[技术]Arizona眼睛模型 [复制链接]

简介 G@.MP| 2  
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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。 IdQ./@?  
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模型 gxN>q4z  
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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。 |M7cB$y  
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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. }5-w,m{8/  
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光源 5J10S  
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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。 q.c)>=!.  
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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。 rZ~w_DK*  
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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。 E5w;75,  
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视网膜的散射 `#N/]4(j  
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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。 ~SnUnNDm`  
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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。 {KG6#/%;  
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脚本 qN $t_  
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内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： EY,jy]|#  
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如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 eU[g@Pq:Y  
余下的脚本计算与屈光度有关的所有参数。 fpD$%.y'J  
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分析 O G`8::S  
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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。 jJy:/!i  
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脚本代码 F (*B1J2_g  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. N
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Dim entity As T_ENTITY k }=<51c  
Dim op As T_OPERATION x:|Y)Dn\  
Dim mat As T_MODELMATERIAL  I//=C6  
Dim A As Double apvcWF%  
Dim pupilDiam As Double <ql,@*Y  
Dim eID As Long =]Wi a
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Dim parID As Long (}: s[cs  
Dim count As Integer 5E]t4"  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double at: li  
Dim tlens As Double, nlens As Double d1b]+AG4  
Dim curv As Double, conic As Double c{z$^)A/  
Dim ok As Long ekM? '9ez  
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Sub Main [q<'ty  
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    '用户输入对话框 XYEwn_Y  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 $Ome]+0  
        TextBox 220,21,40,21,.TextBox1 'default: 0 #Y'eS'lv4  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 d2rs+-  
        OKButton 40,91,90,21 $v^hzC  
        CancelButton 190,91,90,21 !?2)apM  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 T$4{fhV \  
        TextBox 220,49,40,21,.TextBox2 'default: 4 .iXN~*+g  
    End Dialog ]c.w+<  
    Dim dlg As UserDialog Ei;tfB  
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    ok = Dialog (dlg) IGlR,tw_/  
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    If ok=0 Then    'cancel button was pressed iI3:<j l  
        Print "Execution cancelled." 2]>O ZhS  
        End U{U"%XdO  
    End If S;|:ci<[=  
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    'Assign accommodation and pupil diameter & use defaults if field left empty +>$]leqa  
    If dlg.TextBox1 = "" Then p>6`jr  
        A = 0           'Default accommodation ZnG.::&:  
    Else 6Rc=!_v^  
        A = CDbl(dlg.TextBox1) {e|qQ4~h  
    End If K_7pr~D]@r  
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    If dlg.TextBox2 = "" Then *@U{[J  
        pupilDiam = 4   'Default pupil diameter ^ Lth
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    Else H;H=8'  
        pupilDiam = CDbl(dlg.TextBox2) Fn4v/)*H  
    End If f5jl$H.  
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    Print " " aZfMeW  
    Print "Accommodation = " & A & " Diopters" ?J}Q&p.  
    Print "Pupil Diameter = " & pupilDiam & " mm" 7
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    ' Calculate new parameters with accommodation v4$/LUJZp  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness R4?>C-;  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens NBikYxa  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens h ><Sp*z_V  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens TP }a9-9?  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens kfy!T rf  
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    tlens = 3.767 + 0.04*A                  'Lens thickness &|yLTx  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction a#oROb-*~  
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    'Adjust parameters to account for accommodation &|v)
 
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    '************************************************************************* >{#JIG.  
    'Aqueous thickness (Position of Lens) .RD<]BxJ  
    '************************************************************************* 4l D$'`  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) (In{GA7;  
    GetCustomElement eID, entity _O9V"DM  
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    parID = FindFullName( "Geometry.Arizona Eye" ) U82a]i0  
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    ' Delete any shift(s) in z %X}ZX|{O  
    count = 0 $d?+\r:I{,  
    While GetOperationCount(eID)>count /:dLqyQ_V  
        GetOperation eID, count, op `~1!nfFD  
        If op.Type="ShiftZ" Then k.J%rRneN  
            DeleteOperation eID,count ]#/nn),Z  
            count=count-1 `e[S Zj\  
        End If C]^Ep
  
