[技术]Arizona眼睛模型 [复制链接]

简介 ZW-yP2  
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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。 0)%YNaskj  
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模型 bBu,#Mc  
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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
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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. !(mjyr  
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光源 {s)+R[?m<o  
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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。 !$DIc  
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除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处，并增加了pre-propagation distance= -8。尽管光线在光瞳处创建，规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射，而不是在光瞳处入射。 ;lq;X{/  
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在往下看是内置的脚本用来修改屈光度，使其为4（250mm），光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 TK5K_V*7  
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视网膜的散射 T#M,~lD  
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在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 unshH<  
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注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 {SwQ[$k=_  
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脚本 bQE};wM,  
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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： 0F@"b{&0  
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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。 ^sa#8^,K  
余下的脚本计算与屈光度有关的所有参数。 '=[?~0(B  
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分析 7Ok;Lt!x  
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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。 [OHxonU  
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脚本代码 e:DkGy`-s  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. &f!z1d-qg?  
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Dim entity As T_ENTITY D|@/yDQ  
Dim op As T_OPERATION .}'qUPNR  
Dim mat As T_MODELMATERIAL W)9K`hM6  
Dim A As Double VGtC)mG8)  
Dim pupilDiam As Double }tsYJlh5  
Dim eID As Long aD=a,  
Dim parID As Long _Xnqb+  
Dim count As Integer Xua+cVc\y  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double i%ZW3MrY~  
Dim tlens As Double, nlens As Double ZaeqOVp/j  
Dim curv As Double, conic As Double *&?c(JU;<  
Dim ok As Long |o,8V p  
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Sub Main j*F`"df  
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    '用户输入对话框 4$qWiG~  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 jZh';M8"  
        TextBox 220,21,40,21,.TextBox1 'default: 0 v[#9+6P=  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 , FhekaA  
        OKButton 40,91,90,21 !lEY=1nHOJ  
        CancelButton 190,91,90,21 ()K " c#  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 .{
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        TextBox 220,49,40,21,.TextBox2 'default: 4 2rmSo&3@s  
    End Dialog +6UVn\9Q  
    Dim dlg As UserDialog I"Ms-zs  
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    ok = Dialog (dlg) '
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    If ok=0 Then    'cancel button was pressed D@.tkzU@E  
        Print "Execution cancelled." _7IKzUn9g[  
        End j{Hao\F8  
    End If 4Fp0ZVT  
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    'Assign accommodation and pupil diameter & use defaults if field left empty la( <8  
    If dlg.TextBox1 = "" Then =Vy`J)z9  
        A = 0           'Default accommodation _/Gczy4)#  
    Else f@8>HCI  
        A = CDbl(dlg.TextBox1) v3}L`dyh3  
    End If vJ\pR~?  
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    If dlg.TextBox2 = "" Then 70f Klp  
        pupilDiam = 4   'Default pupil diameter r) $+  
    Else >tO`r.5u9  
        pupilDiam = CDbl(dlg.TextBox2) 5QPM t^  
    End If <@}I0  
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    Print " " w=j  
    Print "Accommodation = " & A & " Diopters" I4i2+ *l}  
    Print "Pupil Diameter = " & pupilDiam & " mm" Gp4A.\7  
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    ' Calculate new parameters with accommodation >=UF-xk;  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness si&S%4(  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens dDm):Z*`b  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens yHHt(GM|o  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens )K,F]fc+O  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens UNPezHaz  
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    tlens = 3.767 + 0.04*A                  'Lens thickness ogL EtqT  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction TUHi5K  
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    'Adjust parameters to account for accommodation slg ]#Dy  
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    '************************************************************************* ;QW3CEaUq  
    'Aqueous thickness (Position of Lens) dxZ
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    '************************************************************************* 9cEv&3  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) @J5Jpt*IE  
    GetCustomElement eID, entity )RO<o O  
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    parID = FindFullName( "Geometry.Arizona Eye" ) K'X2dG*  
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    ' Delete any shift(s) in z :JfE QIN  
    count = 0 9G{;?c  
    While GetOperationCount(eID)>count D\[h:8k  
        GetOperation eID, count, op ow0!%|fO  
        If op.Type="ShiftZ" Then bYi`R)  
            DeleteOperation eID,count YO}1(m  
            count=count-1 hGbj0  
        End If 'ihhoW8  
        count=count+1
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    Wend qf=1?=l291  
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    'Set new shift in lu#LCG-.  
