[技术]Arizona眼睛模型 [复制链接]

简介 2TB>d+  
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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。 }t}y  

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模型 >5Y%4++(  
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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。 $'#hCs  
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在FRED中使用0屈光度来创建的，光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. 8."B  
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光源 d>[=]  
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多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 qKu/~0a/  
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除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处，并增加了pre-propagation distance= -8。尽管光线在光瞳处创建，规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射，而不是在光瞳处入射。 57 (bd0@8  
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在往下看是内置的脚本用来修改屈光度，使其为4（250mm），光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 ASA ]7qyO  
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视网膜的散射 BN??3F8C  
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在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 ;7,>2VTm  
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注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 RLl*@SEi"  
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脚本 {vCB$@/o  
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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： KV&4Ep#  
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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。 :Y4m3|  
余下的脚本计算与屈光度有关的所有参数。 |.]sL0;4Z  
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分析 oUSv)G.zb  
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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。 ":
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脚本代码 7LotN6H  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. V.\12P  
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Dim entity As T_ENTITY +g.lLb*#  
Dim op As T_OPERATION 3.0t5F<B  
Dim mat As T_MODELMATERIAL  (zIWJJw  
Dim A As Double 4eD>DW  
Dim pupilDiam As Double kH4xP3. i  
Dim eID As Long $0[t<4K`yn  
Dim parID As Long rl/]Ym4j  
Dim count As Integer "+dByaY  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double bf4QW JZD  
Dim tlens As Double, nlens As Double G
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Dim curv As Double, conic As Double 1@}s:  
Dim ok As Long 4CH/~b1(  
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Sub Main zEBUR%9  
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    '用户输入对话框 2=]Xe#5J=  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 wf`e3S  
        TextBox 220,21,40,21,.TextBox1 'default: 0 %+8"-u  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 P >>VBh?  
        OKButton 40,91,90,21 ;N(9nX}%)  
        CancelButton 190,91,90,21 ]=Tle&yM+T  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 V'M#."Of/  
        TextBox 220,49,40,21,.TextBox2 'default: 4 bI?uV;m>  
    End Dialog $:}sm0;  
    Dim dlg As UserDialog puOAt  
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    ok = Dialog (dlg) ^.gBHZ  
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    If ok=0 Then    'cancel button was pressed >{1 i8 b@  
        Print "Execution cancelled." E7`Q=4@e  
        End 4NK{RN3  
    End If k1_"}B5  
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    'Assign accommodation and pupil diameter & use defaults if field left empty jCK 0+,;  
    If dlg.TextBox1 = "" Then LW#
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        A = 0           'Default accommodation !kQJ6U  
    Else uXuA4o$t-  
        A = CDbl(dlg.TextBox1) Rm&4Pku  
    End If w l#jSj%pd  
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    If dlg.TextBox2 = "" Then H"b}lf  
        pupilDiam = 4   'Default pupil diameter 7=`_UqCV  
    Else 0J z|BE3Y  
        pupilDiam = CDbl(dlg.TextBox2) ,t|qhJF  
    End If &6O0h0Vy  
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    Print " " N@x5h8  
    Print "Accommodation = " & A & " Diopters" P.Gmj;  
    Print "Pupil Diameter = " & pupilDiam & " mm" N= G!r  
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    ' Calculate new parameters with accommodation 6|10OTVu`  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness [,T
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens LUKt!I0l  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens ?Zh,W(7W  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens ;=lQMKx0  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens z/
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    tlens = 3.767 + 0.04*A                  'Lens thickness /I~(*X  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction La8D%N  
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    'Adjust parameters to account for accommodation h {M=V  
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    '************************************************************************* %(ms74R+  
    'Aqueous thickness (Position of Lens) t2hI^J0y  
    '************************************************************************* tdOox87YK  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) 9?I?;l{  
    GetCustomElement eID, entity Xmv^O  
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    parID = FindFullName( "Geometry.Arizona Eye" ) f5P@PG]{  
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    ' Delete any shift(s) in z 'q7&MM'oS^  
    count = 0 tk66Ggi[K  
    While GetOperationCount(eID)>count Q=?YY-*$  
        GetOperation eID, count, op Gq =i-I  
        If op.Type="ShiftZ" Then ftRzgW);  
            DeleteOperation eID,count |wkUnn4UB8  
            count=count-1 Q7pjF`wu  
        End If HSlAm&Y\  
        count=count+1 ,r,$x4*  
    Wend 3Bbd2[<W  
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    'Set new shift in -`ss7j&b3  
    op.Type = "ShiftZ" 2|JtRE+  
    op.val1 = taq @,;VMO  
    op.parent = parID I`uOsZBO/  
    AddOperation eID, op fDrjR6xV  
    Print "Set aqueous humor thickness = " & taq-0.55 v@Bk)Z  
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    '************************************************************************* Rd,5&X$  
    'Radius and conic constant of anterior lens R=<uf:ca  
    '************************************************************************* qs3V2lvYw{  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) ^-g-]?q  
    GetConic eID, entity, curv, conic d_)VeuE2  
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    SetConic eID, entity, 1/Rant, CCant m98w0D@Ee  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant !BEl6h  
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    '************************************************************************* @!,W]?{  
    'Radius and conic constant of posterior lens T3In0LQ  
    '************************************************************************* Y~P* !g  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) XG8UdR|  
    GetConic eID, entity, curv, conic XpT+xv1`;  
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    SetConic eID, entity, 1/Rpost, CCpost JB9
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    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost x]pZcx9  
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    '************************************************************************* H57wzG{xG  
    'Lens thickness (Position of posterior lens surface) Xr]<v%,C  
    '************************************************************************* j7 \y1$w  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) qV:TuR-|w  
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    ' Delete any z-shift(s) 4rH:`494  
    count = 0 ]<:qMLg  
    While GetOperationCount(eID)>count !f)^z9QX8  
        GetOperation eID, count, op *5q_fO  
        If op.Type="ShiftZ" Then p.x!dt\1kC  
            DeleteOperation eID,count 1aS66TS3  
            count=count-1 WNo<0|X  
        End If L /V;;  
        count=count+1 #s0Wx47~  
    Wend Ry"N_Fb  
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    'Set new z-shift Ht&%`\9s  
    op.Type = "ShiftZ" :za:gs0  
    op.val1 = tlens ;]Ko7M(4  
    op.parent = parID 9 $Ud\
 
