[技术]Arizona眼睛模型 [复制链接]

简介 X1Qr_o-BR  
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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。 +vf:z?I
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模型 CA/ -Gb  
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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。 1t.R+1[c  
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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. > V8sm/M  
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光源 ^_sQG  
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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。 $%=G[/i'  
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除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处，并增加了pre-propagation distance= -8。尽管光线在光瞳处创建，规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射，而不是在光瞳处入射。 iUTU*El>  
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在往下看是内置的脚本用来修改屈光度，使其为4（250mm），光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 Bhe{L?}0  
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视网膜的散射 NEw$q4  

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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。 `"c'
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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。 KzNm^^#/$A  
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脚本 f0DK>L  
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内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： E=]]b;u-n  
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如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 Bd&`Xfebj  
余下的脚本计算与屈光度有关的所有参数。 h)cY])tGtK  
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分析 k3>YBf`fC  
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屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 FshC )[w,  
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脚本代码 @^&7$#jq%  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. &I/qG`W  
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Dim entity As T_ENTITY ($8t%jVWJJ  
Dim op As T_OPERATION ;&S;%W>|  
Dim mat As T_MODELMATERIAL uokc:D  
Dim A As Double "%@v++4y  
Dim pupilDiam As Double mp1ttGUtM  
Dim eID As Long C?o6(p"b  
Dim parID As Long lP3h<j  
Dim count As Integer :h*a rT4{  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double 59lj7  
Dim tlens As Double, nlens As Double ||Y<f *  
Dim curv As Double, conic As Double A gWPa.'3  
Dim ok As Long /iG7MC\`  
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Sub Main IPtvuEju\  
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    '用户输入对话框 T$P-<s  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 prrT:Y  
        TextBox 220,21,40,21,.TextBox1 'default: 0  #^0(  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 X{Zm9T  
        OKButton 40,91,90,21 iKAusWj  
        CancelButton 190,91,90,21 !MV@) (.  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 Fe!9y2Mg  
        TextBox 220,49,40,21,.TextBox2 'default: 4 qINTCm j  
    End Dialog  uMd. j$$  
    Dim dlg As UserDialog zk}{ dG^M:  
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    ok = Dialog (dlg) ?fK1  
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    If ok=0 Then    'cancel button was pressed <[i}n55  
        Print "Execution cancelled." G5Ykbw#  
        End 6gU{(H   
    End If v~=\H  
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    'Assign accommodation and pupil diameter & use defaults if field left empty /.Q4~Hw%}  
    If dlg.TextBox1 = "" Then G%{0i20_  
        A = 0           'Default accommodation 2*1ft>Uty  
    Else goZ V.,w  
        A = CDbl(dlg.TextBox1) ^+/kr/  
    End If 4XJiIa?  
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    If dlg.TextBox2 = "" Then T?wzwGp-[  
        pupilDiam = 4   'Default pupil diameter ar^i|`D  
    Else ,={t8lN  
        pupilDiam = CDbl(dlg.TextBox2) X.V[0$.;  
    End If -d=WV:G%e  
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    Print " " .F2:!h$  
    Print "Accommodation = " & A & " Diopters" VR0=SE  
    Print "Pupil Diameter = " & pupilDiam & " mm" bw S*]!*  
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    ' Calculate new parameters with accommodation D1T@R)j  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness ^jSsa  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens DuF"*R~et  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens /aqEJGG>  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens m%r/O&g  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens ,6"l(]0  
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    tlens = 3.767 + 0.04*A                  'Lens thickness $x
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction AkBMwV  
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    'Adjust parameters to account for accommodation l67Jl"v  
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    '************************************************************************* e2)autBe  
    'Aqueous thickness (Position of Lens) !0}\&<8/m  
    '************************************************************************* <48<86TP  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) 0L-!! c3  
    GetCustomElement eID, entity zI;0&  
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    parID = FindFullName( "Geometry.Arizona Eye" ) q1{H~VSn"  
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    ' Delete any shift(s) in z #"*e+.j[;  
    count = 0 elPE%'  
    While GetOperationCount(eID)>count T)iW`vZg8  
        GetOperation eID, count, op |U'I/A  
        If op.Type="ShiftZ" Then Ym8}ZW-  
            DeleteOperation eID,count _aS;!6b8W  
            count=count-1 rZ03x\2  
        End If gAbD7SE  
        count=count+1 =:I+6PlF@  
    Wend 19U]2D/z  
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    'Set new shift in Z;DCI-Wg  
    op.Type = "ShiftZ" zu\`1W^  
    op.val1 = taq  %Y nmuZ  
    op.parent = parID jLVl4h&  
    AddOperation eID, op f'Mop= .  
