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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 Put +<o <  
    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。 1YS{; y[o  
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    模型 M/#<=XhA  
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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。 p~M^' k=d  
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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. /r]IY.  
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    光源 v'DL >Y  
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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。 & }}o9  
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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。 ^Dd$8$?[  
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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。 <S5Am%vo  
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    图2. 字母F光源的设定方法光 4Kx;F 9!%~  
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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 Z.rKV}yjY  
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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。 Dmn6{jy P  
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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。 h*&-[nSo  
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    图5. 视网膜重点采样规格设定
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    脚本 _kgw+NA&-H  
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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: RXLD5$s^  
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    图6. 用户对话框的创建与编辑
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    图7. 用户对话框编辑器
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    如果“OK”按钮按下,将会核对对话框下面的代码行,如果点击取消则脚本终止。然后输入的参数赋予变量,如果此处是保留为空白,则使用默认值。因此,如果没有值输入并点击“OK”按钮,则脚本是以屈光度为0,光瞳直径为4mm来运行的。 #(!>  
    余下的脚本计算与屈光度有关的所有参数。 1_*o(HR  
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    分析 3fM~R+p  
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    屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 h_Q9 c  
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    图7. 字母F在视网膜上颜色分析
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    脚本代码 quVTqhg"  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. KR%DpQ&{'  
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    Dim entity As T_ENTITY hH|3s-o  
    Dim op As T_OPERATION GR Rv0M  
    Dim mat As T_MODELMATERIAL -dZ7;n5&_  
    Dim A As Double ]xfu @''  
    Dim pupilDiam As Double @9-z8PyF  
    Dim eID As Long gI<TfcC  
    Dim parID As Long iLNKC'  
    Dim count As Integer x{j|Tf3,G  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double Kbrb;r59  
    Dim tlens As Double, nlens As Double 9v8{JaI3  
    Dim curv As Double, conic As Double p,Qr9p3y  
    Dim ok As Long 8|OsVIe%  
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    Sub Main O4S~JE3o  
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        '用户输入对话框 d.3-@^P  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 VkZrb2]v  
            TextBox 220,21,40,21,.TextBox1 'default: 0 k$j>_U? P  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 YJ3aJ^m#E  
            OKButton 40,91,90,21 @GK0j"_  
            CancelButton 190,91,90,21 pMe'fC~*  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 "FwbhD0Gb  
            TextBox 220,49,40,21,.TextBox2 'default: 4 R6r'[- B2  
        End Dialog pPuE-EDk  
        Dim dlg As UserDialog yn)K1f^  
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        ok = Dialog (dlg) /Q 8E12  
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        If ok=0 Then    'cancel button was pressed ~D PjTR  
            Print "Execution cancelled." rzsb(  
            End tXV9+AJ  
        End If ?~Fk_#jz,@  
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        'Assign accommodation and pupil diameter & use defaults if field left empty p'M5]G  
        If dlg.TextBox1 = "" Then 4p\<b8(9>  
            A = 0           'Default accommodation Mk Er|w'  
        Else ) wtVFG  
            A = CDbl(dlg.TextBox1) ]d=SkOq  
        End If L}T:Y).  
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        If dlg.TextBox2 = "" Then  \09eH[  
            pupilDiam = 4   'Default pupil diameter Ne!F  p  
        Else s<Px au+A  
            pupilDiam = CDbl(dlg.TextBox2) B2w\  
        End If $T.we+u  
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        Print " " TPH`{  
        Print "Accommodation = " & A & " Diopters" ?mU 3foa  
        Print "Pupil Diameter = " & pupilDiam & " mm" O$%M.C'  
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        ' Calculate new parameters with accommodation e[.c^Hw  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness bi;?)7p&ZY  
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        Rant = 12.0 - 0.4*A                     'Radius of anterior lens 'Alt+O_  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens #Mkwd5S|L  
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        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens 1D%3|_id^  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens |\;oFuCv##  
    (L}  
        tlens = 3.767 + 0.04*A                  'Lens thickness PeT _Ty  
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        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction ,#:*dl  
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        'Adjust parameters to account for accommodation 5 #3/  
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        '************************************************************************* sLrSi  
        'Aqueous thickness (Position of Lens) F9@,T8I  
        '************************************************************************* {\3k(NdEX  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) {G$I|<MD2T  
        GetCustomElement eID, entity y=7WnQc  
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        parID = FindFullName( "Geometry.Arizona Eye" ) itClCEOA  
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        ' Delete any shift(s) in z QFt7L  
        count = 0 K;moV| j  
        While GetOperationCount(eID)>count mC OJ1}  
            GetOperation eID, count, op =%P'?(o|  
            If op.Type="ShiftZ" Then ]k~Vh[[  
                DeleteOperation eID,count H EdOo~/~  
                count=count-1 E`s9SE  
            End If x dDR/KS  
            count=count+1 x}o]R  
        Wend DY1?37h  
    o (fZZ`6Y  
        'Set new shift in a Mp*Ap  
        op.Type = "ShiftZ" 2r;^OWwr?  
        op.val1 = taq %~%1Is`4J  
        op.parent = parID 3S='/^l  
        AddOperation eID, op B198_T!  
