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    [技术]Arizona眼睛模型 [复制链接]

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    只看楼主 倒序阅读 楼主  发表于: 2021-10-22
    简介 ( FRf.mv{  
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    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。 {m?x},  
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    模型 )qIK7;  
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    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。 pf_ /jR  
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    Table 1. AZ眼睛模型的定义
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    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. ao!r6:&v$e  
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    光源 SJ-Sac58r  
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    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 ZLQT  
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    图1. 光源和提示信息使用
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    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。 5PPpX=\  
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    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。 7w*&Yg]  
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    图2. 字母F光源的设定方法光 ^d*>P|n*@e  
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    图3. 字母F在视网膜上位置点列图
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    视网膜的散射 8rYK~Sz  
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    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。 ?r<F\rBT7*  
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    图4. 视网膜朗伯散射设定
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    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。 C.-a:oQ[  
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    图5. 视网膜重点采样规格设定
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    脚本 t,,^^ll  
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    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: GB3B4)cX4Y  
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    图6. 用户对话框的创建与编辑
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    图7. 用户对话框编辑器
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    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。 sBnPS[Oo  
    余下的脚本计算与屈光度有关的所有参数。 8B/9{8  
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    分析 s_!Z+D$K  
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    屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 {6sfa?1j  
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    图7. 字母F在视网膜上颜色分析
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    脚本代码 ]s@8I2_  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. 9K<a}QJP  
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    Dim entity As T_ENTITY ':]a.yA\1  
    Dim op As T_OPERATION 1,'^BgI,  
    Dim mat As T_MODELMATERIAL qhtAtP>i"  
    Dim A As Double ,r;d{  
    Dim pupilDiam As Double  u$8MVP  
    Dim eID As Long wf%Ep#^6}  
    Dim parID As Long f*}E\,V"&  
    Dim count As Integer wlg#c6#q  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double @0,dyg<$>  
    Dim tlens As Double, nlens As Double cV,Dl`1r  
    Dim curv As Double, conic As Double  q)+ n2FM  
    Dim ok As Long 8{ %9%{  
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    Sub Main mp3_n:R?  
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        '用户输入对话框 J6D$ i+  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 }F6b ]  
            TextBox 220,21,40,21,.TextBox1 'default: 0 Zb;$ZUWQX  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 e~]e9-L>I  
            OKButton 40,91,90,21 g8A{aHb1}  
            CancelButton 190,91,90,21 >[4|6k|\x  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 l>Ja[`X@  
            TextBox 220,49,40,21,.TextBox2 'default: 4 iGVb.=)  
        End Dialog bCUh^#]x  
        Dim dlg As UserDialog $ywh%OEH  
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        ok = Dialog (dlg) t`t:qko  
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        If ok=0 Then    'cancel button was pressed ![ID0}MjJ  
            Print "Execution cancelled." }IkEyJsk  
            End {0WID D  
        End If vqz#V=J{  
    1";e'? ^x  
        'Assign accommodation and pupil diameter & use defaults if field left empty l!V| T?  
        If dlg.TextBox1 = "" Then Z;SG<  
            A = 0           'Default accommodation (A fbS=[  
        Else !nBm}E7d  
            A = CDbl(dlg.TextBox1) xh^ZI6L<  
        End If }.V0SM6  
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        If dlg.TextBox2 = "" Then o\;"|O}  
            pupilDiam = 4   'Default pupil diameter nk$V{(FJ  
        Else x][9ptr h  
            pupilDiam = CDbl(dlg.TextBox2) c&?a ,fpb  
        End If f<4q]HCa  
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        Print " " AYu'ptDNr  
        Print "Accommodation = " & A & " Diopters" (g2r\hI  
        Print "Pupil Diameter = " & pupilDiam & " mm" u+'@>%7  
    }rA+W-7  
        ' Calculate new parameters with accommodation S Y>,kwHO  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness ^'53]b:  
    +\[![r^P  
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens 1S]gD&V  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens \{=`F`oB=  
    )bXx9,VL  
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens UEQ'D9  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens S]%U]  
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        tlens = 3.767 + 0.04*A                  'Lens thickness LO}:Ub  
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        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction .Jat^iFj0  
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        'Adjust parameters to account for accommodation ~muIi#4  
    (6#yw`\  
        '************************************************************************* U[e8K  
        'Aqueous thickness (Position of Lens) vV\F^  
        '************************************************************************* LVFsd6:h  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) dIfs 8%kl  
        GetCustomElement eID, entity H^PqYLj N  
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        parID = FindFullName( "Geometry.Arizona Eye" ) -=t3O#  
    )\D40,p  
        ' Delete any shift(s) in z [T[9*6Kt  
        count = 0 w]Ko/;;^2  
        While GetOperationCount(eID)>count Y^ZBA\D2,k  
            GetOperation eID, count, op  2H K  
            If op.Type="ShiftZ" Then uJ/?+5TU  
                DeleteOperation eID,count +`s&i%{1>  
                count=count-1 @+\S!o3m  
            End If $,QpSK`9i  
            count=count+1 "X{aS}  
        Wend NzeI/f3K5  
    ,F`KQ )\"  
        'Set new shift in n@07$lY@;  
        op.Type = "ShiftZ" o&XMgY~  
        op.val1 = taq |N=@E,33  
        op.parent = parID A?;8%00  
        AddOperation eID, op '=K of1  
        Print "Set aqueous humor thickness = " & taq-0.55 Il^ \3T+  
    ,JQxs7@2k  
        '************************************************************************* 'Elj"Iiu  
        'Radius and conic constant of anterior lens h\u0{!@}  
        '************************************************************************* R<lNk<  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) 6mF{ImbRbS  
        GetConic eID, entity, curv, conic Id.Z[owC`Y  
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        SetConic eID, entity, 1/Rant, CCant e@,u`{C[  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant -wf RR>)d  
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        '************************************************************************* ^QXw[th!d  
        'Radius and conic constant of posterior lens a:-)+sgHw  
        '************************************************************************* HL(U~Q6JQ  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) s7.p$r  
        GetConic eID, entity, curv, conic 2 %{YYT   
    rZ!Yi*? f  
        SetConic eID, entity, 1/Rpost, CCpost s?@)a,C%k  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost iO9nvM<  
    ( *9Ip  
        '************************************************************************* FV^4   
        'Lens thickness (Position of posterior lens surface) =~\]3g  
        '************************************************************************* %7NsBR!y  
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        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) }#ep}h  
    ;Y@!:p- H  
        ' Delete any z-shift(s) W8G9rB|T  
        count = 0 4{*tn"y  
        While GetOperationCount(eID)>count SvX=isu!.  