    Print "Set aqueous humor thickness = " & taq-0.55 iz[gHB  
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    '************************************************************************* &#{dWObh  
    'Radius and conic constant of anterior lens 8p^B hd  
    '************************************************************************* n# 7Pr/*0  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) &, a3@i  
    GetConic eID, entity, curv, conic ^A_;#vK  
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    SetConic eID, entity, 1/Rant, CCant nHXX\i  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant Ri7((x]H"  
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    '************************************************************************* Sv[5NZn0&  
    'Radius and conic constant of posterior lens ]+Ixi o  
    '************************************************************************* [:EvTY  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) _8?o'<!8?^  
    GetConic eID, entity, curv, conic 2t#L:vY  
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    SetConic eID, entity, 1/Rpost, CCpost ssQ BSbx
  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost
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    '************************************************************************* ro~+j}*  
    'Lens thickness (Position of posterior lens surface) _.)eL3OF  
    '************************************************************************* rRFAD{5)  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) <yUstz,Xu^  
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    ' Delete any z-shift(s) ~aK?cP  
    count = 0 [\z/Lbn ,.  
    While GetOperationCount(eID)>count B9dt=j3j2  
        GetOperation eID, count, op [5d2D,)  
        If op.Type="ShiftZ" Then clO,}Ph>  
            DeleteOperation eID,count MjL)IgT  
            count=count-1 c,\i"=!$  
        End If &"Ux6mF-"  
        count=count+1 bCv{1]RC2  
    Wend 2h=%K/hhY  
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    'Set new z-shift mu]as: ~  
    op.Type = "ShiftZ" +K",^6%1  
    op.val1 = tlens E>jh"|f:{  
    op.parent = parID ,L> ar)B  
    AddOperation eID, op PXKJ^fa  
    Print "Set lens thickness = " & tlens q>!L6h5]t  
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    '************************************************************************* a6xj
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    'Lens index of refraction =3xE:  
    '************************************************************************* mB'3N;~  
    eID = FindMaterial( "Lens" ) %:v`EjRD0  
    GetModelMaterial eID, mat *~XA'Vw!  
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    mat.Nd = nlens tA.`k;LT  
    SetModelMaterial eID, mat :*514N  
    Print "Set lens index of refraction = " & nlens I<oL}f  
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    '************************************************************************* [IZM.r`Z  
    'Pupil diameter eU+ {*YJg  
    '************************************************************************* U\@
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    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) Y,S\2or$  
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    'Adjust pupil diameter (trimming volume inner hole) )Q;978:  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" ;!>Wz9  
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    ' Adjust pupil location to just in front of the lens ='?:z2lJ  
    parID = FindFullName( "Geometry.Arizona Eye" ) C]u',9,  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) c,EBF\r8*  
    count = 0 I5ss0JSl/  
    While GetOperationCount(eID)>count )}v3q6?_  
        GetOperation eID, count, op -;(Q1)&  
        If op.Type="ShiftZ" Then e0,'+;*=g  
            DeleteOperation eID,count }CL"S_>1  
            count=count-1 F t&+vS  
        End If M5L{*>4|6  
        count=count+1 4Aes#{R3v  
    Wend ^y.nDs%ZT7  
    op.Type = "ShiftZ" IV16d  
    op.val1 = taq-0.01 )P&9A)8  
    op.parent = parID 5i6
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    AddOperation eID, op F4#g?R::U  
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    Print "Set pupil diameter = " & pupilDiam Fe&qwq"  
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    'Update AZ Eye subassembly Description >>Ar$  
    eID = FindFullName( "Geometry.Arizona Eye" ) hi2sec|;<  
    GetEntity eID, entity J:dof:q  
    entity.Description = "Accommodation = " & A & "D" j|fd-<ng  
    SetEntity eID, entity U'( sn  
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    Update nt1CTWKM8^  
    Print "DONE!" *O$CaAr\s  
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End Sub O>y'Nqz  
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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： 4Cb9%Q0  
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Accommodation = 4 Diopters F!!N9VIC  
Pupil Diameter = 4 mm  NW9n  
Set aqueous humor thickness = 2.81 7k%T<;V  
Set anterior lens radius = 10.4 and conic constant = -2.375869 sd re#@n}  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 'X
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Set lens thickness = 3.927 M(q'%XL^  
Set lens index of refraction = 1.42672 ^n.WZUk  
Set pupil diameter = 4 \uOdALZ  
DONE! 8y';\(;