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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 Z<Ke /Xi  
    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。 "0A !fRI~  
    rXg#_c5j  
    模型 ;Quk%6;[N  
    3%SwCYd  
    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。 # Q_ d  
    3SWO_  
    Table 1. AZ眼睛模型的定义
    K9N\E"6ZP  
    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. w 7 j hS  
    zJa,kN|m  
    光源 J |TA12s  
    l?LP:;S  
    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。 d<^o@  
    G8voqP  
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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。 lCMU{)  
    =M+enSu  
    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。 By-A1|4Cp`  
    /MQI5Djg  
    图2. 字母F光源的设定方法光 Oe*+pReSD  
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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 5PU$D`7it  
    34\:1z+s M  
    在散射文件中,有一个名为“Retina surface”的72%的反射型朗伯散射,它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射,改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 ,k5b,}tN  
    .V:H~  
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    图4. 视网膜朗伯散射设定
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    注意在视网膜的表面有散射重点采样规格定义,在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳,半角度10度。 !F&Ss|(}  
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    图5. 视网膜重点采样规格设定
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    脚本 N [iv.B  
    *q.qO )X}3  
    内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框,如下图所示: m;"i4!  
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    图6. 用户对话框的创建与编辑
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    图7. 用户对话框编辑器
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    如果“OK”按钮按下,将会核对对话框下面的代码行,如果点击取消则脚本终止。然后输入的参数赋予变量,如果此处是保留为空白,则使用默认值。因此,如果没有值输入并点击“OK”按钮,则脚本是以屈光度为0,光瞳直径为4mm来运行的。 oAgO 3x   
    余下的脚本计算与屈光度有关的所有参数。 M4:}`p=  
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    分析 |P"p/iY  
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    屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 Jj$N3UCg7  
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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 pkR+H|  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. YQI&8~z  
    ,^UNQO*{GI  
    Dim entity As T_ENTITY k*8 ld-O  
    Dim op As T_OPERATION pU|SUM  
    Dim mat As T_MODELMATERIAL 62X;gb  
    Dim A As Double FM3DJ?\L-  
    Dim pupilDiam As Double `E),G;I  
    Dim eID As Long }I\hO L  
    Dim parID As Long KF"&9nB  
    Dim count As Integer C?3?<FDL  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double T*%Q s&x ;  
    Dim tlens As Double, nlens As Double k2xOu9ncEj  
    Dim curv As Double, conic As Double /k(KA [bS  
    Dim ok As Long t(|\3$z  
    kR0d]"dr  
    Sub Main ]~SOGAFW  
    S"Dw8_y7}  
        '用户输入对话框 ]oN:MS4r  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 tp,e:4\ 8Q  
            TextBox 220,21,40,21,.TextBox1 'default: 0 E r6'Ig|U  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 oD]riA>jC  
            OKButton 40,91,90,21 72gQ<Si  
            CancelButton 190,91,90,21 u*ZRU 4 U  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 ,h'q}5  
            TextBox 220,49,40,21,.TextBox2 'default: 4 etEm#3  
        End Dialog ~ l'dpg  
        Dim dlg As UserDialog sz'IGy%  
    Q]Fm4  
        ok = Dialog (dlg) Sn\S `D  
    {o?+T );Z  
        If ok=0 Then    'cancel button was pressed ]8|cV GMa  
            Print "Execution cancelled." H h4G3h0  
            End |(E.Sb  
        End If 6O^'J~wiI  
    S?W!bkfn  
        'Assign accommodation and pupil diameter & use defaults if field left empty *;~*S4/P   
        If dlg.TextBox1 = "" Then H*DWDJxmV  
            A = 0           'Default accommodation s^X(G!V{c  
        Else ic}M)S FD;  
            A = CDbl(dlg.TextBox1) |=7ouFl  
        End If @iZ"I i&+  
    lD;="b  
        If dlg.TextBox2 = "" Then ^<8 c`k )e  
            pupilDiam = 4   'Default pupil diameter qYHAXc}$  
        Else %E95R8SL  
            pupilDiam = CDbl(dlg.TextBox2) . mDh9V5  
        End If :&#HrD[KT  
    sbZ$h <  
        Print " " &R54?u^A  
        Print "Accommodation = " & A & " Diopters" vV.TK_ y  
        Print "Pupil Diameter = " & pupilDiam & " mm" %z6.}4h  
    -uDB#?q:W  
        ' Calculate new parameters with accommodation &j\<UPn  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness G:f\wK[  
    }t tiL  
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens A4,tv#z  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens !%' 1 x2?  
