切换到宽版
  • 广告投放
  • 稿件投递
  • 繁體中文
    • 2253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
    6621
    光币
    27254
    光券
    0
    只看楼主 倒序阅读 楼主  发表于: 2021-10-22
    简介 |@nXlZE  
     'M{_S  
    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。 xPv&(XZR  
    ),eiJblH  
    模型 Fk:(% ci  
    B~IOM  
    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。 fA^O  
    {3>^nMv@e  
    Table 1. AZ眼睛模型的定义
    `JCC-\9T_  
    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. EUgs2Fsb3  
    :|g{ gi  
    光源 -rfO"D>  
    $) $sApB  
    多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 y;H 3g#  
    _ U\vHa$#  
    ZmDr$iU~  
    图1. 光源和提示信息使用
    g;pymz  
    除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处,并增加了pre-propagation distance= -8。尽管光线在光瞳处创建,规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射,而不是在光瞳处入射。 rRW&29A  
    Jor?;qo3  
    在往下看是内置的脚本用来修改屈光度,使其为4(250mm),光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 _)Ms9RN  
    Z3d&I]Tf  
    图2. 字母F光源的设定方法光 K+Qg=vGY  
    FP$]D~DMo  
    图3. 字母F在视网膜上位置点列图
    sC j3h  
    视网膜的散射 (|-/S0AV  
    .B@;ch,  
    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。 Tm `CA0@  
    =uH`EkY:  
    UcZ3v]$I  
    图4. 视网膜朗伯散射设定
    G7yxCU(I\  
    注意在视网膜的表面有散射重点采样规格定义,在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳,半角度10度。 [T|~K h%#  
    _Z%C{~,7)x  
    -4;u|0_  
    图5. 视网膜重点采样规格设定
    4PdFq*A  
    脚本 l\eq/yg_  
    vgV0a{u"  
    内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框,如下图所示: I4$a#;  
    S=o/n4@}  
    图6. 用户对话框的创建与编辑
    _%x|,vo`(  
    图7. 用户对话框编辑器
    C1_NGOvT  
    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。 B:l(`G  
    余下的脚本计算与屈光度有关的所有参数。 1\BECP+  
    ' ySWf,Q^  
    分析 5VI'hxU4Qg  
    "371`!%  
    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[yp=uI:  
    y ^YrGz.  
    图7. 字母F在视网膜上颜色分析
    Z?~7#F~Z`  
    脚本代码 Z^sO`C  
    sx9 N8T3n  
    Option Explicit     'Remove this to enable non-dimensioned variables to be used. UuN(+&oD-  
    :%Bo)0a9  
    Dim entity As T_ENTITY T+\BX$w/4e  
    Dim op As T_OPERATION u3q!te  
    Dim mat As T_MODELMATERIAL /];F4AO5  
    Dim A As Double .w0?  
    Dim pupilDiam As Double QF>H>=Za=  
    Dim eID As Long \"5\hX~dS  
    Dim parID As Long C'{Z?M>  
    Dim count As Integer GovGh? X#x  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double 8!1o,=I$  
    Dim tlens As Double, nlens As Double E*kS{2NAq  
    Dim curv As Double, conic As Double a+Q)~13  
    Dim ok As Long _onHe"%{  
    v^e[`]u(  
    Sub Main c;j]/R$i  
    fUa`Y ryQ  
        '用户输入对话框 (bXCc  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 M+Dkn3bx  
            TextBox 220,21,40,21,.TextBox1 'default: 0 ?&?y-&.5-  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 HG Pbx$!  
