[技术]Arizona眼睛模型 [复制链接]

简介 B o%Sl  
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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。 c7[Ba\Cr4h  
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模型 f|/ ,eP$  
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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。 /Ah'KN|EN  
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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. 'w<^4/L Q  
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光源 0~[M[T\  
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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。 n\BV*AH  
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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。 ]F;1l3I-  
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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。 ;K4uu<e\  
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视网膜的散射 jJ'NYG  
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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。 ?=-/5A4K  
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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。 >f1fvv
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脚本 F/:%YR;  
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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： ^\\9B-MvY  
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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。 CEzdH!nP  
余下的脚本计算与屈光度有关的所有参数。 [;:ocy  
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分析 mGmZ}H'{  
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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;Ln|._/t  
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脚本代码 )}_}D+2  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. "st+2#{  
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Dim entity As T_ENTITY ^bdXzj
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Dim op As T_OPERATION qn}VW0!  
Dim mat As T_MODELMATERIAL K&"X7fQ  
Dim A As Double A4KkX  
Dim pupilDiam As Double Uw3wR!:  
Dim eID As Long @2_E9{T  
Dim parID As Long ']1a  
Dim count As Integer CqU^bVs  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double _?I*:: I  
Dim tlens As Double, nlens As Double Wu8zK=Ve(  
Dim curv As Double, conic As Double qIh9? |`U  
Dim ok As Long U5?QneK  
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Sub Main 5HY0 *\  
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    '用户输入对话框 2)QZYgfh  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 3m$Qd#|  
        TextBox 220,21,40,21,.TextBox1 'default: 0 hb}QtQ  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 G2P:|R  
        OKButton 40,91,90,21 p&HO~J
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        CancelButton 190,91,90,21 [.CP,Ly  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 (>lH=&%zj  
        TextBox 220,49,40,21,.TextBox2 'default: 4 8;f5;7Mn  
    End Dialog 'Ddzlip  
    Dim dlg As UserDialog E9@Sc>e  
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    ok = Dialog (dlg) rD !GEU
 
