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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 b$ 8R  
    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。 ] NW_oRH  
    b ~]v'|5[  
    模型 * _usVg  
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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。 qOQ8a:]?  
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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. gCRPaF6  
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    光源 ^HuB40  
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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。 plr3&T~,&S  
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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。 HHgv, bC!  
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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。 I;?PDhDb  
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    图2. 字母F光源的设定方法光 /c!^(5K fT  
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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 Bz%wV-  
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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。 ApggTzh@  
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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。 @a=jSB#B  
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    图5. 视网膜重点采样规格设定
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    脚本 {od@S l  
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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:  -V"W  
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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。 >xF&>SDC  
    余下的脚本计算与屈光度有关的所有参数。 nHZhP4W  
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    分析 ![I|hB  
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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。 v<(+ l)Ln  
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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 BT$Oh4y4  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. 3'0Jn6(  
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    Dim entity As T_ENTITY zqQ[uO]m?  
    Dim op As T_OPERATION i]@k'2N  
    Dim mat As T_MODELMATERIAL JnqP`kYbTE  
    Dim A As Double :>H{?  
    Dim pupilDiam As Double COBjJ3  
    Dim eID As Long !HhF*Rlr  
    Dim parID As Long eQ6wEeB9  
    Dim count As Integer ) jM-5}"  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double }1CvbB%,A  
    Dim tlens As Double, nlens As Double c@nh>G:y{&  
    Dim curv As Double, conic As Double J!3;\  
    Dim ok As Long d{B0a1P  
    +^AAik<yl  
    Sub Main Z>X]'q03  
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        '用户输入对话框 V|awbff:  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 ,C_MB1u  
            TextBox 220,21,40,21,.TextBox1 'default: 0 U.I 7p  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 d@b2XCh<K  
            OKButton 40,91,90,21 Are0Nj&?  
            CancelButton 190,91,90,21 &%(SkL_]  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 XgeUS;qtta  
            TextBox 220,49,40,21,.TextBox2 'default: 4 hKnV=Ha(  
        End Dialog 7*WO9R/  
        Dim dlg As UserDialog tuY= )?  
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        ok = Dialog (dlg) 1 >2 /1>  
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        If ok=0 Then    'cancel button was pressed `JGW8 _  
            Print "Execution cancelled." vkG%w;  
            End ^4Se=Hr z2  
        End If $DnR[V}rR!  
    $?[pcgv  
        'Assign accommodation and pupil diameter & use defaults if field left empty nhZ/^`Y<  
        If dlg.TextBox1 = "" Then 8A-*MU`+  
            A = 0           'Default accommodation VuK>lY &  
        Else WqCj;Tj|  
            A = CDbl(dlg.TextBox1) _oefp*iWS  
        End If WZTv  
    G_ ~qk/7mF  
        If dlg.TextBox2 = "" Then lKqFuLHwF  
            pupilDiam = 4   'Default pupil diameter YZ<5-C  
        Else n 1^h;2gz  
            pupilDiam = CDbl(dlg.TextBox2) G"Ey%Q2K  
        End If m<*+^JN  
    2jkma :$'  
        Print " " q$ j  
        Print "Accommodation = " & A & " Diopters" N\?__WlBK7  
        Print "Pupil Diameter = " & pupilDiam & " mm" OKu~Nb*  
    k!6m'}v  
        ' Calculate new parameters with accommodation i`iR7UmHeR  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness [I<J6=  
    W58%Zz4a  
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens ?T|0"|\"'  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens Aq>?G+  
    8&qtF.i-6  
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens X V)ctF4  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens z  61Fq  
    6J$I8b#/  
        tlens = 3.767 + 0.04*A                  'Lens thickness QXy= |  
    Y%r>=Jvu6  
        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction ) <w`:wD  
    wqzpFPk(  
        'Adjust parameters to account for accommodation Q;nC #cg  
    hC]:+.Q+  
        '************************************************************************* )N\B C  
        'Aqueous thickness (Position of Lens) D& &71X '  
        '************************************************************************* (FGH t/!  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) S5UQ   
        GetCustomElement eID, entity +u&3pK>f  
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        parID = FindFullName( "Geometry.Arizona Eye" ) C!6D /S  
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        ' Delete any shift(s) in z u6MU @?  
