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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 X8C7d6ca  
    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。 *z0!=>(  
    S?~0)EXj(  
    模型 -|>~I#vY  
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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。 5EYGA\  
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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. U^m#!hp  
    ( t&RFzE?G  
    光源 f{BF%;  
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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。 wh$bDT Cj  
    c 1YDln  
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    图1. 光源和提示信息使用
    J1w;m/oV  
    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。 #GzALF97  
    8>KUx]AN  
    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。 qTsy'y;Z  
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    图2. 字母F光源的设定方法光 yRXML\Ge  
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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 xo>0j#  
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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。 GJ9>i)+h;  
    <4}m:  
    M @5&.  
    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。 z8\YMr 6o  
    nFnM9 pdMK  
    (Pc>D';{S  
    图5. 视网膜重点采样规格设定
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    脚本 l=DF)#>w  
    #U:|- a.>  
    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: I&-r^6Yx  
    " U\RN  
    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。 uw;Sfx,s  
    余下的脚本计算与屈光度有关的所有参数。 4H{t6t@-:  
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    分析 {&5lZ<nu8A  
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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。 sfF~k-  
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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 .a4,Lr#q.  
    (`(D $%  
    Option Explicit     'Remove this to enable non-dimensioned variables to be used. 8t!jo.g  
    ^/C\:hw  
    Dim entity As T_ENTITY u*C*O4f>OC  
    Dim op As T_OPERATION P:{Aq n~zR  
    Dim mat As T_MODELMATERIAL s~M$Wo8  
    Dim A As Double b A+_/1C  
    Dim pupilDiam As Double 1T!o`*  
    Dim eID As Long q?!HzZ  
    Dim parID As Long `~XksyT  
    Dim count As Integer s= %3`3Fo  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double H^d?(Svh  
    Dim tlens As Double, nlens As Double /.]u%;%r[  
    Dim curv As Double, conic As Double xfRp_;l+R  
    Dim ok As Long Kd:l8%+  
    Wga2).j6  
    Sub Main )7 5 7   
    #b^6>  
        '用户输入对话框 T5:Q_o]  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 8pnD6Lp>  
            TextBox 220,21,40,21,.TextBox1 'default: 0 od=hCQ1 >  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 x Lan1V  
            OKButton 40,91,90,21 wAHuPQ&_Q  
            CancelButton 190,91,90,21 o `YBz~2  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 !v8R(  
            TextBox 220,49,40,21,.TextBox2 'default: 4 ?I+{S  
        End Dialog |[`YGA4  
        Dim dlg As UserDialog 1KZigeHXI  
    #)'Iqaq7  
        ok = Dialog (dlg) <$s6?6P  
    mG~k f]Y  
        If ok=0 Then    'cancel button was pressed /EjXyrn2  
            Print "Execution cancelled." M-@RgWvF  
            End G_+/ e]P  
        End If cZVx4y%kz  
    pX &bX_F{  
        'Assign accommodation and pupil diameter & use defaults if field left empty MT!Y!*-5  
        If dlg.TextBox1 = "" Then riW9l6s'  
            A = 0           'Default accommodation 2;gvo*k  
        Else JC cYFtW  
            A = CDbl(dlg.TextBox1) KElEGW  
        End If 8dR `T}  
    }+@!c%TCx~  
        If dlg.TextBox2 = "" Then 8UU L=  
            pupilDiam = 4   'Default pupil diameter x,C8):\t`B  
        Else 0/v]YK.  
            pupilDiam = CDbl(dlg.TextBox2) YE`Y t  
        End If r^5%0_F]  
    P!79{8  
        Print " " .Y6v#VI  
        Print "Accommodation = " & A & " Diopters" lie,A  
        Print "Pupil Diameter = " & pupilDiam & " mm" C>|.0:[%  
    s4fO4.bnm  
        ' Calculate new parameters with accommodation ~cc }yDe  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness /4T6Z[=s  
    ( v*xW.  
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens /ZyMD(_J  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens Ao\P|K9MyL  
    ].Yz =:  
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens yeiIP  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens ]hV!lG1_  
    7<su8*?  
