[技术]Arizona眼睛模型 [复制链接]

简介 C=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。 kngkG|du  
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模型 sXDS_Q  
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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。 -D?T0>  
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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. S9S8T+  
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光源 D^yZ!}Kl  
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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。 U+>!DtOYK  
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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。 q4'szDYO2  
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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。 
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视网膜的散射 ?$i`K|  
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在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 +EjH9;gx  
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注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 S+Z_Qf  
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脚本 I4{uw ge  
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内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： X`xmV!  
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如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 11t+ a,fM  
余下的脚本计算与屈光度有关的所有参数。 'X_8j` ]#  
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分析 *'4+kj7>  
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屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 TbX#K:l  
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脚本代码 H8.Aq\2S  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. h6J0b_3h4  
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Dim entity As T_ENTITY D=Ia$O0.  
Dim op As T_OPERATION ]."
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Dim mat As T_MODELMATERIAL Y3@\uM`2#  
Dim A As Double `/?XvF\  
Dim pupilDiam As Double _`3'D`s  
Dim eID As Long sjl(  
Dim parID As Long mU0j K@^&M  
Dim count As Integer E_sKDybj  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double q"BM*:W  
Dim tlens As Double, nlens As Double
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Dim curv As Double, conic As Double \AFoxi2h  
Dim ok As Long >K:| +XbH  
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Sub Main
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    '用户输入对话框 ]^aOYtKX  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 12l-NWXf  
        TextBox 220,21,40,21,.TextBox1 'default: 0 <[iw1>  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 C>l{_J)n  
        OKButton 40,91,90,21 |,!]]YO.V  
        CancelButton 190,91,90,21 X*ZTn 7<
 
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 |e{F;8  
        TextBox 220,49,40,21,.TextBox2 'default: 4 p5F
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    End Dialog {Yq"%n'0  
    Dim dlg As UserDialog Cka
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    ok = Dialog (dlg) 'Mp8!9=&  
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    If ok=0 Then    'cancel button was pressed bm/pLC6%.  
        Print "Execution cancelled." <X>lA  
        End ~)J]`el,Q  
    End If D*7JE  
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    'Assign accommodation and pupil diameter & use defaults if field left empty (41BUX  
    If dlg.TextBox1 = "" Then Gg'sgn   
        A = 0           'Default accommodation hd+(M[C<9  
    Else vbFi#|EU  
        A = CDbl(dlg.TextBox1) KmF"
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    End If >i&"{GZ  
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    If dlg.TextBox2 = "" Then RWyDX_z#<  
        pupilDiam = 4   'Default pupil diameter
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    Else K|n%8hRy  
        pupilDiam = CDbl(dlg.TextBox2) x?10^~R  
    End If ]0[Gc \h}  
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    Print " " ^:krfXT  
    Print "Accommodation = " & A & " Diopters" u.\FNa  
    Print "Pupil Diameter = " & pupilDiam & " mm" LWH(bs9U  
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    ' Calculate new parameters with accommodation ?+3vK=Rf}  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness C8^h`B9z&I  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens 1co;U  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens ^Om0~)"q  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens pFB^l|\ ]  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens Rs$fNW@P  
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    tlens = 3.767 + 0.04*A                  'Lens thickness ^nO0/nqz]  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction F!k3/z  
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    'Adjust parameters to account for accommodation C0f<xhp?j  
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    '************************************************************************* ;`")3~M3*  
    'Aqueous thickness (Position of Lens) )GT*HJR(vc  
    '************************************************************************* %|
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    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) kdgU1T@y.  
    GetCustomElement eID, entity VL =19[  
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    parID = FindFullName( "Geometry.Arizona Eye" ) =D>,s)}o3;  
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    ' Delete any shift(s) in z x]6-r`O7r  
    count = 0 D,3Kx ^  
    While GetOperationCount(eID)>count %>];F~z  
        GetOperation eID, count, op b(E}W2-t  
        If op.Type="ShiftZ" Then Q1 t-Z;X  
            DeleteOperation eID,count zh.^> `   
            count=count-1 "=0(a)01p:  
        End If c*m7'\  
        count=count+1 /+U)!$zm*  
    Wend ,ST.pu8N.  
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    'Set new shift in v23Uh2[@Yy  
    op.Type = "ShiftZ" R2ZQBwB  
    op.val1 = taq 4'b]2Mn3   
    op.parent = parID u9~J1s<e  
    AddOperation eID, op &bgi0)>  
    Print "Set aqueous humor thickness = " & taq-0.55 D)Rf  
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    '************************************************************************* wz)9/bL  
    'Radius and conic constant of anterior lens U+M?<4J)"  
    '************************************************************************* E}j8p_p  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) n k3lC/f  
    GetConic eID, entity, curv, conic &nw~gSe  
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    SetConic eID, entity, 1/Rant, CCant C}EDl2  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant 2,nCGSfc  
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    '************************************************************************* ?Gw89r  
    'Radius and conic constant of posterior lens XB 7^Ka  
    '************************************************************************* n{WJ.Y*  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) / {~h?P}  
    GetConic eID, entity, curv, conic ]}y'3aW  
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    SetConic eID, entity, 1/Rpost, CCpost bu9&sQ;  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost 4ux5G`oL  
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    '************************************************************************* X6 :~Rjim*  
    'Lens thickness (Position of posterior lens surface) +Z]%@"S?  
    '************************************************************************* kovzB]  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) =@  
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    ' Delete any z-shift(s) HNT8~s.2  
    count = 0 W/Q%%)J  
    While GetOperationCount(eID)>count gi >{`.]  
        GetOperation eID, count, op Isb^~c_P  
        If op.Type="ShiftZ" Then XnOl*#P  
            DeleteOperation eID,count qEz'l'%(  
            count=count-1 TvwIro  
        End If dig76D_[e  
        count=count+1 ^uzVz1%mM  
    Wend ji=po;g=E  
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    'Set new z-shift VNXVuM )c  
    op.Type = "ShiftZ" RL9BB.  
    op.val1 = tlens Q6>( Z  
    op.parent = parID XS/TYdXB8  
    AddOperation eID, op 0VPa;{i/  
    Print "Set lens thickness = " & tlens KL`>mJo$  
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    '************************************************************************* u)pBFs<dn  
    'Lens index of refraction )>p6h]]a  
    '************************************************************************* (B#|3o  
    eID = FindMaterial( "Lens" ) &N;6G`3  
    GetModelMaterial eID, mat #9Z-Hd<  
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    mat.Nd = nlens *
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    SetModelMaterial eID, mat UC@"<$'C  
    Print "Set lens index of refraction = " & nlens gs>cx]>  
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    '************************************************************************* lh5d6VUA  
    'Pupil diameter cqp#1oM4M  
    '************************************************************************* >m!.l{*j>N  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) v g]&T  
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    'Adjust pupil diameter (trimming volume inner hole) )I4t
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" v2V1&-
  
