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infotek 2021-10-22 09:55

Arizona眼睛模型

简介 iWkWR"ys y  
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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。 ]s'as9s9  
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模型 YkSl^j[DHs  
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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。 vI >w e  
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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. F/{!tx  
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光源 C{rcs'  
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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。 ;$|nrwhy  
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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。 _TZRVa_  
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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。 \}b%E'+_T  
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图2. 字母F光源的设定方法光 YD6'#(  
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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 \M^bD4';>  
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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。 d7upz]K9g  
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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。 wP@(?z  
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图5. 视网膜重点采样规格设定
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脚本 5t]H?b8  
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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: 73;GW4,  
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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。 0GeTS Fj  
余下的脚本计算与屈光度有关的所有参数。 kl:Bfs)b  
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分析 #"~<HG}bR/  
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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。 Dp9+HA9t  
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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 5rik7a)Z]  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. b ]KBgZ  
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Dim entity As T_ENTITY 'H;*W|:-]  
Dim op As T_OPERATION xA*<0O\V  
Dim mat As T_MODELMATERIAL Km$\:Xo  
Dim A As Double x.$FNt(9  
Dim pupilDiam As Double gPPkT"  
Dim eID As Long k<?b(&`J  
Dim parID As Long i/Zd8+.n$  
Dim count As Integer [7y]n;Fy  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double ckCE1e>s  
Dim tlens As Double, nlens As Double FYQS)s  
Dim curv As Double, conic As Double WpvhTX  
Dim ok As Long M_DwUS 1?  
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Sub Main "w<#^d_6  
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    '用户输入对话框 BI@[\aRLQ  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 w7L) '9  
        TextBox 220,21,40,21,.TextBox1 'default: 0 $XH^~i;  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 y6BAH  
        OKButton 40,91,90,21 ~k5W@`"W  
        CancelButton 190,91,90,21 @6-jgw>W2  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 )^hbsMhO  
        TextBox 220,49,40,21,.TextBox2 'default: 4 }jPSUdo  
    End Dialog N;%6:I./  
    Dim dlg As UserDialog d<Tc7vg4|U  
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    ok = Dialog (dlg) jL}v9$  
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    If ok=0 Then    'cancel button was pressed ]Hv[IodJ  
        Print "Execution cancelled." owv[M6lbD  
        End ,V}WM%Km  
    End If Tid aa  
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    'Assign accommodation and pupil diameter & use defaults if field left empty rytyw77t(  
    If dlg.TextBox1 = "" Then f|(M.U-  
        A = 0           'Default accommodation )V9bI(v  
    Else N'=gep0V@  
        A = CDbl(dlg.TextBox1) d0> zS  
    End If #g!.T g'  
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    If dlg.TextBox2 = "" Then |y!A&d=xYn  
        pupilDiam = 4   'Default pupil diameter *VN6cSq  
    Else q@2siI~W  
        pupilDiam = CDbl(dlg.TextBox2) \'j|BJ~L f  
    End If 8q7b_Pq1U  
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    Print " " sDV Q#}a  
    Print "Accommodation = " & A & " Diopters" |4`{]2C  
    Print "Pupil Diameter = " & pupilDiam & " mm" g9F?z2^  
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    ' Calculate new parameters with accommodation apxph2yvS  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness e96k{C`j0  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens +"VP-s0  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens [Vt\$  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens ;A[Q2(w+  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens QmIBaMI#  
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    tlens = 3.767 + 0.04*A                  'Lens thickness ~Cjn7  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction &kw@,];4Z  
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    'Adjust parameters to account for accommodation L/^I*p,  
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    '************************************************************************* "zy7C*)>r  
    'Aqueous thickness (Position of Lens) 40 0#v|b  
    '************************************************************************* as=LIw}Q4  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) 4X|zmr:A  
    GetCustomElement eID, entity t |oR7qa{w  
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    parID = FindFullName( "Geometry.Arizona Eye" ) WjqO@]P6  
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    ' Delete any shift(s) in z o _H`o&xr  
    count = 0 " 2Dngw  
