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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 ZtDpCl_  
    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。 =_Rd0,  
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    模型 <*P1Sd.  
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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。 xmDwoLU  
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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. 65v'/m!ys  
    #A!0KN;GC2  
    光源 G)Y!aX  
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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。 iKwVYL  
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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。 m\yO/9{h1  
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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。 e]QkZg2?Yn  
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    图2. 字母F光源的设定方法光 Dp8(L ]6  
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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 PLD!BD  
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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。 N@}U;x}  
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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。 ` Oi@7 /oT  
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    图5. 视网膜重点采样规格设定
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    脚本 yAOC<d9 E  
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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: ?~!h N,h  
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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。 x {rt\OT  
    余下的脚本计算与屈光度有关的所有参数。 04s N 4C  
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    分析 MmX42;Pw  
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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。 #r1x0s40D  
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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 k@w&$M{tPF  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. z, OMR`W  
    ZrTq)BZ  
    Dim entity As T_ENTITY "783F:mPh  
    Dim op As T_OPERATION B7#;tCf  
    Dim mat As T_MODELMATERIAL Uc4r  
    Dim A As Double ! M bRI  
    Dim pupilDiam As Double ' |4XyU=  
    Dim eID As Long '@$?A>.cj  
    Dim parID As Long F?UL0Q|uv  
    Dim count As Integer oR+Fn}mG  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double p'H5yg3h  
    Dim tlens As Double, nlens As Double 7l?=$q>k"  
    Dim curv As Double, conic As Double ?}W:DGudZ  
    Dim ok As Long w(vf>L6(  
    (k[<>$hL*  
    Sub Main |Oo WGVc  
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        '用户输入对话框 8'zwy d3  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 @FQ@* XD  
            TextBox 220,21,40,21,.TextBox1 'default: 0 9U+^8,5  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 2-$R@ SVy  
            OKButton 40,91,90,21 ]|-y[iu  
            CancelButton 190,91,90,21 ^0r @",  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 Cnn,$R=/s  
            TextBox 220,49,40,21,.TextBox2 'default: 4 9Vp$A$7M  
        End Dialog "DUL} "5T  
        Dim dlg As UserDialog ddw!FH2W (  
    Q[}mH: w  
        ok = Dialog (dlg) +'[iyHBJ  
    *bR _ C"-  
        If ok=0 Then    'cancel button was pressed a1?Y7(alPU  
            Print "Execution cancelled." jildiT[s  
            End b7\nCRY  
        End If Sna7r~ j  
    d~.#KS  
        'Assign accommodation and pupil diameter & use defaults if field left empty poM VB{U  
        If dlg.TextBox1 = "" Then nF7Ozxm#  
            A = 0           'Default accommodation 5^%FEZ&Sp  
        Else ^D!UF(H  
            A = CDbl(dlg.TextBox1) ^fRA$t  
        End If r1,RloyZS  
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        If dlg.TextBox2 = "" Then {~Phc 2z  
            pupilDiam = 4   'Default pupil diameter J H6\;G6  
        Else $[IuEdc/  
            pupilDiam = CDbl(dlg.TextBox2) IuRKj8J)o  
        End If e\\ I,  
    dD#A.C,Rz  
        Print " " w@hm>6j  
        Print "Accommodation = " & A & " Diopters"  M*%iMz  
        Print "Pupil Diameter = " & pupilDiam & " mm" qF>}"m  
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        ' Calculate new parameters with accommodation 9HWtdJ+^C=  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness %h3CQk  
    hMi`n6m  
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens =T9QmEBm  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens YrA#NTB_o  
    y+@7k3"  
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens iQ:]1H s  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens ~Q5L)}8N  
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        tlens = 3.767 + 0.04*A                  'Lens thickness `NrxoU=  
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        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction CmM K\R.  
    )~rN{W<s`H  
        'Adjust parameters to account for accommodation k|1/gd5  
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        '************************************************************************* gaVWfG  
        'Aqueous thickness (Position of Lens) 9=Y-w s  
        '************************************************************************* .#P'NF(5#  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) {73Z$w1%  
        GetCustomElement eID, entity @MTm8E6au  
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        parID = FindFullName( "Geometry.Arizona Eye" ) 6!O~:\`DJ  
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        ' Delete any shift(s) in z A@+pvC&  
        count = 0 ~`(#sjr6KR  
        While GetOperationCount(eID)>count "4|D"|wI)  
            GetOperation eID, count, op o|$l+TC  
            If op.Type="ShiftZ" Then j$siCsF  
                DeleteOperation eID,count *JUP~/Nr  
                count=count-1 < OCy  
            End If b v~"_)C  
            count=count+1 cd#@"&r  
        Wend vEk jd#  
    &+Xj%x.]  