    8]6u]3q#  
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens ESk<*-  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens yv:8=.r}M  
    3@ a  
        tlens = 3.767 + 0.04*A                  'Lens thickness LFsrqdzJ  
    7Vf2Qx1_  
        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction ceakTAB[  
    -9XB.)\#  
        'Adjust parameters to account for accommodation Lw 7,[?,Z  
    i<N[sO  
        '************************************************************************* `mro2A  
        'Aqueous thickness (Position of Lens) m>C}T  
        '************************************************************************* 93="sS  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) V6.xp{[  
        GetCustomElement eID, entity PiD%PBmUl  
    =&QC&CqEi  
        parID = FindFullName( "Geometry.Arizona Eye" )  D(}w$hi8  
    @V/Lqia  
        ' Delete any shift(s) in z O2|[g8(_F  
        count = 0 z~TG~_s  
        While GetOperationCount(eID)>count {*VCR  
            GetOperation eID, count, op :` >|N|i  
            If op.Type="ShiftZ" Then sd;J(<Ofh  
                DeleteOperation eID,count {shf\pm!o  
                count=count-1 > uS?Nz5/  
            End If L&wJ-}'l  
            count=count+1 S^,1N 4  
        Wend R;9H`L/>  
    ?@U7tNI  
        'Set new shift in yoKl.U"&  
        op.Type = "ShiftZ" Byf5~OC  
        op.val1 = taq u<x2"0f  
        op.parent = parID oVPtA@  
        AddOperation eID, op S/}6AX#F4  
        Print "Set aqueous humor thickness = " & taq-0.55 wYtL1D(  
    ,f`435R  
        '************************************************************************* Nf0'>`/  
        'Radius and conic constant of anterior lens _qg)^M6  
        '************************************************************************* 0MK|spc  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) `8Y& KVhu  
        GetConic eID, entity, curv, conic AtRu)v6r  
    si.A"\bm  
        SetConic eID, entity, 1/Rant, CCant -!uut7Z|  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant T+z]ztO  
    }`g:) g J  
        '************************************************************************* ueO&%  
        'Radius and conic constant of posterior lens 7Y$#* 7  
        '************************************************************************* ,3_;JT"5  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) x{Y}1+Y4  
        GetConic eID, entity, curv, conic F|K=].  
    Z:3N*YkL  
        SetConic eID, entity, 1/Rpost, CCpost nQuiRTU<  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost a []Iz8*6e  
    ]3@6o*R;  
        '************************************************************************* =M"H~;f]  
        'Lens thickness (Position of posterior lens surface) p[BF4h{E  
        '************************************************************************* +Hz});ix<  
    ZhqrN]x  
        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) ZV}"k_+-  
    (~F{c0 \C  
        ' Delete any z-shift(s) BZy&;P  
        count = 0 [%(}e1T(  
        While GetOperationCount(eID)>count p<1z!`!P  
            GetOperation eID, count, op )X{x\ /N  
            If op.Type="ShiftZ" Then Qmxe*@{`  
                DeleteOperation eID,count Jy)E!{#x  
                count=count-1  6e,|HV  
            End If :34#z.O  
            count=count+1 rQ|^H Nj  
        Wend L/1zG/@  
    L(a&,cdh  
        'Set new z-shift qd*3| O^  
        op.Type = "ShiftZ" )3<|<jwcx  
        op.val1 = tlens h8;B+#f`  
        op.parent = parID _jK    
        AddOperation eID, op 8<(qN> R  
        Print "Set lens thickness = " & tlens "dfq  
    \\F^uM7,  
        '************************************************************************* OE87&Cl"{t  
        'Lens index of refraction CW*Kd t  
        '************************************************************************* [:gPp)f,  
        eID = FindMaterial( "Lens" ) 2XhtK  
        GetModelMaterial eID, mat yidUtSv=,  
    :5!>h8p;  
        mat.Nd = nlens J2cqnwUV  
        SetModelMaterial eID, mat K*;e>{p  
        Print "Set lens index of refraction = " & nlens VXt8y)?a  
    fl| 8#\r  
        '************************************************************************* T^LpoN/T  
        'Pupil diameter X|+o4R?  
        '************************************************************************* :uhU<H<,f  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) Wbo{v r[2+  
    8A/;a{   
        'Adjust pupil diameter (trimming volume inner hole) <p"[jC2zF;  
    n1OxT"tD  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" PI{;3X}9$,  
    c$?(zt ;  
        ' Adjust pupil location to just in front of the lens VW^6qf/,  
        parID = FindFullName( "Geometry.Arizona Eye" ) Cz=HxU80J  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) zfvMH"1  
        count = 0  X._skq  
        While GetOperationCount(eID)>count 4;anoqiG\  
            GetOperation eID, count, op gL%%2 }$  
            If op.Type="ShiftZ" Then 06@^knm  
                DeleteOperation eID,count _`yd"0 Ux  
                count=count-1 }{>)2S  
            End If \7W>3  
            count=count+1 z3!j>X_w  
        Wend )eFXjnHN  
        op.Type = "ShiftZ" x] [/9e  
        op.val1 = taq-0.01 K)z{R n  
        op.parent = parID C[f'1O7  
        AddOperation eID, op JCoDe.  
    *_G(*yAe(  
        Print "Set pupil diameter = " & pupilDiam ]IbX<  
    R`}C/'Ty  
        'Update AZ Eye subassembly Description nulCk33x'=  
        eID = FindFullName( "Geometry.Arizona Eye" ) @c&}\#;  
        GetEntity eID, entity f,QoA  
        entity.Description = "Accommodation = " & A & "D" !u@XEN>/  
        SetEntity eID, entity ]dzBm!u  
    O$QtZE61  
        Update AF ,*bb  
        Print "DONE!" u{#}Lo>B #  
         sywSvnPuYZ  
    End Sub 3m RP.<=  
    /Y=Cg%+  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: +ZH-'l  
    j8k5B"  
    Accommodation = 4 Diopters V<X[>C'  
    Pupil Diameter = 4 mm oNW.-gNT  
    Set aqueous humor thickness = 2.81 Y ,1ZvUOB  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 uw'>tb@  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 5`su^  
    Set lens thickness = 3.927 )8`7i{F  
    Set lens index of refraction = 1.42672 HgH\2QL3&  
    Set pupil diameter = 4 Yj%hgb:)  
    DONE! wOW#A}m'vj  
    Z>=IP-,>  
    (文章来源:讯技光电)
     
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