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    [转载]FRED运用:Arizona眼睛模型 [复制链接]

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    离线xunjigd
     
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    只看楼主 倒序阅读 楼主  发表于: 2016-02-24
    简介 O0:q;<>z  
    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。 QWU-m{@~&  
    'fW-Y!k%  
    模型 ^f@=:eWI  
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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。 tX[WH\(xI  
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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. {)Xy%QV  
    r|Z{-*`  
    光源 NlXimq  
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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。 _ dg\\c  
    ,//S`j$S  
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    图1. 光源和提示信息使用
    .]Z"C&"N]  
    除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处,并增加了pre-propagation distance= -8。尽管光线在光瞳处创建,规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射,而不是在光瞳处入射。 Zd&S@Z  
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    在往下看是内置的脚本用来修改屈光度,使其为4(250mm),光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 {+Jv+J9  
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    图2. 字母F光源的设定方法光 :KO2| v\  
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    图3. 字母F在视网膜上位置点列图
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    视网膜的散射 xD$\,{  
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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。 =c7;r]Ol  
    'q.!|G2U  
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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。 ,?3G;-  
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    图5. 视网膜重点采样规格设定
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    脚本 45oR=At n  
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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: PW4q~rc=:  
    ;d?R:Uw8  
    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。 F!do~Z  
    余下的脚本计算与屈光度有关的所有参数。 "5 A! jq  
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    分析 7o4\oRGV  
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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。 Ep}s}Stlr}  
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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 liSmjsk  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. \Cj B1] I  
    \DzGQ{`~m  
    Dim entity As T_ENTITY <QvOs@i*  
    Dim op As T_OPERATION P*o9a  
    Dim mat As T_MODELMATERIAL <}LC~B!  
    Dim A As Double j#6.Gq  
    Dim pupilDiam As Double 0aAoV0fMDz  
    Dim eID As Long =T_g}pu  
    Dim parID As Long ME dWLFf  
    Dim count As Integer Ls%MGs9PI  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double #b`k e/P  
    Dim tlens As Double, nlens As Double u4j5w  
    Dim curv As Double, conic As Double b]y2+A.n  
    Dim ok As Long ~m |BC*)  
    M`>E|" <  
    Sub Main % `3jL7|  
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        '用户输入对话框 ]{iQ21`a-  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 f<H2-(m  
            TextBox 220,21,40,21,.TextBox1 'default: 0 VE24ToI?W"  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 MJvp6n  
            OKButton 40,91,90,21 #F#%`Rv1  
            CancelButton 190,91,90,21 L$-T,Kze  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 3u;oQ5<(v  
            TextBox 220,49,40,21,.TextBox2 'default: 4 >/|*DI-HJ  
        End Dialog 6 r"<jh#  
        Dim dlg As UserDialog 3Y &d=  
    +0~YP*I`/  
        ok = Dialog (dlg) :>*7=q=  
    JO;Uus{?  
        If ok=0 Then    'cancel button was pressed /NlGFO*Z  
            Print "Execution cancelled." /\Ef%@  
            End G9lUxmS<  
        End If 99S ^f:t  
    :0ep( <|;  
        'Assign accommodation and pupil diameter & use defaults if field left empty  eIlva?  
        If dlg.TextBox1 = "" Then <!+Az,-  
            A = 0           'Default accommodation G#CXs:1pd+  
        Else k\IbIv7?i  
            A = CDbl(dlg.TextBox1) s>en  
        End If RpK@?[4s  
    R2;  
        If dlg.TextBox2 = "" Then O}P`P'Y|'  
            pupilDiam = 4   'Default pupil diameter hc1N ~$3!G  
        Else 8QK&_n*  
            pupilDiam = CDbl(dlg.TextBox2) ;,TFr}p`  
        End If "z c l|@  
    aYeR{Y]  
        Print " " GmG 5[?)  
        Print "Accommodation = " & A & " Diopters" g\U-VZ6;p  
        Print "Pupil Diameter = " & pupilDiam & " mm" G6/m#  
    iwq!w6+  
        ' Calculate new parameters with accommodation C}X\|J  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness .N3mb6#[R  
    m[$_7a5  
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens (mOtU8e  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens u!s2 BC0}N  
    [Zrr)8A  
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens ;`Z{7'^U  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens %C0Dw\A*:  
    ~[ F`"  
        tlens = 3.767 + 0.04*A                  'Lens thickness i?/qY&~  
    =v\.h=~~  
        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction K'xV;r7Nt  
    O2+6st  
        'Adjust parameters to account for accommodation lFk R=!?=  
    5N]"~w*  
        '************************************************************************* FsPw1A$y  
        'Aqueous thickness (Position of Lens) <$YlH@;)`a  
        '************************************************************************* i@q&5;%%  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) wq{hF<  
        GetCustomElement eID, entity 6LZCgdS{  
    }qUX=s GG  
