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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 wx^Det  
    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。 Sl/]1[|mb  
    , # =TputM  
    模型 )r^vrCNy>  
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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。 fLnwA|n=  
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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. >TMd1? ,  
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    光源 Z#.1p'3qm1  
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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。 nfbR"E jXr  
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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。 ,`JYFh M  
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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。 <l(n)|H1P  
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    图2. 字母F光源的设定方法光 PChew3  
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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 hs[x\:})/  
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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。  4d\^  
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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。 +l^tT&s;f  
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    图5. 视网膜重点采样规格设定
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    脚本 E{EO9EI  
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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: XjF@kQeM=  
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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。 YZ5,K6u  
    余下的脚本计算与屈光度有关的所有参数。 #m,H1YH M  
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    分析 R|n  
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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。 N2O *g`YC  
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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 ?>Sv_0  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. &J)<1!|  
    uR ?W|a  
    Dim entity As T_ENTITY eJ99W=  
    Dim op As T_OPERATION H"FK(N\  
    Dim mat As T_MODELMATERIAL .JPN';  
    Dim A As Double X>8,C^~$1  
    Dim pupilDiam As Double B:T s_9*  
    Dim eID As Long 2 ^m}5:0  
    Dim parID As Long G9f6'5 O  
    Dim count As Integer sq!$+=1-X  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double 5Jbwl$mZ  
    Dim tlens As Double, nlens As Double 3]l)uoNt/  
    Dim curv As Double, conic As Double D`T;j[SsS#  
    Dim ok As Long SI=$s>1  
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    Sub Main fZ$b8  
    umIGI  
        '用户输入对话框 i)?7+<X  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 C`hdj/!A  
            TextBox 220,21,40,21,.TextBox1 'default: 0 23wztEp{a  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 6nZ]y&$G-k  
            OKButton 40,91,90,21 e0TYHr)X>3  
            CancelButton 190,91,90,21 C(ij_>  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 UGSZg|&6#*  
            TextBox 220,49,40,21,.TextBox2 'default: 4 &"^F;z/  
        End Dialog hZx&j{  
        Dim dlg As UserDialog 8M99cx*K  
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        ok = Dialog (dlg) *4}_2"[  
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        If ok=0 Then    'cancel button was pressed sp,-JZD  
            Print "Execution cancelled." r[S(VPo[()  
            End CRK%^3g  
        End If 9MMCWMV  
    2!{D~Gfl=  
        'Assign accommodation and pupil diameter & use defaults if field left empty yp#!$+a}  
        If dlg.TextBox1 = "" Then AJ\&>6GZ(b  
            A = 0           'Default accommodation Cz0FA]-g  
        Else lL}NiN-)t  
            A = CDbl(dlg.TextBox1) IrMH AM5K  
        End If h[W`P%xZ  
    hzo> :U  
        If dlg.TextBox2 = "" Then x4WCAqi/2  
            pupilDiam = 4   'Default pupil diameter ubwM*P  
        Else aV\i3\da  
            pupilDiam = CDbl(dlg.TextBox2) n9B5D:.G  
        End If X' `n>1z  
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        Print " " rYb5#aT[  
        Print "Accommodation = " & A & " Diopters" wZ(1\ M(  
        Print "Pupil Diameter = " & pupilDiam & " mm" lq-KM8j  
    }u_D{bz  
        ' Calculate new parameters with accommodation A NhqS  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness 8A#,*@V[  
    W/qXQORv  
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens cnu&!>8V  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens o701RG ~)  
    ` ,\b_SFg  
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens ?2]fE[SqY  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens g(@F`W[  
    ,"EaZ/Bl/  
        tlens = 3.767 + 0.04*A                  'Lens thickness > Vm}u`x  
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        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction _4by3?<c  
    P~j#8cH7  
        'Adjust parameters to account for accommodation Db|f"3rq?  
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        '************************************************************************* wW%b~JX  
        'Aqueous thickness (Position of Lens) 0~U#DTx0  
        '************************************************************************* =-r"@2HBq  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) Rw?w7?I  
        GetCustomElement eID, entity o%_-u +  
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        parID = FindFullName( "Geometry.Arizona Eye" ) L^JU{\C  
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        ' Delete any shift(s) in z ~su>RolaX  
        count = 0 Gdow[x  
        While GetOperationCount(eID)>count [+\He/M6  
            GetOperation eID, count, op eKiDc=@  
            If op.Type="ShiftZ" Then w|f+OlPXq  
                DeleteOperation eID,count % !@E)%d0  
                count=count-1 <f>77vh0  
            End If tK3$,9+  
            count=count+1 fEBi'Ad  
        Wend Qsbyy>o)  
    [j6]!p]S$  
        'Set new shift in G#%Sokkb'  
        op.Type = "ShiftZ" I'5[8  
        op.val1 = taq Ae2N"%Ej  
        op.parent = parID =F \Xt "  
        AddOperation eID, op F@<cp ?dR  
        Print "Set aqueous humor thickness = " & taq-0.55 JG;}UuHYM  
    U^_\V BAk  
        '************************************************************************* <WUgH6"  
        'Radius and conic constant of anterior lens f#l9rV"@g  
        '************************************************************************* tR!C8:u  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) <-1:o*8:}  
        GetConic eID, entity, curv, conic /we]i1-9  
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        SetConic eID, entity, 1/Rant, CCant fM.#FT??  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant Uh.swBC n  
    |sGJum&=  
        '************************************************************************* .i;.5)shsu  
        'Radius and conic constant of posterior lens fq>{5ODO  
        '************************************************************************* AWcbbj6Nd  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) `+Nv =vk  
        GetConic eID, entity, curv, conic g[~{iu_$d  
    #w''WOk@ZG  
        SetConic eID, entity, 1/Rpost, CCpost "M:ui0YP  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost Z` kVyuQ  
    +(!/(2>~  
        '************************************************************************* u0W6u} 4;  
        'Lens thickness (Position of posterior lens surface) Z(q]rX5"  
        '************************************************************************* qlM<X?  