        Print "Set aqueous humor thickness = " & taq-0.55 BkfWZ O{7  
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        '************************************************************************* $T* ##kyE9  
        'Radius and conic constant of anterior lens 9Br2}!Ny  
        '************************************************************************* dv3+x\`9  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) $__e7  
        GetConic eID, entity, curv, conic ]}z;!D>  
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        SetConic eID, entity, 1/Rant, CCant Y#'mALC2  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant cy)b/4h@  
    fq-$u;~h  
        '************************************************************************* G#n99X@-  
        'Radius and conic constant of posterior lens N}{CL(xi  
        '************************************************************************* [?TQ!l}8A  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) OdX-.FFl  
        GetConic eID, entity, curv, conic ,])@?TJb@  
    'TclH80  
        SetConic eID, entity, 1/Rpost, CCpost bm1+|gssn  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost 'G z>X :  
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        '************************************************************************* ),`MAevp  
        'Lens thickness (Position of posterior lens surface) 3$f%{~3  
        '************************************************************************* .UNh\R?r  
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        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) 4eb<SNi  
    N{n}]Js1D-  
        ' Delete any z-shift(s) a(CZGIB  
        count = 0 E\!:MCL  
        While GetOperationCount(eID)>count KLBV(`MS  
            GetOperation eID, count, op  /bA\O   
            If op.Type="ShiftZ" Then Sd'Meebu  
                DeleteOperation eID,count lh`inAt)"  
                count=count-1 kfb+OE:7  
            End If Gjuc"JR7  
            count=count+1 $ hB;r  
        Wend ;aYPv8s~,:  
    20gPx;  
        'Set new z-shift 'R6D+Vk/  
        op.Type = "ShiftZ" =DTn9}u  
        op.val1 = tlens #|*;~:fz  
        op.parent = parID HN>eS Y+  
        AddOperation eID, op =0xuH>WY}w  
        Print "Set lens thickness = " & tlens cqeId&Cg  
    2^Gl;3  
        '************************************************************************* n`f},.NM|  
        'Lens index of refraction ?!(/;RU1  
        '************************************************************************* G 8|[.n  
        eID = FindMaterial( "Lens" ) Lc^nNUzPo  
        GetModelMaterial eID, mat QQ@, v@j5  
    s<0yQ-=.?N  
        mat.Nd = nlens js Tb0  
        SetModelMaterial eID, mat o*/\ oVOq  
        Print "Set lens index of refraction = " & nlens SqY;2:  
    sw*k(i  
        '************************************************************************* | (P%<  
        'Pupil diameter sBp|Lo  
        '************************************************************************* C|"T!1MlY4  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) XboOvdt^|  
    GN{\ccej  
        'Adjust pupil diameter (trimming volume inner hole) i2b\` 805  
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        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" T,(IdVlJ  
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        ' Adjust pupil location to just in front of the lens Wf_aEW&n  
        parID = FindFullName( "Geometry.Arizona Eye" ) dv4)fG]W;_  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) IC[SJVH;  
        count = 0 P>euUVMPz4  
        While GetOperationCount(eID)>count do*`-SDy  
            GetOperation eID, count, op aGp <%d  
            If op.Type="ShiftZ" Then 8s8q`_.)(  
                DeleteOperation eID,count 3f's>+,#%  
                count=count-1 F~a5yW:R=)  
            End If b7v] g]*  
            count=count+1 05*_h0}  
        Wend A4';((OXy  
        op.Type = "ShiftZ" u!g=>zEu  
        op.val1 = taq-0.01 8q7KqYu  
        op.parent = parID cv:nlq)  
        AddOperation eID, op } 3:TPW5S  
    eJ{"\c(  
        Print "Set pupil diameter = " & pupilDiam SfJ/(q  
    lGG1d  
        'Update AZ Eye subassembly Description H#U{i  
        eID = FindFullName( "Geometry.Arizona Eye" ) "+nURdicO  
        GetEntity eID, entity toTAWT D  
        entity.Description = "Accommodation = " & A & "D" vo Q,K9  
        SetEntity eID, entity *-+~H1tP  
    !::k\}DS  
        Update { KwLcSn  
        Print "DONE!" nS?HH6H  
         3}g?d/^E3  
    End Sub ?0[%+AD hM  
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    如果屈光度是4,光瞳直径是4,则会输出如下数据: >jl"Yr#  
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    Accommodation = 4 Diopters [%l+ C~m  
    Pupil Diameter = 4 mm Q k-y 0  
    Set aqueous humor thickness = 2.81 |&n dQ(!l  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 e@]cI/j  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 vW$] :).  
    Set lens thickness = 3.927 R~RY:[5?w  
    Set lens index of refraction = 1.42672 Rz=]KeZu  
    Set pupil diameter = 4 tY# F8a&  
    DONE! m$LZ3=v%8  
    D4#,9?us  
    (文章来源:讯技光电)
     
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