[技术]Arizona眼睛模型 [复制链接]

简介 \_VmY!I5\  
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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。 ET-Vm >]  
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模型 FT.@1/)  
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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。 M#a&\cqC  
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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. A[H;WKn0  
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光源 2B` 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。 <HQ&-jx  
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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。 \hbiU]  
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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。 54q3R`y  
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视网膜的散射 b
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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。 >IY,be6>P  
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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。 ;&,.TC?l  
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脚本 6[?}6gQ  
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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： %;O}FyP  
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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。 -3hCiKq  
余下的脚本计算与屈光度有关的所有参数。 >5Lexj  
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分析 <4mQ*6  
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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。 Fe$/t(  
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脚本代码 1r571B*O  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. >V!LitdJ  
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Dim entity As T_ENTITY xj
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Dim op As T_OPERATION 0ar=cuDm  
Dim mat As T_MODELMATERIAL k'+}9
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Dim A As Double 4P kfUMX  
Dim pupilDiam As Double ]rW8y%yD  
Dim eID As Long h0VzIuV  
Dim parID As Long N5 n>  
Dim count As Integer 0*7*RX  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double 2k1aX~?  
Dim tlens As Double, nlens As Double FA$zZs10\  
Dim curv As Double, conic As Double !R:y'Y%j  
Dim ok As Long z $6JpG  
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Sub Main ,{{SI  
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    '用户输入对话框 xl] ;*&  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 <NB41/  
        TextBox 220,21,40,21,.TextBox1 'default: 0 'b[0ci:  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 I/p]DT  
        OKButton 40,91,90,21 zvf3b!}  
        CancelButton 190,91,90,21 N z~"vi(t  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 &" h]y?Q  
        TextBox 220,49,40,21,.TextBox2 'default: 4 U9ZbVjqv@  
    End Dialog @{}rG8  
    Dim dlg As UserDialog ,Y!zORv<7  
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    ok = Dialog (dlg) t26ij`V  
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    If ok=0 Then    'cancel button was pressed kuS/S\Z5K  
        Print "Execution cancelled." p4mY0Y]mP  
        End FH\CK  
    End If BGqa-d  
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    'Assign accommodation and pupil diameter & use defaults if field left empty NWKi ()nA%  
    If dlg.TextBox1 = "" Then (9GbG"   
        A = 0           'Default accommodation ULl_\5s2  
    Else iBvOJs  
        A = CDbl(dlg.TextBox1) I;j3*lV_  
    End If Z
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    If dlg.TextBox2 = "" Then uec|S\~M  
        pupilDiam = 4   'Default pupil diameter uva\0q  
    Else l$XA5#k  
        pupilDiam = CDbl(dlg.TextBox2) XxOn3i  
    End If r95
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    Print " " GqUSVQ  
    Print "Accommodation = " & A & " Diopters" Lt>7hBe"  
    Print "Pupil Diameter = " & pupilDiam & " mm" A3s57.Z]|  
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    ' Calculate new parameters with accommodation gaeOgP.0  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness r/AHJU3&eY  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens Q]\j>>  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens >L[lV_M_>
 