        tlens = 3.767 + 0.04*A                  'Lens thickness \Y!#Y#c  
    ^]sb=Amw  
        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction Nvd(?+c  
    w=#'8ZuU  
        'Adjust parameters to account for accommodation 'LMj.#A<g  
    @_kF&~  
        '************************************************************************* vv.E6D^x(  
        'Aqueous thickness (Position of Lens) sT;wHtU  
        '************************************************************************* GQYR`;>  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) 0B(s+#s  
        GetCustomElement eID, entity Rq|6d M6H  
    3O,nNt;L{  
        parID = FindFullName( "Geometry.Arizona Eye" ) {wC*61@1  
    IL|Q-e}Ol  
        ' Delete any shift(s) in z @ eJ8wf]  
        count = 0 {dZ]+2Z~+  
        While GetOperationCount(eID)>count U;W9`JT<.f  
            GetOperation eID, count, op PIU@ }:}  
            If op.Type="ShiftZ" Then x|m9?[ !_  
                DeleteOperation eID,count HQ@g6  
                count=count-1 joI)6c  
            End If `,'/Sdr  
            count=count+1 Bf*>q*%B{  
        Wend fHd[8{;P:  
    <<!fA ><W  
        'Set new shift in OTF/Pu$  
        op.Type = "ShiftZ" '^TeV=  
        op.val1 = taq /K|(O^nw  
        op.parent = parID p{5m5x  
        AddOperation eID, op qHZDo[  
        Print "Set aqueous humor thickness = " & taq-0.55 PcC@}3  
    0Agse)  
        '************************************************************************* "r46Rfa  
        'Radius and conic constant of anterior lens ]mMJ6n  
        '************************************************************************* &IN%2c  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) jMn,N9Mf  
        GetConic eID, entity, curv, conic SAdT#0J  
    zjA]Tr  
        SetConic eID, entity, 1/Rant, CCant N" L&Z4Z  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant ~yJ2@2I  
    lQ?jdi  
        '************************************************************************* ~)f^y!PMQ  
        'Radius and conic constant of posterior lens bg Ux&3  
        '************************************************************************* zx%WV@O9  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) Rq}lW.<r  
        GetConic eID, entity, curv, conic Mw0>p5+ cy  
    *,JE[M  
        SetConic eID, entity, 1/Rpost, CCpost :e7\z  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost @[lMh9`  
    ES4Wtc)&  
        '************************************************************************* ],SQD3~9  
        'Lens thickness (Position of posterior lens surface) o=R(DK# U  
        '************************************************************************* 7}VqXUwabx  
    #VrIU8Q7'  
        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) ^m%#1Zd  
    #B5,k|"/,M  
        ' Delete any z-shift(s) ] :;x,$k  
        count = 0 gl+d0<R zw  
        While GetOperationCount(eID)>count K\2{SjL:B  
            GetOperation eID, count, op rD=D.1_   
            If op.Type="ShiftZ" Then 14 & KE3`  
                DeleteOperation eID,count uj6'T Sl  
                count=count-1 ?zBu` 7j  
            End If ]i#p2?BR  
            count=count+1 YHEn{z7  
        Wend U|3!ixk>>w  
    ~bZ =]i  
        'Set new z-shift j4owo#OB-  
        op.Type = "ShiftZ" I5M\PK/  
        op.val1 = tlens ZHK>0>;  
        op.parent = parID ]$"eGHX  
        AddOperation eID, op 5VV}wR  
        Print "Set lens thickness = " & tlens 0:v !'  
    Oin9lg-jR  
        '************************************************************************* =3X>Ur  
        'Lens index of refraction :$"{-n  
        '************************************************************************* >IIq_6Z#  
        eID = FindMaterial( "Lens" ) JjS+'A$A5  
        GetModelMaterial eID, mat mU-2s%X<.^  
    +b-ON@9]J`  
        mat.Nd = nlens w~u{"E$  
        SetModelMaterial eID, mat R->x_9y-R  
        Print "Set lens index of refraction = " & nlens a|FkU%sjzZ  
    Qx4)'n  
        '************************************************************************* ,m<YS MKX  
        'Pupil diameter \!\:p/f  
        '************************************************************************* J|BElBY  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) FC1rwXL(  
    2{h2]F  
        'Adjust pupil diameter (trimming volume inner hole) 6o^>q&e}%  
    yq-~5ui  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" W p)!G  
    R0=f`;  
        ' Adjust pupil location to just in front of the lens i%9vZ  
        parID = FindFullName( "Geometry.Arizona Eye" ) tLOGj?/r  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) eaFkDl  
        count = 0 kD#n/R Bgf  
        While GetOperationCount(eID)>count  Lw\u{E@  
            GetOperation eID, count, op |<c9ZS+  
            If op.Type="ShiftZ" Then 0ZjT.Ep  
                DeleteOperation eID,count h*VDd3[#  
                count=count-1 &|XgWZS5  
            End If %<>:$4U@]  
            count=count+1 I#MPJ@*WT  
        Wend >.qFhO\1so  
        op.Type = "ShiftZ" 5b:1+5iF-  
        op.val1 = taq-0.01 ZhY{,sy?QO  
        op.parent = parID zls^JTE  
        AddOperation eID, op pX_  
    4;L|Ua  
        Print "Set pupil diameter = " & pupilDiam Yd3lL:M  
    Bb=r?;zjO  
        'Update AZ Eye subassembly Description MUl`0H"tR  
        eID = FindFullName( "Geometry.Arizona Eye" ) ''9]`B,:a0  
        GetEntity eID, entity 0HWSdf|w  
        entity.Description = "Accommodation = " & A & "D" k)3N0]q6  
        SetEntity eID, entity R%3yxnM*  
    ~3 bV~H#~m  
        Update >3/ mV<g f  
        Print "DONE!" b*Qd9  
         |6Y:W$7k  
    End Sub C?|sQcCE  
    eA1g}ipm  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: ,&,%B|gT]  
    KRxJ2  
    Accommodation = 4 Diopters e&x)g;bn  
    Pupil Diameter = 4 mm wxHd^b  
    Set aqueous humor thickness = 2.81 #+o$Tg  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 c $1u  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 Q qF<HCO  
    Set lens thickness = 3.927 4vL\t uoz  
    Set lens index of refraction = 1.42672 _zDS-e@  
    Set pupil diameter = 4 j(y<oxh  
    DONE! 7D<Aa?cv_l  
    r#WqXh_uk  
    (文章来源:讯技光电)
     
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