    AddOperation eID, op (laVmU?I7  
    Print "Set lens thickness = " & tlens \>)#cEX5  
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    '************************************************************************* {7d\du&G  
    'Lens index of refraction (x/xqDpmBS  
    '************************************************************************* /tu\q  
    eID = FindMaterial( "Lens" ) cnR18NK  
    GetModelMaterial eID, mat lJdwbuB6  
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    mat.Nd = nlens ;Ff5oo
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    SetModelMaterial eID, mat qTrb)95  
    Print "Set lens index of refraction = " & nlens -"/l)1ox,  
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    '************************************************************************* `Uy4>?  
    'Pupil diameter DH'0#  
    '************************************************************************* '<%;Nv  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) Usf7 AS=  
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    'Adjust pupil diameter (trimming volume inner hole) S%2qX"8  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" 2PG= T/  
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    ' Adjust pupil location to just in front of the lens cB|Rj}40v  
    parID = FindFullName( "Geometry.Arizona Eye" ) xL}~R7  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) F92et<y.  
    count = 0 qZ rv2dT  
    While GetOperationCount(eID)>count 8mv}-;  
        GetOperation eID, count, op Bb@m-+f  
        If op.Type="ShiftZ" Then +w9X$<?_  
            DeleteOperation eID,count taqmtXU=(  
            count=count-1 kqt.?iJw  
        End If 6/l{e)rX2o  
        count=count+1 3B3l)eX  
    Wend l@<yC-Xd  
    op.Type = "ShiftZ" 2t1u{  
    op.val1 = taq-0.01 v>E3|w%  
    op.parent = parID _l$X![@6=  
    AddOperation eID, op 7)  
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    Print "Set pupil diameter = " & pupilDiam MT(G=r8  
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    'Update AZ Eye subassembly Description Nk@ag)  
    eID = FindFullName( "Geometry.Arizona Eye" ) {p)=#Jd`.P  
    GetEntity eID, entity 8bW,.to(?x  
    entity.Description = "Accommodation = " & A & "D" y5$AAas  
    SetEntity eID, entity sq1v._^s  
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    Update ~-K<gT/  
    Print "DONE!" ^K`Vqo  
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End Sub c
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如果屈光度是4，光瞳直径是4，则会输出如下数据： Lk:Sju  
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Accommodation = 4 Diopters 5#hsy;q;[  
Pupil Diameter = 4 mm Lzy Ix!S  
Set aqueous humor thickness = 2.81 3{R7y  
Set anterior lens radius = 10.4 and conic constant = -2.375869 j  hrpS  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 *$EcP`K$  
Set lens thickness = 3.927 GK
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Set lens index of refraction = 1.42672 sB
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Set pupil diameter = 4 Nx^r&pr  
DONE! IPEJ7n49