[技术]Arizona眼睛模型 [复制链接]

简介 .wm<l:  
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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。 RToX[R;1E  
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模型 J=^5GfM)J  
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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。 N]c:8dOj  
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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. Q(8W5Fb?  
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光源 _;(QMeR  
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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。 ?aG~E  
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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。 1d.>?^uE  
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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。 Q"xDRQA  
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视网膜的散射 yNx"Ey dk`  
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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。 t^
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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。 UgO\+cI  
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脚本 2gjA>ET`N  
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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''Wm.>g(+  
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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。 s*}d`"YvH  
余下的脚本计算与屈光度有关的所有参数。  })w5`?Y  
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分析 0P53dF  
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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。 %nc+VL4  
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脚本代码 ae1fCw3k  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. 
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Dim entity As T_ENTITY Kd,m;S\  
Dim op As T_OPERATION bmddh2  
Dim mat As T_MODELMATERIAL QnOa?0HL/  
Dim A As Double CGg6nCB  
Dim pupilDiam As Double ,|c_l)  
Dim eID As Long z?YGE iR/}  
Dim parID As Long cRfX  
Dim count As Integer T@HozZ  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double ;NPb  
Dim tlens As Double, nlens As Double ,>jm|BTD {  
Dim curv As Double, conic As Double nocH~bAf2  
Dim ok As Long KJkcmF}Q  
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Sub Main rC*nZ*  
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    '用户输入对话框 u})JQ<|  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 1!NaOfP;@  
        TextBox 220,21,40,21,.TextBox1 'default: 0 #5I "M WA  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 2I4P":q  
        OKButton 40,91,90,21 +1623E  
        CancelButton 190,91,90,21 [E/3&3  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1  JuI,wA  
        TextBox 220,49,40,21,.TextBox2 'default: 4 f3h9CV  
    End Dialog J/*[wj  
    Dim dlg As UserDialog nBj7Q!lW  
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    ok = Dialog (dlg) y@z#Jw<  
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    If ok=0 Then    'cancel button was pressed JZ7-? o  
        Print "Execution cancelled." 7I
 
        End cK } Qu  
    End If =@f;s<v/  
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    'Assign accommodation and pupil diameter & use defaults if field left empty `jkn*:m  
    If dlg.TextBox1 = "" Then g<-cHF  
        A = 0           'Default accommodation ~!OjdE!u  
    Else sOW|TN>y\  
        A = CDbl(dlg.TextBox1) 3N21[i2/m  
    End If Pg36'aTe%j  
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    If dlg.TextBox2 = "" Then U|QDV16f  
        pupilDiam = 4   'Default pupil diameter -d~'tti  
    Else WveFB%@`;  
        pupilDiam = CDbl(dlg.TextBox2) V]2z5u_q  
    End If (qrT0D6  
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    Print " " 3PGyqt(   
    Print "Accommodation = " & A & " Diopters" 2P}RZvUd  
    Print "Pupil Diameter = " & pupilDiam & " mm" A0ToX) |C  
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    ' Calculate new parameters with accommodation (r4\dp&  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness ]lY9[~ v  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens \zUsHK?L"t  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens ccSSau5N  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens g]#Wve  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens luT8>9X^:a  
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    tlens = 3.767 + 0.04*A                  'Lens thickness h(-&.Sm")H  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction Dhoj|lc  
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    'Adjust parameters to account for accommodation j
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    '************************************************************************* jHCKV  
    'Aqueous thickness (Position of Lens) JPG!c
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    '************************************************************************* M6sDtL9l  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) pg)g&ifKl  
    GetCustomElement eID, entity o{p_s0IX;S  
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    parID = FindFullName( "Geometry.Arizona Eye" ) |Y11sDa9h  
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    ' Delete any shift(s) in z eZi<C}z  
    count = 0 "_j7kYAl  
    While GetOperationCount(eID)>count YC<I|&"  
        GetOperation eID, count, op pt#[.n#f  
        If op.Type="ShiftZ" Then -huZnDN  
            DeleteOperation eID,count N}G(pq}  
            count=count-1 VHCzlg  
        End If <*(R+to^d  
        count=count+1 "S:N-Tf%U  
    Wend +.I'U9QeUN  
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    'Set new shift in F.D1;,x  
    op.Type = "ShiftZ" 5QJL0fc  
    op.val1 = taq 
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    op.parent = parID UAZ&*{MM^  
    AddOperation eID, op !++62Lf  
    Print "Set aqueous humor thickness = " & taq-0.55 (02(:;1  
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    '************************************************************************* J *?_SnZ  
    'Radius and conic constant of anterior lens 0pa^O$?p  
    '************************************************************************* Ai18]QD-  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) 6~WE#z_  
    GetConic eID, entity, curv, conic wf%Ep#^6}  
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    SetConic eID, entity, 1/Rant, CCant %)Dd{|c  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant d|RmU/
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    '************************************************************************* T l(uqY?9  
    'Radius and conic constant of posterior lens v^fOT5\  
    '************************************************************************* L"%eQHEC&  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) m?$G(E5  
    GetConic eID, entity, curv, conic x)ZH;)  
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    SetConic eID, entity, 1/Rpost, CCpost Ilb |:x"L  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost XF$]KAL0  
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    '************************************************************************* z|)1l`  
    'Lens thickness (Position of posterior lens surface) {NgY8wQB  
    '************************************************************************* v=1S
  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) arVf"3a  
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    ' Delete any z-shift(s) M|e n>P  
    count = 0 xGv,%'
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    While GetOperationCount(eID)>count _kX/LR"L+  
        GetOperation eID, count, op mIEaWE;E"  
        If op.Type="ShiftZ" Then ![ID0}MjJ  
            DeleteOperation eID,count }IkEyJsk  
            count=count-1 p+UHJ&  
        End If b:cK>fh0_  
        count=count+1 1";e'?^x  
    Wend l!V| T?  
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    'Set new z-shift (A fbS=[  
    op.Type = "ShiftZ" ]{+M>i[  
    op.val1 = tlens }SN44 di(  
    op.parent = parID qZ_fQ@   
    AddOperation eID, op ,h.Jfo54,  
    Print "Set lens thickness = " & tlens UH&1c8y}  

