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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 < C\snB  
    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。 XW6>;:4k  
    .bbl-a/ 3  
    模型 `gq@LP"o  
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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。 9)p VDS  
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    Table 1. AZ眼睛模型的定义
    %&bO+$H3  
    在FRED中使用0屈光度来创建的,光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. =iy%;>I `  
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    光源 =!_e(J  
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    多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 oB8u[ !  
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    图1. 光源和提示信息使用
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    除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处,并增加了pre-propagation distance= -8。尽管光线在光瞳处创建,规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射,而不是在光瞳处入射。 E1:{5F5/  
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    在往下看是内置的脚本用来修改屈光度,使其为4(250mm),光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 ;5 cg<~t  
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    图2. 字母F光源的设定方法光 [QA@XBy6  
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    图3. 字母F在视网膜上位置点列图
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    视网膜的散射 ,qJ/Jt$A  
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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。 A P><l@  
    q#Az\B:  
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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。 g$e b@0$  
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    图5. 视网膜重点采样规格设定
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    脚本 TFWV(<  
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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: TI:-Y@8  
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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。 xN0n0  
    余下的脚本计算与屈光度有关的所有参数。 a6"Pe07t  
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    分析 hZ-No  
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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。 : 'M$:ZJ  
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    图7. 字母F在视网膜上颜色分析
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    脚本代码 ,tv P"@d  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. s2)a8 <  
    =ZjF5,@  
    Dim entity As T_ENTITY `s(T (l  
    Dim op As T_OPERATION P31}O2 Nh  
    Dim mat As T_MODELMATERIAL DSad[>Uj],  
    Dim A As Double ^il'Q_-{  
    Dim pupilDiam As Double x|n2,3%  
    Dim eID As Long mR:G,XytxM  
    Dim parID As Long ,TaaXI  
    Dim count As Integer !VU[=~  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double  UN[rW0*  
    Dim tlens As Double, nlens As Double SU9qF73Y  
    Dim curv As Double, conic As Double o:jLM7$=  
    Dim ok As Long B ?96d'A  
    :<f7;.  
    Sub Main bIt%KG{PY6  
    `sOCJ|rc5  
        '用户输入对话框 f.cIhZF  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 % \Nfj) 9  
            TextBox 220,21,40,21,.TextBox1 'default: 0 E]V:@/(M'  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 7H~StdL/>  
            OKButton 40,91,90,21 1a 4 [w  
            CancelButton 190,91,90,21 j+NOT`&  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 T :IKyb  
            TextBox 220,49,40,21,.TextBox2 'default: 4 IM),cOp=  
        End Dialog B;?)   
        Dim dlg As UserDialog #jn6DL@[{  
    vQ"EI1=7Z  
        ok = Dialog (dlg) H5uWI  
    k/hE68<6i  
        If ok=0 Then    'cancel button was pressed JPW+(n|g  
            Print "Execution cancelled." Y,z15i3j?  
            End /H&:  
        End If 0@z=0}0Z  
    LM }0QL m?  
        'Assign accommodation and pupil diameter & use defaults if field left empty nAv@^G2  
        If dlg.TextBox1 = "" Then *#{[9d  
            A = 0           'Default accommodation .q#2 op  
        Else YFgQ!\&59  
            A = CDbl(dlg.TextBox1) VXlTA>a }  
        End If )]~'zOE_  
    VE1 B"s</  
        If dlg.TextBox2 = "" Then z%5i^P  
            pupilDiam = 4   'Default pupil diameter [4B.;MS(  
        Else Wo&10S w  
            pupilDiam = CDbl(dlg.TextBox2)  N)G.^9  
        End If } <; y,4f  
    v[WbQ5AND  
        Print " " +ou5cQ^  
        Print "Accommodation = " & A & " Diopters" MFO}E!9`q  
        Print "Pupil Diameter = " & pupilDiam & " mm" a.QF`J4"'  
    .n1]Yk;,1  
        ' Calculate new parameters with accommodation }3 NGMGu$  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness l&cYN2T b  
    e#]=-^  
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens uSp=,2)  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens %cJ]Ds%V  
    fXCx!3m  
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens zB`)\  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens zS*GYE(l^  
    4SSq5Ve<  
        tlens = 3.767 + 0.04*A                  'Lens thickness rSDS9Vf(  
    ]Ija,C!#  
        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction KY$6=/?U_  
    ;B>2oq  
        'Adjust parameters to account for accommodation +*-u_L\'  
    jz(}P8  
        '************************************************************************* g(m3 &  
        'Aqueous thickness (Position of Lens) w. exLC  
        '************************************************************************* P<yd  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) tAH,3Sz( /  
        GetCustomElement eID, entity |mvy@hm  
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        parID = FindFullName( "Geometry.Arizona Eye" ) 4h wUH  
    {:M5t1^UC  
        ' Delete any shift(s) in z ?h4-D:!$L  
        count = 0 Rg~ ~[6G>  
        While GetOperationCount(eID)>count VKRj 1LXz  
            GetOperation eID, count, op I;kKY  
            If op.Type="ShiftZ" Then k6-.XW  
                DeleteOperation eID,count x gP/BK2"  
                count=count-1 3#vhQ*xU  
            End If RkP g&R;i  
            count=count+1 7KU/ 1l9$9  
        Wend :FOMRrf7.  
    uTY5.8  
        'Set new shift in .hW_P62\#  
        op.Type = "ShiftZ" gf2<dEff  
        op.val1 = taq DP`$gd  
        op.parent = parID Xao 0cb.R  
        AddOperation eID, op aLapb5VV  
        Print "Set aqueous humor thickness = " & taq-0.55 I8 Ai_^P  
    ':6!f  
        '************************************************************************* Z'iXuI49  
        'Radius and conic constant of anterior lens >en,MT|  
        '************************************************************************* WMfu5x7e4  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) ;\yY*  
        GetConic eID, entity, curv, conic Wi]Mp7b  
    HH/ bBM!  
