[分享]Arizona眼睛模型 [复制链接]

简介 ]
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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。 |lY`9-M`I  
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模型 x?gQ\0S<  
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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。 f:&)"  
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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,(j$Id  
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光源 1NW>wo  
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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。 c|+y9(0|y  
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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。 n~.%p  
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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。 3#B@83C0Z  
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视网膜的散射 w gmWo8  
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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。 \6Xn]S
 
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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。 t6j-?c('  
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脚本 7bHE!#L`0  
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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： xJ$Rs/9C  
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如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 mSy|&(l  
余下的脚本计算与屈光度有关的所有参数。 n<=y"*  
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屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 )8 oEs  
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脚本代码 >xklt"*U,  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. }5QZ6i#  
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Dim entity As T_ENTITY kx:c*3q.k  
Dim op As T_OPERATION 
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Dim mat As T_MODELMATERIAL o7m99(  
Dim A As Double l# }As.o}  
Dim pupilDiam As Double 2*N&q|ED  
Dim eID As Long /j`i/Ha1  
Dim parID As Long )r-T=  
Dim count As Integer zw}@nqp  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double ~W2:NQ>i  
Dim tlens As Double, nlens As Double -$'~;O3s  
Dim curv As Double, conic As Double oXnC"y}0P  
Dim ok As Long Iq^~  
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Sub Main SJso'6 g  
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    '用户输入对话框 (xI)"{   
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 H(  
        TextBox 220,21,40,21,.TextBox1 'default: 0 8XLxT(YFIs  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 Ry3+
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        OKButton 40,91,90,21 r))$XM  
        CancelButton 190,91,90,21 A@9U;8k  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 |Ba4 G`
 
        TextBox 220,49,40,21,.TextBox2 'default: 4 !l sy&6  
    End Dialog Z'7 c^c7_  
    Dim dlg As UserDialog |!?2
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    ok = Dialog (dlg) 2U-#0,ll]  
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    If ok=0 Then    'cancel button was pressed GN"M:L^k`  
        Print "Execution cancelled." )^*9oqQ
 
        End .6lY*LI  
    End If L,s|gtv  
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    'Assign accommodation and pupil diameter & use defaults if field left empty (mD-FR@#  
    If dlg.TextBox1 = "" Then ">0/>>Ry  
        A = 0           'Default accommodation ,mAB)at  
    Else GC5#1+fQ  
        A = CDbl(dlg.TextBox1) eXskwV+7  
    End If \'\N"g`Fr  
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    If dlg.TextBox2 = "" Then
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        pupilDiam = 4   'Default pupil diameter /K2.V@T  
    Else PCV58n3  
        pupilDiam = CDbl(dlg.TextBox2) .{'Uvn  
    End If 6xDl=*&%  
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    Print " " v*C+U$_3\1  
    Print "Accommodation = " & A & " Diopters" *:fw6mnJ#  
    Print "Pupil Diameter = " & pupilDiam & " mm" ~pX(w!^  
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    ' Calculate new parameters with accommodation 1j${,>4tQ  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness V7KtbL#  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens tk3<sr"IQ  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens h%CEb<  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens _{2Fx[m%  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens L.I}-n  
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    tlens = 3.767 + 0.04*A                  'Lens thickness b]tA2~e  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction 1?e>x91  
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    'Adjust parameters to account for accommodation \>aa8LOe  
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    '************************************************************************* 3[|:sa8?s  
    'Aqueous thickness (Position of Lens) N%n1>!X)!  
    '************************************************************************* ..Uw8u/  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) \@ WsF$  
    GetCustomElement eID, entity $Z(
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    parID = FindFullName( "Geometry.Arizona Eye" ) BRSgB-Rr7  
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    ' Delete any shift(s) in z 0$F _hZU  
    count = 0 k_En_\c?p2  
    While GetOperationCount(eID)>count {'=Nb 5F  
        GetOperation eID, count, op Z+`{JE#  
        If op.Type="ShiftZ" Then [#P`_hx  
            DeleteOperation eID,count jr#g>7yM  
            count=count-1 #<W
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        End If Jegx[*O>b  
        count=count+1 K,L>
  
