[技术]Arizona眼睛模型 [复制链接]

简介 2B`#c}PP  
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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。 d&a
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模型 6-!U\R2Z>  
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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。 w/UZ6fu  
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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. *Z:'jV<  
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光源 QnN cGH  
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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。 IyJHKDFk  
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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。 .lE7v-e  
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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。 ^p}|""\j  
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视网膜的散射 e|2@z-Sp-  
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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。 ZA{T0:  
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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。 `j)S7KN  
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脚本 Al-;-t#Dc  
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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： yDe6f(D  
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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。 E8LA+dKN:  
余下的脚本计算与屈光度有关的所有参数。 vj,OX~|  

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分析 aTLu7C\-e  
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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。 Q!*}^W  
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脚本代码 ~4^~w#R  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. ?_V&~?r   
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Dim entity As T_ENTITY T0TgV  
Dim op As T_OPERATION orON)Sks  
Dim mat As T_MODELMATERIAL PXrv2q[5?  
Dim A As Double #ExNiFZ  
Dim pupilDiam As Double :f_fp(T  
Dim eID As Long hb="J34
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Dim parID As Long #X t|"Z  
Dim count As Integer w]O[{3"  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double "&Rt&S  
Dim tlens As Double, nlens As Double sFbN)Cx  
Dim curv As Double, conic As Double scQnL'\  
Dim ok As Long ?%A9}"q]  
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Sub Main SPN5H;{[]K  
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    '用户输入对话框 n4sO#p)'  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 uEui{_2$  
        TextBox 220,21,40,21,.TextBox1 'default: 0 H~:EPFi.(  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 a${<~
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        OKButton 40,91,90,21 slTE.  
        CancelButton 190,91,90,21 e%_J O7  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 'B\7P*L"p  
        TextBox 220,49,40,21,.TextBox2 'default: 4 Q&]f9j_  
    End Dialog |5TzRz  
    Dim dlg As UserDialog G$mAyK:  
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    ok = Dialog (dlg) L.?QZN%cN  
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    If ok=0 Then    'cancel button was pressed cXo
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        Print "Execution cancelled." F87/p  
        End ItD&L ))  
    End If CC B'  
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    'Assign accommodation and pupil diameter & use defaults if field left empty (Cb;=:3G  
    If dlg.TextBox1 = "" Then MSaOFv_Q  
        A = 0           'Default accommodation nq5qUErew  
    Else JnIE6@g<y  
        A = CDbl(dlg.TextBox1) ^_gH}~l+U  
    End If XY^]nm-{I  
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    If dlg.TextBox2 = "" Then Qg]+&8!*  
        pupilDiam = 4   'Default pupil diameter p|+TgOYOc  
    Else 0,whTnH|  
        pupilDiam = CDbl(dlg.TextBox2) \,S4-~(:!  
    End If 6,cJ3~!48  
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    Print " " g{^~g  
    Print "Accommodation = " & A & " Diopters" )uu(I5St  
    Print "Pupil Diameter = " & pupilDiam & " mm" =}g-N)^  
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    ' Calculate new parameters with accommodation ryNe=9p  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness H
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens FBxg^g%PB@  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens B~B,L*kC2  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens 3Fw7q"  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens MY}/h@  
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    tlens = 3.767 + 0.04*A                  'Lens thickness Cto>~pV  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction rf+Z0C0WYi  
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    'Adjust parameters to account for accommodation 8]mRX~  
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    '************************************************************************* !dq$qUl/  
    'Aqueous thickness (Position of Lens) a<J<Oc!  
    '************************************************************************* ^8KxU  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) <JIqkGeAi  
    GetCustomElement eID, entity I?RUVs  
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    parID = FindFullName( "Geometry.Arizona Eye" ) ,BFw-A  
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    ' Delete any shift(s) in z RzU
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    count = 0 _(-i46x}  
    While GetOperationCount(eID)>count ,xg-H6Xfa{  
        GetOperation eID, count, op xR8y"CpE  
        If op.Type="ShiftZ" Then {n&GZG"f  
            DeleteOperation eID,count x_t$*  
            count=count-1 ZUD{V  
        End If 
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        count=count+1 rJh$>V+ '  
    Wend 6"?#E[ #[  
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    'Set new shift in 5=\^DeM@ H  
    op.Type = "ShiftZ" WcQkeh3n  
    op.val1 = taq 8"TlWHF`  
    op.parent = parID 4V c``Um  
    AddOperation eID, op P%ThW9^vnj  
    Print "Set aqueous humor thickness = " & taq-0.55 Jd~Mq9(  
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    '************************************************************************* I@5$<SN  
    'Radius and conic constant of anterior lens 1]9l SE!E7  
    '************************************************************************* bI^F(  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) cc3/XBo  
    GetConic eID, entity, curv, conic BNe>Lko  
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    SetConic eID, entity, 1/Rant, CCant 5`@yX[G  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant /;vHAtt;f  
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    '************************************************************************* cY Qm8TR<  
    'Radius and conic constant of posterior lens v_WF.sb~  
    '************************************************************************* EEMRy  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) @-Y,9mM  
    GetConic eID, entity, curv, conic re,}}'  
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    SetConic eID, entity, 1/Rpost, CCpost R#i`H(N  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost bN6i*)}  
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    '************************************************************************* O\gVB!x  
    'Lens thickness (Position of posterior lens surface) ;VEKrVD  
    '************************************************************************* scTt53v^  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) ;.<HpDfG_  
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    ' Delete any z-shift(s) R\Ckk;<$  
    count = 0 u{w,y.l1h  
    While GetOperationCount(eID)>count #2lvRJB  
        GetOperation eID, count, op E^A!k=>  
        If op.Type="ShiftZ" Then ]826kpq_  
            DeleteOperation eID,count G*,7pc  
            count=count-1 ef!f4u\  
        End If aK]AhOG  
        count=count+1 4CtWEq  
    Wend |lk:(~DM  
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    'Set new z-shift m>3\1`ZF~<  
    op.Type = "ShiftZ" :6Tv4ZUvcG  
    op.val1 = tlens So75h*e  
    op.parent = parID u#`51Hr
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    AddOperation eID, op KV-h~C  
    Print "Set lens thickness = " & tlens 6'x3g2C/  
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    '************************************************************************* O4:_c-V2  
    'Lens index of refraction :Rnwyj])  
    '************************************************************************* ic4hO>p&  
    eID = FindMaterial( "Lens" ) zD<8.AIGC  
    GetModelMaterial eID, mat ];5Auh0o  
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    mat.Nd = nlens B9Wd '  
    SetModelMaterial eID, mat G'';VoW=  
    Print "Set lens index of refraction = " & nlens I~Qi):&x  
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    '************************************************************************* LU8:]zOY  
    'Pupil diameter Ct zWdo.  
    '************************************************************************* +\u\BJ!LAJ  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) FQE(qltf,
 