            GetOperation eID, count, op &$b\=  
            If op.Type="ShiftZ" Then 0~Iu7mPY  
                DeleteOperation eID,count p- "Z'$A`  
                count=count-1 q?imE~&U  
            End If jNe(w<',P  
            count=count+1 GJIWG&C03  
        Wend "xDx/d8B  
    B=Zl&1  
        'Set new z-shift GP[6nw_'^  
        op.Type = "ShiftZ" G%7 4v|cd  
        op.val1 = tlens c?!YFm  
        op.parent = parID ] Wx>)LT  
        AddOperation eID, op 6Iv(  
        Print "Set lens thickness = " & tlens =mHkXHE~:  
    e}'#Xv  
        '************************************************************************* poXLy/K  
        'Lens index of refraction :H!(?(Pie  
        '************************************************************************* tjZ\h=  
        eID = FindMaterial( "Lens" ) HDF!`  
        GetModelMaterial eID, mat  Y8)E]D  
    o~v_PD[S  
        mat.Nd = nlens J$#h( D%  
        SetModelMaterial eID, mat y:[BP4H?y  
        Print "Set lens index of refraction = " & nlens ex` xkZ+  
    . ]o3A8  
        '************************************************************************* ioC@n8_[G  
        'Pupil diameter <i_> y~v`  
        '************************************************************************* u\{qH!?t  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) $nB-ADRu@  
    )p$\gwr=2  
        'Adjust pupil diameter (trimming volume inner hole) .O5LI35,  
    <91t`&aWW  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" 1Yc%0L(  
    tmO;:n<N  
        ' Adjust pupil location to just in front of the lens kAZC"qM%i  
        parID = FindFullName( "Geometry.Arizona Eye" ) $uEJn&n7}  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) Z69+yOJI  
        count = 0 pOqGAD{D$  
        While GetOperationCount(eID)>count Yv)Bj  
            GetOperation eID, count, op )!'n&UxPo$  
            If op.Type="ShiftZ" Then AIuMX4nb  
                DeleteOperation eID,count Y]C; T  
                count=count-1 n K+lE0  
            End If R<f#r03@|  
            count=count+1 9o-!ecx}  
        Wend B0f_kH~p~  
        op.Type = "ShiftZ" 9pWi.J  
        op.val1 = taq-0.01 UdT&cG  
        op.parent = parID `S"W8_m  
        AddOperation eID, op jja{*PZ6H  
    ZlthYuJ  
        Print "Set pupil diameter = " & pupilDiam SHMl%mw  
    IE&_!ce  
        'Update AZ Eye subassembly Description DdBxqkh  
        eID = FindFullName( "Geometry.Arizona Eye" ) mfXD1]<.  
        GetEntity eID, entity ~O \}/I28  
        entity.Description = "Accommodation = " & A & "D" (# JMB)  
        SetEntity eID, entity yh S#&)O  
    7t'(`A 6t/  
        Update }o-|8P:Y  
        Print "DONE!" 2 9q?$V(  
         Mv|vRx^b  
    End Sub @ru<4`h  
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    如果屈光度是4,光瞳直径是4,则会输出如下数据: 53B.2 4Tm  
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    Accommodation = 4 Diopters 2 =>*O  
    Pupil Diameter = 4 mm UM<@t%|>  
    Set aqueous humor thickness = 2.81 +H7y/#e+3  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 E]NY (1  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 {5>3;.  
    Set lens thickness = 3.927 Ba<ngG !  
    Set lens index of refraction = 1.42672 p~h4\ .*`  
    Set pupil diameter = 4 [M4xZHd#o  
    DONE! &]w#z=5SXi  
     
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