[技术]Arizona眼睛模型 [复制链接]

简介 j`D%Wx_  
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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。 f}!Eu  
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模型 {^T_m)|n  
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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。 u_Wftb?9  
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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. NT0im%  
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光源 W"v"mjYud  
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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。 QVR8b3T@  
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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。 [0?W>A*h  
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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。 W^k|*Y|  
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视网膜的散射 fZtuP1-4  
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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。 $`&zIz  
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注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 :pCv!g2  
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脚本 <}Hs@`jS  
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内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： 0a}a  
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如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 V%Ww;Ca]I  
余下的脚本计算与屈光度有关的所有参数。 t
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分析  va[r~  
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屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 {fI"p;|  
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脚本代码 sXwa`_{  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used.  =$-+~  
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Dim entity As T_ENTITY >/+R~ n  
Dim op As T_OPERATION isU4D  
Dim mat As T_MODELMATERIAL NHQi_U  
Dim A As Double (H6Mi.uZ
 
Dim pupilDiam As Double )wNcz~ Y  
Dim eID As Long 'Bwv-J  
Dim parID As Long K"jS,a?s 6  
Dim count As Integer dCA! R"HD  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double M.9w_bW]#D  
Dim tlens As Double, nlens As Double tF:AqR:(~  
Dim curv As Double, conic As Double FWW*f _L  
Dim ok As Long l.xKv$uOGR  
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Sub Main %W^Zob  
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    '用户输入对话框 C@3UsD\s(  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 yVe<+Z\7  
        TextBox 220,21,40,21,.TextBox1 'default: 0 \DcO.`L  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 qH(HcsgD  
        OKButton 40,91,90,21 ZkryoIQ%=  
        CancelButton 190,91,90,21 $kBcnk  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 tu's]3RE  
        TextBox 220,49,40,21,.TextBox2 'default: 4 8osP$"/o  
    End Dialog v Q51-.g  
    Dim dlg As UserDialog o]DYS,v  
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    ok = Dialog (dlg)  }=d}q *  
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    If ok=0 Then    'cancel button was pressed yRR[M@Y  
        Print "Execution cancelled." bT^(D^  
        End Xc$Zkfmms  
    End If ^/I.? :+  
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    'Assign accommodation and pupil diameter & use defaults if field left empty .=zBUvy  
    If dlg.TextBox1 = "" Then >P ~j@Lv  
        A = 0           'Default accommodation tYp 185  
    Else On0,#i=  
        A = CDbl(dlg.TextBox1) +DaKP)H\:  
    End If +~"(Wooi  
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    If dlg.TextBox2 = "" Then +ryB
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        pupilDiam = 4   'Default pupil diameter FXul u6"SX  
    Else *i {e$Zv'  
        pupilDiam = CDbl(dlg.TextBox2) Xp9] 9H.  
    End If C]&/k_k  
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    Print " " &g~NkJc0c  
    Print "Accommodation = " & A & " Diopters" KQ^|prN?y  
    Print "Pupil Diameter = " & pupilDiam & " mm" ECk3Da  
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    ' Calculate new parameters with accommodation bg5i+a,?  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness tn;{r  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens }tL]EW^  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens c-"vQ>ux+  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens R'pfA B|!  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens BIEq(/-  
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    tlens = 3.767 + 0.04*A                  'Lens thickness sR^b_/ElxT  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction =@c;%
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    'Adjust parameters to account for accommodation Wt.['`c<  
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    '*************************************************************************
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    'Aqueous thickness (Position of Lens) L)qUBp@MW  
    '************************************************************************* ,w f6gmh8  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) cG&@PO]+.  
    GetCustomElement eID, entity z<%dWz  
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    parID = FindFullName( "Geometry.Arizona Eye" )
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    ' Delete any shift(s) in z G'`^U}9V\  
    count = 0 jrpki<D  
    While GetOperationCount(eID)>count 4C )sjk?m  
        GetOperation eID, count, op 8@b`a]lgrd  
        If op.Type="ShiftZ" Then hiv {A9a?  