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    If ok=0 Then    'cancel button was pressed (eHTXk*V`  
        Print "Execution cancelled." 'UuHyC2Ha3  
        End i]qxF&1  
    End If S{{wcH$n'i  
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    'Assign accommodation and pupil diameter & use defaults if field left empty (/{bJt~b  
    If dlg.TextBox1 = "" Then BV}sN{  
        A = 0           'Default accommodation K&T.~2'>  
    Else ^D ;EbR  
        A = CDbl(dlg.TextBox1) ;Qc^xIPy  
    End If ]bstkf}~u  
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    If dlg.TextBox2 = "" Then Jq8v69fyQ  
        pupilDiam = 4   'Default pupil diameter wk1/&  
    Else 79h'sp6;  
        pupilDiam = CDbl(dlg.TextBox2) PO:sF]5  
    End If N]\)Ok  
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    Print " " <$K7f  
    Print "Accommodation = " & A & " Diopters" 7m:TY>{  
    Print "Pupil Diameter = " & pupilDiam & " mm" u4 ~.[3E*  
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    ' Calculate new parameters with accommodation .VohW=D3  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness J?hs\nA  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens {*<%6?  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens 8u1?\SYnb  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens f=7[GZoDn  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens *,=8x\Shp  
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    tlens = 3.767 + 0.04*A                  'Lens thickness 2NB$(4/  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction OgHqF,0MN  
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    'Adjust parameters to account for accommodation /1Ss |.  
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    '************************************************************************* k3
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    'Aqueous thickness (Position of Lens) us.IdG  
    '************************************************************************* 19%zcYTe  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) ~w.y9)",  
    GetCustomElement eID, entity ^E~1%Md.  
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    parID = FindFullName( "Geometry.Arizona Eye" ) wT-Kg=-q  
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    ' Delete any shift(s) in z G6xNR  
    count = 0 (aq-aum-I  
    While GetOperationCount(eID)>count HJd{j,M  
        GetOperation eID, count, op `91Z]zGpU  
        If op.Type="ShiftZ" Then ^SM5
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            DeleteOperation eID,count 6:Y2z!MLO  
            count=count-1 j'lC]}kH  
        End If wbg?IvY[  
        count=count+1 /fU-0a8  
    Wend o'Y/0hkh  
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    'Set new shift in BaMF5f+  
    op.Type = "ShiftZ" :lK8i{o  
    op.val1 = taq ~3%aEj  
    op.parent = parID Y)#,6\=U  
    AddOperation eID, op !JVv`YN  
    Print "Set aqueous humor thickness = " & taq-0.55 }VHvC"  
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    '************************************************************************* <$C3] =2  
    'Radius and conic constant of anterior lens . +,{|){c  
    '************************************************************************* p1T0FBV L  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) @xk;]H80  
    GetConic eID, entity, curv, conic vN~joQ=d  
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    SetConic eID, entity, 1/Rant, CCant u<+"#.[2v~  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant =-qYp0sVP  
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    '************************************************************************* 5XuQQ!`  
    'Radius and conic constant of posterior lens _94R8?\_V7  
    '************************************************************************* %MEWw  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) |;I"Oc.w^R  
    GetConic eID, entity, curv, conic JbN,K  
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    SetConic eID, entity, 1/Rpost, CCpost W*,$0 t  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost #F6M<V'  
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    '************************************************************************* &2n5m&  
    'Lens thickness (Position of posterior lens surface) u(PUbxJ
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    '************************************************************************* WmRu3O  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) by$mD_sr  
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    ' Delete any z-shift(s) iP1yy5T  
    count = 0 |3hNTH?  
    While GetOperationCount(eID)>count m6Qm }""  
        GetOperation eID, count, op Qv
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        If op.Type="ShiftZ" Then 57_AJT hR  
            DeleteOperation eID,count Qtt3;5m  
            count=count-1 n;QFy5HB8  
        End If =GiN~$d  
        count=count+1 Z!4
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    Wend Nk1p)V SC  
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    'Set new z-shift O:8Ne*L`D  
    op.Type = "ShiftZ" ?KE:KV[Y  
    op.val1 = tlens Zq:c2/\c}  
    op.parent = parID jHV) TBr  
    AddOperation eID, op X+/^s)  
    Print "Set lens thickness = " & tlens Pj5:=d8z(  
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    '************************************************************************* A-h[vP!v|  
    'Lens index of refraction ']Z%6_WF  
    '************************************************************************* e488}h6#m  
    eID = FindMaterial( "Lens" ) };f^*KZ=0  
    GetModelMaterial eID, mat &G?w*w_n  
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    mat.Nd = nlens
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    SetModelMaterial eID, mat }|nEbM]#  
    Print "Set lens index of refraction = " & nlens '>Thn{  
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    '************************************************************************* J?1Eh14KZ  
    'Pupil diameter we kb&?  
    '************************************************************************* ?!3u?Kd  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) bP%X^q~]A  
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    'Adjust pupil diameter (trimming volume inner hole) u]]mbER*t#  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" R''2o_F6  

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    ' Adjust pupil location to just in front of the lens /2 qxJvZ  
    parID = FindFullName( "Geometry.Arizona Eye" ) 6B}V{2  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) uX6rCokr  
    count = 0 aFL<(,~r  
    While GetOperationCount(eID)>count V|<'o<h8  
        GetOperation eID, count, op mt[ #=Yba  
        If op.Type="ShiftZ" Then IiY%y:!g  
            DeleteOperation eID,count gyU=v{].  
            count=count-1 l vBcEg  
        End If yvnvIy  
        count=count+1 b$tf9$f  
    Wend %2^V.`0T  
    op.Type = "ShiftZ" BG6Lky/omz  
    op.val1 = taq-0.01 -WGlOpg0;  
    op.parent = parID M"$g*j  
    AddOperation eID, op iaQFVROu  
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    Print "Set pupil diameter = " & pupilDiam R?J8#JPXD  
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    'Update AZ Eye subassembly Description >}d6)s|   
    eID = FindFullName( "Geometry.Arizona Eye" )
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    GetEntity eID, entity #(Yd'qKo  
    entity.Description = "Accommodation = " & A & "D" ~N)(|N  
    SetEntity eID, entity @2>c
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    Update %2beoH'  
    Print "DONE!" V h5\'Sn  
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End Sub "Q{7X[$$^  
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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： V-"#Kf9  
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Accommodation = 4 Diopters ft!D2M  
Pupil Diameter = 4 mm CYM>4C~>JW  
Set aqueous humor thickness = 2.81 v(,YqT>q@U  
Set anterior lens radius = 10.4 and conic constant = -2.375869 F'ez{B\AX  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 R0F&!y!B  
Set lens thickness = 3.927 %mOQIXr1s  
Set lens index of refraction = 1.42672 Ki /j\  
Set pupil diameter = 4 1`Uu;m
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DONE! 'a~F'FN$