[技术]Arizona眼睛模型 [复制链接]

简介 <"HbX  
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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。 ;Svs|]d  
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模型 4lsg%b6_%,  
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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。 -+,3aK<[  
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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. ]IeyJ  
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光源 #Ks2a):8  
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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。 KL^hYjC  
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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。 W,-fnJk  
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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。 tZ*z.3\<  
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视网膜的散射 /AhN$)(
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在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 5rPK7Jh`B  
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注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 0fP-[7P  
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脚本 alz2F.%Y  
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内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： MFqM6_  
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如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 pj/w9j G6  
余下的脚本计算与屈光度有关的所有参数。 i?D KKjN$  
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分析 jc-$l  
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屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 V+- ]txu|  
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脚本代码 #s]'2O  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. wr{ [4$O  
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Dim entity As T_ENTITY dRu|*s  
Dim op As T_OPERATION %FSY}
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Dim mat As T_MODELMATERIAL 9:1[4o)~  
Dim A As Double vpL3XYs`  
Dim pupilDiam As Double F!pgec%]'  
Dim eID As Long zd-qQ.j0  
Dim parID As Long 3,[#%}1(S  
Dim count As Integer 9?L,DThQ  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double 2SHS!6
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Dim tlens As Double, nlens As Double =&YhA}l\O  
Dim curv As Double, conic As Double Dg~L"  
Dim ok As Long QxS=W2iN  
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Sub Main =}^J6+TVL  
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    '用户输入对话框 w(-h!d51+  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 {j!+\neL  
        TextBox 220,21,40,21,.TextBox1 'default: 0 3sF^6<E  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 o b,%); m  
        OKButton 40,91,90,21 ?X5Y8n]y\h  
        CancelButton 190,91,90,21 M
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        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 >Ndck2@  
        TextBox 220,49,40,21,.TextBox2 'default: 4 nlsif  
    End Dialog 6L4<c+v_  
    Dim dlg As UserDialog unZYFA}(  
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    ok = Dialog (dlg) K|^'`FpPO  

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    If ok=0 Then    'cancel button was pressed =/zb$d cz  
        Print "Execution cancelled." N:nhS3N<L  
        End "2 "gT
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    End If DJ.n8hne  
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    'Assign accommodation and pupil diameter & use defaults if field left empty #'lqE)T  
    If dlg.TextBox1 = "" Then h#o?O k  
        A = 0           'Default accommodation G>f2E49BXt  
    Else Q-7C'|  
        A = CDbl(dlg.TextBox1) 8AgKK=C=  
    End If D_2~ 6  
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    If dlg.TextBox2 = "" Then e$=UA%  
        pupilDiam = 4   'Default pupil diameter !wNj;S
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    Else 7 S6@[-E
 
        pupilDiam = CDbl(dlg.TextBox2) @})]4H  
    End If !eE;MaS>  
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    Print " " (]gd$BgD
 
    Print "Accommodation = " & A & " Diopters" q"C(`S.@  
    Print "Pupil Diameter = " & pupilDiam & " mm" !${7)=|=1  
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    ' Calculate new parameters with accommodation 9hn+eU  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness pB0p?D)n  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens SSo7 U  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens p;0p!~F=49  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens rO3.%B}  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens ^T&@(|o  
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    tlens = 3.767 + 0.04*A                  'Lens thickness }fT5(+ Wo  