        parID = FindFullName( "Geometry.Arizona Eye" ) {_}I!`opr$  
    r^ XVB`v  
        ' Delete any shift(s) in z gr{ DWCK  
        count = 0 |:o4w  
        While GetOperationCount(eID)>count _GPe<H  
            GetOperation eID, count, op 3R/bz0 V>  
            If op.Type="ShiftZ" Then >_TZ'FT  
                DeleteOperation eID,count ,+VGSd  
                count=count-1 0_/[k*Re  
            End If >~f]_puT  
            count=count+1 TvM~y\s  
        Wend "tZe>>I  
    m'U0'}Ld};  
        'Set new shift in K}y f>'O  
        op.Type = "ShiftZ" AX INThJ  
        op.val1 = taq cK@wsA^4  
        op.parent = parID 54,er$$V  
        AddOperation eID, op xk5 ]^yDp  
        Print "Set aqueous humor thickness = " & taq-0.55 h;Kx!5)y  
    }vuARZ>  
        '************************************************************************* Y2TtY;  
        'Radius and conic constant of anterior lens :0/ 7,i  
        '************************************************************************* sA~]$A;DM!  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) b>W %t  
        GetConic eID, entity, curv, conic sKWfX Cd  
    i%/+5gq  
        SetConic eID, entity, 1/Rant, CCant / FII07V  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant FmW(CGs  
    [^)g%|W  
        '************************************************************************* (:_$5&i7  
        'Radius and conic constant of posterior lens 1 zZlC#V  
        '************************************************************************* [0of1eCSl  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) b>|6t~}M  
        GetConic eID, entity, curv, conic #c J@uqR  
    DXo|.!P=3  
        SetConic eID, entity, 1/Rpost, CCpost K9[UB  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost gi8FHSU|G  
    M:8R -c#![  
        '************************************************************************* ! if   
        'Lens thickness (Position of posterior lens surface) c$,P ~W s'  
        '************************************************************************* | Iib|HQ)  
    \zY!qpX<  
        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) ZNoDFf*h  
    Q8NX)R  
        ' Delete any z-shift(s) XX@ZQcN  
        count = 0 ' %qr.T %  
        While GetOperationCount(eID)>count uH]OEz\H'  
            GetOperation eID, count, op KXy6Eno  
            If op.Type="ShiftZ" Then *hx  
                DeleteOperation eID,count d$RIS+V  
                count=count-1 NUZl`fu1Z4  
            End If p?!/+  
            count=count+1 =(Mch~  
        Wend 3Ul*QN{6  
    = &]L00u.  
        'Set new z-shift BLttb  
        op.Type = "ShiftZ" Ey2^?  
        op.val1 = tlens 8Wx=p#_  
        op.parent = parID DrR@n~  
        AddOperation eID, op ,2q-D&)\Z  
        Print "Set lens thickness = " & tlens L#J1b!D&<6  
    >j/w@Fj  
        '************************************************************************* ![1rzQvGDb  
        'Lens index of refraction *T/']t  
        '************************************************************************* vgPCQO([  
        eID = FindMaterial( "Lens" ) $]d^-{|  
        GetModelMaterial eID, mat qna8|3eP  
    NOva'qk  
        mat.Nd = nlens "x-j~u?  
        SetModelMaterial eID, mat +rd+0 `}C  
        Print "Set lens index of refraction = " & nlens 29Ki uP  
    ;`&kZi60Hz  
        '************************************************************************* ? k/`  
        'Pupil diameter <YY14p  
        '************************************************************************* {mg2pfhB!  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) b;n[mk  
    ! mHO$bQ"  
        'Adjust pupil diameter (trimming volume inner hole) ]esC[r]PJ  
    }tz7b#  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" C_Dn{  
    ~Y;*u]^  
        ' Adjust pupil location to just in front of the lens icgfB-1|i  
        parID = FindFullName( "Geometry.Arizona Eye" ) uFE)17E  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) se)TzI^]b@  
        count = 0 UNYqft4  
        While GetOperationCount(eID)>count d6O[ @CyP  
            GetOperation eID, count, op _/|\aqF.  
            If op.Type="ShiftZ" Then @]j1:PN-  
                DeleteOperation eID,count { FkF  
                count=count-1 p{_ " bB  
            End If ;pAK_>  
            count=count+1 J5qZFD  
        Wend hb$Ce'}N  
        op.Type = "ShiftZ" jp,4h4C^)  
        op.val1 = taq-0.01 7! Nsm  
        op.parent = parID TbU#96"~.  
        AddOperation eID, op A^g(k5M*  
    6m93puY`7  
        Print "Set pupil diameter = " & pupilDiam F8=+j_UGI  
    LVGe]lD  
        'Update AZ Eye subassembly Description s;e\ pt  
        eID = FindFullName( "Geometry.Arizona Eye" ) @{Q4^'K"  
        GetEntity eID, entity /: "1Z]@  
        entity.Description = "Accommodation = " & A & "D" f|5co>Hk  
        SetEntity eID, entity qX%_uOw:%  
    )7F/O3Tq  
        Update .*oU]N%K=  
        Print "DONE!" ]^E?;1$f?  
         ye&;(30Oq  
    End Sub kVgTGC"L=  
    CJY$G}rk  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: P:c w|Q  
    ^q5#ihM  
    Accommodation = 4 Diopters oR'm2d^  
    Pupil Diameter = 4 mm uRvP hkqm  
    Set aqueous humor thickness = 2.81 u 9e@a9c  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 [0!(xp^  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 %b$>qW\*&  
    Set lens thickness = 3.927 q V =!ORuj  
    Set lens index of refraction = 1.42672 04ui`-c(  
    Set pupil diameter = 4 Lbgi7|&  
    DONE! y[;>#j$  
    zhQJy?>'m  
    (文章来源:讯技光电)
     
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