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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 j9 4=hJVKi  
    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。 )E@.!Ut4o  
    Ln<`E|[29  
    模型 }mq6]ZrK  
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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。 OXSmt DvJ  
    #crQ1p) \  
    Table 1. AZ眼睛模型的定义
    %D}kD6=  
    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. (%e .:W${  
    9_rYBX  
    光源 JG!mc7  
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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。 mD0f<gJ1  
    7>Ouqxh21  
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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。 >WQMqQ^t@  
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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。 6YLj^w] %  
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    图2. 字母F光源的设定方法光 Ym{tR,g7  
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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 B^Nf #XN(  
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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。 qL&[K>2z  
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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。 U;V7 u/{  
    }QcCS2)Ud  
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    图5. 视网膜重点采样规格设定
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    脚本 q J=~Y|(  
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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: be{H$9'  
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    图6. 用户对话框的创建与编辑
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    图7. 用户对话框编辑器
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    如果“OK”按钮按下,将会核对对话框下面的代码行,如果点击取消则脚本终止。然后输入的参数赋予变量,如果此处是保留为空白,则使用默认值。因此,如果没有值输入并点击“OK”按钮,则脚本是以屈光度为0,光瞳直径为4mm来运行的。 :q7Wy&ow  
    余下的脚本计算与屈光度有关的所有参数。 I^]2K0+x x  
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    分析 FQ2  
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    屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 /W30~y  
    Xy&A~F  
    图7. 字母F在视网膜上颜色分析
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    脚本代码 el<s8:lA  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. mpEK (p  
    SSg8}m5)Q  
    Dim entity As T_ENTITY Ae^~Cz1qz  
    Dim op As T_OPERATION swoQ'  
    Dim mat As T_MODELMATERIAL @=Uh',F  
    Dim A As Double -.@r#d/  
    Dim pupilDiam As Double eRstD>r  
    Dim eID As Long Z{Qu<vy_  
    Dim parID As Long }wjw:M  
    Dim count As Integer };bEU wGWf  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double {G0T$,'DR  
    Dim tlens As Double, nlens As Double ksqQM  
    Dim curv As Double, conic As Double V/LLaZ TE  
    Dim ok As Long 9y8&9<#  
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    Sub Main <X^@*79m  
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        '用户输入对话框 4*#18<u5  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 UWJ8amA  
            TextBox 220,21,40,21,.TextBox1 'default: 0 B =T'5&  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 |t&>5HM  
            OKButton 40,91,90,21 S_4?K)n #  
            CancelButton 190,91,90,21 Ugt/rf5n  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 VUGmi]qd  
            TextBox 220,49,40,21,.TextBox2 'default: 4 $}q23  
        End Dialog \?ZB]*Fu  
        Dim dlg As UserDialog |A9F\A->4  
    T_ <@..C  
        ok = Dialog (dlg) @#>rYAb8,  
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        If ok=0 Then    'cancel button was pressed -1_)LO&H  
            Print "Execution cancelled." Jk11fn;\>  
            End f=Gg9bnm3  
        End If ")5":V~fN  
    T#Z^s~7&I  
        'Assign accommodation and pupil diameter & use defaults if field left empty ,vawzq[oSy  
        If dlg.TextBox1 = "" Then !cLo> ,4  
            A = 0           'Default accommodation z`}qkbvi  
        Else S-b/S5  
            A = CDbl(dlg.TextBox1) aQcleTb  
        End If ]t,BMu=%  
    (9 GWbB?  
        If dlg.TextBox2 = "" Then uc\Kg1{  
            pupilDiam = 4   'Default pupil diameter KYhwOGN  
        Else {.|CdqwY  
            pupilDiam = CDbl(dlg.TextBox2) ~.nmI&3  
        End If aEWWP]  
    P%VSAh\|n  
        Print " " }W8;=$jr  
        Print "Accommodation = " & A & " Diopters" nYSiS}?S .  
