[技术]Arizona眼睛模型 [复制链接]

简介 #6[FGM  
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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。 )wQR2$x~  
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模型 <VS\z(K  
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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。 EX7gTf#  
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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
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光源 !G.)%+Z  
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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。 9s5gi+l_O  
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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。 V/j+Z1ZW  
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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。 n a])bBn  
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视网膜的散射 m/r4f279  
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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。 ,~`R{,N`  
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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。 &uI`Xq.  
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脚本 X3 D(2W  
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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： 8q{ %n   
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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。 D|} y{~  
余下的脚本计算与屈光度有关的所有参数。 Z.Z+cFi  
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分析 r%A-  
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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。 }A;J-7g6  
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脚本代码 H@GiHej  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. (E )@@p7,:  
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Dim entity As T_ENTITY ^noKk6Aaa  
Dim op As T_OPERATION pwU l&hwte  
Dim mat As T_MODELMATERIAL WQv%57+  
Dim A As Double O$ui:<]dS  
Dim pupilDiam As Double ,E2Tw-%  
Dim eID As Long gF,9Kv~  
Dim parID As Long #9uNJla
 
Dim count As Integer BR*,E~%  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double E8j>Toz  
Dim tlens As Double, nlens As Double e$}x;&cQ  
Dim curv As Double, conic As Double cl:h'aG  
Dim ok As Long }w^Hm3Y^&  
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Sub Main s ki'I  
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    '用户输入对话框 9;KQ3.Fa}q  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 h BD .IB  
        TextBox 220,21,40,21,.TextBox1 'default: 0 ^u`1W^>  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 *o <S{  
        OKButton 40,91,90,21 yU]NgG=z:-  
        CancelButton 190,91,90,21 f-&4x_5  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 D#R5G   
        TextBox 220,49,40,21,.TextBox2 'default: 4 Gv?3T Am8  
    End Dialog ".Z|zt6C  
    Dim dlg As UserDialog IGqg,OEAp  
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    ok = Dialog (dlg) ZqH.$nXP  
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    If ok=0 Then    'cancel button was pressed <=2\xJfxB  
        Print "Execution cancelled." Hy}oSy26  
        End DtLga[M  
    End If =?hGa;/rb  
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    'Assign accommodation and pupil diameter & use defaults if field left empty uL| Wuq  
    If dlg.TextBox1 = "" Then 91'i7&~xdG  
        A = 0           'Default accommodation X}x"+#\<@  
    Else sI>I  
        A = CDbl(dlg.TextBox1) \>,[5|GU  
    End If &[QvMh  
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    If dlg.TextBox2 = "" Then *l\wl @{  
        pupilDiam = 4   'Default pupil diameter c
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    Else 5Us$.p  
        pupilDiam = CDbl(dlg.TextBox2) RN2^=$'.  
    End If KWwEK]  
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    Print " " UqHk
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    Print "Accommodation = " & A & " Diopters" v;_m1UpuW  
    Print "Pupil Diameter = " & pupilDiam & " mm" pK/r{/>r  
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    ' Calculate new parameters with accommodation kF{'?R5w  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness gt]
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens qaE>])  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens 'YKyY:eZ  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens =zaf{0c  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens Ss>ez8q  
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    tlens = 3.767 + 0.04*A                  'Lens thickness ~@Yiwp\"  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction PD,s,A  
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    'Adjust parameters to account for accommodation 5D9n>K4|  
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    '************************************************************************* *GUQz  
    'Aqueous thickness (Position of Lens) | R\PQ/)  
    '*************************************************************************
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    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) LsW7JIQd  
    GetCustomElement eID, entity >a
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    parID = FindFullName( "Geometry.Arizona Eye" ) [Q0n-b,Q  
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    ' Delete any shift(s) in z ,oin
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    count = 0 ,#/%Fn%T  
    While GetOperationCount(eID)>count %X|fp{C  
        GetOperation eID, count, op ]{.iv_I  
        If op.Type="ShiftZ" Then D5Z@6RVt  
            DeleteOperation eID,count E}qW'  
            count=count-1 *P:!lO\|  
        End If x`3F?[#l  
        count=count+1 O%Hc%EfG  
    Wend #3~#`&  
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    'Set new shift in e@j&c:p(Y  
    op.Type = "ShiftZ" s:O8dL /  
    op.val1 = taq ?:$aX@r  
    op.parent = parID frh!dN   
    AddOperation eID, op x^sSAI(  
    Print "Set aqueous humor thickness = " & taq-0.55 VoG_'P  
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    '************************************************************************* dp|VQWCq  
    'Radius and conic constant of anterior lens Z=KHsMnB  
    '************************************************************************* FN+x<VXo(  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) &eA!h  
    GetConic eID, entity, curv, conic f)_k_<  
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    SetConic eID, entity, 1/Rant, CCant +<})`(8  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant ._X|Ye9/  
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    '************************************************************************* ,
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    'Radius and conic constant of posterior lens 7QXp\<7  
    '************************************************************************* U,g)N[|  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) hJc^NU5  
    GetConic eID, entity, curv, conic dEu\}y|  
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    SetConic eID, entity, 1/Rpost, CCpost xo GX&^=  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost 8 *Y(wqH  
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    '************************************************************************* ?PSJQ3BC|  
    'Lens thickness (Position of posterior lens surface) #qcF2&a%  
    '************************************************************************* 6uu49x_^L4  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) 3vc2t6S%*  
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    ' Delete any z-shift(s) o4qB0h  
    count = 0 qX"m"ko  
    While GetOperationCount(eID)>count qKjUp"  
        GetOperation eID, count, op 3?x}48  
        If op.Type="ShiftZ" Then zI&).  
