切换到宽版
  • 广告投放
  • 稿件投递
  • 繁體中文
    • 1776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 CG@3z@*?.  
    iveJh2!#<  
    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。 (I(?oCQ  
    1+wmR4o  
    模型 e5\/:HpI  
     6/u]r  
    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。 S#km`N`  
    Ht >5R  
    Table 1. AZ眼睛模型的定义
    -*`7Q'}%  
    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. 04;E^,V  
    NX wthc3  
    光源 c3S}(8g5.  
    H&$L1CrdL  
    多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 +qN}oyL  
    ~SKV%  
    eBUexxBY  
    图1. 光源和提示信息使用
    0PfjD  
    除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处,并增加了pre-propagation distance= -8。尽管光线在光瞳处创建,规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射,而不是在光瞳处入射。 ylFoYROO  
    z;T_%?u  
    在往下看是内置的脚本用来修改屈光度,使其为4(250mm),光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 (2 nSZRB  
    S*"uXTS  
    图2. 字母F光源的设定方法光 FA5|`  
    W4MU^``   
    图3. 字母F在视网膜上位置点列图
    h2k"iO }  
    视网膜的散射 1Ce7\A  
    Ax"]+pb  
    在散射文件中,有一个名为“Retina surface”的72%的反射型朗伯散射,它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射,改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 ^"lVTDsU  
    dnEIR5%+.  
    pl#2J A8  
    图4. 视网膜朗伯散射设定
    /\7E&n:)2  
    注意在视网膜的表面有散射重点采样规格定义,在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳,半角度10度。 2A>s a3\  
    @k+&89@G  
    \kN?7b^  
    图5. 视网膜重点采样规格设定
    \zCw&#D0Z  
    脚本 bCa%$  
    7+(on  
    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: hQWo ]WF(J  
    Z;v5L/;  
    图6. 用户对话框的创建与编辑
    CjRU3 (Q  
    图7. 用户对话框编辑器
    io&FW!J.  
    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。 }Gvu!a#R  
    余下的脚本计算与屈光度有关的所有参数。 L0lqm0h  
    + *xi&|%  
    分析 .ei5+?V<i  
    u; ]4 ydp  
    屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 ` x|=vu-  
    zf4\V F  
    图7. 字母F在视网膜上颜色分析
    5>Kk>[|.  
    脚本代码 5%r:hO @S  
    u~pBMg ,  
    Option Explicit     'Remove this to enable non-dimensioned variables to be used. "26=@Q^Y  
    Mg"e$m  
    Dim entity As T_ENTITY }xa~U,#5  
    Dim op As T_OPERATION =)c^ik%F&  
    Dim mat As T_MODELMATERIAL twWzS 4;  
    Dim A As Double ^-^ii 3G`  
    Dim pupilDiam As Double z=FOymv C  
    Dim eID As Long C0K0c6A (4  
    Dim parID As Long ;_~9".'<d  
    Dim count As Integer V|3^H^\5P  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double 1 ORA6  
    Dim tlens As Double, nlens As Double ;% <[*T:*'  
    Dim curv As Double, conic As Double M*gbA5  
    Dim ok As Long JGHQzC  
    ?-v]+<$Y  
    Sub Main m[}@\y  
    `R!%k]$  
        '用户输入对话框 f1$'av  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 "Snt~:W>  
            TextBox 220,21,40,21,.TextBox1 'default: 0 o#K*-jOfiH  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 w}qLI4  
            OKButton 40,91,90,21 A8X3|<n=  
            CancelButton 190,91,90,21 \1ncr4  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 agGgj>DDd  
            TextBox 220,49,40,21,.TextBox2 'default: 4 ;5 p;i 8m  
        End Dialog %,UTFuM`  
        Dim dlg As UserDialog |!q,J  
    ]r\FC\n6e  
        ok = Dialog (dlg) R>D[I.  