        SetConic eID, entity, 1/Rant, CCant zTb!$8D"g  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant gd3~R+Kd  
    S;[g0j  
        '************************************************************************* F/;uN5{o  
        'Radius and conic constant of posterior lens {2?o:  
        '************************************************************************* yZFm<_9>  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) D hy  
        GetConic eID, entity, curv, conic .zf#S0y%(  
    g}nlb.b]{m  
        SetConic eID, entity, 1/Rpost, CCpost j]i:~9xKW  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost }Jkz0JY~  
    _hlLM,p  
        '************************************************************************* o#Q0J17i?  
        'Lens thickness (Position of posterior lens surface) L2:v#c()#)  
        '************************************************************************* 3n-~+2l  
    tM3eB= .*  
        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) N3 qtq9{  
    *k$&U3=  
        ' Delete any z-shift(s) 2:0'fNXop  
        count = 0 ??Zh$^No:  
        While GetOperationCount(eID)>count +$R4'{9q  
            GetOperation eID, count, op 6rlafISvO  
            If op.Type="ShiftZ" Then >g8H  
                DeleteOperation eID,count kd^CZ;O  
                count=count-1 k fS44NV  
            End If ab4(?-'-  
            count=count+1 K~Lh'6  
        Wend lJHV c"*/  
    O^(ji8[l  
        'Set new z-shift 5*QNE!  
        op.Type = "ShiftZ" Ul#||B .c{  
        op.val1 = tlens 2uw1R;zw  
        op.parent = parID nRq @hk  
        AddOperation eID, op !#P|2>>u  
        Print "Set lens thickness = " & tlens 1"k"<{%  
    F&? &8.  
        '************************************************************************* .9X,)^D  
        'Lens index of refraction LlAMtw"  
        '************************************************************************* .*+?]  
        eID = FindMaterial( "Lens" ) wWV`k  
        GetModelMaterial eID, mat QRb iO  
    c\.Hs9T >  
        mat.Nd = nlens *3 .+19Q  
        SetModelMaterial eID, mat =ZdP0l+V=k  
        Print "Set lens index of refraction = " & nlens \ci'Cbn\o  
    f4F13n_0X  
        '************************************************************************* D=*3Xd  
        'Pupil diameter rXR=fj= 2  
        '************************************************************************* {=n-S2%  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) m]t`;lr<  
    UzZzt$Kw  
        'Adjust pupil diameter (trimming volume inner hole) &~`Ay4hq  
    *N5cC#5`=  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" y" 4Nw]kU  
    CMk0(sztU_  
        ' Adjust pupil location to just in front of the lens Th&-n%r9K  
        parID = FindFullName( "Geometry.Arizona Eye" ) .{,PC  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) Bn>"lDf,  
        count = 0 Lo"w,p`n@  
        While GetOperationCount(eID)>count Jv*[@ -.k  
            GetOperation eID, count, op Fy(-.S1  
            If op.Type="ShiftZ" Then h>>KH*dQ  
                DeleteOperation eID,count xb`,9.a7  
                count=count-1 |ymw])L  
            End If 8}9B*m  
            count=count+1 Ww8<f$  
        Wend QkMK\Up  
        op.Type = "ShiftZ" Y`$dtg {  
        op.val1 = taq-0.01 Z)=S. )  
        op.parent = parID JBY`Y ]V3  
        AddOperation eID, op 3q +C8_:  
    %6-5hBzZN  
        Print "Set pupil diameter = " & pupilDiam IK#W80y  
    Z4+S4cqnh  
        'Update AZ Eye subassembly Description 6:Eu[PE~w  
        eID = FindFullName( "Geometry.Arizona Eye" ) p6=L}L  
        GetEntity eID, entity ""LCyKu   
        entity.Description = "Accommodation = " & A & "D" U;%I" p`Z/  
        SetEntity eID, entity D|zlC,J,  
    rof&O   
        Update 3=r#=u5z  
        Print "DONE!" WO=X*O ne  
         GTvp)^ h  
    End Sub SRL`!  
    ci]IH]x  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: v]`}T/n  
    +C`h*%BW  
    Accommodation = 4 Diopters 6]`XW 0{C  
    Pupil Diameter = 4 mm -Ucj|9+(a  
    Set aqueous humor thickness = 2.81 uK_Q l\d  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 e+Qq a4  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 vAeh#V~#  
    Set lens thickness = 3.927 cT8b$P5w  
    Set lens index of refraction = 1.42672 iR k.t=B  
    Set pupil diameter = 4 w.tQ)x1h  
    DONE! 3I|&}+Z6  
    )`Zj:^bz9  
    (文章来源:讯技光电)
     
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