[技术]Arizona眼睛模型 [复制链接]

简介 ph%/;?wY  
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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。 hUB_[#8#  
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模型 yXR$MT+~  
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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。 l>7`D3  
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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. a0CmCv2#  
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光源 e6QUe.S  
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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。 4mQ:i7~  
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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。 M7fw/i  
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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。 "S_t%m&R  
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视网膜的散射 j0Kj>  
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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。 y5RcJM  
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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。 !WR(H&uBr\  
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脚本 #78p#E  
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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： 1*Yf[;L  
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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。 +5JCbT@y  
余下的脚本计算与屈光度有关的所有参数。 S>/p6}3]  
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分析 G{

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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。 _rR+u56y-  
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脚本代码 \j+O |#`|)  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. cuO(*%Is1  
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Dim entity As T_ENTITY N/p9Ws  
Dim op As T_OPERATION Vl%AN;o  
Dim mat As T_MODELMATERIAL m$ )yd~  
Dim A As Double d(3F:dbk  
Dim pupilDiam As Double r`qMif'  
Dim eID As Long =!w5%|r.  
Dim parID As Long ,^pM]+NF|  
Dim count As Integer @{iws@.  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double zH0%; o}  
Dim tlens As Double, nlens As Double ug'I:#@2  
Dim curv As Double, conic As Double A[ 9 @:z  
Dim ok As Long n#uH^@#0  
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Sub Main J;W(}"cFq  
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    '用户输入对话框 #=V%S 2~  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 ZR.1SA0x?O  
        TextBox 220,21,40,21,.TextBox1 'default: 0 Sf);j0G,D  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1
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        OKButton 40,91,90,21 |NJe4lw+?  
        CancelButton 190,91,90,21 SpPG  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 orVsMT[A  
        TextBox 220,49,40,21,.TextBox2 'default: 4 *Z>Yv37P  
    End Dialog ]( V+ qj
 
    Dim dlg As UserDialog M#LQz~E  
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    ok = Dialog (dlg) A{iI,IFe  
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    If ok=0 Then    'cancel button was pressed &$?e D{  
        Print "Execution cancelled." h!5^d!2,  
        End %C\Q{_AS  
    End If '%_1eaH  
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    'Assign accommodation and pupil diameter & use defaults if field left empty ?VrZ
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    If dlg.TextBox1 = "" Then bj\v0NKN4  
        A = 0           'Default accommodation '(m
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    Else 8Y*SZTzV  
        A = CDbl(dlg.TextBox1) a% |[m,FvP  
    End If [HI&>dm=$  
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    If dlg.TextBox2 = "" Then 9_h3<3
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        pupilDiam = 4   'Default pupil diameter nF~</>  
    Else `au(' xi<  
        pupilDiam = CDbl(dlg.TextBox2) z~Ph=1O
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    End If @[#U_T- I  
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    Print " " fzO4S^mTo8  
    Print "Accommodation = " & A & " Diopters" b#bdz1@s  
    Print "Pupil Diameter = " & pupilDiam & " mm" [_hHZMTH  
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    ' Calculate new parameters with accommodation >8_#L2@  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness py`RH)  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens s\i=-`  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens e
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens A"x1MjuqLM  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens Vo}3E]  
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    tlens = 3.767 + 0.04*A                  'Lens thickness nv1'iSEeOl  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction g <^Y^~+E  
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    'Adjust parameters to account for accommodation FL% GW:  
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    '************************************************************************* }$!bD  
    'Aqueous thickness (Position of Lens) Oe4 l` =2  
    '************************************************************************* p.^mOkpt  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) Zs<}{`-  
    GetCustomElement eID, entity g66=3c9</6  
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    parID = FindFullName( "Geometry.Arizona Eye" ) ,oX48Wg_+  
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    ' Delete any shift(s) in z c|3%0=,`  
    count = 0 ot]eaad  
    While GetOperationCount(eID)>count ]2(vO0~  
        GetOperation eID, count, op S>OfUrt  
        If op.Type="ShiftZ" Then K]' 84
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            DeleteOperation eID,count h^^zR)EVb  
            count=count-1 v39`ct=e  
        End If jIJVl \i]  
        count=count+1 r7Bv?M^!  
    Wend 9;2PoW8  
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    'Set new shift in `fh^[Q|4n0  
    op.Type = "ShiftZ" J_YbeZ]  
    op.val1 = taq }[}u5T`w>  
    op.parent = parID 0#4_vg .  
    AddOperation eID, op GdG1e%y]z  
    Print "Set aqueous humor thickness = " & taq-0.55 *F*c  
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    '************************************************************************* 1}#v<b$  
    'Radius and conic constant of anterior lens Be}e%Rk  
    '************************************************************************* /:v+:-lU  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) GY<E
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    GetConic eID, entity, curv, conic ~ ui/Qf2|  
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    SetConic eID, entity, 1/Rant, CCant &?>h#H222  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant {PgB
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    '************************************************************************* eO;i1>  
    'Radius and conic constant of posterior lens BM=`zGh"  
    '************************************************************************* ,\!4A  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) DLcfOOn1I  
    GetConic eID, entity, curv, conic ,!t1( H  
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    SetConic eID, entity, 1/Rpost, CCpost L,!?'.*/]  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost -q' np0H  
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    '************************************************************************* :0IxnK(r&  
    'Lens thickness (Position of posterior lens surface) %F-/|x1#Q  
    '************************************************************************* I7TdBe-  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) L>+g;GJ  
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    ' Delete any z-shift(s) _?>!Bz m  
    count = 0 mN+~fuh  
    While GetOperationCount(eID)>count 9+@"DuYc6  
        GetOperation eID, count, op #S2LQ5U  
        If op.Type="ShiftZ" Then kwNXKn/
 