        'Set new shift in ma,H<0R  
        op.Type = "ShiftZ" C8%q?.nH=  
        op.val1 = taq pq*W;6(-  
        op.parent = parID 0DV .1  
        AddOperation eID, op ;i@,TU  
        Print "Set aqueous humor thickness = " & taq-0.55 ilHZx2 k  
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        '************************************************************************* L W 8LD|@  
        'Radius and conic constant of anterior lens ~A(fn:d  
        '************************************************************************* l`4hWs\I  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) _f8Wa u# "  
        GetConic eID, entity, curv, conic p<: bP w  
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        SetConic eID, entity, 1/Rant, CCant '1_CMr  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant \ym3YwP4/:  
    := C-P7  
        '************************************************************************* K1Snag  
        'Radius and conic constant of posterior lens _?]bd-E  
        '************************************************************************* 8XIG<Nc  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) ;*Ldnj;B  
        GetConic eID, entity, curv, conic gi#bU  
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        SetConic eID, entity, 1/Rpost, CCpost ]yiwdQ  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost | U )  
    w3WBgH  
        '************************************************************************* 7j| ^ZuI+  
        'Lens thickness (Position of posterior lens surface) ZxF RE#y~2  
        '************************************************************************* t2uX+1F  
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        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) )!z<q}i5  
    V{+'(<SV  
        ' Delete any z-shift(s) V(3^ev/  
        count = 0 T)? : q  
        While GetOperationCount(eID)>count MH7 n@.t  
            GetOperation eID, count, op ""q76cx  
            If op.Type="ShiftZ" Then <[Oe.0SGu  
                DeleteOperation eID,count H]As2$[  
                count=count-1 !tJQ75Hwv  
            End If 1fUg  
            count=count+1 (?4m0Sn>#h  
        Wend 0}H7Xdkp  
    WR,MqM20  
        'Set new z-shift |C"(K-do  
        op.Type = "ShiftZ" (d mLEt  
        op.val1 = tlens &y_Ya%Z3*e  
        op.parent = parID "sh*,K5x|  
        AddOperation eID, op `Y]t*` e|  
        Print "Set lens thickness = " & tlens [}:;B$,  
    VZF;  
        '************************************************************************* )}w2'(!X8  
        'Lens index of refraction ?TTtGbvU  
        '************************************************************************* t$~CLq5ad  
        eID = FindMaterial( "Lens" ) m'HAt~  
        GetModelMaterial eID, mat _[F(8Q x"  
    %  ]G'u  
        mat.Nd = nlens bji5X')~#  
        SetModelMaterial eID, mat [>--U)/  
        Print "Set lens index of refraction = " & nlens 69< <pm,m  
    FJ-X~^  
        '************************************************************************* <OgwA$abl%  
        'Pupil diameter Ql>bsr}  
        '************************************************************************* P! cfe@;<4  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) /vgEDw  
    b:B+x6M  
        'Adjust pupil diameter (trimming volume inner hole) 0MpZdJ  
    "xWrYq'"  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" R` g'WaDk  
    "{9^SPsp  
        ' Adjust pupil location to just in front of the lens _\&v A5-  
        parID = FindFullName( "Geometry.Arizona Eye" ) 2nra@  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) wCQ.?*7-9Q  
        count = 0  GY`mF1b  
        While GetOperationCount(eID)>count xQUskjv/  
            GetOperation eID, count, op 2P, %}Ms  
            If op.Type="ShiftZ" Then d)>b/0CZ  
                DeleteOperation eID,count u~c75Mk_v  
                count=count-1 kF]sy8u]  
            End If f?JP=j  
            count=count+1 mY= Q#nG  
        Wend 8yCt(ms  
        op.Type = "ShiftZ" _w}l,   
        op.val1 = taq-0.01 MD98N{+[|  
        op.parent = parID mP*Ct6628n  
        AddOperation eID, op  #nq$^H  
    Efp[K}Z^$  
        Print "Set pupil diameter = " & pupilDiam 9QP-~V{$  
    /6 y9 u}  
        'Update AZ Eye subassembly Description 6L<Y   
        eID = FindFullName( "Geometry.Arizona Eye" ) u_HCXpP!Q  
        GetEntity eID, entity ]A=yj@o$xN  
        entity.Description = "Accommodation = " & A & "D" w%1-_;.aU6  
        SetEntity eID, entity O\J{4EB@.  
    N?EeT}m_  
        Update d%Ls'[Y^_0  
        Print "DONE!" 3p1U,B}  
         G)IK5zCDd  
    End Sub b9;w3Ba  
    k3+LP7|*  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: HT:V;?"  
    -{XDQ{z<%  
    Accommodation = 4 Diopters ;RK;kdZ  
    Pupil Diameter = 4 mm i&TWIl8  
    Set aqueous humor thickness = 2.81 XvSng"f.  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 ?WP*At0  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 gb{8SG5ac  
    Set lens thickness = 3.927 lFtH;h,==v  
    Set lens index of refraction = 1.42672 G\z5Ue*  
    Set pupil diameter = 4 dOT7;@   
    DONE! 4 _P6P  
    <KX fh  
    (文章来源:讯技光电)
     
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