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    '************************************************************************* U{uWk3I_b  
    'Lens index of refraction G:C6`uiy`  
    '************************************************************************* }6,bq`MN  
    eID = FindMaterial( "Lens" ) A6y~_dt  
    GetModelMaterial eID, mat !vVjZ  
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    mat.Nd = nlens ^ R^N`V   
    SetModelMaterial eID, mat [piF MxZP  
    Print "Set lens index of refraction = " & nlens Yn]yd1  
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    '************************************************************************* fZ~kw*0*  
    'Pupil diameter >c\v&k>6.  
    '************************************************************************* Sb9=$0%\  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) m<,G:?RM  
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    'Adjust pupil diameter (trimming volume inner hole) r]O@HVbt$  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" -WBz]GW4r  
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    ' Adjust pupil location to just in front of the lens b|8>eY  
    parID = FindFullName( "Geometry.Arizona Eye" ) Q()RO*9  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) m/c&/6nk  
    count = 0 g6/N\[b%  
    While GetOperationCount(eID)>count MD ?F1l"}%  
        GetOperation eID, count, op cvXI]+`<3\  
        If op.Type="ShiftZ" Then -,fa{yt-  
            DeleteOperation eID,count uyRA`<&w  
            count=count-1 )C01fZ
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        End If %v+fN?%x,d  
        count=count+1 (06Vcqg  
    Wend eo*u(@  
    op.Type = "ShiftZ" .m]=JC5'  
    op.val1 = taq-0.01 ~UJu @M  
    op.parent = parID e(;`9T  
    AddOperation eID, op :_QAjU  
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    Print "Set pupil diameter = " & pupilDiam $sL|'ZMbS  
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    'Update AZ Eye subassembly Description ['OCw {<  
    eID = FindFullName( "Geometry.Arizona Eye" ) )lDIzLp  
    GetEntity eID, entity #u<oEDQ  
    entity.Description = "Accommodation = " & A & "D" 7fW=5wc  
    SetEntity eID, entity eFj6p
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    Update {Sr=
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    Print "DONE!" _[{:!?-?  
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End Sub F@K*T2uh  
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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： bhqq  
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Accommodation = 4 Diopters @ Zgl>
  
Pupil Diameter = 4 mm R<lNk<  
Set aqueous humor thickness = 2.81 A M1C $  
Set anterior lens radius = 10.4 and conic constant = -2.375869 ^`jZKh8)h  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 C>:/(O  
Set lens thickness = 3.927 }rY?=I  
Set lens index of refraction = 1.42672 eb.cq"C  
Set pupil diameter = 4 l\=-+'Y  
DONE! >: W-C{%