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens 4<}A]BQVkJ  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens &jm[4'$ *z  
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    tlens = 3.767 + 0.04*A                  'Lens thickness IVteF*8hU  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction p>p'.#M  
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    'Adjust parameters to account for accommodation E5{n?e  
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    '************************************************************************* 3*WS"bt  
    'Aqueous thickness (Position of Lens)  :]c=pH  
    '************************************************************************* x/I;nMY  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) Yu3_=: <C  
    GetCustomElement eID, entity ]{Ek[Av  
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    parID = FindFullName( "Geometry.Arizona Eye" ) btQet.  
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    ' Delete any shift(s) in z fn1pa@P  
    count = 0 :[?!\m%
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    While GetOperationCount(eID)>count E@pFTvo  
        GetOperation eID, count, op Z#7U "G-A  
        If op.Type="ShiftZ" Then vlQ0gsXK  
            DeleteOperation eID,count }n95< {  
            count=count-1 kfCKhx   
        End If z!CD6W1n  
        count=count+1 v3^t/[e~:  
    Wend W5/};K\.  
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    'Set new shift in /{we;Ut=g  
    op.Type = "ShiftZ" \)R-A '*U  
    op.val1 = taq JS7dsO0;  
    op.parent = parID &<h?''nCy  
    AddOperation eID, op K:w]>a  
    Print "Set aqueous humor thickness = " & taq-0.55 }+DDJ6Jzs  
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    '************************************************************************* wOcg4HlW  
    'Radius and conic constant of anterior lens ]fC7%"nB  
    '************************************************************************* ND*]gM  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) ^&m?qKN8  
    GetConic eID, entity, curv, conic STB-guia5  
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    SetConic eID, entity, 1/Rant, CCant XnA6/^  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant pqq?*\W&[v  
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    '************************************************************************* CB
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    'Radius and conic constant of posterior lens 0n5!B..m}  
    '************************************************************************* z8tl
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    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) YFqZe6g0$  
    GetConic eID, entity, curv, conic 2 `&<bt[g  
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    SetConic eID, entity, 1/Rpost, CCpost {]["6V6W  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost u _X}-U  
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    '************************************************************************* 8m7;x/0ld  
    'Lens thickness (Position of posterior lens surface) "Q?_ EE
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    '************************************************************************* xgs@gw7!n0  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) h--45`cE  
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    ' Delete any z-shift(s) [`9^QEj  
    count = 0 dyl 0]Z  
    While GetOperationCount(eID)>count qmID-t"  
        GetOperation eID, count, op mt^`1ekoY  
        If op.Type="ShiftZ" Then N(BiOLZL6  
            DeleteOperation eID,count 9m~t j_
  
            count=count-1 P5
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        End If 3W'FcE)|E  
        count=count+1 1t#XQ?8  
    Wend ^Po,(iIn  
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    'Set new z-shift AZBC P  
    op.Type = "ShiftZ" 0V7 _n  
    op.val1 = tlens '$*[SauAG  
    op.parent = parID 19&)Yd1  
    AddOperation eID, op R9r)C{63S&  
    Print "Set lens thickness = " & tlens  z \^  


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    '************************************************************************* E@mkm  
    'Lens index of refraction %HVD^. V  
    '************************************************************************* sL8>GtVo  
    eID = FindMaterial( "Lens" ) 2_.CX(kI  
    GetModelMaterial eID, mat e3pnk =u  
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    mat.Nd = nlens I3An57YV].  
    SetModelMaterial eID, mat (QKsB3X  
    Print "Set lens index of refraction = " & nlens :fW.-^"VP  
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    '************************************************************************* vgN@~Xa  
    'Pupil diameter ?#i|>MRR>  
    '************************************************************************* >'.[G:b  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) _1\poAy  
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    'Adjust pupil diameter (trimming volume inner hole) @Rf^P(  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" cPSti  
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    ' Adjust pupil location to just in front of the lens EFD?di)s  
    parID = FindFullName( "Geometry.Arizona Eye" ) St_Sl:m$  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) hu&n=6  
    count = 0 ~9bv Wd1D  
    While GetOperationCount(eID)>count Z) t{JHm:  
        GetOperation eID, count, op <a fO 6?`  
        If op.Type="ShiftZ" Then eZA6D\  
            DeleteOperation eID,count cXMa\#P  
            count=count-1 yduuFK  
        End If h*l cEzG?A  
        count=count+1 lZBv\JE  
    Wend 1Lc8fP$  
    op.Type = "ShiftZ" t)KPp|&  
    op.val1 = taq-0.01 C&e8a9*,(a  
    op.parent = parID 8ZFH}v@V1'  
    AddOperation eID, op R7,pukK  
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    Print "Set pupil diameter = " & pupilDiam i"<ZVw  
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    'Update AZ Eye subassembly Description q{[1fE"[K4  
    eID = FindFullName( "Geometry.Arizona Eye" ) g(1"GKg3K  
    GetEntity eID, entity y%JF8R;n  
    entity.Description = "Accommodation = " & A & "D" _E&U?>g+  
    SetEntity eID, entity YT][\x  
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    Update :ET x*c  
    Print "DONE!" n00z8B1j(l  
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End Sub M`(;>Kp7  
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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： $G)&J2z
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Accommodation = 4 Diopters ]LMiMj  
Pupil Diameter = 4 mm t&38@p  
Set aqueous humor thickness = 2.81 1T:)Zv'  
Set anterior lens radius = 10.4 and conic constant = -2.375869 ]bf'  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 $f9 ,##/  
Set lens thickness = 3.927 X,&`WPA:S  
Set lens index of refraction = 1.42672 a$A2IkD  
Set pupil diameter = 4 d4Ixuux<3  
DONE! Sio1Q0