    While GetOperationCount(eID)>count m j@13$=  
        GetOperation eID, count, op N}YkMJy  
        If op.Type="ShiftZ" Then !{41!O,K#  
            DeleteOperation eID,count t&DEb_"De  
            count=count-1 WMg~Y"W  
        End If KY] C6kh  
        count=count+1 ^sg,\zD 'X  
    Wend b>9>uC@J15  
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    'Set new shift in tklH@'q  
    op.Type = "ShiftZ" ws^ np  
    op.val1 = taq ~^b/(  
    op.parent = parID BFW&2  
    AddOperation eID, op Zj4Uak  
    Print "Set aqueous humor thickness = " & taq-0.55 ;6hOx(>`=  
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    '************************************************************************* H 7 ^/q7  
    'Radius and conic constant of anterior lens =E{`^IT'R  
    '************************************************************************* k-""_WJ~^  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) Pr,q*_Yy  
    GetConic eID, entity, curv, conic NW)1#]gg%  
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    SetConic eID, entity, 1/Rant, CCant .w ,q0<}  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant /|&*QLy  
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    '************************************************************************* G9vpt M  
    'Radius and conic constant of posterior lens IdxzE_@  
    '************************************************************************* pFz`}?c0  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) BDZ?Ez \Sg  
    GetConic eID, entity, curv, conic 9 JK Ew  
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    SetConic eID, entity, 1/Rpost, CCpost gbagi+8s`%  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost e64^ChCoV  
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    '************************************************************************* ROZF)|l  
    'Lens thickness (Position of posterior lens surface) 7i1q wRv  
    '************************************************************************* uhutg,[  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) O!bOp=  
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    ' Delete any z-shift(s) *s iFj CN<  
    count = 0 N=g"(%  
    While GetOperationCount(eID)>count &XUiKnNW  
        GetOperation eID, count, op [;myHI`tw  
        If op.Type="ShiftZ" Then Ef13Q]9|  
            DeleteOperation eID,count K )k<Rh[<  
            count=count-1 TrR8?-  
        End If (0kK_k'T  
        count=count+1 2jCfT>`3  
    Wend QoH6  
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    'Set new z-shift DrK{}uM  
    op.Type = "ShiftZ" 'a.qu9PJ  
    op.val1 = tlens \:F_xq  
    op.parent = parID ^@NU}S):yN  
    AddOperation eID, op V,N%;iB}  
    Print "Set lens thickness = " & tlens ! #2{hQRu  
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    '************************************************************************* uOdl*|T?  
    'Lens index of refraction [Cv/{f3]u{  
    '************************************************************************* )p%E%6p  
    eID = FindMaterial( "Lens" ) `%WU8Yv  
    GetModelMaterial eID, mat ijx0gh`~  
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    mat.Nd = nlens n#_$\ p>Yd  
    SetModelMaterial eID, mat Vj>8a)"B5a  
    Print "Set lens index of refraction = " & nlens UU0,!?o4  
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    '************************************************************************* Hc(OI|z~  
    'Pupil diameter q;)JISf.  
    '************************************************************************* %z 4Nl$\  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) ,:\|7F  
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    'Adjust pupil diameter (trimming volume inner hole) SS.dY""89  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" #|PS&}6wU  
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    ' Adjust pupil location to just in front of the lens ^eYVWQ'  
    parID = FindFullName( "Geometry.Arizona Eye" ) &H:(z4/  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) t |A-9^t'!  
    count = 0 )U{Qj5W+F  
    While GetOperationCount(eID)>count y;@:ulv[  
        GetOperation eID, count, op m5Di=8  
        If op.Type="ShiftZ" Then P1' al  
            DeleteOperation eID,count pr UM-u8  
            count=count-1 ]yPqLJ  
        End If O55 xS+3^k  
        count=count+1 D]Xsvv #  
    Wend $43qME  
    op.Type = "ShiftZ" HBx=\%;n  
    op.val1 = taq-0.01 .z}~4BY  
    op.parent = parID <1\Nb{5  
    AddOperation eID, op agW@ {c  
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    Print "Set pupil diameter = " & pupilDiam +@iA;2&  
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    'Update AZ Eye subassembly Description @A ^;jk  
    eID = FindFullName( "Geometry.Arizona Eye" ) H-fX(9  
    GetEntity eID, entity LvUj9eVb/L  
    entity.Description = "Accommodation = " & A & "D" Is?La  
    SetEntity eID, entity ':m,)G5&  
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    Update oJ|j#+Ft  
    Print "DONE!" 2n"V}p>8i#  
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End Sub ptxbDzOz  
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如果屈光度是4,光瞳直径是4,则会输出如下数据: i|*)I:SHU  
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Accommodation = 4 Diopters VrQmP  
Pupil Diameter = 4 mm \%N!5>cZ{  
Set aqueous humor thickness = 2.81 g:Xhw$x9  
Set anterior lens radius = 10.4 and conic constant = -2.375869 ILShd)]Rw  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 j@uOOhy  
Set lens thickness = 3.927  dZ0vA\z|  
Set lens index of refraction = 1.42672 o@i#|kx,  
Set pupil diameter = 4 bsA-2*Q+  
DONE! @;?p&.W`D  
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