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    'Adjust pupil diameter (trimming volume inner hole)  DO9
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" }W(t>>  
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    ' Adjust pupil location to just in front of the lens NB86+2stu  
    parID = FindFullName( "Geometry.Arizona Eye" ) lDF7~N9J_  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) rhX?\_7o  
    count = 0 :7JP(j2  
    While GetOperationCount(eID)>count PfB9 .f{  
        GetOperation eID, count, op 94]i|2qj*  
        If op.Type="ShiftZ" Then U.b|3E/^  
            DeleteOperation eID,count *UXa.kT@  
            count=count-1 Fey^hx w =  
        End If jGo\_O<of  
        count=count+1 /[ft{:#&t  
    Wend ;O5I
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    op.Type = "ShiftZ" &3xda1H  
    op.val1 = taq-0.01 jxt]Z3a~0  
    op.parent = parID <b\8<mTr  
    AddOperation eID, op .2_
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    Print "Set pupil diameter = " & pupilDiam (H:A|Lw  
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    'Update AZ Eye subassembly Description 4L4u
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    eID = FindFullName( "Geometry.Arizona Eye" ) =W2I0nr.  
    GetEntity eID, entity hd[t&?{=  
    entity.Description = "Accommodation = " & A & "D" wlslG^^(!  
    SetEntity eID, entity I3izLi
 
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    Update Nez '1  
    Print "DONE!" _JA)""l%  
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End Sub 0]$-}A
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如果屈光度是4，光瞳直径是4，则会输出如下数据： g:U -kK!i  
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Accommodation = 4 Diopters sJl>evw  
Pupil Diameter = 4 mm )7Qp9Fxo  
Set aqueous humor thickness = 2.81 C@-cLk  
Set anterior lens radius = 10.4 and conic constant = -2.375869 b^(
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Set posterior lens radius = -4.424557 and conic constant = -3.081019 yJlRW!@&:  
Set lens thickness = 3.927 )KkV<$  
Set lens index of refraction = 1.42672 "A5z!6T{  
Set pupil diameter = 4 jqTK7b  
DONE! ,9ew75Jl