    9;7|MPbR  
        If ok=0 Then    'cancel button was pressed i5 0c N<o  
            Print "Execution cancelled." l`<1Y|  
            End "wR1=&gk  
        End If QOR92}yC  
    (fun,(R6"  
        'Assign accommodation and pupil diameter & use defaults if field left empty XiM d|D  
        If dlg.TextBox1 = "" Then tMiy`CPh  
            A = 0           'Default accommodation ]iY O}JuX  
        Else QJy1j~9x  
            A = CDbl(dlg.TextBox1) lyD=n  
        End If _iF*BnmN  
    ~s{ V!)0  
        If dlg.TextBox2 = "" Then Y#t9DhzFWo  
            pupilDiam = 4   'Default pupil diameter (M2hK[  
        Else  X`20=x  
            pupilDiam = CDbl(dlg.TextBox2) FnPn#Cv>*  
        End If w `nm}4M  
    dczq,evp  
        Print " " 7J ;\&q'  
        Print "Accommodation = " & A & " Diopters" wq7h8Z}l  
        Print "Pupil Diameter = " & pupilDiam & " mm" "Q`Le{  
    vW-o%u*  
        ' Calculate new parameters with accommodation gHtflS  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness L0)w~F ?m  
    xOx=Z\ c  
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens y8ODoXk  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens &. MUSqo9  
    `x`zv1U  
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens -asjBSo*D  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens 2f0mr?l)N  
    6j Rewj  
        tlens = 3.767 + 0.04*A                  'Lens thickness BJt]k7ku+  
    NY6;\ 7!n  
        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction }X6w"  
     {DD #&B  
        'Adjust parameters to account for accommodation !>#gm7  
    yAFt|<  
        '************************************************************************* =q(?ALGc  
        'Aqueous thickness (Position of Lens) H;seT XL  
        '************************************************************************* d`,z4 _  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" )  Q@!XVQx4  
        GetCustomElement eID, entity ^3ai}Ei3  
    x];i? 4  
        parID = FindFullName( "Geometry.Arizona Eye" ) KF6N P  
    xn>N/+,  
        ' Delete any shift(s) in z Mh2Zj  
        count = 0 A34O(fE  
        While GetOperationCount(eID)>count 5,pEJ>dDD3  
            GetOperation eID, count, op 1En:QQ4/  
            If op.Type="ShiftZ" Then :NL[NbQYt  
                DeleteOperation eID,count 0 ;].q*|#  
                count=count-1 h1)ny1;  
            End If / */"gz%  
            count=count+1 -Q/wW4dE=  
        Wend ::_bEmk  
    icQQLSU5  
        'Set new shift in e)y+]  
        op.Type = "ShiftZ" }; R2M  
        op.val1 = taq ->*~e~T  
        op.parent = parID r0@s3/  
        AddOperation eID, op K_n GZ/`[  
        Print "Set aqueous humor thickness = " & taq-0.55 ILx4 [m7  
    o@hj.)u  
        '************************************************************************* O)ose?Z  
        'Radius and conic constant of anterior lens W7c B  
        '************************************************************************* MJ$.ST  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) [%P[ x]-  
        GetConic eID, entity, curv, conic nly}ly Q/  
    }(!rB#bf  
        SetConic eID, entity, 1/Rant, CCant Kf6 D)B 26  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant gi>W&6  
    0Y'ow=8M  
        '************************************************************************* P @J)S ?  
        'Radius and conic constant of posterior lens H]W'mm  
        '************************************************************************* >oN Wf  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) |&@`~OBa  
        GetConic eID, entity, curv, conic 4 aE{}jp1  
    W56VA>ia  
        SetConic eID, entity, 1/Rpost, CCpost 4\ |/S@.  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost q{%~(A5*H  
    ;W|GUmADf  
        '************************************************************************* .2U3_1dX  
        'Lens thickness (Position of posterior lens surface) ESk:$`P  
        '************************************************************************* @FZ_[CYg  
    #|3,DZ|)F  
        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) ,hr v  
    >Q'*~S@v3  
        ' Delete any z-shift(s) D>^g2!b:  
        count = 0 DAg*  
        While GetOperationCount(eID)>count Pe-rwM  
            GetOperation eID, count, op cq5^7.  
