[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。
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模型 ^|FVc48{  
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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。 j(@g  
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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. t[f9Z  
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光源 @MlU!oR&  
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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。 7tf81*e  
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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。 $8X tI  
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在往下看是内置的脚本用来修改屈光度，使其为4（250mm），光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 )L(d$N=Bd  
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视网膜的散射 ! 6p)t[s  
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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。 "j.oR}s9?#  
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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。 #8Id:56  
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脚本 ik1L  
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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： Mc$v~|i6  
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如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 \HP,LH[P:  
余下的脚本计算与屈光度有关的所有参数。 j$mt*z L  
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分析 *09
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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。 vRb(eg  
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脚本代码 Ti@P4:q  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. XvzV lKL  
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Dim entity As T_ENTITY \")YKN=W  
Dim op As T_OPERATION e/HX,sf_g  
Dim mat As T_MODELMATERIAL /P8eI3R  
Dim A As Double [[66[;  
Dim pupilDiam As Double !7NzW7j  
Dim eID As Long r/q1&*T  
Dim parID As Long 1O3<%T#LOZ  
Dim count As Integer "za*$DU  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double _"w!KNX>(~  
Dim tlens As Double, nlens As Double ]-s`#  
Dim curv As Double, conic As Double C#?d
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Dim ok As Long _KkVI7a  
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Sub Main 9 K /  
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    '用户输入对话框 y1"^S  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1
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        TextBox 220,21,40,21,.TextBox1 'default: 0 M4hN#0("4  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1  RoM*Qjw  
        OKButton 40,91,90,21 jf)JPa_  
        CancelButton 190,91,90,21 7quwc'!  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 7jg(j~tQ  
        TextBox 220,49,40,21,.TextBox2 'default: 4 p2NB~t7Z  
    End Dialog Y)j,(9  
    Dim dlg As UserDialog 8s5ru)  
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    ok = Dialog (dlg) ]MA)='~  
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    If ok=0 Then    'cancel button was pressed g`8 mh&u%  
        Print "Execution cancelled." x]J-q5  
        End ohtn^o;C}  
    End If 1yRd10  
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    'Assign accommodation and pupil diameter & use defaults if field left empty owY_cDzrH  
    If dlg.TextBox1 = "" Then LYq2A,wm$  
        A = 0           'Default accommodation "KTnX#<0  
    Else o(SJuZC/U  
        A = CDbl(dlg.TextBox1) +U/"F|M  
    End If zUgkY`]:BJ  

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    If dlg.TextBox2 = "" Then 0_zSQn9c  
        pupilDiam = 4   'Default pupil diameter ]aW.b_7<9  
    Else
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        pupilDiam = CDbl(dlg.TextBox2) NCM{OAjS5U  
    End If zt?wn*_  
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    Print " " WT {Cjn  
    Print "Accommodation = " & A & " Diopters" S+xGHi)  
    Print "Pupil Diameter = " & pupilDiam & " mm" I/-w65J]  
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    ' Calculate new parameters with accommodation Uus)2R7  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness awW\$Q  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens n|,Vm@zV  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens :@8.t,|  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens 5'Ay@FJ:  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens &+{xR79+&  
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    tlens = 3.767 + 0.04*A                  'Lens thickness L#@$Mtc  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction jW$f(qAbm  
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    'Adjust parameters to account for accommodation ,F9wc
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    '************************************************************************* (V?`W7  
    'Aqueous thickness (Position of Lens) |w]i$`3
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    '************************************************************************* C)^\?DH  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) '0M0F'R  
    GetCustomElement eID, entity $`{q =  
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    parID = FindFullName( "Geometry.Arizona Eye" ) g#3x)97Z  
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    ' Delete any shift(s) in z jtpNo~O  
    count = 0 e/D\7Pf  
    While GetOperationCount(eID)>count um;U;%?Q  
        GetOperation eID, count, op P3FpU<OBwp  
        If op.Type="ShiftZ" Then "Ksd9,J\b  
            DeleteOperation eID,count 54_m{&hb  
            count=count-1 |Q
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        End If W]
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        count=count+1 TEyPlSGG  
    Wend \/%Q PE8  
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    'Set new shift in  cJ{P,K  
    op.Type = "ShiftZ" -*
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    op.val1 = taq a2)*tbM9\  
    op.parent = parID m,fr?d/;  
    AddOperation eID, op m,_oX1h  
    Print "Set aqueous humor thickness = " & taq-0.55 .kDCcnm  
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    '************************************************************************* gz:c_HJ  
    'Radius and conic constant of anterior lens )p](*Z^  
    '*************************************************************************  0d)n}fm  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) Y mSaIf  
    GetConic eID, entity, curv, conic iU|C<A%Hh  
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    SetConic eID, entity, 1/Rant, CCant "d*  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant Ase1R=0  
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    '************************************************************************* }E_zW.{!  
