[分享]Arizona眼睛模型 [复制链接]

简介 }sU\6~

  
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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。 ;Z_C3/b  
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模型 9-^p23.@[j  
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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。 M::iU_  
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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. pQY>  
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光源 uLM_KZ  
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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。 Snu;5:R  
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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。 @RIEO%S  
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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。 NR&9:?  
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视网膜的散射 k#JG  
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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。 @t8kN6.  
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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。 8M9\<k6  
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脚本 @a\SR'8  
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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： pHB35=p28  
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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。 Gc!8v}[7J  
余下的脚本计算与屈光度有关的所有参数。 BQ&q<6Tk  
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分析 dMmka
  
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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。 H#6^-6;/  
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脚本代码 G=HxD4l  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. [Cqqjv;_  
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Dim entity As T_ENTITY #S%Y;ilq  
Dim op As T_OPERATION `uZv9I"  
Dim mat As T_MODELMATERIAL +`zi>=  
Dim A As Double 9m!!b{  
Dim pupilDiam As Double ;c- ]bhBB  
Dim eID As Long Z#
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Dim parID As Long r`R~{;oT  
Dim count As Integer
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Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double M:Y*Tb6w  
Dim tlens As Double, nlens As Double PT#eXS9_  
Dim curv As Double, conic As Double &s^>S?L-  
Dim ok As Long 04PoBv~g  
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Sub Main Cz@FZb8  
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    '用户输入对话框 3zTE4pHzu+  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 Yuo1'gE+  
        TextBox 220,21,40,21,.TextBox1 'default: 0 `X<`j6zaG  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 :{b6M/  
        OKButton 40,91,90,21 Sci4EGc  
        CancelButton 190,91,90,21 gO:Z6}3vM  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 Bf:tal6 -M  
        TextBox 220,49,40,21,.TextBox2 'default: 4 g"]<J&  
    End Dialog lIVxW+  
    Dim dlg As UserDialog ,+/9K)X  
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    ok = Dialog (dlg) HKiVEg  
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    If ok=0 Then    'cancel button was pressed 5+bFy.UW  
        Print "Execution cancelled." ?S@R~y0K  
        End S -
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    End If <F)w=_%&  
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    'Assign accommodation and pupil diameter & use defaults if field left empty dT]L-uRZgy  
    If dlg.TextBox1 = "" Then +t>*l>[  
        A = 0           'Default accommodation <,@H;|mZ  
    Else <DXmZ1  
        A = CDbl(dlg.TextBox1) "VDk1YX_&l  
    End If 1]>$5 1Q  
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    If dlg.TextBox2 = "" Then L8:]`MQ0  
        pupilDiam = 4   'Default pupil diameter 0Q$~
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    Else V9zywM  
        pupilDiam = CDbl(dlg.TextBox2) 2~M;L&9-  
    End If ]M~8@K  
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    Print " " }0BL0N`_  
    Print "Accommodation = " & A & " Diopters" G}P)vfcH  
    Print "Pupil Diameter = " & pupilDiam & " mm" JN&MyA"  
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    ' Calculate new parameters with accommodation 0):uF_t<  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness TZh\#dp4l  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens X:G&5  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens 7MO  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens .'5
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    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens l5=u3r9WYC  
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    tlens = 3.767 + 0.04*A                  'Lens thickness }c` ?0
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction (|g").L  
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    'Adjust parameters to account for accommodation VLh%XoQx[  
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    '************************************************************************* 9m\)\/V  
    'Aqueous thickness (Position of Lens) |.b%rVu  
    '************************************************************************* 0W~.WkD  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) H\)gE>  
    GetCustomElement eID, entity d[Rb:Yw  
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    parID = FindFullName( "Geometry.Arizona Eye" ) <G\ <QV8W  
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    ' Delete any shift(s) in z $zC6(C(l  
    count = 0 x*unye7  
    While GetOperationCount(eID)>count V.;:u#{@-Q  
        GetOperation eID, count, op /:#j?c  
        If op.Type="ShiftZ" Then _Fy4DVCg  
            DeleteOperation eID,count !Z U_,[  
            count=count-1 EvwbhvA(  
        End If E7rX1YdR  
        count=count+1 [#7y[<.P  
    Wend i^je.,Bi  
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    'Set new shift in 3AvVU]@&Z@  
    op.Type = "ShiftZ" 4-y6MH  
    op.val1 = taq d@-wi%,^  
    op.parent = parID 4JGE2ArR  
    AddOperation eID, op m9#}X_&x  
    Print "Set aqueous humor thickness = " & taq-0.55 nHSTeFI?  
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    '************************************************************************* TT|-aS0l(u  
    'Radius and conic constant of anterior lens w`M]0'zls  
    '************************************************************************* >W8bWQ^fK  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) )*!1bgXQ  
    GetConic eID, entity, curv, conic *I=_*LoG2  
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    SetConic eID, entity, 1/Rant, CCant ewo*7j4*  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant %v]7BV^%6  
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    '************************************************************************* U8YO0}_z  
    'Radius and conic constant of posterior lens /r-8T>m  
    '************************************************************************* v-ThdE$G#  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) 9U]pH%.9  
    GetConic eID, entity, curv, conic a|UqeNI{  
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    SetConic eID, entity, 1/Rpost, CCpost !loO%3_)  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost e:qo_eSC^-  
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    '************************************************************************* *7\W=-  
    'Lens thickness (Position of posterior lens surface) e d_m +NM  
    '************************************************************************* /a%*u6z@  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) WI6(#8^p  
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    ' Delete any z-shift(s) q=njKC  
    count = 0 au}s=ua~i  
    While GetOperationCount(eID)>count u-kZW1wrQ  
        GetOperation eID, count, op 7g5@vYS+  
        If op.Type="ShiftZ" Then {(%~i37  
            DeleteOperation eID,count ( :iPm<  
            count=count-1 <z',]hy  
        End If -rO*7HO
 