    op.Type = "ShiftZ" v.:3"<ur}  
    op.val1 = taq 2Fz|fW_  
    op.parent = parID A |3tI  
    AddOperation eID, op - /(s#D  
    Print "Set aqueous humor thickness = " & taq-0.55 jCrpL~tWT  
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    '************************************************************************* 7ULqo>j  
    'Radius and conic constant of anterior lens d3W0-INL  
    '************************************************************************* iJZ/jCI  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) nPs7c %  
    GetConic eID, entity, curv, conic ?V}j`r8|\4  
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    SetConic eID, entity, 1/Rant, CCant H(Q.a=&4!p  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant 2*N_5&9mE  
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    '************************************************************************* OvUI@,Ef  
    'Radius and conic constant of posterior lens \mw(cM#:  
    '*************************************************************************  ;b`[&g  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) ^-rfvc  
    GetConic eID, entity, curv, conic \MK*by  
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    SetConic eID, entity, 1/Rpost, CCpost Rb%%?*|  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost $&"V^@  
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    '************************************************************************* YKbaf(K)9  
    'Lens thickness (Position of posterior lens surface) ?UK|>9y}Z  
    '************************************************************************* ]D@0|  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) "H&"(=  
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    ' Delete any z-shift(s) B%KG3]  
    count = 0 QT9n,lX
 
    While GetOperationCount(eID)>count Dk+&X-]6x5  
        GetOperation eID, count, op kl
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        If op.Type="ShiftZ" Then Qb!PRCHQ  
            DeleteOperation eID,count ;L|uIg;.s  
            count=count-1 ?7M.o  
        End If 0<8XI>.3D  
        count=count+1 6<'rG''  
    Wend e#,~,W.H  
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    'Set new z-shift Wm H~m k"  
    op.Type = "ShiftZ" _{Sm k[  
    op.val1 = tlens / }Rz=&  
    op.parent = parID $5v0m#[^  
    AddOperation eID, op Yp0/Ab(v  
    Print "Set lens thickness = " & tlens d/}SAvtt  
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    '************************************************************************* ~GuMlV8  
    'Lens index of refraction "+zCS|   
    '************************************************************************* kGL1!=>  
    eID = FindMaterial( "Lens" ) \`ZW* EtPI  
    GetModelMaterial eID, mat U~W
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    mat.Nd = nlens [w\9as/ E  
    SetModelMaterial eID, mat K_ lVISBQ  
    Print "Set lens index of refraction = " & nlens I+ es8  
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    '************************************************************************* h(qQsxIOhS  
    'Pupil diameter xAu/  
    '************************************************************************* p~.8\bI=  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) e(NLX`  
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    'Adjust pupil diameter (trimming volume inner hole) S!PzLTc  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" %+ FG,d  
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    ' Adjust pupil location to just in front of the lens  6l$L~>  
    parID = FindFullName( "Geometry.Arizona Eye" ) hk/! 'd  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) 2"fO6!hh  
    count = 0 \uME+NF  
    While GetOperationCount(eID)>count .[u>V  
        GetOperation eID, count, op 1
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        If op.Type="ShiftZ" Then :L_BG)dM  
            DeleteOperation eID,count p'sc0@}_O  
            count=count-1 XE3'`D!  
        End If 9S[
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        count=count+1 eZr&x~] -w  
    Wend 4
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    op.Type = "ShiftZ" l%Gw_0.?e  
    op.val1 = taq-0.01 =pA IvU  
    op.parent = parID ~^^ NHq  
    AddOperation eID, op c9j*n;Q  
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    Print "Set pupil diameter = " & pupilDiam O)kgBrB  
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    'Update AZ Eye subassembly Description \([WH!7  
    eID = FindFullName( "Geometry.Arizona Eye" ) b dJ+@r  
    GetEntity eID, entity \<vNVz7.D  
    entity.Description = "Accommodation = " & A & "D" ?R-9W+U%f  
    SetEntity eID, entity 9_fePS|Z4  
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    Update N~pIC2Woo  
    Print "DONE!" }X;U|]d  
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End Sub Pv<FLo%u<  
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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： *2}O-e  
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Accommodation = 4 Diopters .$", *d  
Pupil Diameter = 4 mm $KjTa#[RX7  
Set aqueous humor thickness = 2.81 -ng=l;  
Set anterior lens radius = 10.4 and conic constant = -2.375869 Fg/dS6=n`?  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 DWt*jX*  
Set lens thickness = 3.927 ED$DSz)x  
Set lens index of refraction = 1.42672 j<pw\k{i  
Set pupil diameter = 4 .[DthEF  
DONE! m}$+Hdk+7