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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 $+JS&k/'m  
    人眼光学模型可用来设计眼科用设备,光学系统注定了要与人眼一起使用。本文演示了这样一个模型:Arizona眼睛模型,在Jim Schwiegerling教授的书中有详细描述:《Field Guide to Visual and Ophthalmic Optics》。AZ眼睛模型达到了基于平均临床数据所决定的轴上和轴外像差等级。FRED文件包含了此眼睛模型及几个用来分析它的光源,并包括一个基于想要的屈光度来调整模型的内嵌脚本。 r3E!dTDWq  
    !pTJ./  
    模型 E`int?C!  
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    模型的定义如表1种所示,由半径、圆锥常数、折射率、阿贝数、到下一面的距离等一系列表面组成。一些参数由屈光度(A)来决定。 6!x&LoM  
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    Table 1. AZ眼睛模型的定义
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    在FRED中使用0屈光度来创建的,光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. Hnknly  
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    光源 -fhN"B)  
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    多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 >~%e$a7}+  
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    图1. 光源和提示信息使用
    :NJ_n6E  
    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。 O[tvR:Nh  
    *eI)Z=8  
    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。 Lbe\@S   
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    图2. 字母F光源的设定方法光 O~j> ?  
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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 f}g\D#`]/  
    +uay(3m((  
    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。 7Q\|=$2  
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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, U*yj  
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    图5. 视网膜重点采样规格设定
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    脚本 W3`>8v1?o  
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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: fXrXV~'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。 U qG .:@T  
    余下的脚本计算与屈光度有关的所有参数。 !9 fz(9  
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    分析 Aw&tP[N[  
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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。 Y*mbjyt[?X  
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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 ySI~{YVM  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. % ,+leKs  
    2^?:&1:  
    Dim entity As T_ENTITY >X*Mio8P#  
    Dim op As T_OPERATION 4CGPO c  
    Dim mat As T_MODELMATERIAL NcY608C  
    Dim A As Double 'X shmZ0&  
    Dim pupilDiam As Double N},n `Yl.  
    Dim eID As Long Jx'i2&hGN  
    Dim parID As Long '\jd#Kn'h  
    Dim count As Integer l<M'=-Y  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double mKYeD%Pm*  
    Dim tlens As Double, nlens As Double 6e7{Iy  
    Dim curv As Double, conic As Double N!*_La=TuH  
    Dim ok As Long Z@hD(MS(C  
    aZ\UrV4,  
    Sub Main fu~ +8CE.  
    ;5@  t[r  
        '用户输入对话框 SNY~9:;]f  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 ~o n(3|$  
            TextBox 220,21,40,21,.TextBox1 'default: 0 }NsUnbxT  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 {3&|tk!*  
            OKButton 40,91,90,21 ! !PYP'e  
            CancelButton 190,91,90,21 {d?$m*YR3`  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 Qt|c1@J  
            TextBox 220,49,40,21,.TextBox2 'default: 4 np~~mdmRK  
        End Dialog "s\L~R.&  
        Dim dlg As UserDialog OgX6'E\E  
    >0l"P"]  
        ok = Dialog (dlg) 7'OtruJ   
    !0N7^Z"gtz  
        If ok=0 Then    'cancel button was pressed s: 3z'4oX  
            Print "Execution cancelled." D-,L&R!`  
            End M,ir`"s  
        End If JgHM?AWg|  
    \e`~i@) ~Z  
        'Assign accommodation and pupil diameter & use defaults if field left empty 2.d|G `  
        If dlg.TextBox1 = "" Then umdG(osR  
            A = 0           'Default accommodation H{t_xL)k.  
        Else @BNEiOAZ#  
            A = CDbl(dlg.TextBox1) KM`eIw>8  
        End If *28pRvY:b  
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        If dlg.TextBox2 = "" Then bO<CR  
            pupilDiam = 4   'Default pupil diameter X6^},C'E.:  
        Else `SVmQSwO[  
            pupilDiam = CDbl(dlg.TextBox2) zq%D/H6J,  
        End If Ux+Q  
    ;U_QvN|  
        Print " "  \lSU  
        Print "Accommodation = " & A & " Diopters" JAI)Eqqv]  
        Print "Pupil Diameter = " & pupilDiam & " mm" hUm'8)OJ  
    J+f!Ar  
        ' Calculate new parameters with accommodation +&["HoKg}&  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness ,6r{VLN  
    R N@ctRS  
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens ,k G>?4  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens k#5}\w!  
    5^j45'%I  
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens D0BI5q  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens 57 #6yXQ  
    I<A6Z&*un  
        tlens = 3.767 + 0.04*A                  'Lens thickness $U/YR&vcw  
    :\=CRaA  
        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction ~/_SMPLo  
    Zc?ppO  
        'Adjust parameters to account for accommodation j+HHQd7Y  
    P bQk<"J1  
        '************************************************************************* kkK kf'  
        'Aqueous thickness (Position of Lens) (< =}]v  
        '************************************************************************* |^9BA-nA  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) ]f1{n  
        GetCustomElement eID, entity 72,rFYvpK  
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        parID = FindFullName( "Geometry.Arizona Eye" ) ]@Sj`J[fd  
    f#Xyoa%  
        ' Delete any shift(s) in z $k$4% 7  
        count = 0 _FwK-?4E-  
        While GetOperationCount(eID)>count }=!,o  
            GetOperation eID, count, op KOwOIDt  
            If op.Type="ShiftZ" Then V"!G2&  
                DeleteOperation eID,count <`0h|m'U  
                count=count-1 0T>H)c6:\  
            End If Ig5L$bAM~  
            count=count+1 &  =/  
        Wend wYlf^~#"  
    %K]euEqs  
        'Set new shift in W}|'#nR  
        op.Type = "ShiftZ" PH{_ ,X  
        op.val1 = taq z ;u  
        op.parent = parID F H1Z 2  
        AddOperation eID, op ]#.]/f >-  
        Print "Set aqueous humor thickness = " & taq-0.55 YA&g$!  