    Wend
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    'Set new shift in |/T<]+X;  
    op.Type = "ShiftZ" @dT:
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    op.val1 = taq H[_uVv;}6  
    op.parent = parID s:m<(8WRw  
    AddOperation eID, op {Y@-*pL]  
    Print "Set aqueous humor thickness = " & taq-0.55 ^]sMy7X0IK  
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    '************************************************************************* nX.sh  
    'Radius and conic constant of anterior lens 4MF}FS2)  
    '************************************************************************* ^b `>/>  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) VT.{[Kl  
    GetConic eID, entity, curv, conic $jm>tW&;  
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    SetConic eID, entity, 1/Rant, CCant HA3SQ  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant ad3z]dUZ9  
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    '************************************************************************* l~Wk07r3  
    'Radius and conic constant of posterior lens bh;b` 5  
    '************************************************************************* !ovZ>,1  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) }96/: ;:k  
    GetConic eID, entity, curv, conic SFk11  
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    SetConic eID, entity, 1/Rpost, CCpost ,TfI  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost Y4~wNs6  
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    '************************************************************************* ,d [b"]Zy  
    'Lens thickness (Position of posterior lens surface) /YugQ.>| l  
    '************************************************************************* ,C@hTOT  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) A2O_pbQti  
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    ' Delete any z-shift(s) Eztz~oFo  
    count = 0 ZNH*[[Pf  
    While GetOperationCount(eID)>count 5dNf$a0E  
        GetOperation eID, count, op ]x(2}h^
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        If op.Type="ShiftZ" Then m9<[bEO<$  
            DeleteOperation eID,count LG@c)H74  
            count=count-1 LOb'<R\p  
        End If ga1gd~a  
        count=count+1 l^eNZ3:H  
    Wend eze(>0\f  
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    'Set new z-shift FnQ_=b  
    op.Type = "ShiftZ" Q"K>ML>0  
    op.val1 = tlens /&!d  
    op.parent = parID a^}P_hg}-  
    AddOperation eID, op Z"%O&O  
    Print "Set lens thickness = " & tlens 1PTu3o&3  

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    '************************************************************************* >LaL!PnZ  
    'Lens index of refraction Gv+
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    '************************************************************************* Q}f}Jf3P  
    eID = FindMaterial( "Lens" ) QB|fFj58u  
    GetModelMaterial eID, mat DGfQo5#  
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    mat.Nd = nlens acju!,G  
    SetModelMaterial eID, mat IweK!,:>dN  
    Print "Set lens index of refraction = " & nlens Q3O .<9S  
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    '************************************************************************* 674oL,  
    'Pupil diameter s$\8)V52  
    '************************************************************************* jUR#  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) Qx,$)|_  
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    'Adjust pupil diameter (trimming volume inner hole) gWv+i/,  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" ,JBw$C  
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    ' Adjust pupil location to just in front of the lens }:D~yEP  
    parID = FindFullName( "Geometry.Arizona Eye" ) V?J,ab$X#  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) rn5g+%jX*  
    count = 0 ~$ qJw?r  
    While GetOperationCount(eID)>count N[bf.5T  
        GetOperation eID, count, op -r'seb5  
        If op.Type="ShiftZ" Then KJJb^6P48W  
            DeleteOperation eID,count XM@i|AK M0  
            count=count-1 2GKU9cV*`  
        End If GV@E<dg$R  
        count=count+1 &b6@_C9  
    Wend xv%USm  
    op.Type = "ShiftZ" dQ|Ht[s=  
    op.val1 = taq-0.01 hSKH#NS  
    op.parent = parID Z#t)Z "
 
    AddOperation eID, op Aag)c~D  
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    Print "Set pupil diameter = " & pupilDiam IS4K$Ac.  
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    'Update AZ Eye subassembly Description wJR i;fvi  
    eID = FindFullName( "Geometry.Arizona Eye" ) N3c)ce7[  
    GetEntity eID, entity NEou2y+}  
    entity.Description = "Accommodation = " & A & "D" sr@XumT  
    SetEntity eID, entity ]9< 9F ?  
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    Update L{,7(C=  
    Print "DONE!" WJ8vHPSM  
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End Sub 14YV#o:  
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如果屈光度是4，光瞳直径是4，则会输出如下数据： ,zw=&)W1  
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Accommodation = 4 Diopters SWO!E  
Pupil Diameter = 4 mm y*Q-4_%,  
Set aqueous humor thickness = 2.81 9.#R?YP$  
Set anterior lens radius = 10.4 and conic constant = -2.375869 R/cq00g
 
Set posterior lens radius = -4.424557 and conic constant = -3.081019 (0m$W<  
Set lens thickness = 3.927 zYF&Dv/u/  
Set lens index of refraction = 1.42672 |=}~>!!  
Set pupil diameter = 4 SA n=9MG  
DONE! |A/_Qe|s2  
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QQ：2987619807 7:q-NzE\6