            OKButton 40,91,90,21 ,7eN m>$  
            CancelButton 190,91,90,21 (A1!)c  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 FrB19  
            TextBox 220,49,40,21,.TextBox2 'default: 4 LG;xZQx'  
        End Dialog ?L_#AdK  
        Dim dlg As UserDialog 2-8<uUy  
    ~!UxmYgO  
        ok = Dialog (dlg) ,Qp58u2V  
    #x'C  
        If ok=0 Then    'cancel button was pressed ^b&aDm~(7  
            Print "Execution cancelled." Z#9{1sHEP  
            End 7bTs+C_;7  
        End If  pxP7yJL`  
    8,%y`tUn>u  
        'Assign accommodation and pupil diameter & use defaults if field left empty q+SDJ?v  
        If dlg.TextBox1 = "" Then M5D,YC3<  
            A = 0           'Default accommodation  Wkf)4!  
        Else y1P?A]v  
            A = CDbl(dlg.TextBox1) (!;4Y82#  
        End If 3wD6,x-e   
    R_/T bz  
        If dlg.TextBox2 = "" Then J`\%'pEn  
            pupilDiam = 4   'Default pupil diameter zVp|%&  
        Else lO<Ujb#"R  
            pupilDiam = CDbl(dlg.TextBox2) BHa!jw_~o  
        End If y9:|}Vh  
    ^5xY&1j  
        Print " " a}MOhM6T  
        Print "Accommodation = " & A & " Diopters" {<&x9<f9  
        Print "Pupil Diameter = " & pupilDiam & " mm" x_#yH3kJ  
    <TDgv%eg0  
        ' Calculate new parameters with accommodation >:8GU f*  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness :  wb\N'b  
    c_%vD~6W-  
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens oU67<jq  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens aMT&}3  
    KrG$W/<tg  
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens W)o-aX!P  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens GT`:3L  
    CI ~+(+q  
        tlens = 3.767 + 0.04*A                  'Lens thickness 6D) vY  
    Ktg6*L/  
        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction !Il<'+ ^  
    n&k1'KL&  
        'Adjust parameters to account for accommodation r*y4Vx7  
    ~u7a50  
        '************************************************************************* s!uewS.  
        'Aqueous thickness (Position of Lens) KK/~W  
        '************************************************************************* =p ^Sn,t  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) 0!\pS{$zB  
        GetCustomElement eID, entity yG{'hx6H  
    JoIffI?{(D  
        parID = FindFullName( "Geometry.Arizona Eye" ) iwrS>Sm  
    @>&UoH}2  
        ' Delete any shift(s) in z Ig*!0(v5$  
        count = 0 [Nsv]Yz  
        While GetOperationCount(eID)>count Vtr 0=-m&  
            GetOperation eID, count, op ]#KZ W)M  
            If op.Type="ShiftZ" Then J!~?}Fq/z  
                DeleteOperation eID,count >4b-NS/}0  
                count=count-1 `TBau:ElI  
            End If [iB`- dE,  
            count=count+1 dKi+~m'w  
        Wend g/J ^ YT!  
    PG+ICg  
        'Set new shift in szGp<xv_p  
        op.Type = "ShiftZ" FNtcI7  
        op.val1 = taq H~Hh $-z  
        op.parent = parID 8?J\  
        AddOperation eID, op e%u1O -*  
        Print "Set aqueous humor thickness = " & taq-0.55 \k;*Ej~.  
    `gSqwN<x%  
        '************************************************************************* -}4<P}.5T  
        'Radius and conic constant of anterior lens VYMs`d[  
        '************************************************************************* ~;9B\fE`  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) H<Ed"-n$I<  
        GetConic eID, entity, curv, conic u#ag|b/C:  
    oX8e}  
        SetConic eID, entity, 1/Rant, CCant mtvfG  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant ?1JS*LQ$  
    ,=.&  
        '************************************************************************* IhhB^E|  
        'Radius and conic constant of posterior lens T&j_7Q\;vI  
        '************************************************************************* $i7iv  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) M\ B A+  
        GetConic eID, entity, curv, conic &>XIK8*  
    [yJcM [p\  
        SetConic eID, entity, 1/Rpost, CCpost OjcxD5"v9  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost =TE6R 0b  
    A|Up >`QH  
        '************************************************************************* {|9x*I  
        'Lens thickness (Position of posterior lens surface) MDM/~Qpj_  
        '************************************************************************* I&,gCZ#  
    )`, Bt  
        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) %ZDo;l+<F6  
    7`9J.L&,;  
        ' Delete any z-shift(s) R/VrBiw  
        count = 0 TO ^}z  
        While GetOperationCount(eID)>count pdUrVmW"'  
            GetOperation eID, count, op Yg3Vj=  
            If op.Type="ShiftZ" Then ""|vhgP  
                DeleteOperation eID,count .v?Ir)  
                count=count-1 8!(4;fN$j.  
