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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 [UquI "  
    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。 FpE83}@".w  
    Qp<?[C}'W  
    模型  M}}9  
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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。 epm  t  
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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. bvn?wK   
    .G1NY1\  
    光源 m^h"VH,   
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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。 B4R!V!Z*  
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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。 H|T:_*5  
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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。 oo3ZYA  
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    图2. 字母F光源的设定方法光 h|dVVCsN  
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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 {gl-tRC3  
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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。 RX>kOp29  
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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。 NaG1j+LN  
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    图5. 视网膜重点采样规格设定
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    脚本 wsP3hE' ]  
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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: k$}XZ,Q  
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    图6. 用户对话框的创建与编辑
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    图7. 用户对话框编辑器
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    如果“OK”按钮按下,将会核对对话框下面的代码行,如果点击取消则脚本终止。然后输入的参数赋予变量,如果此处是保留为空白,则使用默认值。因此,如果没有值输入并点击“OK”按钮,则脚本是以屈光度为0,光瞳直径为4mm来运行的。 Mc~(S$FU$  
    余下的脚本计算与屈光度有关的所有参数。 +KDB^{  
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    分析 FM0)/6I'x  
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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。 xv's52x  
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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 ;Y j_@=   
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. g$?B!!qT  
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    Dim entity As T_ENTITY Dq*>+1eW2  
    Dim op As T_OPERATION +=|Q'V  
    Dim mat As T_MODELMATERIAL /Y:_qsO1  
    Dim A As Double sJ7r9 O`x  
    Dim pupilDiam As Double 9/{+,RpC  
    Dim eID As Long er,R}v  
    Dim parID As Long Sq UoXNw  
    Dim count As Integer 4cr >sz  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double {]] nQ  
    Dim tlens As Double, nlens As Double engql;  
    Dim curv As Double, conic As Double z++*,2F  
    Dim ok As Long %@G<B  
    %K;,qS'N_  
    Sub Main %xyt4}-)m  
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        '用户输入对话框 ToCB*GlL  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 st|$Fu  
            TextBox 220,21,40,21,.TextBox1 'default: 0 IJs*zzR  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 g/mVd;#o  
            OKButton 40,91,90,21 J Q%e'  
            CancelButton 190,91,90,21 WA8Qt\Q  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 7cr+a4T33  
            TextBox 220,49,40,21,.TextBox2 'default: 4 lK9us  
        End Dialog ]b.@i&M  
        Dim dlg As UserDialog gr4Hh/V  
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        ok = Dialog (dlg) O=MO M  
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        If ok=0 Then    'cancel button was pressed )mB+#T<k-  
            Print "Execution cancelled." %TPnC'2  
            End |5Mhrb4.  
        End If %QVX1\>]  
    /.aZXC$]  
        'Assign accommodation and pupil diameter & use defaults if field left empty O!hg@[\B+  
        If dlg.TextBox1 = "" Then ?Re@`f+*  
            A = 0           'Default accommodation 1G=1FGvP  
        Else d\3L.5]X  
            A = CDbl(dlg.TextBox1) Aw;~b&.U{_  
        End If  ;B^G<  
    dum! AO  
        If dlg.TextBox2 = "" Then Jq l#z/z  
            pupilDiam = 4   'Default pupil diameter s59v* /  
        Else 0J7[n*~  
            pupilDiam = CDbl(dlg.TextBox2) 1 [[` ^v  
        End If !Jh-v  
    pOyM/L   
        Print " " DCPK1ql  
        Print "Accommodation = " & A & " Diopters" bguhx3s  
        Print "Pupil Diameter = " & pupilDiam & " mm" DFwkd/3"  
    sI@m"A  
        ' Calculate new parameters with accommodation ..Zuy|?w  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness \"V7O'S)&  
    !\}Dxt  
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens mSY;hJi  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens w_ kHy_)  
    UkG|5P`  
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens m_W\jz??k  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens ]-bA{@tP.  
    Zuo7MR  
        tlens = 3.767 + 0.04*A                  'Lens thickness R^1sbmwk  
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        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction zg.'  
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        'Adjust parameters to account for accommodation W% YJ.%I  
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        '************************************************************************* U8c0N<j  
        'Aqueous thickness (Position of Lens) 2Y(P hw2%  
        '************************************************************************* e=o<yf9>Q  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) MQ$[jOAqP  
        GetCustomElement eID, entity eZ[CqUJ&  
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        parID = FindFullName( "Geometry.Arizona Eye" ) g:dw%h  
    6^H64jM  
        ' Delete any shift(s) in z Pg{Dy>&2`I  
        count = 0 mEa\0oPGB  
        While GetOperationCount(eID)>count @g }r*U?  