    'Radius and conic constant of posterior lens ~z"->.u  
    '************************************************************************* N.J:Qn`(  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) ~.SU$  
    GetConic eID, entity, curv, conic :9>nY  
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    SetConic eID, entity, 1/Rpost, CCpost Q'LU?>N)/  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost ]z@]Fi33Y  
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    '************************************************************************* L(YT6Vmm+t  
    'Lens thickness (Position of posterior lens surface) xk<0QYv   
    '************************************************************************* 'a9.JS[pj  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) e=C,`&sz  
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    ' Delete any z-shift(s) N* QI>kzU  
    count = 0 ;0W
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    While GetOperationCount(eID)>count J#^M  
        GetOperation eID, count, op BW1O1zIh\  
        If op.Type="ShiftZ" Then #-8/|_*  
            DeleteOperation eID,count /;J;,G`?  
            count=count-1 ![Y$[l  
        End If wjs7K|PK  
        count=count+1 ~'Hwszpb  
    Wend cwM0Z6  
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    'Set new z-shift T~d';P  
    op.Type = "ShiftZ" !h;VdCCi#  
    op.val1 = tlens Iu]P^8  
    op.parent = parID $NSYQF%aO  
    AddOperation eID, op L.(k8eX  
    Print "Set lens thickness = " & tlens
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    '************************************************************************* q2Dg~et  
    'Lens index of refraction ZGBcy}U(k  
    '************************************************************************* 2^:nlM{u  
    eID = FindMaterial( "Lens" ) f+RDvgkKU  
    GetModelMaterial eID, mat TlJF{ <E  
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    mat.Nd = nlens NH!!.Z"  
    SetModelMaterial eID, mat fNumY|%3  
    Print "Set lens index of refraction = " & nlens }r[BME  
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    '************************************************************************* $$w 1%#F=  
    'Pupil diameter >U].k8a)  
    '************************************************************************* e78}  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) x3 <Lx^;  
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    'Adjust pupil diameter (trimming volume inner hole) T/nRc_I+^B  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" w;O '6"  
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    ' Adjust pupil location to just in front of the lens -`JY] H  
    parID = FindFullName( "Geometry.Arizona Eye" ) Smo'&x  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) -rBj-4|"  
    count = 0 YrX{,YtiX  
    While GetOperationCount(eID)>count 1{qg@xlj  
        GetOperation eID, count, op iW)Ou?aS  
        If op.Type="ShiftZ" Then ?UzHQr  
            DeleteOperation eID,count "7d_$.Z  
            count=count-1 ;
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        End If ]v@,>!Wn  
        count=count+1 >{[J+f{~|  
    Wend NoT oLt\  
    op.Type = "ShiftZ" #N:o)I  
    op.val1 = taq-0.01 ofV{SeD67  
    op.parent = parID C\Rd]P8\  
    AddOperation eID, op 60m1 >"  
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    Print "Set pupil diameter = " & pupilDiam }_S]!AWz  
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    'Update AZ Eye subassembly Description uu:BN0  
    eID = FindFullName( "Geometry.Arizona Eye" ) <cS1}"  
    GetEntity eID, entity ,k4 (b  
    entity.Description = "Accommodation = " & A & "D" bk|>a=o3  
    SetEntity eID, entity ]`x~v4JU  
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    Update asb")NfIm  
    Print "DONE!" mi+I)b=  
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End Sub L=>N#QR7  
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如果屈光度是4，光瞳直径是4，则会输出如下数据： H"sey +-  
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Accommodation = 4 Diopters q>?oV(sF  
Pupil Diameter = 4 mm U-(d~]$  
Set aqueous humor thickness = 2.81 %NuS!v>  
Set anterior lens radius = 10.4 and conic constant = -2.375869 d] {^  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 3:r;(IaX  
Set lens thickness = 3.927 2
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Set lens index of refraction = 1.42672 t_3XqjuA  
Set pupil diameter = 4 3s+D x$Ud  
DONE! SExd-=G