            End If c*sK| U7)  
            count=count+1 Vcm9:,Xlw  
        Wend S:"R/EE(  
    +l+8Z:i<  
        'Set new z-shift vN=e1\  
        op.Type = "ShiftZ" 38ChS.(  
        op.val1 = tlens yj13>"nh  
        op.parent = parID 2y s'q !  
        AddOperation eID, op z%Pbs[*C  
        Print "Set lens thickness = " & tlens BG\g`NK}Z  
    z~i=\/~tZ  
        '************************************************************************* -!zyit5B  
        'Lens index of refraction PQ9.aJdw@-  
        '************************************************************************* ;-Fr^|do y  
        eID = FindMaterial( "Lens" ) =B-a]?lM  
        GetModelMaterial eID, mat %eW[`uyV  
    I CCmE#n  
        mat.Nd = nlens +n_`*@SE  
        SetModelMaterial eID, mat KjFNb;mM  
        Print "Set lens index of refraction = " & nlens n%yMf!M .:  
    MhaN+N  
        '************************************************************************* O{:_-eI&d  
        'Pupil diameter $Hh3*reSg-  
        '************************************************************************* vu-QyPnS|w  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) >*rH Nf  
    >U?HXu/TJr  
        'Adjust pupil diameter (trimming volume inner hole) 9)N/J\b  
    BiI?eT +  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" b~uz\%'3  
    }A)>sQ  
        ' Adjust pupil location to just in front of the lens DG1C_hu i  
        parID = FindFullName( "Geometry.Arizona Eye" ) $n>|9(K8  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) vl+vzAd  
        count = 0 g|L" |Q  
        While GetOperationCount(eID)>count unn2MP'  
            GetOperation eID, count, op 0kEz i  
            If op.Type="ShiftZ" Then lW}"6@0,  
                DeleteOperation eID,count 4|i.b?"  
                count=count-1 vd+yU9  
            End If lrQ +G@#  
            count=count+1 }H2<w-,+  
        Wend M8j%bmd(,  
        op.Type = "ShiftZ" 29#&q`J  
        op.val1 = taq-0.01 XoI,m8A  
        op.parent = parID Pt<lHfd  
        AddOperation eID, op G,,c,  
    MW&ww14  
        Print "Set pupil diameter = " & pupilDiam ,2hZtJ<A  
    *p )1c_  
        'Update AZ Eye subassembly Description I|@'2z2  
        eID = FindFullName( "Geometry.Arizona Eye" ) A#t#c*  
        GetEntity eID, entity `}uOl C]I  
        entity.Description = "Accommodation = " & A & "D" 1QkAFSl3  
        SetEntity eID, entity ^3`CP4DT  
    :$eg{IXC"  
        Update QI\&D)  
        Print "DONE!" DxX333vC  
         1%W|>M`  
    End Sub oB$7m4xO\  
    W '54g$T  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: 0>PO4WFVJ  
    (W.euQy  
    Accommodation = 4 Diopters Mx& P^#B3  
    Pupil Diameter = 4 mm \VJ7ahg[\  
    Set aqueous humor thickness = 2.81 )./pS~  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 Sw!/ I PO  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 _ElA\L4g%  
    Set lens thickness = 3.927 "n'LF?/H'  
    Set lens index of refraction = 1.42672 jTjGbC]X  
    Set pupil diameter = 4 P8#;a  
    DONE! .^]=h#[e  
     
    分享到