            DeleteOperation eID,count /*p4(D_A  
            count=count-1 Ntr5Q IPd  
        End If b9ysxuUdS  
        count=count+1 W!q'wrIx(  
    Wend ^4(CO[|c~  
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    'Set new z-shift 3S1V^C-eBx  
    op.Type = "ShiftZ" S_LY>k?  
    op.val1 = tlens 0h!2--Aur  
    op.parent = parID h`+Gs{1qw  
    AddOperation eID, op HRIf)n&~f  
    Print "Set lens thickness = " & tlens MK9?81xd  
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    '************************************************************************* |57KTiiNLI  
    'Lens index of refraction r5Ej  
    '************************************************************************* WS9n.opl}  
    eID = FindMaterial( "Lens" ) w8:F^{  
    GetModelMaterial eID, mat K+2bNKZ0  
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    mat.Nd = nlens Gp9>R~$  
    SetModelMaterial eID, mat 5&7)hMppI  
    Print "Set lens index of refraction = " & nlens }<7Dyn,  
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    '************************************************************************* 8=gr F  
    'Pupil diameter r4t|T^{sl  
    '************************************************************************* P]!$MOt  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) $D5[12X
 
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    'Adjust pupil diameter (trimming volume inner hole) ?15k~1nA  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" n>>hfxv(O!  
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    ' Adjust pupil location to just in front of the lens jjBcoQU$o  
    parID = FindFullName( "Geometry.Arizona Eye" ) hor ok:{  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) &=fBqod  
    count = 0 R<LW*8  
    While GetOperationCount(eID)>count U#G uB&V  
        GetOperation eID, count, op I
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        If op.Type="ShiftZ" Then G+4a%?JH  
            DeleteOperation eID,count I'"*#QOX  
            count=count-1 RL~|Kr<7J  
        End If QI~s~j  
        count=count+1 WzgzI/  
    Wend As@~%0 S  
    op.Type = "ShiftZ" X^%I 3  
    op.val1 = taq-0.01 ]]o7ej  
    op.parent = parID %s$_KG!&  
    AddOperation eID, op Xn.zN>m
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    Print "Set pupil diameter = " & pupilDiam L6BHh_*E  
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    'Update AZ Eye subassembly Description Xfx(X4$9  
    eID = FindFullName( "Geometry.Arizona Eye" ) ERL(>)  
    GetEntity eID, entity mDipP  
    entity.Description = "Accommodation = " & A & "D" SynxMUlA  
    SetEntity eID, entity 598xV|TON  
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    Update WP32t@  
    Print "DONE!" L"zOa90ig  
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End Sub /.'1i4Xa1P  
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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： ( NjX?^  
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Accommodation = 4 Diopters <S $Z  
Pupil Diameter = 4 mm fouy??  
Set aqueous humor thickness = 2.81 S7aSUt!  
Set anterior lens radius = 10.4 and conic constant = -2.375869 wX#\\Jgi  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 1|/2%IDUI  
Set lens thickness = 3.927 Y+upZ@Ga  
Set lens index of refraction = 1.42672 dp)lHBV  
Set pupil diameter = 4 XT>e/x9'  
DONE! BOL_kp"