    ~C{:G;Iy0  
        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) {+lU4u  
    4rDV CXE  
        ' Delete any z-shift(s) GJdL1ptc  
        count = 0 }k.yLcXM  
        While GetOperationCount(eID)>count e#hg,I  
            GetOperation eID, count, op :?UcD_F  
            If op.Type="ShiftZ" Then >)D=PvGlmp  
                DeleteOperation eID,count Ko&4{}/  
                count=count-1 =R:O`qdC4e  
            End If @:im/SE  
            count=count+1 +o@:8!IM1  
        Wend w7` pbcY,  
    4M%|N  
        'Set new z-shift Bvvja C  
        op.Type = "ShiftZ" `Hw][qy#  
        op.val1 = tlens -~c-mt  
        op.parent = parID Z'A 3\f   
        AddOperation eID, op 3rK\ f4'  
        Print "Set lens thickness = " & tlens bj`GGxzOb  
    Hya.OW{  
        '************************************************************************* 8d$|JN;)  
        'Lens index of refraction kB?/_a`]  
        '************************************************************************* <cZ/_+H%C  
        eID = FindMaterial( "Lens" ) i+(>w'=m  
        GetModelMaterial eID, mat sf$hsPC^  
    P84YriLo  
        mat.Nd = nlens (Q*x"G#4>  
        SetModelMaterial eID, mat r?u4[ Oe#  
        Print "Set lens index of refraction = " & nlens +8xT}mX  
    dG+$!*6Z  
        '************************************************************************* N( 7(~D=)B  
        'Pupil diameter 3XB`|\:  
        '************************************************************************* )o:sDj`b]  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) &bq1n_  
    R<f F ^^  
        'Adjust pupil diameter (trimming volume inner hole) dfAw\7v/  
    #do%u"q  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" @-K[@e/uwy  
    i+5Qs-dHA  
        ' Adjust pupil location to just in front of the lens [f\Jcjc  
        parID = FindFullName( "Geometry.Arizona Eye" ) 9:g A0Z  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) YFu>`w^Y  
        count = 0 ]["%e9#aX  
        While GetOperationCount(eID)>count ,){#J"W  
            GetOperation eID, count, op T*@o?U  
            If op.Type="ShiftZ" Then #qk=R7" Q  
                DeleteOperation eID,count MA_YMxP.'  
                count=count-1 VMF?qT3Nd  
            End If Q_p&~PNy5  
            count=count+1 =}tomN(F~[  
        Wend Kn3Xn`P?  
        op.Type = "ShiftZ" 3=U#v<  
        op.val1 = taq-0.01 DZmVm['l  
        op.parent = parID I*j~5fsS'  
        AddOperation eID, op a~@f,bw  
    ] 7[#K^  
        Print "Set pupil diameter = " & pupilDiam VOC$Kqg;  
    >`3F`@1L0  
        'Update AZ Eye subassembly Description A",}Ikh='`  
        eID = FindFullName( "Geometry.Arizona Eye" ) Y,L[0%  
        GetEntity eID, entity iVnMn1h  
        entity.Description = "Accommodation = " & A & "D" lO|LvJyx  
        SetEntity eID, entity "6IZf>N@#  
    _\yR/W~  
        Update L<oQKe7Q:  
        Print "DONE!" A`M-N<T  
         [;aM8N  
    End Sub )H]L/n  
    s>G]U)d<'  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: }D!tB  
    b3_P??yp  
    Accommodation = 4 Diopters Bx\ o8k  
    Pupil Diameter = 4 mm 9;I%Dv  
    Set aqueous humor thickness = 2.81 Q=%W-  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 0\"#Xa+}8  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 &c "!Y)%G  
    Set lens thickness = 3.927 ?7)v:$(G}  
    Set lens index of refraction = 1.42672 |J`v w  
    Set pupil diameter = 4 VJw7defc  
    DONE! )c*xKij  
    Gjq7@F'  
    (文章来源:讯技光电)
     
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