[技术]Arizona眼睛模型 [复制链接]

简介 {a;my"ly  
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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。 ;n0VF77>O  
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模型 EFSln*|  
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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。 X] cI ?  
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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. C{^U^>bU  
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光源 D; i%J  
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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。 U(*k:Fw  
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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。 pH!e<m  
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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。 *>"k/XUn$  
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视网膜的散射 Ut|G.%1Vd%  
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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。 o$disJ  
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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。 /8](M5X]f  
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脚本 N i\*<:_  
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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： UTT7a"  
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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。 H#zsk*=QD  
余下的脚本计算与屈光度有关的所有参数。 ~
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分析 "j(?fVx  
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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。 &tKr ?l  
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脚本代码 HZ>8@AVa\  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. \:`'!X1*U  
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Dim entity As T_ENTITY dM|&Y6
  
Dim op As T_OPERATION "w0[l"3V  
Dim mat As T_MODELMATERIAL 1a|Z!Vzi  
Dim A As Double XnBpL6"T`  
Dim pupilDiam As Double 2`|1 !x  
Dim eID As Long ^&nC)T<w  
Dim parID As Long 7x,c)QES`  
Dim count As Integer wTT_jyH)  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double 4d\"gk  
Dim tlens As Double, nlens As Double [5KzawV  
Dim curv As Double, conic As Double N001c)*7Q  
Dim ok As Long ~Z ,b
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Sub Main T!GX^nn*O  
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    '用户输入对话框 xUp[)B6?:  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 GoVB
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        TextBox 220,21,40,21,.TextBox1 'default: 0 g\Gx
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        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 mQV
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        OKButton 40,91,90,21 m%mA0r  
        CancelButton 190,91,90,21 -85]x)JE  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 fWr6f`de  
        TextBox 220,49,40,21,.TextBox2 'default: 4 t6zc$0-j"  
    End Dialog ubq4Zv7'   
    Dim dlg As UserDialog A..,.   
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    ok = Dialog (dlg) <4
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    If ok=0 Then    'cancel button was pressed cyR K&J  
        Print "Execution cancelled."  pt`^4}  
        End uydy[n\
  
    End If IV"OzQONx  
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    'Assign accommodation and pupil diameter & use defaults if field left empty .kv/db  
    If dlg.TextBox1 = "" Then D/T&0  
        A = 0           'Default accommodation X)-9u8  
    Else ~j1.;WId[  
        A = CDbl(dlg.TextBox1) bzI!;P1&  
    End If qNhV zx  
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    If dlg.TextBox2 = "" Then jGM+  
        pupilDiam = 4   'Default pupil diameter t>W^^'=E  
    Else XDtr{r6z  
        pupilDiam = CDbl(dlg.TextBox2) ?A!Lh,  
    End If NT qtr="  
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    Print " " Bl)znJ^
 
