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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 D\^WXY5e%y  
    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。 69kJC/1+l  
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    模型 NYABmI/0c  
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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。 5&CDHc7Oj  
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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. P&*sB%B  
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    光源 W[NEe,.>  
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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。 r^HA aGpC  
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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。 e=/&(Y  
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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。 v| z08\a[  
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    图2. 字母F光源的设定方法光 7s'- +~  
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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 XeUC0K[D  
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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。 ~3WL)%  
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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。 Q^eJ4{Ya:  
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    图5. 视网膜重点采样规格设定
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    脚本 XOb}<y)r~  
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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: (N~$x  
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    图6. 用户对话框的创建与编辑
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    图7. 用户对话框编辑器
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    如果“OK”按钮按下,将会核对对话框下面的代码行,如果点击取消则脚本终止。然后输入的参数赋予变量,如果此处是保留为空白,则使用默认值。因此,如果没有值输入并点击“OK”按钮,则脚本是以屈光度为0,光瞳直径为4mm来运行的。 96|[}:+$&:  
    余下的脚本计算与屈光度有关的所有参数。 +6W(z3($  
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    分析 p{;i& HNdp  
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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。 K <`>O, F  
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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 T|'&K:[TJ  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. -rY 7)=  
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    Dim entity As T_ENTITY y62%26 [  
    Dim op As T_OPERATION sy<iKCM\  
    Dim mat As T_MODELMATERIAL lxb8xY  
    Dim A As Double 2wh#$zGy  
    Dim pupilDiam As Double XQ;I,\m  
    Dim eID As Long H/cTJ9zz  
    Dim parID As Long E'dX)J9e$/  
    Dim count As Integer (6xDu.u?A  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double :\}U9QfCw  
    Dim tlens As Double, nlens As Double L`K;IV%;  
    Dim curv As Double, conic As Double Ky9W/dCR  
    Dim ok As Long we]>(|  
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    Sub Main tEhr  
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        '用户输入对话框 Y)p4]>lT+8  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 r+g jc?Ol  
            TextBox 220,21,40,21,.TextBox1 'default: 0 Lar r}o=  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 lmFA&s"m  
            OKButton 40,91,90,21 9D4-^M:a  
            CancelButton 190,91,90,21 E/ O5e(h  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 pt!'v$G/*  
            TextBox 220,49,40,21,.TextBox2 'default: 4 _PB@kH#  
        End Dialog X8 qIia  
        Dim dlg As UserDialog Cd~LsdKE5  
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        ok = Dialog (dlg) }:#dV B+  
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        If ok=0 Then    'cancel button was pressed P/ aDd@j  
            Print "Execution cancelled." %8D?$v"#Z  
            End zl)&U=4l  
        End If  X4I]9 t\  
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        'Assign accommodation and pupil diameter & use defaults if field left empty ;QPy:x3  
        If dlg.TextBox1 = "" Then .uDM_ 34  
            A = 0           'Default accommodation Vipp /WV  
        Else ?`. XK}  
            A = CDbl(dlg.TextBox1) v ($L  
        End If >h7$v~nra  
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        If dlg.TextBox2 = "" Then xwLy|&  
            pupilDiam = 4   'Default pupil diameter 5P\N"Yjx'  
        Else wgZrrq/W|  
            pupilDiam = CDbl(dlg.TextBox2) Mo|yv[(K ,  
        End If )0|):g   
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        Print " " J#@lV  
        Print "Accommodation = " & A & " Diopters" "_)|8|gN  
        Print "Pupil Diameter = " & pupilDiam & " mm" RZ6~c{  
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        ' Calculate new parameters with accommodation u+DX$#-n!]  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness >Z"9rF2SW  
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        Rant = 12.0 - 0.4*A                     'Radius of anterior lens 3U o]> BG  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens {Q<0\`A  
    +2yF|/WW#  
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens 'z](xG<  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens 1 PIzV:L\  
    @YB85p"]J.  
        tlens = 3.767 + 0.04*A                  'Lens thickness ?Ccw4]YO,=  
    T9y768%  
        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction A^vvST%7  
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        'Adjust parameters to account for accommodation {Y "8~  
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        '************************************************************************* jJ-d/"(  
        'Aqueous thickness (Position of Lens) SJ[AiHR  
        '************************************************************************* `U#Po_hq  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) %O_t`wz  
        GetCustomElement eID, entity vnVZJ}]w\  
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        parID = FindFullName( "Geometry.Arizona Eye" ) V^vLN[8_\  
    /.)2d8,  
        ' Delete any shift(s) in z tx)OJY  
        count = 0 w5 Z2N[hy  
        While GetOperationCount(eID)>count PC0HH  
            GetOperation eID, count, op N*':U^/t4J  
            If op.Type="ShiftZ" Then Un\Ubqi0  
                DeleteOperation eID,count i :EO(`  
                count=count-1 Ff&R0v  
            End If t .L4%1OF  
            count=count+1 IadK@?X6j  
        Wend j`hNZ%a  
    #AvEH=:  
        'Set new shift in zM\IKo_"  
        op.Type = "ShiftZ" <L2GUX36#  
        op.val1 = taq *LEu=3lp%>  
        op.parent = parID D2V v\f  
        AddOperation eID, op q /:T1a7!  
