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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 +?zyFb]Km  
    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。 oJVpNE[3]  
    cpz}!D  
    模型 RX4O1Z0  
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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。 "tBdz V  
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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. G5egyP;  
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    光源 us\@n"  
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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。 3}= .7qm  
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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。 ]|<PV5SY3.  
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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。 1*S It5?4  
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    图2. 字母F光源的设定方法光 @4^5C-  
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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 p<?~~7V  
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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。 L7_(KCh  
    .FK[Y?ci#  
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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。 MB" uJUk  
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    图5. 视网膜重点采样规格设定
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    脚本 9"52b 9U  
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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: NoO>CjeFb  
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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。 >&TSz5Q  
    余下的脚本计算与屈光度有关的所有参数。 Y;6<AIx>  
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    分析 jWLZ!a3+  
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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。 (9*s:)zD-  
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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 q~p,A>K  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. !H{)L@f  
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    Dim entity As T_ENTITY >9a%"<(2#  
    Dim op As T_OPERATION N#@xo)-H  
    Dim mat As T_MODELMATERIAL MG>g?s'!  
    Dim A As Double leiED'  
    Dim pupilDiam As Double </t_<I0{  
    Dim eID As Long E$.|h;i]Q  
    Dim parID As Long FH)bE#4  
    Dim count As Integer kuu9'Sqc'b  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double 3:<+9X  
    Dim tlens As Double, nlens As Double kMKI=>s+  
    Dim curv As Double, conic As Double )wP0U{7?v  
    Dim ok As Long Odxq]HlbO  
    x,E#+ m  
    Sub Main :{h,0w'd  
    <Xm5re.  
        '用户输入对话框 9<kKno  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 k^Tu9}[W1  
            TextBox 220,21,40,21,.TextBox1 'default: 0 ?)<zrE5p  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 5IW^^<kiu  
            OKButton 40,91,90,21 _t6siB_u  
            CancelButton 190,91,90,21 ,a?)#X  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 |.=Ee+HZ  
            TextBox 220,49,40,21,.TextBox2 'default: 4 -?e~dLu  
        End Dialog >4ebvM 0|  
        Dim dlg As UserDialog *0{MAm  
    Z%Y=Lx  
        ok = Dialog (dlg) >ly= O  
    W0tBF&E"  
        If ok=0 Then    'cancel button was pressed Q}^ n  
            Print "Execution cancelled." [4 g5 {eX  
            End aBr%"&Z.MG  
        End If JnhHV(H  
    q\O'r[&V  
        'Assign accommodation and pupil diameter & use defaults if field left empty {5.,gb@6  
        If dlg.TextBox1 = "" Then j_&/^-;e  
            A = 0           'Default accommodation cmt3ceCb  
        Else 9V?MJZ@aG  
            A = CDbl(dlg.TextBox1) c1wgb8  
        End If L}nj#z4g  
    2c5>0f  
        If dlg.TextBox2 = "" Then 4I"QT(;  
            pupilDiam = 4   'Default pupil diameter cy)L%`(7  
        Else & ?/h5<  
            pupilDiam = CDbl(dlg.TextBox2) gwThhwR  
        End If 6TfL|W<  
    ~Az20RrK)  
        Print " " u~LisZ&tP  
        Print "Accommodation = " & A & " Diopters" EM vV  
        Print "Pupil Diameter = " & pupilDiam & " mm" A&$!s)8z  
    g]$>G0E`oD  
        ' Calculate new parameters with accommodation 8Qu7x[tK?  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness $7TYix8=  
    5ez"B]&T  
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens _ H$ Cm  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens ~#I1!y~`  
    U(W#H|  
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens @WhcY*R2  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens 7Yk6C5C  
    &lBfW$PZjk  
        tlens = 3.767 + 0.04*A                  'Lens thickness RK'3b/T  
    ;TmwIZ  
        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction +/\.%S/  
    'QeqWn  
        'Adjust parameters to account for accommodation IZJV6clM  
    3(^9K2.s}  
        '************************************************************************* kt[#@M!}  
        'Aqueous thickness (Position of Lens) F!pUfF,&  
        '************************************************************************* &^9f)xb  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) l3-Ksw U  
        GetCustomElement eID, entity 3WPMS/  
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        parID = FindFullName( "Geometry.Arizona Eye" ) X?>S24I"9  
    {nryAXK  
        ' Delete any shift(s) in z }y=7r!{@  
        count = 0 rRT9)wDa  
        While GetOperationCount(eID)>count S31 :}   
            GetOperation eID, count, op bn<&Xe  
            If op.Type="ShiftZ" Then )KXLL;]  
                DeleteOperation eID,count k B2+ Tr  
                count=count-1 B'yN &3  
            End If OMKEn!Wq  
            count=count+1 UY}lJHp0  
        Wend hJFQ/(  
    O(&EnNm[2  
        'Set new shift in qf)]!w U9  
        op.Type = "ShiftZ" g^B 6N F  
        op.val1 = taq 71K6] ~<  
        op.parent = parID $|(roC(  
        AddOperation eID, op .]r[0U  
        Print "Set aqueous humor thickness = " & taq-0.55 aMv  
    @Z3b^G[  
        '************************************************************************* Yo7ctwzdH;  
        'Radius and conic constant of anterior lens f$2lq4P{  
        '************************************************************************* ),M8W15  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) zc/S  
        GetConic eID, entity, curv, conic ^4s#nf:}  
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        SetConic eID, entity, 1/Rant, CCant 50_%Tl[  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant q#OLb"bTr  
    /^4)V8D_S  
        '************************************************************************* !o*oT}6n  
        'Radius and conic constant of posterior lens X+&@$v1  
        '************************************************************************* ld9 zOq  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) ShCAkaj_  
        GetConic eID, entity, curv, conic 5fVdtJk7  
    5n(p 1OM2q  
        SetConic eID, entity, 1/Rpost, CCpost r\Man'h$  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost m{b(^K9}  
    cG"jrQ  
        '************************************************************************* z2"2Xqy<U  
        'Lens thickness (Position of posterior lens surface) @Ki`g(],P  
        '************************************************************************* u;=("S{"0  
    7RdL/21K  
        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) bE0S) b)  
    VaX>tUW  
        ' Delete any z-shift(s) W9eR3q  
        count = 0 T( ;BEyc?  