    Print "Accommodation = " & A & " Diopters" lnXb]t
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    Print "Pupil Diameter = " & pupilDiam & " mm" fxW,S  
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    ' Calculate new parameters with accommodation @uIY+_E40g  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness WK{{U$:$  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens ?dWfupO{  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens 3YtFO;-  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens $_
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    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens SUSam/xeg"  
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    tlens = 3.767 + 0.04*A                  'Lens thickness Z0f0tL&A<  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction LGxQ>f[V  
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    'Adjust parameters to account for accommodation X>i`z  
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    '************************************************************************* SC'F,!  
    'Aqueous thickness (Position of Lens) /xK5%cE>B  
    '************************************************************************* k\:f2%!!  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) ?*I _'2  
    GetCustomElement eID, entity S Z@ JzOA  
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    parID = FindFullName( "Geometry.Arizona Eye" ) O2W EA  
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    ' Delete any shift(s) in z \\j98(i  
    count = 0 In-W,   
    While GetOperationCount(eID)>count #3:;&@#  
        GetOperation eID, count, op &hK5WP6whW  
        If op.Type="ShiftZ" Then m?Gb5=qo  
            DeleteOperation eID,count =c
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            count=count-1 \M]w I  
        End If G4!$48  
        count=count+1 J6*Zy[)%&S  
    Wend <lk_]+ XJ3  
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    'Set new shift in P,S$qD*4  
    op.Type = "ShiftZ" yPKDn.1  
    op.val1 = taq $Cr? }'a  
    op.parent = parID {J:ZM"GS  
    AddOperation eID, op dHU#Y,v  
    Print "Set aqueous humor thickness = " & taq-0.55 {.W$<y (j7  
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    '*************************************************************************
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    'Radius and conic constant of anterior lens Sb&sW?M  
    '************************************************************************* !}sYPz]7!  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) m"B)%?C#  
    GetConic eID, entity, curv, conic RI#Cr+/  
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    SetConic eID, entity, 1/Rant, CCant b"Hg4i)  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant NN<kO#c+2  
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    '************************************************************************* NT~L=xsY  
    'Radius and conic constant of posterior lens WMB~? EDhv  
    '************************************************************************* U=<E,tM  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) c;,jb  
    GetConic eID, entity, curv, conic ]xf lfZ  
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    SetConic eID, entity, 1/Rpost, CCpost v})0zz?,1  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost K5x&:z  
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    '************************************************************************* =bUVGjr%96  
    'Lens thickness (Position of posterior lens surface) 2?LZW1
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    '************************************************************************* xACAtJ'gc  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) U8?%Dq%i  
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    ' Delete any z-shift(s) B\2<r5|QG  
    count = 0 OQ<|XdI$  
    While GetOperationCount(eID)>count ]R^?Pa1Te4  
        GetOperation eID, count, op =G*rfV@__V  
        If op.Type="ShiftZ" Then .K(IRWuw  
            DeleteOperation eID,count E<>Ev_5>  
            count=count-1 \NbMSC&H  
        End If RdlcJxM  
        count=count+1 v&}mbt-  
    Wend i(q%E
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    'Set new z-shift &Y"u*)bm  
    op.Type = "ShiftZ" 62&E]>A(i  
    op.val1 = tlens oDp!^G2A"  
    op.parent = parID =@b/Gl  
    AddOperation eID, op  WpX)[au  
    Print "Set lens thickness = " & tlens 9)p VDS  
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    '************************************************************************* u\zRWX  
    'Lens index of refraction |+//pGx  
    '************************************************************************* R9gK>}>Y  
    eID = FindMaterial( "Lens" ) *]
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    GetModelMaterial eID, mat  +Io^U  
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    mat.Nd = nlens H kDT14 `&  
    SetModelMaterial eID, mat QK-_~9V  
    Print "Set lens index of refraction = " & nlens }<w/2<T[  
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    '************************************************************************* .63:
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    'Pupil diameter nG&=$7x^  
    '************************************************************************* ]Y;EIn  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) h^ ex?  
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    'Adjust pupil diameter (trimming volume inner hole) xg)cA C\=  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" ,qJ/Jt$A  
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    ' Adjust pupil location to just in front of the lens A P><l@  
    parID = FindFullName( "Geometry.Arizona Eye" ) q#Az\B:  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) aG QC  
    count = 0 qve2?,i8hM  
    While GetOperationCount(eID)>count bLoAtI  
        GetOperation eID, count, op siw } }}  
        If op.Type="ShiftZ" Then w\KO1 Ob  
            DeleteOperation eID,count g7@G&Ro9J\  
            count=count-1 zDY!0QZLF\  
        End If F*rU=cu  
        count=count+1 ',nGH|K.  
    Wend )r-t$ L  
    op.Type = "ShiftZ" AQ 3n=Lr   
    op.val1 = taq-0.01 WlU^+ctS  
    op.parent = parID "exph$  
    AddOperation eID, op EY;C5P4  
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    Print "Set pupil diameter = " & pupilDiam D]v=/43  
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    'Update AZ Eye subassembly Description "NSm2RU3  
    eID = FindFullName( "Geometry.Arizona Eye" ) 0V ,R|Ln  
    GetEntity eID, entity Z8tQ#Pu{  
    entity.Description = "Accommodation = " & A & "D" oEvXZ;F@.  
    SetEntity eID, entity !]4'f/  
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    Update _7?o/Q?F%  
    Print "DONE!" x3O$eKy\|5  
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End Sub MrEyN8X  
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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： x|n2,3%  
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Accommodation = 4 Diopters ,TaaXI  
Pupil Diameter = 4 mm
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Set aqueous humor thickness = 2.81 A~&Tp  
Set anterior lens radius = 10.4 and conic constant = -2.375869 5an#,vCn{  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 /10 I}3D  
Set lens thickness = 3.927 xM}lX(V!w  
Set lens index of refraction = 1.42672 @x?7J@:  
Set pupil diameter = 4 j_c0oclSz  
DONE! i6M_Gk}