            GetOperation eID, count, op YjdCCju  
            If op.Type="ShiftZ" Then fZ`b~ZBwIj  
                DeleteOperation eID,count <K=:_  
                count=count-1 ZK[4n5}  
            End If 'VS!<  
            count=count+1 -;a}'1HOE  
        Wend N$aLCX  
    beRpA;  
        'Set new shift in .5p"o-:D  
        op.Type = "ShiftZ" W2O =dG`  
        op.val1 = taq ^o,P>u!9  
        op.parent = parID Y#{ L}  
        AddOperation eID, op 4'Z=T\:  
        Print "Set aqueous humor thickness = " & taq-0.55  "9!ln  
    Wrf('  
        '************************************************************************* %`F6>J  
        'Radius and conic constant of anterior lens U; JZN  
        '************************************************************************* b/:9^&z  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) #~^#%G  
        GetConic eID, entity, curv, conic VU J*\Sg  
    a}|B[b  
        SetConic eID, entity, 1/Rant, CCant SQDllG84E  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant Jt\?,~,  
    Z*tB=  
        '************************************************************************* e%uPZ >'q  
        'Radius and conic constant of posterior lens |a%&7-;   
        '************************************************************************* (TM1(<j  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) ;+'x_'a  
        GetConic eID, entity, curv, conic gtHWd;1&f  
    dT4?8:  
        SetConic eID, entity, 1/Rpost, CCpost OCnQSkj  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost kO{A]LnAH  
    $ jWe!]ASU  
        '************************************************************************* wb~#=6Y  
        'Lens thickness (Position of posterior lens surface) L9M0vkgri  
        '************************************************************************* yDg`9q.ckm  
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        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) @;_xFL;{g  
    5MfbO3  
        ' Delete any z-shift(s) qPDe;$J)  
        count = 0 9_)*b  
        While GetOperationCount(eID)>count cK%Sty'8+  
            GetOperation eID, count, op bW\OKI1  
            If op.Type="ShiftZ" Then 87l(a,#J  
                DeleteOperation eID,count -f@~{rK.L  
                count=count-1 Jte:U*2  
            End If ZX[ @P?A+-  
            count=count+1 `qnSq(tNq  
        Wend FBJw (.Jr  
    N9QHX  
        'Set new z-shift o *)>aw  
        op.Type = "ShiftZ" 1 41@$mMzE  
        op.val1 = tlens P&@ 2DI3m  
        op.parent = parID 1vk& ;  
        AddOperation eID, op OPOL-2<wiy  
        Print "Set lens thickness = " & tlens MKzIY:u g  
    21Mr2-#z  
        '************************************************************************* m<qPj"g~L  
        'Lens index of refraction n`gW&5,,z  
        '************************************************************************* j ;}!Yn  
        eID = FindMaterial( "Lens" ) 0aj4.H*%  
        GetModelMaterial eID, mat *;@V5[^3I?  
     -i*{8t  
        mat.Nd = nlens l&#&}3M  
        SetModelMaterial eID, mat HjCcfOej  
        Print "Set lens index of refraction = " & nlens  #~QkS_  
    9>?3FMKdY  
        '************************************************************************* ]yI~S(  
        'Pupil diameter M9so3L<N0  
        '************************************************************************* F7[ 55RcP  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) 'b(V8x  
    Iow45R~]  
        'Adjust pupil diameter (trimming volume inner hole) 1~rZka[s  
    /`$9H|  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" -=5]B ;  
    .rpKSf.  
        ' Adjust pupil location to just in front of the lens BN\Y N  
        parID = FindFullName( "Geometry.Arizona Eye" ) K@d,8[  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" )  {}x{OP  
        count = 0 (Klvctoy  
        While GetOperationCount(eID)>count d0ZbusHHb  
            GetOperation eID, count, op S 2vjjS  
            If op.Type="ShiftZ" Then bz$)@gLc  
                DeleteOperation eID,count Y6<"_  
                count=count-1 l@C39VP  
            End If G_OLUuK?C  
            count=count+1 vhsHyb  
        Wend !<'0 GOl  
        op.Type = "ShiftZ" !| ObNS  
        op.val1 = taq-0.01 -hv<8bC~4  
        op.parent = parID Ib V 7}  
        AddOperation eID, op '1rHvz`B/"  
    W<']Q_su  
        Print "Set pupil diameter = " & pupilDiam y?Vsp<  
    P:Nj;Cxh  
        'Update AZ Eye subassembly Description U42B( ow  
        eID = FindFullName( "Geometry.Arizona Eye" ) %#gHa  
        GetEntity eID, entity En&`m  
        entity.Description = "Accommodation = " & A & "D" \M(#FS  
        SetEntity eID, entity *Y"j 0Yob  
    #\DKU@|h  
        Update .MUoNk!  
        Print "DONE!" a[).'$S}'  
         %N.qu_,IZ  
    End Sub -%I 0Q  
    tZ4Zj`x|^  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: #@qd.,]2  
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    Accommodation = 4 Diopters *21foBfqh  
    Pupil Diameter = 4 mm 0xZX%2E  
    Set aqueous humor thickness = 2.81 22`N(_  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 &n 1 \^:  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 uIeD.I'@{5  
    Set lens thickness = 3.927 L"Vi:zdp  
    Set lens index of refraction = 1.42672 fwWE`BB  
    Set pupil diameter = 4 iRwlK5(&  
    DONE! e3YdHp  
    6B pm+}  
    (文章来源:讯技光电)
     
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