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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 :ye)%UU"|:  
    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。 HkrNh>^=  
    q*'hSt@+D  
    模型 75^-93  
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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。 zIdQ^vm8Q  
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    Table 1. AZ眼睛模型的定义
    - MBK/  
    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. ~t#'X8.)  
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    光源 +mF}j=k  
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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。 <(^-o4Cl  
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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。 @aj"1 2  
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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。 m6 IZG l7%  
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    图2. 字母F光源的设定方法光 KDn`XCnk,  
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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 b!`:|!7r'  
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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。 u6%56 %^f  
    y XS/3_A{  
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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。 S++}kR);  
    (:hPT-1  
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    图5. 视网膜重点采样规格设定
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    脚本 0~FX!1;  
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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: UO!OO&l!  
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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。 *Qyw _Q  
    余下的脚本计算与屈光度有关的所有参数。 3Um\?fj>}(  
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    分析 dXdU4YJ X  
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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。 40:YJ_n  
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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 jh=:QP/  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. S:t7U %  
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    Dim entity As T_ENTITY /,B"H@ J  
    Dim op As T_OPERATION bu$5gGWVf  
    Dim mat As T_MODELMATERIAL uQ&xoDCB  
    Dim A As Double !E$S&zVMQ  
    Dim pupilDiam As Double ['sIR+c%'O  
    Dim eID As Long Bp4QHv9xqL  
    Dim parID As Long `N|WCiBV.  
    Dim count As Integer xXHz)w  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double CBO8^M<K  
    Dim tlens As Double, nlens As Double JBg",2w |C  
    Dim curv As Double, conic As Double MiRMjQ2  
    Dim ok As Long -@i2]o  
    :v&GA s6H  
    Sub Main x9@%L{*  
    4RdpROK  
        '用户输入对话框 u}u2{pO!  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 7dW9i7Aj  
            TextBox 220,21,40,21,.TextBox1 'default: 0 h~F uuL  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 Q <78< #I  
            OKButton 40,91,90,21 H:0-.a^ZS  
            CancelButton 190,91,90,21 <'s1+^LC  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 VT+GmS  
            TextBox 220,49,40,21,.TextBox2 'default: 4 g*^"x&  
        End Dialog Gb8LW,$IT-  
        Dim dlg As UserDialog V{a7@_y  
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        ok = Dialog (dlg) 4;j #7  
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        If ok=0 Then    'cancel button was pressed |e+I5  
            Print "Execution cancelled." KiCZEA  
            End eo,m ^&  
        End If N|Rlb5\  
    ;9;.!4g/T  
        'Assign accommodation and pupil diameter & use defaults if field left empty 5 bMVDw/  
        If dlg.TextBox1 = "" Then "qwRcuHY  
            A = 0           'Default accommodation iVmf/N@A|  
        Else 9hLPo  
            A = CDbl(dlg.TextBox1) gS"@P:wYzs  
        End If (/FPGYu3h  
    ko  ~iDT  
        If dlg.TextBox2 = "" Then La3f{;|u5M  
            pupilDiam = 4   'Default pupil diameter /V3*[  
        Else `~*qjA  
            pupilDiam = CDbl(dlg.TextBox2) m6g+ B>  
        End If J7mT&U&Ru  
    lOZ.{0{f,  
        Print " " Tm` QZh3  
        Print "Accommodation = " & A & " Diopters" VEz&TPu  
        Print "Pupil Diameter = " & pupilDiam & " mm" *Z{W,8h*s  
    Ue-HO  
        ' Calculate new parameters with accommodation X'iki4  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness >.M `Fz.  
    ts)0+x  
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens t6 js@Ih  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens \r<&7x#j  
    "jAV7lP  
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens "7gS*v,r  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens '3 |OgV  
    |=GRPvvi  
        tlens = 3.767 + 0.04*A                  'Lens thickness o#w6]Fmc  
    xazh8X0P  
        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction &Vl,x/  
    'OJXllGi  
        'Adjust parameters to account for accommodation Nz$O D_]  
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        '************************************************************************* if_e$,dh~>  
        'Aqueous thickness (Position of Lens) 5t0i/&zX  
        '************************************************************************* Gb~q:&IUr  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) 62Jn8DwAT  
        GetCustomElement eID, entity IO,kP`Wcx  
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        parID = FindFullName( "Geometry.Arizona Eye" ) mflI>J=g  
    o@ ;w!'  
        ' Delete any shift(s) in z Zwq uS9  
        count = 0 G#l zB`i  
        While GetOperationCount(eID)>count d8Upr1_  
            GetOperation eID, count, op 1eT|  
            If op.Type="ShiftZ" Then d(fgv  
                DeleteOperation eID,count S%Ja:0=}?  
                count=count-1 5X~ko>  
            End If a^sR?.+3  
            count=count+1 TTqOAo[-Z  
        Wend b6Ntt Y!3  
    f+/^1~^  
        'Set new shift in /:%^Vh3XF  
        op.Type = "ShiftZ" Jr1^qY`0+  
        op.val1 = taq ,PIdPaV--  
        op.parent = parID 9Z#37)  
        AddOperation eID, op !3T x\a`?/  
        Print "Set aqueous humor thickness = " & taq-0.55 0.+iVOz+Y  
    faJ5f.  