            DeleteOperation eID,count iRx`Nx<@  
            count=count-1 ttls.~DG  
        End If -3 Sb%V\  
        count=count+1 &DjA?0`J  
    Wend U2LD_-HZ  
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    'Set new shift in V5p^]To!  
    op.Type = "ShiftZ" j7$xHnV4  
    op.val1 = taq XMz*}B6GQ  
    op.parent = parID s>W :vV@  
    AddOperation eID, op  f^KN8N  
    Print "Set aqueous humor thickness = " & taq-0.55 &3J^z7kU  
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    '************************************************************************* 5$Kd<ky  
    'Radius and conic constant of anterior lens ox_DEg7l  
    '************************************************************************* Kz
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    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) UFLx'VXd  
    GetConic eID, entity, curv, conic p]<)6sZ  
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    SetConic eID, entity, 1/Rant, CCant fP6\Ur  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant  U ^nv)  
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    '************************************************************************* e"*1l>g  
    'Radius and conic constant of posterior lens ]')y(_{  
    '************************************************************************* r)Vpt fg;  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) A@Lr(L  
    GetConic eID, entity, curv, conic A6J:!sY4A  
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    SetConic eID, entity, 1/Rpost, CCpost 5;G0$M0  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost C#
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    '************************************************************************* j9yOkaVEg  
    'Lens thickness (Position of posterior lens surface)  NEPK  
    '************************************************************************* m`):= ^nC  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) s5 {B1e  
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    ' Delete any z-shift(s) 2(x| %  
    count = 0 w^=(:`  
    While GetOperationCount(eID)>count f$9|qfW'$  
        GetOperation eID, count, op *B\ @L  
        If op.Type="ShiftZ" Then 3,`M\#z%K  
            DeleteOperation eID,count TvS<;0~K  
            count=count-1 +'+Nr<  
        End If "5z@A/Z/  
        count=count+1 Q2)(tB= )  
    Wend )q.ZzijG/  
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    'Set new z-shift )Vrp<"v  
    op.Type = "ShiftZ" /I1n${{5  
    op.val1 = tlens :WsHP\r  
    op.parent = parID j
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    AddOperation eID, op R'6(eA[K  
    Print "Set lens thickness = " & tlens )_n(u3'  
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    '************************************************************************* J7C?
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    'Lens index of refraction x!vyjp  
    '************************************************************************* <L11s%5-  
    eID = FindMaterial( "Lens" ) >,tJq%  
    GetModelMaterial eID, mat <}h<
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    mat.Nd = nlens c~ vql4  
    SetModelMaterial eID, mat $Ff6nc=  
    Print "Set lens index of refraction = " & nlens y\(xYB>T  
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    '************************************************************************* 3 {hUp81>  
    'Pupil diameter Z!Z{Gm3  
    '************************************************************************* aMxj{*v7  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) m/jyc# L:u  
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    'Adjust pupil diameter (trimming volume inner hole) G<k.d"<  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" [s\8@5?E  
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    ' Adjust pupil location to just in front of the lens 8a]g>g  
    parID = FindFullName( "Geometry.Arizona Eye" ) MK@rx6<9  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) wq,&0P-v  
    count = 0 Y<kz+d,C  
    While GetOperationCount(eID)>count !Q<3TfC  
        GetOperation eID, count, op Vgkj4EE  
        If op.Type="ShiftZ" Then l:bbc!3  
            DeleteOperation eID,count .Y^3G7On  
            count=count-1 6d6Dk>(V  
        End If mF!4*k  
        count=count+1 =R 4]Kf  
    Wend DfU= i'R  
    op.Type = "ShiftZ" iOCs%J  
    op.val1 = taq-0.01 +-SO}P  
    op.parent = parID ;($xAAR  
    AddOperation eID, op PhV/WjCZ  
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    Print "Set pupil diameter = " & pupilDiam /ueOc<[8"  
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    'Update AZ Eye subassembly Description ]dl.~;3~~  
    eID = FindFullName( "Geometry.Arizona Eye" ) O"kb*//  
    GetEntity eID, entity 1zG6^U  
    entity.Description = "Accommodation = " & A & "D" k%\y,b*  
    SetEntity eID, entity J%B
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    Update ^!i4d))  
    Print "DONE!" i `p1e5$  
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End Sub  )*6  
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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： {Y=k`t,  
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Accommodation = 4 Diopters !FyO5`v  
Pupil Diameter = 4 mm {06ClI  
Set aqueous humor thickness = 2.81 JY"J}  
Set anterior lens radius = 10.4 and conic constant = -2.375869 py':36'  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 )?B-en\  
Set lens thickness = 3.927 $bF+J8%D  
Set lens index of refraction = 1.42672 jk_yrbLc  
Set pupil diameter = 4 -|s%5p|  
DONE! iRcac[uV