        While GetOperationCount(eID)>count 4{fi=BA   
            GetOperation eID, count, op &=02.E@  
            If op.Type="ShiftZ" Then H2k>E}`  
                DeleteOperation eID,count Bb-x1{t  
                count=count-1 P6IhpB59  
            End If v[Ar{t&  
            count=count+1 N4HnW0  
        Wend {{2ZWK 6|  
    OsC1('4@  
        'Set new z-shift V]vk9M2q[l  
        op.Type = "ShiftZ" 3!Bekn]  
        op.val1 = tlens hKX-]+6"  
        op.parent = parID /j S  
        AddOperation eID, op c&'T By  
        Print "Set lens thickness = " & tlens .5ingB3%  
    :UScbPG  
        '************************************************************************* 9KAXc(-  
        'Lens index of refraction bZtjg  
        '************************************************************************* 0Q>Yoa 11  
        eID = FindMaterial( "Lens" ) 0|4XV{\qT$  
        GetModelMaterial eID, mat I}?fy\1A&  
    B&.XGo)  
        mat.Nd = nlens cT.1oaAM0  
        SetModelMaterial eID, mat -.z~u/uL  
        Print "Set lens index of refraction = " & nlens nnr(\r~  
    C:P,q6  
        '************************************************************************* 1lMU('r%  
        'Pupil diameter IClnh1=  
        '************************************************************************* D$ `yxc  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) a&y%|Gs^f  
    RJd55+h  
        'Adjust pupil diameter (trimming volume inner hole) hg\$>W~ 2  
    fmloh1{4  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" N %0F[sY6  
    N$_Rzh"9rr  
        ' Adjust pupil location to just in front of the lens x:?1fvVR  
        parID = FindFullName( "Geometry.Arizona Eye" ) ,T1 t`  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) O<o_MZN  
        count = 0 wcV~z:&^5  
        While GetOperationCount(eID)>count 1[B?nk  
            GetOperation eID, count, op *K0CUir|  
            If op.Type="ShiftZ" Then WH'[~O  
                DeleteOperation eID,count fv`%w  
                count=count-1 v}[7)oj|  
            End If \mv7"TM  
            count=count+1 >B~p[wh0  
        Wend U24?+/5D]  
        op.Type = "ShiftZ" PW.W.<CL  
        op.val1 = taq-0.01 Zx`hutCv  
        op.parent = parID ZM4q@O)/  
        AddOperation eID, op vw+ @'+  
    |yQ3H)qB#  
        Print "Set pupil diameter = " & pupilDiam )7J@A%u  
    E#_}y}7JY  
        'Update AZ Eye subassembly Description 4Jo:^JV  
        eID = FindFullName( "Geometry.Arizona Eye" ) qFvtqv2  
        GetEntity eID, entity "4L' 2w+  
        entity.Description = "Accommodation = " & A & "D" 4$vya+mAk5  
        SetEntity eID, entity #PtV=Ee1  
    6AzH'H F  
        Update >F@7}Y(  
        Print "DONE!" -*tP_=-Dg  
         (MbI8B>  
    End Sub <PJwBA%{  
    RQ|!?\a=  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: V&NOp  
    5v>(xl  
    Accommodation = 4 Diopters ##yi^;3Y  
    Pupil Diameter = 4 mm |4 wVWJ7   
    Set aqueous humor thickness = 2.81 v>0xHQD*<M  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 JNk ]$ xz  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 TQbhK^]  
    Set lens thickness = 3.927 >dZ x+7  
    Set lens index of refraction = 1.42672 hv7!x=?8  
    Set pupil diameter = 4 3LX<&."z  
    DONE! SOeL@!_  
    wCc:HfmjJ  
    (文章来源:讯技光电)
     
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