        '************************************************************************* 2RM1-j ($  
        'Radius and conic constant of anterior lens R o%S_!  
        '************************************************************************* crvWAsm  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) 5[*MT%ms  
        GetConic eID, entity, curv, conic |y=CmNG,  
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        SetConic eID, entity, 1/Rant, CCant ;1eu8N8  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant  H) (K  
    wmoOp;C  
        '************************************************************************* sIELkF?.  
        'Radius and conic constant of posterior lens E}a3.6)p  
        '************************************************************************* gc(1,hv  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) .h*&$c/l  
        GetConic eID, entity, curv, conic I>P</TE7  
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        SetConic eID, entity, 1/Rpost, CCpost g%\e80~1(  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost 8zpK; +  
    "@ox=  
        '************************************************************************* ^?juY}rZ=|  
        'Lens thickness (Position of posterior lens surface) k $+&  
        '************************************************************************* <F!:dyl  
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        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) s )To#  
    [NKWudq  
        ' Delete any z-shift(s) iP_rEi*-J  
        count = 0 ,*C^ixNE  
        While GetOperationCount(eID)>count i[YYR,X|  
            GetOperation eID, count, op t zV"|s=o  
            If op.Type="ShiftZ" Then !C/`"JeYL  
                DeleteOperation eID,count -7+Fb^"L  
                count=count-1 -<<!eH  
            End If B3yn:=80  
            count=count+1 :F<a~_k  
        Wend E8-p ,e,  
    r[\47cG  
        'Set new z-shift ME |"pJ  
        op.Type = "ShiftZ" JP@UvDE|  
        op.val1 = tlens B 1p9pr  
        op.parent = parID 1 9)78kV{  
        AddOperation eID, op C8{CKrVE  
        Print "Set lens thickness = " & tlens C6, Bqlio  
    _VMJq9.  
        '************************************************************************* zR5D)`Ph   
        'Lens index of refraction vhUuf+P*  
        '************************************************************************* B! -W765Y  
        eID = FindMaterial( "Lens" ) Sa<R8X' J  
        GetModelMaterial eID, mat LLU>c]a  
    LpF6e9V\Wp  
        mat.Nd = nlens 1yE~#KpH  
        SetModelMaterial eID, mat $~9U-B\  
        Print "Set lens index of refraction = " & nlens I5D\Z  
    rhUZ9Fdv  
        '************************************************************************* 9GQTe1[t4  
        'Pupil diameter P0 89Mh9  
        '************************************************************************* XBeHyQp  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) Dic(G[  
    L ~;_R*Th  
        'Adjust pupil diameter (trimming volume inner hole) 2OZdj  
    JUXK}0d%eN  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" t71 0sWh{  
    M.l;!U!}  
        ' Adjust pupil location to just in front of the lens I]$kVa1iN  
        parID = FindFullName( "Geometry.Arizona Eye" ) N.2rF  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) ^7_<rs   
        count = 0 u(lq9; ;Th  
        While GetOperationCount(eID)>count Yhx~5p  
            GetOperation eID, count, op x,1&ml5  
            If op.Type="ShiftZ" Then 6: M   
                DeleteOperation eID,count 0u0Hl%nl  
                count=count-1 pFG~XW  
            End If JEAqSZak#  
            count=count+1 R.RCa$  
        Wend 55[K[K  
        op.Type = "ShiftZ" v/m6(z  
        op.val1 = taq-0.01 QR,i b  
        op.parent = parID }wUF#  
        AddOperation eID, op mqE&phF,  
    2xjS;lpw  
        Print "Set pupil diameter = " & pupilDiam z#-&MJ  
    9w AP%xh  
        'Update AZ Eye subassembly Description S5uV\Y/A  
        eID = FindFullName( "Geometry.Arizona Eye" ) c[;I\g  
        GetEntity eID, entity XCt}>/"s\h  
        entity.Description = "Accommodation = " & A & "D" !WIL|\jbh  
        SetEntity eID, entity }ShZ4 xMz  
    U 26Iz  
        Update Y${ $7+@  
        Print "DONE!" JY_' d,O  
         QX8N p{g-  
    End Sub )@sz\yI%U  
    eH6#'M4+\  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: 4sva%Up  
    `@:^(sMo  
    Accommodation = 4 Diopters G.BqT\ o'  
    Pupil Diameter = 4 mm /Db~-$K  
    Set aqueous humor thickness = 2.81 4f/8APA  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 LOOv8'%O8  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 yX)2 hj:s  
    Set lens thickness = 3.927 ?vk&k(FT  
    Set lens index of refraction = 1.42672 uH7u4f1Q  
    Set pupil diameter = 4 a u#IA  
    DONE! gFW1Nm_DJ  
    :oZ30}  
    (文章来源:讯技光电)
     
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