            If op.Type="ShiftZ" Then W]Nc6B*gI  
                DeleteOperation eID,count ;" D~F  
                count=count-1 7SN61)[m  
            End If E^gN]Z"O  
            count=count+1 &*E! %57  
        Wend $BT[fJ'k  
    >$yA ,N  
        'Set new z-shift ho)JY $#6  
        op.Type = "ShiftZ" i`Qa7  
        op.val1 = tlens B'mUDW8\D  
        op.parent = parID k ]T  
        AddOperation eID, op azNv(|eeJL  
        Print "Set lens thickness = " & tlens (`_fP.Ogb  
    yye5GVY$  
        '************************************************************************* 2#00<t\  
        'Lens index of refraction ,`OQAJ)>  
        '************************************************************************* 2s> BNWTU  
        eID = FindMaterial( "Lens" ) D SWmQQ  
        GetModelMaterial eID, mat ,jtaTG.>  
    pr1bsrMuL  
        mat.Nd = nlens 19-V;F@;  
        SetModelMaterial eID, mat 717G CL@  
        Print "Set lens index of refraction = " & nlens r&Qa;-4Pl  
    j:>0XP  
        '************************************************************************* QoZZXCU  
        'Pupil diameter :>o 0zG[;f  
        '************************************************************************* FA;-D5=  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) ,%BDBZ  
    k.jBu  
        'Adjust pupil diameter (trimming volume inner hole) eMdf [eS  
    Zy.ls&<:  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" /u_9uJ"-K(  
    4*9t:D|}  
        ' Adjust pupil location to just in front of the lens ?Bl/bY$*h  
        parID = FindFullName( "Geometry.Arizona Eye" ) ?FUK_]  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) #D%6b  
        count = 0 Mu-kvgO`L  
        While GetOperationCount(eID)>count Wv9L }@J  
            GetOperation eID, count, op &cJ?mSI  
            If op.Type="ShiftZ" Then ~'0ZW<X.  
                DeleteOperation eID,count Lz p}<B  
                count=count-1 )''V}Zn.X  
            End If q_ryW$/_  
            count=count+1 _%Ua8bR$  
        Wend =kzp$ i  
        op.Type = "ShiftZ" 3:8p="$F  
        op.val1 = taq-0.01 En#Q p3  
        op.parent = parID bBXLW}W  
        AddOperation eID, op &['x+vL9  
    "wg$ H1K  
        Print "Set pupil diameter = " & pupilDiam h^qZi@L  
    sWMln:=  
        'Update AZ Eye subassembly Description 3&5b!Y  
        eID = FindFullName( "Geometry.Arizona Eye" ) ZZHzC+O#^  
        GetEntity eID, entity 12hD*,A5j  
        entity.Description = "Accommodation = " & A & "D" | 5:2?S2R  
        SetEntity eID, entity } XhL`%  
    dKC*QHU  
        Update NP.i,H  
        Print "DONE!" 6 >;OVX  
         zK1]o-wSAT  
    End Sub Ycq )$7p  
    *RVCz|0%w  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: Lj#xZ!mQS  
    nCp_RJu  
    Accommodation = 4 Diopters /V`SJ"  
    Pupil Diameter = 4 mm N{&Lo}6F  
    Set aqueous humor thickness = 2.81 /':64#'  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 ($/l_F  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 S w%6-  
    Set lens thickness = 3.927 NWPT89@l  
    Set lens index of refraction = 1.42672 aPK:k$.  
    Set pupil diameter = 4 >;Vfs{Z(q  
    DONE! +kEM%z  
     
    分享到