        Print "Pupil Diameter = " & pupilDiam & " mm" 7#a-u<HF"  
    jo@6?( *4  
        ' Calculate new parameters with accommodation l0 m-$/  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness D|p9qe5%  
    I)[DTCJ~  
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens 1{. |+S Z!  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens Y%^w:|f^  
    ,HV(l+k {|  
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens 2(+2+ }  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens 'ya{9EdlT  
    XJ\DVZ  
        tlens = 3.767 + 0.04*A                  'Lens thickness At>DjKx]O  
    T/~f~Zz  
        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction iB yf{I>+  
    ,Vm < rK  
        'Adjust parameters to account for accommodation ]^7@}Ce_  
    s`8= 3]w  
        '************************************************************************* UHkMn  
        'Aqueous thickness (Position of Lens) q!7ANib6O  
        '************************************************************************* Y =I'czg  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) OLGE!&!>  
        GetCustomElement eID, entity i$#;Kpb`^  
    Pn1^NUMZJ  
        parID = FindFullName( "Geometry.Arizona Eye" ) _8J.fT$${  
    ((;!<5-`s  
        ' Delete any shift(s) in z -f^tE,-  
        count = 0 q`7PhA  
        While GetOperationCount(eID)>count &`r-.&Y  
            GetOperation eID, count, op 9:|{6_Y  
            If op.Type="ShiftZ" Then k%#EEMh  
                DeleteOperation eID,count `UaD6Mc<Mz  
                count=count-1 ZvX*t)VjTz  
            End If s^9Voi.y  
            count=count+1 ^ VyKd  
        Wend exUFS5d  
    [ l??A3G  
        'Set new shift in lb3b m)@:  
        op.Type = "ShiftZ" RSRS wkC  
        op.val1 = taq #gN&lY:CFn  
        op.parent = parID ,w4(kcg%iQ  
        AddOperation eID, op T3<4B!UB&  
        Print "Set aqueous humor thickness = " & taq-0.55  7xlkZF  
    xLajso1g69  
        '************************************************************************* :eCwY  
        'Radius and conic constant of anterior lens Pmx -8w  
        '************************************************************************* }R2u@%n{  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) V2EUW!gn 2  
        GetConic eID, entity, curv, conic b_taC^-l  
    iWkWR"ys y  
        SetConic eID, entity, 1/Rant, CCant \*?~Yj #  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant _;y9$"A  
    VCkq"f7c w  
        '************************************************************************* Q3~H{)[Kq  
        'Radius and conic constant of posterior lens Hvi49c]]  
        '************************************************************************* t{9GVLZ  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) $%d*@ 'c  
        GetConic eID, entity, curv, conic oZgjQM$YP  
    H%td hu\e  
        SetConic eID, entity, 1/Rpost, CCpost F/{!tx  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost ="H`V V_  
    C{rcs'  
        '************************************************************************* 0#hlsfc]\  
        'Lens thickness (Position of posterior lens surface) !f [_+CD  
        '************************************************************************* q?yVR3]M  
    8TKnL\aar  
        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) >+1duAC  
    U7F!Z( 9  
        ' Delete any z-shift(s) tcI*a>  
        count = 0 !e<^? r4  
        While GetOperationCount(eID)>count 0s[Hkhls  
            GetOperation eID, count, op 2%m BK  
            If op.Type="ShiftZ" Then X+9>A.92  
                DeleteOperation eID,count b8UO,fY q  
                count=count-1 v\ )W?i*l  
            End If ~36!?&eA8  
            count=count+1 {VRf0c  
        Wend {!L~@r  
    ;6$jf:2m  
        'Set new z-shift C1)!f j=  
        op.Type = "ShiftZ" Bwxd&;E  
        op.val1 = tlens 6bC3O4Rw  
        op.parent = parID 2[W&s&  
        AddOperation eID, op ZY+qA  
        Print "Set lens thickness = " & tlens 5t]H?b8  
    Jnov<+  
        '************************************************************************* Q1 97mN+0  
        'Lens index of refraction Y:[u1~a  
        '************************************************************************* ~$^XP.a.  
        eID = FindMaterial( "Lens" ) L="}E rmK  
        GetModelMaterial eID, mat :"c*s4  
    0GeTS Fj  
        mat.Nd = nlens rV#ch(  
        SetModelMaterial eID, mat onzxx4bax  
        Print "Set lens index of refraction = " & nlens #"~<HG}bR/  
    wmLs/:~  
        '************************************************************************* #_p\Ie*rd  
        'Pupil diameter U Cjld  
        '************************************************************************* H.MI5O(Q  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) e\L8oOk#r  
    f-Z/t fC  
        'Adjust pupil diameter (trimming volume inner hole) .ioEI sg  
    rx|pOz,:  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" 5$k:t  
    ;i+jJ4  
        ' Adjust pupil location to just in front of the lens &^jXEz;  
        parID = FindFullName( "Geometry.Arizona Eye" ) L!xi  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) tWc Hb #  
        count = 0 Dlvz )  
        While GetOperationCount(eID)>count +M/ %+l  
            GetOperation eID, count, op  @q) d  
            If op.Type="ShiftZ" Then YT,{E,U;  
                DeleteOperation eID,count 3Y$GsN4ln  
                count=count-1 cvL;3jRo  
            End If K}Qa~_  
            count=count+1 y:uE3Apm  
        Wend tCt#%7J;a  
        op.Type = "ShiftZ" <a3 WKw  
        op.val1 = taq-0.01 eHUOU>&P]  
        op.parent = parID r~['VhI!;E  
        AddOperation eID, op (E1~H0^  
    CrTw@AW9)  
        Print "Set pupil diameter = " & pupilDiam $XH^~i;  
    %xLh Z\  
        'Update AZ Eye subassembly Description Ny/MJ#Lq  
        eID = FindFullName( "Geometry.Arizona Eye" ) p]c%f 2E>d  
        GetEntity eID, entity 5z)~\;[ -  
        entity.Description = "Accommodation = " & A & "D" J{G?-+`  
        SetEntity eID, entity A04U /;  
    v3>UV8c'  
        Update GM<9p_ B  
        Print "DONE!" jPkn[W# 6  
         *o ix6  
    End Sub E]r?{t`]  
    0"z9Q\{}  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: F!K>Kz  
    dPRra{  
    Accommodation = 4 Diopters u*9V&>o  
    Pupil Diameter = 4 mm (QB2T2x  
    Set aqueous humor thickness = 2.81 )+Pus~w  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 9>#6*/Oa7  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 u ^RxD^=L  
    Set lens thickness = 3.927 M',?u  
    Set lens index of refraction = 1.42672  %;!.n{X  
    Set pupil diameter = 4 _q^E,P  
    DONE! _@/8gPT*i  
    7{Wny&[0  
    (文章来源:讯技光电)
     
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