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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 I4UsDs*BD  
    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。 u%1JdEWZd  
    =eDC{/K  
    模型 Ic&YiATj  
    U%#Vz-r  
    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。 -y3[\zNe  
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    Table 1. AZ眼睛模型的定义
    jJ2{g> P0P  
    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. Qn-nO_JL  
    j!;E>`g  
    光源 Kg /,  
    $`vXI%|.  
    多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 }&s |~  
    KZ65# UVX  
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    图1. 光源和提示信息使用
    :8N by$#V  
    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。 [{& OcEf  
    ajM\\a?  
    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。 9j-;-`$S  
    YbZ?["S&  
    图2. 字母F光源的设定方法光 zc,X5R1  
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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 LRS,bl3}/  
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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。 )S#?'gt*  
    )`gxaT>&l  
    ajkpU.6E:  
    图4. 视网膜朗伯散射设定
    2sEG# /Y=  
    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|[A7<|  
    BPOT!-  
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    图5. 视网膜重点采样规格设定
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    脚本 {`> pigo  
    p-!/p#  
    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: ?a?4;Y!  
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    图6. 用户对话框的创建与编辑
    zpNt[F?~1  
    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。 N?A}WW#  
    余下的脚本计算与屈光度有关的所有参数。 W55kR.X6M  
    PBL=P+  
    分析 ~~p)_  
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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。 G#E8xA"{/  
    !SLfAFcS  
    图7. 字母F在视网膜上颜色分析
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    脚本代码 tpgD{BY^wJ  
    <p` F/p-  
    Option Explicit     'Remove this to enable non-dimensioned variables to be used. U:PtRSdn!b  
    <<@F{B7h  
    Dim entity As T_ENTITY o?#-Tkb  
    Dim op As T_OPERATION V-63   
    Dim mat As T_MODELMATERIAL $}0\sj%  
    Dim A As Double [8acan+ 2l  
    Dim pupilDiam As Double ]\ZmK0q<:  
    Dim eID As Long ^ZBTd5t#  
    Dim parID As Long a'>n'Y~E  
    Dim count As Integer (8NE'd8  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double 3_{rXtT)'  
    Dim tlens As Double, nlens As Double H5jk#^FD  
    Dim curv As Double, conic As Double j:^gmZ;J  
    Dim ok As Long l @E {K|  
    c;#gvE  
    Sub Main 6mxzE3?G  
    (H]NL   
        '用户输入对话框 CRNt5T>qH  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 T*(mi{[T  
            TextBox 220,21,40,21,.TextBox1 'default: 0 >LVGNicQ  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 diKl}V#u  
            OKButton 40,91,90,21 /f=31<+MtF  
            CancelButton 190,91,90,21 . lSoC`HE  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 nH+wU;M  
            TextBox 220,49,40,21,.TextBox2 'default: 4 I&% Z*H  
        End Dialog g-/ }*m l  
        Dim dlg As UserDialog _.m|Ml,`{  
    @)ls+}=Y  
        ok = Dialog (dlg) og4mLoLA  
    fzN?X=  
        If ok=0 Then    'cancel button was pressed !bn=b>+  
            Print "Execution cancelled." sP>-k7K.  
            End <(45(6fQ  
        End If +z~bH!$2  
    Vw&# Lo  
        'Assign accommodation and pupil diameter & use defaults if field left empty .W\x{h  
        If dlg.TextBox1 = "" Then p$Floubh]  
            A = 0           'Default accommodation I 6L3M\+-  
        Else e=[@HVr   
            A = CDbl(dlg.TextBox1) ^--8 cLB n  
        End If ;[:IC^9fv  
    6R#igLm  
        If dlg.TextBox2 = "" Then !R[~Z7b6  
            pupilDiam = 4   'Default pupil diameter Vf$$e)  
        Else qtz~Y~h|>  
            pupilDiam = CDbl(dlg.TextBox2) srS)"Jt  
        End If AO(z l*4  
    b4(,ls  
        Print " " }E&:  
        Print "Accommodation = " & A & " Diopters" bUuQ"!>ppu  
        Print "Pupil Diameter = " & pupilDiam & " mm" NjO_Y t  
    8RcLs1n/  
        ' Calculate new parameters with accommodation @E"lN  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness j.\0p-,  
    CFu^i|7o  
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens Wo5%@C#M  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens \9R=fA18  
    _C,9c7K4  
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens 1c*;Lr.K  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens 4)p ID`  
    R}D[ z7  
        tlens = 3.767 + 0.04*A                  'Lens thickness ]\/"-Y#4Q  
    $gCN[%+j  
        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction cG1iO:  
    Tsdgg?#  
        'Adjust parameters to account for accommodation {f;DhB-jj  
    RW<4",  
        '************************************************************************* UMK9[Iy$<M  
        'Aqueous thickness (Position of Lens) DbYnd%k*4  
        '************************************************************************* bicbCC6kC  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) #@E:|^$1y  
        GetCustomElement eID, entity  I*n]8c  
    f @Vd'k<  
        parID = FindFullName( "Geometry.Arizona Eye" ) mA^3?y j  
    #9{2aRCJ  
        ' Delete any shift(s) in z 4hkyq>c}  
        count = 0 .S]*A b  
        While GetOperationCount(eID)>count hd`jf97*  
            GetOperation eID, count, op j rX`_Y  
            If op.Type="ShiftZ" Then #JN4K>_4  
                DeleteOperation eID,count /bLL!nD=^  
                count=count-1 0#~k)>(7lR  
            End If f6{.Uq%SGp  
            count=count+1 7W>(T8K X\  
        Wend Uz%ynH  
    A.~wgJDO  
        'Set new shift in }[(v(1j='~  
        op.Type = "ShiftZ"  6NSSuK3  
        op.val1 = taq 8EBd`kiq  
        op.parent = parID wn\ R|'Rdz  
        AddOperation eID, op sj6LrE=1  
        Print "Set aqueous humor thickness = " & taq-0.55 s}bLA>~Ta  
    01NP  
        '************************************************************************* ;jBS:k?  