        Print "Set aqueous humor thickness = " & taq-0.55 ]p\u$VY9  
    )5'rw<:="  
        '************************************************************************* hw|t8 ShW  
        'Radius and conic constant of anterior lens gu!](yEgl  
        '************************************************************************* XUf7yD  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) S_j1=6 #^  
        GetConic eID, entity, curv, conic F/xCG nP-  
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        SetConic eID, entity, 1/Rant, CCant 7\f{'KL  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant _Ws#UL+Nq  
    +R9%~Z.=  
        '************************************************************************* K,G,di  
        'Radius and conic constant of posterior lens f%L:<4  
        '************************************************************************* a" ^#!G<+  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) QYH."7X >  
        GetConic eID, entity, curv, conic u*U_7Uw$  
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        SetConic eID, entity, 1/Rpost, CCpost '1Y<RD>x  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost k+f1sV[4}  
    R !Fx)xj  
        '************************************************************************* ZRX^^yN  
        'Lens thickness (Position of posterior lens surface) $vW^n4!  
        '************************************************************************* {uEu >D$8  
    8NxUx+]  
        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) (I>HWRH  
    6W]OpM  
        ' Delete any z-shift(s) >,kL p|gA  
        count = 0 3>H2xh3Y  
        While GetOperationCount(eID)>count <|B$dz?r  
            GetOperation eID, count, op {qY3L8b  
            If op.Type="ShiftZ" Then ?U}sQ;c$  
                DeleteOperation eID,count %Fs*#S  
                count=count-1 V/@[%w=  
            End If ; A x=]Q  
            count=count+1 -<]\l3E&J  
        Wend VtD@&N  
    7Y%!,ff  
        'Set new z-shift q|R+x7x  
        op.Type = "ShiftZ" Nz3zsP$  
        op.val1 = tlens KSF5)CZ5  
        op.parent = parID F19;RaP+  
        AddOperation eID, op "L ^TT2  
        Print "Set lens thickness = " & tlens t) ;   
    _RN/7\  
        '************************************************************************* 6.k^m&-A  
        'Lens index of refraction 9cl{hdP{  
        '************************************************************************* f&=K]:WDe  
        eID = FindMaterial( "Lens" ) v!nm &"  
        GetModelMaterial eID, mat qK<aZ%V  
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        mat.Nd = nlens rat=)n)"t  
        SetModelMaterial eID, mat "ugX /r$_  
        Print "Set lens index of refraction = " & nlens JJ^iy*v  
    s.<olxXRW  
        '************************************************************************* C<zx'lw!  
        'Pupil diameter 9"m, p  
        '************************************************************************* >&*6Fqd  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) Ti0 (VdY  
    eUX@9eML  
        'Adjust pupil diameter (trimming volume inner hole) tVC@6Z$  
    [6Uudiw  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" 3FGbQ_  
    plzE  
        ' Adjust pupil location to just in front of the lens 8yY"x ['  
        parID = FindFullName( "Geometry.Arizona Eye" ) B)( p9]q  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) j:3A;r\  
        count = 0 R tXF  
        While GetOperationCount(eID)>count L-^# 02  
            GetOperation eID, count, op k/$Ja;  
            If op.Type="ShiftZ" Then Rh wt<  
                DeleteOperation eID,count "r5'lQI  
                count=count-1 4U}.Skzq  
            End If n,C D4Nv  
            count=count+1 jrDz7AfA  
        Wend daaga}]d  
        op.Type = "ShiftZ" ^4n2 -DvG  
        op.val1 = taq-0.01 dbf^A1HI  
        op.parent = parID + TPbIRA  
        AddOperation eID, op eyI-s9#t  
    ?K= gg<  
        Print "Set pupil diameter = " & pupilDiam |HKHN? )  
    |U;w!0  
        'Update AZ Eye subassembly Description V Z4nAG  
        eID = FindFullName( "Geometry.Arizona Eye" ) YHwVj?6W  
        GetEntity eID, entity >=Rd3dgDG  
        entity.Description = "Accommodation = " & A & "D" ?^e*UJNM  
        SetEntity eID, entity (E2lv#[  
    m)tI  
        Update :X1`wBu  
        Print "DONE!" DzX6U[=  
         KD[)O7hYC  
    End Sub Zq2H9^![y~  
    E 6>1Fm8%V  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: $6 Q2)^LJ  
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    Accommodation = 4 Diopters UgOGBj,&5W  
    Pupil Diameter = 4 mm $G^H7|PzdC  
    Set aqueous humor thickness = 2.81 f_z2#,g  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 ]ly)z[is"]  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 s5_1}KKCs  
    Set lens thickness = 3.927 K284R=j -&  
    Set lens index of refraction = 1.42672 ss|6_H =  
    Set pupil diameter = 4 OI;L9\MJc  
    DONE! K4K3< Pg  
    ynOc~TN  
    (文章来源:讯技光电)
     
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