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    [转载]FRED运用: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: 2016-02-24
    简介 =*zde0T?l  
    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。 _V0%JE'  
    O,v C:av  
    模型 hsYE&Np_Q  
    c9c3o{(6Y  
    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。 TiG?r$6v%  
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    Table 1. AZ眼睛模型的定义
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    在FRED中使用0屈光度来创建的,光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. gSj0+|  
    &@BAVc z  
    光源 EwuRIe;D  
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    多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 Q"c/]Sk)  
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    图1. 光源和提示信息使用
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    除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处,并增加了pre-propagation distance= -8。尽管光线在光瞳处创建,规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射,而不是在光瞳处入射。 KK6z3"tk5  
     s_+.xIZ  
    在往下看是内置的脚本用来修改屈光度,使其为4(250mm),光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 h;y}g/HZ  
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    图2. 字母F光源的设定方法光 N^PkSf[)h5  
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    图3. 字母F在视网膜上位置点列图
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    视网膜的散射 \Y8 sIs  
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    在散射文件中,有一个名为“Retina surface”的72%的反射型朗伯散射,它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射,改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 Iu5 9W >  
    Yo=$@~vN]  
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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。 F#RNm5  
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    图5. 视网膜重点采样规格设定
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    脚本 r ?<kWR?w  
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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: so/0f1R?~  
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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。 +xsGa{`  
    余下的脚本计算与屈光度有关的所有参数。 6BEpnw>p(  
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    分析 ^6F, lS_t  
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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。 pzUr9  
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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 1LhZmv  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. %hw4IcWJ|  
    -1NR]#P'  
    Dim entity As T_ENTITY m,62'  
    Dim op As T_OPERATION [Ob'E!;<  
    Dim mat As T_MODELMATERIAL Li0+%ijM  
    Dim A As Double bb\XZ~)F  
    Dim pupilDiam As Double }u$c*}  
    Dim eID As Long i+< v7?:`#  
    Dim parID As Long rnp; R  
    Dim count As Integer [e@m -/B  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double A{k1MA<F6  
    Dim tlens As Double, nlens As Double Y6hV ;[\F  
    Dim curv As Double, conic As Double wq!9wk9  
    Dim ok As Long f8=qnY2j  
    W/WP }QM  
    Sub Main MU2kA&LH  
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        '用户输入对话框 f7!48,(fB  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 rz-61A) _  
            TextBox 220,21,40,21,.TextBox1 'default: 0 { D|ST2:E  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 x _d   
            OKButton 40,91,90,21 NZADHO@0  
            CancelButton 190,91,90,21 H\E%.QIx  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 &m[}%e%~0  
            TextBox 220,49,40,21,.TextBox2 'default: 4 ' S,g3  
        End Dialog -MsL>F.]  
        Dim dlg As UserDialog F$|:'#KN  
    Qb%; |li  
        ok = Dialog (dlg) qwnVtD  
    .d$Q5Qae  
        If ok=0 Then    'cancel button was pressed y;4g>ma0  
            Print "Execution cancelled." v*.iNA;&i  
            End BhbfPQ  
        End If gW4fwE^  
    C?]eFKS."  
        'Assign accommodation and pupil diameter & use defaults if field left empty ePIN<F;I  
        If dlg.TextBox1 = "" Then n5BD0q  
            A = 0           'Default accommodation )+8r$ i  
        Else V EsM  
            A = CDbl(dlg.TextBox1) G|-RscPe  
        End If c9Cc%EK  
    *)I^+zN  
        If dlg.TextBox2 = "" Then ].aFdy  
            pupilDiam = 4   'Default pupil diameter :sLg$OF  
        Else m-;8O /  
            pupilDiam = CDbl(dlg.TextBox2) ,O-_Pv  
        End If >hq{:m  
    q@XJ,e1A  
        Print " " *icaKy3  
        Print "Accommodation = " & A & " Diopters" _5(p=Zc  
        Print "Pupil Diameter = " & pupilDiam & " mm" h"Wpb}FT  
    `'3 De(  
        ' Calculate new parameters with accommodation 5WxNH}{  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness w2/3[VZ}l  
    fO^s4gWTg  
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens /38I (0  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens YPq:z"`-y4  
    $3&XM  
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens 'NfsAE  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens mvt-+K?U  
    KHC Fz  
        tlens = 3.767 + 0.04*A                  'Lens thickness ZF#n(Y?  
    !Icznou\  
        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction $^czqA-&  
    Oj_F1. r  
        'Adjust parameters to account for accommodation aUc#,t;Qd  
    zw$\d1-+h  
        '************************************************************************* KU0Ad);e  
        'Aqueous thickness (Position of Lens) L>E{~yh  
        '************************************************************************* ^J^FGo|M  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) n <> ^cD  
        GetCustomElement eID, entity Fn4yx~0  
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        parID = FindFullName( "Geometry.Arizona Eye" ) B~qo^ppVU  
    C\ Yf]J  
        ' Delete any shift(s) in z O&;d82IA{  
        count = 0 ; qbK[3.  
        While GetOperationCount(eID)>count t:P]bp^#  
            GetOperation eID, count, op EL z5P}L6  
            If op.Type="ShiftZ" Then wmXI8'~F&  
                DeleteOperation eID,count QkHG`yW  
                count=count-1 i1KjQ1\a+  
            End If c>3? T^=  
            count=count+1 J]S30&?  