        'Radius and conic constant of anterior lens  SWyJ`  
        '************************************************************************* uavyms^  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) bgkBgugZhX  
        GetConic eID, entity, curv, conic N1" bH~  
    t$?#@8Yk  
        SetConic eID, entity, 1/Rant, CCant }'Ph^ %ox  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant o'8%5 M@  
    7G0;_f{  
        '************************************************************************* zjzEmX  
        'Radius and conic constant of posterior lens Fl}!3k>c  
        '************************************************************************* G2b"R{i/,  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) ja(ZJ[<`  
        GetConic eID, entity, curv, conic j]aIJbi  
    {Z178sik  
        SetConic eID, entity, 1/Rpost, CCpost b~(S;1NS'  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost IYa(B+nB)  
    _,igN>  
        '************************************************************************* fUZCP*7>  
        'Lens thickness (Position of posterior lens surface) MPF({Pnx7  
        '************************************************************************* +fq\K]  
    yw1Xxwc  
        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) ,fo7. h4{  
    OF:0jOW  
        ' Delete any z-shift(s) v9(N}hoP  
        count = 0 bfkFk  
        While GetOperationCount(eID)>count -OnKvpeI  
            GetOperation eID, count, op ?~cO\(TY["  
            If op.Type="ShiftZ" Then `'gcF });  
                DeleteOperation eID,count q Oa*JA`  
                count=count-1 w{N8Y ~O  
            End If 9fO E .  
            count=count+1 L=P8;Gj)  
        Wend ^==Tv+T9U  
    %Z8pPH~T  
        'Set new z-shift ?v'CuWS  
        op.Type = "ShiftZ" C IRMAX  
        op.val1 = tlens IoV"t,  
        op.parent = parID 5glEV`.je  
        AddOperation eID, op e)3Mg^  
        Print "Set lens thickness = " & tlens G;U SVF-'K  
    dP#7ev]'  
        '************************************************************************* ZT`" {#L  
        'Lens index of refraction p0}Yo8?OW  
        '************************************************************************* ,'sDauFn  
        eID = FindMaterial( "Lens" ) MYR\W*B'b  
        GetModelMaterial eID, mat h]IoH0/  
    kV3LFPf>0  
        mat.Nd = nlens A;f)`i0l,  
        SetModelMaterial eID, mat S&;)F|-q  
        Print "Set lens index of refraction = " & nlens $#wi2Ve=6b  
    = \K/ulZo  
        '************************************************************************* a FWTm,)  
        'Pupil diameter ::3[H$  
        '************************************************************************* 4`7~~:W!M5  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) ETR7% 0$r  
    hqwsgJ  
        'Adjust pupil diameter (trimming volume inner hole) &v9"lR=_k  
    0rif,{"  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" ^}:0\;|N  
    YF%]%^n  
        ' Adjust pupil location to just in front of the lens {xP-p"?p  
        parID = FindFullName( "Geometry.Arizona Eye" ) jP<6Q|5F  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) E;"VI2F  
        count = 0 u!fZ>kS  
        While GetOperationCount(eID)>count W&m3"~BJ  
            GetOperation eID, count, op mXsSOAD<  
            If op.Type="ShiftZ" Then x_l8&RIB*  
                DeleteOperation eID,count w[G-=>;  
                count=count-1 #kJ8 qN  
            End If R1.Yx?  
            count=count+1 ]n$ v ^  
        Wend rERtOgi  
        op.Type = "ShiftZ" Lf{pTxKr  
        op.val1 = taq-0.01 CM `Q((  
        op.parent = parID kpk ^Uw%f  
        AddOperation eID, op r8A'8g4cM  
    R80|q#h,]  
        Print "Set pupil diameter = " & pupilDiam TBHd)BhI.  
    DnN+W  
        'Update AZ Eye subassembly Description ol_&epG;ST  
        eID = FindFullName( "Geometry.Arizona Eye" ) K5(T7S  
        GetEntity eID, entity -7EwZRS@9  
        entity.Description = "Accommodation = " & A & "D" 472'P  
        SetEntity eID, entity P)ne^_   
    z3w;W{2Q;V  
        Update [y<s]C6E  
        Print "DONE!" ]0{,P !  
         Z(J 1A x  
    End Sub Exat_ L'?  
    \`8F.oZ^)  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: ]!@!qp@  
    gUp9yV  
    Accommodation = 4 Diopters ubsx NCqD  
    Pupil Diameter = 4 mm XU}" h&>  
    Set aqueous humor thickness = 2.81 UG6\OgkL+  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 #O'g*]j  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 O /h1ew  
    Set lens thickness = 3.927 BpF}H^V-  
    Set lens index of refraction = 1.42672 EE qlsH  
    Set pupil diameter = 4 9 Lqz:4}  
    DONE! [c99m:*+  
    g~OG~g@  
    (文章来源:讯技光电)
     
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