        count = 0 #v6<9>%  
        While GetOperationCount(eID)>count 6 Pdao{P  
            GetOperation eID, count, op :$P1ps3B  
            If op.Type="ShiftZ" Then gp'k(rGH  
                DeleteOperation eID,count "\5 T  6  
                count=count-1 z('t#J!b  
            End If 3Jj&wHp]  
            count=count+1 T;S6<J  
        Wend <P]%{msGH  
    sx'eu;S  
        'Set new shift in ~K(mt0T )  
        op.Type = "ShiftZ" % ;a B#:p6  
        op.val1 = taq ?<Mx*l  
        op.parent = parID `9\^.g)  
        AddOperation eID, op mSk";UCn  
        Print "Set aqueous humor thickness = " & taq-0.55 g{kjd2  
    ]U }B~Y  
        '************************************************************************* Jq8v69fyQ  
        'Radius and conic constant of anterior lens wk1/&  
        '************************************************************************* 79h'sp6;  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) PO:sF]5  
        GetConic eID, entity, curv, conic 6X4r2Vq  
    # 00?]6`z  
        SetConic eID, entity, 1/Rant, CCant nmyDGuzk  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant ,,7hVw  
    nXjSf  
        '************************************************************************* kD)]\   
        'Radius and conic constant of posterior lens \}YAQ'T  
        '************************************************************************* |M18/{  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) +NeoGnj  
        GetConic eID, entity, curv, conic #GUD^#Jh  
    7E5 =Qx  
        SetConic eID, entity, 1/Rpost, CCpost tOo\s&j  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost }2Y`Lr  
    6X!jNh$oF  
        '************************************************************************* NR%_&%qQA  
        'Lens thickness (Position of posterior lens surface) 80Q%c(i  
        '************************************************************************* ^a1k"|E?f  
    ]a[2QQ+g  
        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) 53^3. .E|  
    5FsfJpw  
        ' Delete any z-shift(s) >Qg-dJt[  
        count = 0 -av=5hm  
        While GetOperationCount(eID)>count *V[I&dKq  
            GetOperation eID, count, op O.-A)S@  
            If op.Type="ShiftZ" Then  J2Qt!-  
                DeleteOperation eID,count I<Mb /!TQ  
                count=count-1 lc]cs D  
            End If S5YEz XG  
            count=count+1 ,v?FR }v  
        Wend ;*=7>"o'`  
    t5P8?q\  
        'Set new z-shift b7gN|Hw5 H  
        op.Type = "ShiftZ" 4i<GqG  
        op.val1 = tlens $ P2*qpqy  
        op.parent = parID bHXoZix  
        AddOperation eID, op 7Rc>LI* '  
        Print "Set lens thickness = " & tlens b+L!p.:  
    u_FN'p=.  
        '************************************************************************* .*z$vl  
        'Lens index of refraction sN) xNz  
        '************************************************************************* RS@G.|  
        eID = FindMaterial( "Lens" ) SA%)xGRW  
        GetModelMaterial eID, mat BaMF5f+  
    [<d_#(]h'  
        mat.Nd = nlens ~~Rq$'q}  
        SetModelMaterial eID, mat aEun *V^,  
        Print "Set lens index of refraction = " & nlens YtXd>@7  
    tGSX TF}G  
        '************************************************************************* 9Sl5jn  
        'Pupil diameter !\'HKk~V  
        '************************************************************************* /)?qD  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) y k\/Cf  
    ,jl4W+s  
        'Adjust pupil diameter (trimming volume inner hole) >\3N#S"PF  
    43~v1pf{!  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" ]3Jb$Q@  
    IIF <Zkpb  
        ' Adjust pupil location to just in front of the lens 1 qp"D_h  
        parID = FindFullName( "Geometry.Arizona Eye" ) 5X uQQ!`  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) kxmsrQ>av  
        count = 0 %MEWw  
        While GetOperationCount(eID)>count |;I"Oc.w^R  
            GetOperation eID, count, op "{c@}~  
            If op.Type="ShiftZ" Then 7 h>,  
                DeleteOperation eID,count itcM-?  
                count=count-1 %zhSSB =BJ  
            End If X?(R!=a  
            count=count+1 z f >(Y7M  
        Wend VJ1rU mO~  
        op.Type = "ShiftZ" (nYGN$qC9  
        op.val1 = taq-0.01  @l&{ j  
        op.parent = parID H;[?8h(  
        AddOperation eID, op OM`Ws5W}f  
    NceK>:: 56  
        Print "Set pupil diameter = " & pupilDiam E 5mYFVK  
    k7(lwEgNG  
        'Update AZ Eye subassembly Description Ds{DVdqA$c  
        eID = FindFullName( "Geometry.Arizona Eye" ) 2(P<TP._E  
        GetEntity eID, entity ?=HoU3  
        entity.Description = "Accommodation = " & A & "D" _{GD\Ai_W  
        SetEntity eID, entity WHu[A/##']  
    =GiN~$d  
        Update L[U?{  
        Print "DONE!" B3I0H6O  
         $yUPua/-  
    End Sub nj-LG!"a  
    =NWzsRl,  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: L(C0236r  
    $J0o%9K   
    Accommodation = 4 Diopters gf^y3F[\  
    Pupil Diameter = 4 mm  "Id 1H  
    Set aqueous humor thickness = 2.81 4E$d"D5]>p  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 A-h[vP!v|  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 +,)Iv_Xl$  
    Set lens thickness = 3.927 7Jpq7;  
    Set lens index of refraction = 1.42672 " BU4\QF-  
    Set pupil diameter = 4 Kp!A ay  
    DONE! R{6M(!x  
    v|@EuN14<  
    (文章来源:讯技光电)
     
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