationCount(eID)>count Yq0# #__  
            GetOperation eID, count, op 4$i}Xk#3  
            If op.Type="ShiftZ" Then "A7<XN<  
                DeleteOperation eID,count `cO|RhD @  
                count=count-1 [a NhP;<  
            End If YKq0f=Ij  
            count=count+1 %]GV+!3S  
        Wend ('HxHOh2  
    =, TSMV  
        'Set new shift in b]K>vhQV  
        op.Type = "ShiftZ" I7bi@t  
        op.val1 = taq ?360SQ<  
        op.parent = parID JX&~y.F  
        AddOperation eID, op ~>w:;M=sV8  
        Print "Set aqueous humor thickness = " & taq-0.55 \P@S"QO  
    =AzOnXW:S  
        '************************************************************************* S~|tfJpL  
        'Radius and conic constant of anterior lens hg#c[sZL  
        '************************************************************************* +I.v!P!^  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) bZXlJa`'S  
        GetConic eID, entity, curv, conic I9,8HtnA  
    }#|2z}!  
        SetConic eID, entity, 1/Rant, CCant h/9Sg*k  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant AgCs;k&IG  
    e#m1X6$.e  
        '************************************************************************* VwC4QK,d;  
        'Radius and conic constant of posterior lens  0/*X=5  
        '************************************************************************* 85 Dm8~  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) qu!<lW~c  
        GetConic eID, entity, curv, conic :P"9;$FY  
    &&*wmnWCS{  
        SetConic eID, entity, 1/Rpost, CCpost ZZwBOGVU  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost mVHFT~x7}  
    i2U/RXu  
        '************************************************************************* \aB&{`iG  
        'Lens thickness (Position of posterior lens surface) ja:\W\xhJ  
        '************************************************************************* YOlH*cZtg  
    v<`$bvv?  
        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) 3m~U(yho  
    P8u"T!G  
        ' Delete any z-shift(s) BMF3XcH~G  
        count = 0 rSbQ}O4V  
        While GetOperationCount(eID)>count 6iyt2q kh  
            GetOperation eID, count, op G*=H;Upi  
            If op.Type="ShiftZ" Then ?Cc$]  
                DeleteOperation eID,count :g/{(#E@Z  
                count=count-1 E8 \\X  
            End If ![j(o!6&  
            count=count+1 5 5a@)>h  
        Wend w[|y0jtw  
    *eMLbU7  
        'Set new z-shift 7~L|;^(  
        op.Type = "ShiftZ" r"6lLc  
        op.val1 = tlens w zdxw$E  
        op.parent = parID $*wu~  
        AddOperation eID, op J ( =4  
        Print "Set lens thickness = " & tlens cx<h_  
    `dP? 2-Z  
        '************************************************************************* QZz&1n  
        'Lens index of refraction &,F elB0*  
        '************************************************************************* ~LSy7$rz  
        eID = FindMaterial( "Lens" ) f)qPFM]%z  
        GetModelMaterial eID, mat 9B& }7kk  
    "hz>{oe  
        mat.Nd = nlens yM W'-\  
        SetModelMaterial eID, mat ;A`IYRzt  
        Print "Set lens index of refraction = " & nlens g+VRT, r  
    ;Kt'Sit  
        '************************************************************************* r';Hxa '  
        'Pupil diameter }`?7\\6  
        '************************************************************************* &qG? [R{  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) O#A8t<f|M  
    E`U &Z  
        'Adjust pupil diameter (trimming volume inner hole) 8U8P g2  
    .Ydr[  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" oXvdR(Sb^  
    8a_ UxB  
        ' Adjust pupil location to just in front of the lens <d3PDO@w/  
        parID = FindFullName( "Geometry.Arizona Eye" ) Q=dw 6  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) /YS@[\j4  
        count = 0 JvT %R`i  
        While GetOperationCount(eID)>count 8|fLe\"  
            GetOperation eID, count, op +!D=SnBGs  
            If op.Type="ShiftZ" Then +?ws !LgF  
                DeleteOperation eID,count 5+o 2 T]  
                count=count-1 >B@i E  
            End If gF$1wV]e  
            count=count+1 .dy#n`eP  
        Wend p`shY yE  
        op.Type = "ShiftZ" HCI'q\\  
        op.val1 = taq-0.01 IS3e|o*]MP  
        op.parent = parID eV@4VxaZ  
        AddOperation eID, op B4PW4>GF  
    u Zo]8mV  
        Print "Set pupil diameter = " & pupilDiam #p']-No  
    @&/s~3  
        'Update AZ Eye subassembly Description IptB.bYc  
        eID = FindFullName( "Geometry.Arizona Eye" ) V.O<|tl.  
        GetEntity eID, entity u<BHf@AI  
        entity.Description = "Accommodation = " & A & "D" nL "g23  
        SetEntity eID, entity ]?v?Qfh2  
    HQ ELK  
        Update BYhmJC|  
        Print "DONE!" EOMuqP)  
         oAIY=z  
    End Sub 4f_ZY5=  
    H8(0. IR  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: 5WrIg(l  
    LC~CPV'F  
    Accommodation = 4 Diopters (,d4"C  
    Pupil Diameter = 4 mm FN{H\W1cf  
    Set aqueous humor thickness = 2.81 E#IiyZ  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 <(u3+`f1s  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 w !=_  
    Set lens thickness = 3.927 0:7v/S!:  
    Set lens index of refraction = 1.42672 ]{q- Y<{"  
    Set pupil diameter = 4 pe`TH::p  
    DONE! /h.:br?M#P  
     
    分享到