    aC< KN:TN6  
        '************************************************************************* *~/OOH$"  
        'Radius and conic constant of anterior lens LjU'z#  
        '************************************************************************* =rR~`  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) ?i`l[+G  
        GetConic eID, entity, curv, conic K|oacOF9  
    d`1I".y  
        SetConic eID, entity, 1/Rant, CCant |!F5.%PY  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant g&n)fF  
    p^iRPI  
        '************************************************************************* 3R&lqxhg  
        'Radius and conic constant of posterior lens wd/< 8>2X  
        '************************************************************************* . <tq6 1  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) b}Zd)2G  
        GetConic eID, entity, curv, conic q:<{% U$  
    ujJI 1I  
        SetConic eID, entity, 1/Rpost, CCpost fQP{|+4  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost }(<%`G6N  
    C4}*) a  
        '************************************************************************* }y%oT P&  
        'Lens thickness (Position of posterior lens surface) !p1qJ [  
        '************************************************************************* U?!>Nd  
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        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) ,hVvve,j}  
    apk4 j\i?5  
        ' Delete any z-shift(s) dik9 >*"|o  
        count = 0 * 9p |HX=  
        While GetOperationCount(eID)>count 7n90f2"m  
            GetOperation eID, count, op {-A^g!jT&  
            If op.Type="ShiftZ" Then X";@T.ZGut  
                DeleteOperation eID,count _GKB6e%  
                count=count-1 3/#:~a9Q  
            End If -n0C4kZ2o  
            count=count+1 O+RP3ox"  
        Wend GQ_p-/p R  
    }$\M{# C~  
        'Set new z-shift X w.p  
        op.Type = "ShiftZ" zX#%{#9  
        op.val1 = tlens ^;c16  
        op.parent = parID n8hRaNHl2  
        AddOperation eID, op VtOZ%h[#  
        Print "Set lens thickness = " & tlens j|tC@0A  
    <|?K%FP7Z  
        '************************************************************************* IHp_A  
        'Lens index of refraction  KQ[!o!%  
        '************************************************************************* ql<rU@  
        eID = FindMaterial( "Lens" ) LB/C-n.`  
        GetModelMaterial eID, mat l6kmS  
    [Ei1~n)o  
        mat.Nd = nlens VB<Jf'NU  
        SetModelMaterial eID, mat "G:<7oTa  
        Print "Set lens index of refraction = " & nlens V]S1X^  
    1T)Zh+?)}  
        '************************************************************************* VzJ5.mRQ  
        'Pupil diameter oQ=>'w  
        '************************************************************************* -{ u*qtp  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) 1.q_f<U  
    ,^8MB.  
        'Adjust pupil diameter (trimming volume inner hole) VGqa)ri"  
    yFhB>i  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" _owjTo}  
    `c+/q2M  
        ' Adjust pupil location to just in front of the lens umLb+GbI4  
        parID = FindFullName( "Geometry.Arizona Eye" ) xug)aE  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) pb0E@C/R  
        count = 0 )~jqW=d 2  
        While GetOperationCount(eID)>count :D7|%KK  
            GetOperation eID, count, op 'lZ.j&  
            If op.Type="ShiftZ" Then !AJ]j|@VBd  
                DeleteOperation eID,count @/UfD ye  
                count=count-1 iK{T^vvk  
            End If }`yiT<z  
            count=count+1 s/Xb^XjS1  
        Wend &L^CCi  
        op.Type = "ShiftZ" &6Il(3-^  
        op.val1 = taq-0.01 #0;HOeIiH  
        op.parent = parID zX{.^|  
        AddOperation eID, op ESb ]}c:  
    $j)hNWI  
        Print "Set pupil diameter = " & pupilDiam X5 ITF)&  
    E2B>b[  
        'Update AZ Eye subassembly Description 8dK0o>|}  
        eID = FindFullName( "Geometry.Arizona Eye" ) *^ \FIUd  
        GetEntity eID, entity  uIMe  
        entity.Description = "Accommodation = " & A & "D" S'B6jJK2x  
        SetEntity eID, entity >5T_g2pkv  
    `:M^8SYrL  
        Update nU`Lhh8y  
        Print "DONE!" ji+{ :D  
         a <X0e>  
    End Sub W 4YE~  
    (Y(E%  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: dRvin[R8  
    .I$}KE)  
    Accommodation = 4 Diopters q6`G I6  
    Pupil Diameter = 4 mm }jF+`!*!  
    Set aqueous humor thickness = 2.81 GJ 'spgz  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 3kmeD".  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 ep(g`e  
    Set lens thickness = 3.927 VF0dE  
    Set lens index of refraction = 1.42672 8n4V cu  
    Set pupil diameter = 4 #G3N(wV3  
    DONE! /-0' Qa+*  
    TOI4?D]  
    (文章来源:讯技光电)
     
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