        Wend ~7g$T Ae{  
    l7VTuVGUJ  
        'Set new shift in t>*(v#WeZ  
        op.Type = "ShiftZ" 60A!Gob  
        op.val1 = taq 8<C@I/  
        op.parent = parID Z0y~%[1X  
        AddOperation eID, op l. l)w  
        Print "Set aqueous humor thickness = " & taq-0.55 NYG!\u\Rm  
    5P\A++2 2Y  
        '************************************************************************* kv+^U^WoU  
        'Radius and conic constant of anterior lens |F<iu2\  
        '************************************************************************* <}8G1<QZ'.  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) /Lm~GmPt  
        GetConic eID, entity, curv, conic 2P@6Qe ?  
    RIO?rt;  
        SetConic eID, entity, 1/Rant, CCant Mk973 'K'  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant >m <T+{`  
    /Qef[$!(  
        '************************************************************************* v+79#qWK|n  
        'Radius and conic constant of posterior lens kdV9F  
        '************************************************************************* Yjd/  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) n$7*L9)(C  
        GetConic eID, entity, curv, conic D2gyn-]\  
    R-OO1~W=  
        SetConic eID, entity, 1/Rpost, CCpost ,`YBTU  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost P7bb2"_9  
    >g~IP>  
        '************************************************************************* ~$j;@ 4  
        'Lens thickness (Position of posterior lens surface) l`:u5\ rM  
        '************************************************************************* $G }9iV7  
    Y{#*;p*I  
        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) /'_<~A  
    I\c7V~^hnG  
        ' Delete any z-shift(s) kZrc^  
        count = 0 S-~)|7d.  
        While GetOperationCount(eID)>count HJym|G>%?  
            GetOperation eID, count, op XIZN9/;  
            If op.Type="ShiftZ" Then kw gLK@@%1  
                DeleteOperation eID,count LayK&RwL  
                count=count-1 aot2F60J,  
            End If ]vs}-go  
            count=count+1 -%%Xx5D  
        Wend Iu`S0#+  
    JZ5";*,  
        'Set new z-shift AL,7rYZG$  
        op.Type = "ShiftZ" .sM,U  
        op.val1 = tlens ^EkxZ4*g  
        op.parent = parID N81M9#,["~  
        AddOperation eID, op y0&vsoT  
        Print "Set lens thickness = " & tlens UF }[%Sa  
    l Ib d9F  
        '************************************************************************* /N<aN9Z<x,  
        'Lens index of refraction r7R.dD /.  
        '************************************************************************* -KfK~P3PF  
        eID = FindMaterial( "Lens" ) c?}G;$  
        GetModelMaterial eID, mat XOI"BLd  
    tu* uQ:Ipk  
        mat.Nd = nlens mD&I6F[s  
        SetModelMaterial eID, mat <-n^h~,4  
        Print "Set lens index of refraction = " & nlens *mJ#|3I<  
    Y3(MKq  
        '************************************************************************* $U9]v5  
        'Pupil diameter t6mv  
        '************************************************************************* 'kY/=*=Q  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) yE,qLiH  
    w3sU&  |N  
        'Adjust pupil diameter (trimming volume inner hole) c?. i;4yh  
    +/RR!vG,  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" EU|IzUjFj|  
    n=F rv*"Z  
        ' Adjust pupil location to just in front of the lens IpSWg  
        parID = FindFullName( "Geometry.Arizona Eye" ) :b %2qBv  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) |mHf 7gCX  
        count = 0 8Q)|8xpYS  
        While GetOperationCount(eID)>count `aG _m/7|  
            GetOperation eID, count, op G}+@C]  
            If op.Type="ShiftZ" Then v@q&B|0  
                DeleteOperation eID,count U.I w/T-5  
                count=count-1 C,$o+q*)W9  
            End If X;UEq]kcmn  
            count=count+1 |&W4Dk n  
        Wend %D:VcY9OC  
        op.Type = "ShiftZ" Yk?q\1  
        op.val1 = taq-0.01 zp}pS2DU  
        op.parent = parID ^dhx/e%s  
        AddOperation eID, op }d>.Nj#zh  
    +L.D3  
        Print "Set pupil diameter = " & pupilDiam FJCORa@?_  
    3c,4 wyn  
        'Update AZ Eye subassembly Description y?O-h1"3,  
        eID = FindFullName( "Geometry.Arizona Eye" ) vazA@|^8  
        GetEntity eID, entity ISFNP&& K  
        entity.Description = "Accommodation = " & A & "D" c^pQitPv  
        SetEntity eID, entity "a~r'+'<  
    $%"hhju  
        Update ob2_=hQnC  
        Print "DONE!" Y%0rji  
         {J,"iJKop  
    End Sub (GpP=lSSeY  
    0#8, (6  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: a)=|{QR>W  
    m;{HlDez  
    Accommodation = 4 Diopters rXMc0SPk  
    Pupil Diameter = 4 mm se2Y:v  
    Set aqueous humor thickness = 2.81 hE`d@  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 'Rsr*gX#  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 9{j`eAUZl  
    Set lens thickness = 3.927 K\;4;6 g  
    Set lens index of refraction = 1.42672 ~1}fL 1~5  
    Set pupil diameter = 4 c_+fA  
    DONE! 4^:dmeMZ`  
    e Ru5/y~  
    (文章来源:讯技光电)
     
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