[技术]Arizona眼睛模型 [复制链接]

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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。 Dg](?^  
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模型 s UX%{|T_  
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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。 \yeo-uN8  
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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. GY9CU=-  
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光源 67zCil  
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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。 871taL
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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。 4f+R}Ee7  
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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。 \ UCOe  
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视网膜的散射 Q)}_S@v|%  
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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。  3LKL,z  
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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。 XI#1)  
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脚本 Q9v OY8  
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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： %hcn|-"F  
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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。 ^,`;x  
余下的脚本计算与屈光度有关的所有参数。 FM\yf]'  
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分析 )@"iWQ3K  
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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。 %W!C  
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脚本代码 t#pF.!9=  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. C(( 7  
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Dim entity As T_ENTITY tBS
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Dim op As T_OPERATION y_bb//IAG  
Dim mat As T_MODELMATERIAL {<f_,Nlc  
Dim A As Double # fvt:iE  
Dim pupilDiam As Double *` }Rt  
Dim eID As Long N5$
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Dim parID As Long {Vy2uow0  
Dim count As Integer Gt9(@USK  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double ~y@,d  
Dim tlens As Double, nlens As Double !?t#QDo  
Dim curv As Double, conic As Double bDh,r!I  
Dim ok As Long e C\;n  
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Sub Main Eg&oAY.U  
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    '用户输入对话框 \4;}S&`k  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 )TNAgTmqK  
        TextBox 220,21,40,21,.TextBox1 'default: 0 $]eU'!
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        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 u,]?_bK)  
        OKButton 40,91,90,21 2)O-EAn  
        CancelButton 190,91,90,21 ySyA!Z  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 Oj6PmUK4  
        TextBox 220,49,40,21,.TextBox2 'default: 4 yht|0mZV  
    End Dialog yb)!jLnH  
    Dim dlg As UserDialog oqu; D'8  

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    ok = Dialog (dlg) fQZ,kl  
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    If ok=0 Then    'cancel button was pressed rGPFPsMQ]  
        Print "Execution cancelled." 1A>>#M=A
 