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    ' Adjust pupil location to just in front of the lens jU$PO\UTk  
    parID = FindFullName( "Geometry.Arizona Eye" ) P+UK@~D+G  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) Tp13V.|  
    count = 0 nj$K4_  
    While GetOperationCount(eID)>count 3>6o=7/PU  
        GetOperation eID, count, op qQ_QF
 
        If op.Type="ShiftZ" Then qT4s*kqr  
            DeleteOperation eID,count Y)`+u#` R  
            count=count-1 ND>}t#^$  
        End If p'*UM%@SIY  
        count=count+1 9h{G1XL  
    Wend n21J7;\/+  
    op.Type = "ShiftZ" E.9F~&DPJ<  
    op.val1 = taq-0.01 r
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    op.parent = parID U|nk86r  
    AddOperation eID, op Jk*MxlA.b  
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    Print "Set pupil diameter = " & pupilDiam JSU\Hh!  
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    'Update AZ Eye subassembly Description f7'%AuSQ(  
    eID = FindFullName( "Geometry.Arizona Eye" ) S SXSgp  
    GetEntity eID, entity ks}o9[D3  
    entity.Description = "Accommodation = " & A & "D" O]>`B
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    SetEntity eID, entity ;l'I.j  
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    Update $u :=lA:N  
    Print "DONE!" =j0V/=  
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End Sub 6D],275`J  
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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： gi)/iz`  
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Accommodation = 4 Diopters CvN~  
Pupil Diameter = 4 mm r!S iR(  
Set aqueous humor thickness = 2.81 d:D2[  
Set anterior lens radius = 10.4 and conic constant = -2.375869 HD ~9EK~  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 qU}DOL|  
Set lens thickness = 3.927 4]bTO  
Set lens index of refraction = 1.42672 ZeO>Ag^
 
Set pupil diameter = 4 O,cx9N  
DONE!
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