        count=count+1 kY0HP a  
    Wend [%W'd9`>  
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    'Set new shift in 2e48L677-  
    op.Type = "ShiftZ" QcegT/vO  
    op.val1 = taq %?~'A59  
    op.parent = parID s%[F,hQRk  
    AddOperation eID, op %6K7uvTq  
    Print "Set aqueous humor thickness = " & taq-0.55 ,'L>:pF3  
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    '************************************************************************* 8}/DD^M  
    'Radius and conic constant of anterior lens Vk5Z[w a  
    '*************************************************************************  hfB$4s9  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) ;(Yb9Mr)z  
    GetConic eID, entity, curv, conic A40DbD\^ad  
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    SetConic eID, entity, 1/Rant, CCant d^=BXCoC  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant >P6"-x,["  
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    '************************************************************************* l;8t%JV5  
    'Radius and conic constant of posterior lens )f8>kz(  
    '************************************************************************* u6iW1,
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    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" )
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    GetConic eID, entity, curv, conic @T1G#[C~t  
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    SetConic eID, entity, 1/Rpost, CCpost q^X7x_  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost GwWK'F'2  
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    '************************************************************************* (leX` SN0u  
    'Lens thickness (Position of posterior lens surface) #qRoTtMq7  
    '************************************************************************* (P>nA3:UXB  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) G?Et$r7:R  
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    ' Delete any z-shift(s) 7UT
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    count = 0 kBUkE-~  
    While GetOperationCount(eID)>count A|biOz
 
        GetOperation eID, count, op f\&X$
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        If op.Type="ShiftZ" Then v>X!/if<y  
            DeleteOperation eID,count D]]e6gF$e  
            count=count-1 lZzW- %K  
        End If y4\X~5kU  
        count=count+1 $q!A1Fgk0  
    Wend e=]SIR()`  
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    'Set new z-shift Y:*% [\R  
    op.Type = "ShiftZ" M1jT+  
    op.val1 = tlens :s)cTq|3  
    op.parent = parID KGt:  
    AddOperation eID, op &X4anH>O  
    Print "Set lens thickness = " & tlens 2H%9l@}u  
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    '************************************************************************* ^}  {r@F  
    'Lens index of refraction IIk_!VzT  
    '************************************************************************* ?XKX&ws  
    eID = FindMaterial( "Lens" ) T CT8OU|  
    GetModelMaterial eID, mat pl8b&bLzi  
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    mat.Nd = nlens <Bo\a3Z  
    SetModelMaterial eID, mat HDm]njF%qQ  
    Print "Set lens index of refraction = " & nlens ._+cvXy  
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    '************************************************************************* .Ys e/oEo  
    'Pupil diameter '}agi.z  
    '************************************************************************* kBP?_ O  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) .AN1Yt  
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    'Adjust pupil diameter (trimming volume inner hole) &5 7c!)  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" l|q-kRRjn  
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    ' Adjust pupil location to just in front of the lens Mi]^wCF  
    parID = FindFullName( "Geometry.Arizona Eye" ) F .S^KK  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) ~[=<Os  
    count = 0 tSy 9v  
    While GetOperationCount(eID)>count %oBP6|e  
        GetOperation eID, count, op [kg^S`gc#  
        If op.Type="ShiftZ" Then u|KjoO   
            DeleteOperation eID,count 8Z!%rS  
            count=count-1 Wvl~|Sx]  
        End If loA/d  
        count=count+1 {@X>!]  
    Wend ByY^d#oE  
    op.Type = "ShiftZ" 2: QT`e&  
    op.val1 = taq-0.01 ByqVNz0L  
    op.parent = parID ,nf}4  
    AddOperation eID, op #cQ5-R-1  
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    Print "Set pupil diameter = " & pupilDiam ^i@anbH  
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    'Update AZ Eye subassembly Description 2l?^\9&
 
    eID = FindFullName( "Geometry.Arizona Eye" ) O=__w *<  
    GetEntity eID, entity 2G.y.#W  
    entity.Description = "Accommodation = " & A & "D"   Z9:  
    SetEntity eID, entity 3cHYe  
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    Update $WIE`P%  
    Print "DONE!" GZO:lDdA  
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End Sub pW+uVv,  
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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： h: yJ  
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Accommodation = 4 Diopters }etdXO_^  
Pupil Diameter = 4 mm ?Uq"zq  
Set aqueous humor thickness = 2.81 :G>w MMv&z  
Set anterior lens radius = 10.4 and conic constant = -2.375869 t]I9[5Pq\  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 'goKYl#1Q  
Set lens thickness = 3.927 KBM*7raA  
Set lens index of refraction = 1.42672 *AV%=  
Set pupil diameter = 4 Cu`  
DONE! % PzkVs