        count=count+1 I :@|^PYw  
    Wend bGu([VB  
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    'Set new z-shift w?_`/oqd|  
    op.Type = "ShiftZ" SAy{YOLtl  
    op.val1 = tlens W]zw
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    op.parent = parID 4j
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    AddOperation eID, op N2T&,&,t  
    Print "Set lens thickness = " & tlens J]dW1boT@  
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    '************************************************************************* [T-*/}4$  
    'Lens index of refraction gn^!"MN+g  
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    eID = FindMaterial( "Lens" ) k&!6fZ)  
    GetModelMaterial eID, mat [EER4@_  
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    mat.Nd = nlens D&-vq,c  
    SetModelMaterial eID, mat Tv1]v.  
    Print "Set lens index of refraction = " & nlens $C$ub&D ~"  
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    '************************************************************************* %7 /,m  
    'Pupil diameter B>,A(X&  
    '************************************************************************* q=+wI"[  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) jI A#!4  
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    'Adjust pupil diameter (trimming volume inner hole) Mb1wYh  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" @%:E }  

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    ' Adjust pupil location to just in front of the lens s*.3ZS5  
    parID = FindFullName( "Geometry.Arizona Eye" ) I3PQdAs~&h  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) FllX za)  
    count = 0 Zt_r9xs>  
    While GetOperationCount(eID)>count
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        GetOperation eID, count, op y] y9'5_  
        If op.Type="ShiftZ" Then bJPJ.+G7  
            DeleteOperation eID,count T6X}Ws"  
            count=count-1 ']h IfOD"r  
        End If ;t!9]1  
        count=count+1 !vVT]k[N  
    Wend u-:MVEm  
    op.Type = "ShiftZ" ly=a>}F_  
    op.val1 = taq-0.01 #"<?_fao~  
    op.parent = parID E<k^S{  
    AddOperation eID, op zIm-X,~I$  
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    Print "Set pupil diameter = " & pupilDiam D7gHE  
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    'Update AZ Eye subassembly Description W "k|K:  
    eID = FindFullName( "Geometry.Arizona Eye" ) C99&L3bz^(  
    GetEntity eID, entity DN<M?u]  
    entity.Description = "Accommodation = " & A & "D" x;(g  
    SetEntity eID, entity 6bUl>4  
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    Update fbV@=(y?  
    Print "DONE!" }/"4|U  
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End Sub 7f r>ZY^  
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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： }uiPvO+&p  
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Accommodation = 4 Diopters =Epq%,4nG  
Pupil Diameter = 4 mm d'OGVN  
Set aqueous humor thickness = 2.81 &`@lB (m  
Set anterior lens radius = 10.4 and conic constant = -2.375869 A%n?}  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 d- kZt@DL=  
Set lens thickness = 3.927 lQ$+JX;n(y  
Set lens index of refraction = 1.42672 | k}e&Q_/G  
Set pupil diameter = 4
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DONE! !5~k:1=  
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