            DeleteOperation eID,count X[E!q$ag  
            count=count-1 P3_&(  
        End If 3E$h W  
        count=count+1 FdE9k\E#/)  
    Wend p5V.O20  
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    'Set new z-shift *7`amF-  
    op.Type = "ShiftZ" +01bjM6F_1  
    op.val1 = tlens 5uAUi=XA>S  
    op.parent = parID jQX9KwSP  
    AddOperation eID, op )J(@e4;Rv  
    Print "Set lens thickness = " & tlens #W2#'J:l  
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    '************************************************************************* +9NI=s6  
    'Lens index of refraction q+1SU6x'm  
    '************************************************************************* (U_dPf  
    eID = FindMaterial( "Lens" ) dz"HO!9  
    GetModelMaterial eID, mat s g
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    mat.Nd = nlens d$<1Ma}  
    SetModelMaterial eID, mat $1.l|  
    Print "Set lens index of refraction = " & nlens JrJTIUf_  
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    '************************************************************************* 3F\UEpQ  
    'Pupil diameter m'"Ra-  
    '************************************************************************* Vd+5an?  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) 'U{6LSaCb  
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    'Adjust pupil diameter (trimming volume inner hole) IEQ6J}L  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" Mw{skK>b  
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    ' Adjust pupil location to just in front of the lens W}.p,d  
    parID = FindFullName( "Geometry.Arizona Eye" ) G}0fk]%\:  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) nTH!_S>b(Y  
    count = 0 7p+
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    While GetOperationCount(eID)>count .9u,54t  
        GetOperation eID, count, op  |7wiwdD"  
        If op.Type="ShiftZ" Then od`:w[2\  
            DeleteOperation eID,count O/{W:hJjd  
            count=count-1 2@+MT z  
        End If I3D#wXW  
        count=count+1 DOGg=`XK1  
    Wend #7dM %  
    op.Type = "ShiftZ" r/BiR0$E  
    op.val1 = taq-0.01 Nk/Ms:57y  
    op.parent = parID M$AQZ')9  
    AddOperation eID, op d+Bz pS@p  
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    Print "Set pupil diameter = " & pupilDiam GcA!I!j/  
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    'Update AZ Eye subassembly Description $jKeJn8,  
    eID = FindFullName( "Geometry.Arizona Eye" ) Q=cbHDB  
    GetEntity eID, entity G##^xFx  
    entity.Description = "Accommodation = " & A & "D" %Q[+bN[/  
    SetEntity eID, entity gKay3}w  
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    Update `<kV)d%xEF  
    Print "DONE!" K#],4OG  
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End Sub -"Q[n,"Y  
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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： | QI-gw  
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Accommodation = 4 Diopters w=H4#a?fc  
Pupil Diameter = 4 mm dwt<s[k  
Set aqueous humor thickness = 2.81 q;a#?Du o  
Set anterior lens radius = 10.4 and conic constant = -2.375869 hhvP*a_J  
Set posterior lens radius = -4.424557 and conic constant = -3.081019
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Set lens thickness = 3.927 .1C|J  
Set lens index of refraction = 1.42672 :j m|)  
Set pupil diameter = 4 |Zo_x}0  
DONE! Oz1ou[8k