        End s d-5AE  
    End If +&t`"lRl&  
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    'Assign accommodation and pupil diameter & use defaults if field left empty >lZ9Y{Y4v  
    If dlg.TextBox1 = "" Then @9yY`\"ed  
        A = 0           'Default accommodation p#['CqP8  
    Else Bismd21F6=  
        A = CDbl(dlg.TextBox1) zT;F4_p3G-  
    End If pDW4DF:`(  
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    If dlg.TextBox2 = "" Then 6pyLb3[e  
        pupilDiam = 4   'Default pupil diameter !3]}3jZ.  
    Else |7 .WP;1  
        pupilDiam = CDbl(dlg.TextBox2) ,yZvT7  
    End If KW&5&~)2  
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    Print " " \EP<r  
    Print "Accommodation = " & A & " Diopters" 51:NL[[6  
    Print "Pupil Diameter = " & pupilDiam & " mm" \\\%pBT7]\  
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    ' Calculate new parameters with accommodation } v#Tm  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness sA( e  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens &<Gs@UX~w  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens 8Ja't8  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens (]*otVJ  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens u ##.t  
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    tlens = 3.767 + 0.04*A                  'Lens thickness @@&([f  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction 9eA2v{!S  
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    'Adjust parameters to account for accommodation zUw=e}?:  
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    '************************************************************************* W{z7h[?5,  
    'Aqueous thickness (Position of Lens) lwY2zX&%)/  
    '************************************************************************* ^o`;C\  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) I-=H;6w7  
    GetCustomElement eID, entity "YUh4uZ~P  
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    parID = FindFullName( "Geometry.Arizona Eye" ) =3~u.iq$  
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    ' Delete any shift(s) in z VR/*
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    count = 0 }ioHSkCD  
    While GetOperationCount(eID)>count h[%t7qo=  
        GetOperation eID, count, op ;@I4[4ph}  
        If op.Type="ShiftZ" Then I2U/\  
            DeleteOperation eID,count z?9vbx  
            count=count-1 jJ(()EJ  
        End If {w,g~ew `  
        count=count+1 /hNZ7\|P  
    Wend ENmfbJ4d~  
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    'Set new shift in rKK{*%n  
    op.Type = "ShiftZ" B~[}E]WEK  
    op.val1 = taq 1Wz -Z  
    op.parent = parID Rds_Cd C  
    AddOperation eID, op 0N" VOEvG  
    Print "Set aqueous humor thickness = " & taq-0.55 nPAVrDg O  
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    '************************************************************************* >= G{
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    'Radius and conic constant of anterior lens -d|Q|zF^x  
    '************************************************************************* X4- _l$j  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) d[cqs9=
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    GetConic eID, entity, curv, conic %fv;C  
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    SetConic eID, entity, 1/Rant, CCant C(RZ09,.S  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant @raw8w\Zj+  
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    '************************************************************************* |oYqkP|  
    'Radius and conic constant of posterior lens e@Cv')]B  
    '************************************************************************* _8-iO.T+2  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) S 54N  
    GetConic eID, entity, curv, conic LF2@qvwD  
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    SetConic eID, entity, 1/Rpost, CCpost V>8)1)dF  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost Y,?!"  
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    '************************************************************************* LjE@[@d  
    'Lens thickness (Position of posterior lens surface) e58  
    '************************************************************************* {iz,iv/U  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) \R m2c8Z2  
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    ' Delete any z-shift(s) Awip qDAu  
    count = 0 H[cHF  
    While GetOperationCount(eID)>count M;14s*g  
        GetOperation eID, count, op mKsTA;  
        If op.Type="ShiftZ" Then a!_vd B  
            DeleteOperation eID,count "*ot:;I  
            count=count-1 *%{  
        End If HQpw2bdy  
        count=count+1 Qh3V[br  
    Wend `|Ll  
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    'Set new z-shift 0<,Q7onDD:  
    op.Type = "ShiftZ" pPC_ub  
    op.val1 = tlens 't3
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    op.parent = parID =nq9)4o  
    AddOperation eID, op R%(ww  
    Print "Set lens thickness = " & tlens n@hf{hA[a  
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    '************************************************************************* S%+$  
    'Lens index of refraction 01/?  
    '************************************************************************* %XpYiW#AK  
    eID = FindMaterial( "Lens" ) (Wj2%*NT  
    GetModelMaterial eID, mat N@oNg}D&:  
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    mat.Nd = nlens GN7\p)  
    SetModelMaterial eID, mat vlHE\%{  
    Print "Set lens index of refraction = " & nlens s+=JT+g  
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    '************************************************************************* /7bIE!Cn  
    'Pupil diameter [P,/J$v^~  
    '************************************************************************* kpe7\nd=>  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) fnZaIV=H  
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    'Adjust pupil diameter (trimming volume inner hole) eX+FtN  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" |o:[*2-  
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    ' Adjust pupil location to just in front of the lens 3\=iB&Gf|  
    parID = FindFullName( "Geometry.Arizona Eye" ) <])w@QOA#  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) AADvk_R  
    count = 0
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    While GetOperationCount(eID)>count "8bxb  
        GetOperation eID, count, op ]h Dy]  
        If op.Type="ShiftZ" Then c:a5pd7T  
            DeleteOperation eID,count Esc*+}ck  
            count=count-1 6Y#V;/gK!5  
        End If Is87 9_Z  
        count=count+1 ~7N>tjB  
    Wend D^E+#a 1  
    op.Type = "ShiftZ" ,O9rL :?  
    op.val1 = taq-0.01 LPg1G+e  
    op.parent = parID jslfq@5v  
    AddOperation eID, op 5`ma#_zk|f  
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    Print "Set pupil diameter = " & pupilDiam [n53eC  
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    'Update AZ Eye subassembly Description L@b8,  
    eID = FindFullName( "Geometry.Arizona Eye" ) .
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    GetEntity eID, entity bt$+l[U^J  
    entity.Description = "Accommodation = " & A & "D" STC'j1U  
    SetEntity eID, entity _` %z  
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    Update l )hg!(  
    Print "DONE!" w% Ug9  
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End Sub ..ig jc#UF  
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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： ~(TS>ck@  
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Accommodation = 4 Diopters b,?@_*qv+  
Pupil Diameter = 4 mm H:~41f[  
Set aqueous humor thickness = 2.81 (IbT5  
Set anterior lens radius = 10.4 and conic constant = -2.375869
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Set posterior lens radius = -4.424557 and conic constant = -3.081019 ^,Sl^ 9K  
Set lens thickness = 3.927 =xs{Ov=  
Set lens index of refraction = 1.42672 a;Nj'M~U  
Set pupil diameter = 4 ,{@,dw`lUz  
DONE! a\wpJ|3{=T