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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction INjr$'*  
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    'Adjust parameters to account for accommodation -'%>Fon  
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    '************************************************************************* :XFr"aSt  
    'Aqueous thickness (Position of Lens) J<;@RK,c_  
    '************************************************************************* cM 5V%w  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) }"x#uG  
    GetCustomElement eID, entity 3[F9qDAy  
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    parID = FindFullName( "Geometry.Arizona Eye" ) Z`]r)z%f  
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    ' Delete any shift(s) in z )Bw}T  
    count = 0 <reALC  
    While GetOperationCount(eID)>count DV{0|E  
        GetOperation eID, count, op s{9G//  
        If op.Type="ShiftZ" Then pB5#Ho>S  
            DeleteOperation eID,count <N'v-9=2jl  
            count=count-1 '^!#*O  
        End If :tf'Gw6v  
        count=count+1 l' mdj!{&  
    Wend L'L[Vpx  
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    'Set new shift in `~k`m{4.a  
    op.Type = "ShiftZ" ,[UK32KWI  
    op.val1 = taq N(Sc!rX  
    op.parent = parID gzd<D}2F~  
    AddOperation eID, op +=MN_  
    Print "Set aqueous humor thickness = " & taq-0.55 6"YcM:5~  
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    '************************************************************************* PrqyJ  
    'Radius and conic constant of anterior lens (|9t+KP  
    '************************************************************************* 4..M *U  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) m"/ o4  
    GetConic eID, entity, curv, conic Aw$+Ew[8 2  
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    SetConic eID, entity, 1/Rant, CCant q5xF~SQGw2  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant w<&R|= 93  
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    '************************************************************************* ^V7'
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    'Radius and conic constant of posterior lens z3Zo64V~7  
    '************************************************************************* g^: &D
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    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) zvbO q  
    GetConic eID, entity, curv, conic G_]zymXQ  
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    SetConic eID, entity, 1/Rpost, CCpost b[KZJLZ)  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost %zz,qs)Eu  
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    '************************************************************************* "IN[(  
    'Lens thickness (Position of posterior lens surface) BIh^b?:zU  
    '************************************************************************* vzFo"  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) ey@ccc*sZ9  
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    ' Delete any z-shift(s) 4$+1&
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    count = 0 +Ly@5y"  
    While GetOperationCount(eID)>count +L|x^B3  
        GetOperation eID, count, op mg]t)+PQ  
        If op.Type="ShiftZ" Then FrC)2wX  
            DeleteOperation eID,count V+5av Z}  
            count=count-1 q ;"/i*+3  
        End If ykYef  
        count=count+1 fE"-W{M  
    Wend Z 4QL&?U  
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    'Set new z-shift *#9?9SYSk  
    op.Type = "ShiftZ" jwpahy;\WL  
    op.val1 = tlens Du #>y!  
    op.parent = parID "`NAg  
    AddOperation eID, op uaE
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    Print "Set lens thickness = " & tlens
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    '************************************************************************* 6WX?Xc]$3  
    'Lens index of refraction 6UI6
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    '************************************************************************* q|V|Jl  
    eID = FindMaterial( "Lens" ) KM"BHaSkF  
    GetModelMaterial eID, mat ,_TE@]!$  
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    mat.Nd = nlens 1~
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    SetModelMaterial eID, mat vnWt8?)]^  
    Print "Set lens index of refraction = " & nlens (mplo|>  
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    '************************************************************************* EM(%|#  
    'Pupil diameter ++n_$Qug  
    '************************************************************************* K~4b
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    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) $*`E;}S0  
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    'Adjust pupil diameter (trimming volume inner hole) 9k\M<jA  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" $xCJ5M4  
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    ' Adjust pupil location to just in front of the lens _Wq;bKG  
    parID = FindFullName( "Geometry.Arizona Eye" ) +/ {lz8^,  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) WcQkeh3n  
    count = 0 8"TlWHF`  
    While GetOperationCount(eID)>count 4V c``Um  
        GetOperation eID, count, op T"t.t%(8  
        If op.Type="ShiftZ" Then E@EP9X >  
            DeleteOperation eID,count j
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            count=count-1 Yxy!&hPLv:  
        End If YC$>D?FW  
        count=count+1 #0?3RP  
    Wend Apj[z2nr  
    op.Type = "ShiftZ" 3-oKY*jO  
    op.val1 = taq-0.01 p()LQT!  
    op.parent = parID <*+[E!oi  
    AddOperation eID, op <,Pl31g^  
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    Print "Set pupil diameter = " & pupilDiam f:t j   
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    'Update AZ Eye subassembly Description v_WF.sb~  
    eID = FindFullName( "Geometry.Arizona Eye" ) f|ERZN`uB  
    GetEntity eID, entity nBLb1T  
    entity.Description = "Accommodation = " & A & "D" =dwy 4  
    SetEntity eID, entity OsW*@v(  
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    Update gW^4@q  
    Print "DONE!" )?I*zc  
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End Sub 6Eus_aP  
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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： NB5lxaL  
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Accommodation = 4 Diopters GvvKM=1  
Pupil Diameter = 4 mm a_]l?t  
Set aqueous humor thickness = 2.81 \%9QE  
Set anterior lens radius = 10.4 and conic constant = -2.375869 )TyP{X>  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 OG_v[  C5  
Set lens thickness = 3.927 _k;HhLj`  
Set lens index of refraction = 1.42672 )||CU]"b?  
Set pupil diameter = 4 J qmL|
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DONE! ;JMmr-@