[技术]Arizona眼睛模型 [复制链接]

简介 CG@3z@*?.  
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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。 (I(?oCQ  
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模型 e5\/:HpI  
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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。 S#km`N`  
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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. 04;E^,V  
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光源 c3S}(8g5.  
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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。 +qN}oyL  
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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。 ylFoYROO  
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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。 (2 nSZRB  
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视网膜的散射 1Ce7\A  
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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。 ^"lVTDsU  
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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。 2A>s a3\  
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脚本 bCa%$  
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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： hQWo ]WF(J  
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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。 }Gvu!a#R  
余下的脚本计算与屈光度有关的所有参数。 L0lqm0h  
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分析 .ei5+?V<i  
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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。 ` x|=vu-  
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脚本代码 5%r:hO @S  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. "26=@Q^Y  
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Dim entity As T_ENTITY }xa~U,#5  
Dim op As T_OPERATION =)c^ik%F&  
Dim mat As T_MODELMATERIAL twWzS 4;  
Dim A As Double ^-^ii3G`  
Dim pupilDiam As Double z=FOymvC  
Dim eID As Long C0K0c6A(4  
Dim parID As Long ;_~9".'<d  
Dim count As Integer V|3^H^\5P  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double 1 ORA6  
Dim tlens As Double, nlens As Double ;% <[*T:*'  
Dim curv As Double, conic As Double M*gbA5  
Dim ok As Long JG
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Sub Main m[}@\y  
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    '用户输入对话框 f1$'av
 
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 "Snt~:W>  
        TextBox 220,21,40,21,.TextBox1 'default: 0 o#K*-jOfiH  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 w}qLI4  
        OKButton 40,91,90,21 A8X3|<n=  
        CancelButton 190,91,90,21 \1ncr4  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 agGgj>DDd  
        TextBox 220,49,40,21,.TextBox2 'default: 4 ;5p;i8m  
    End Dialog %,UTFuM`  
    Dim dlg As UserDialog |!q,J  
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    ok = Dialog (dlg) R>D
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    If ok=0 Then    'cancel button was pressed i5 0c N<o  
        Print "Execution cancelled." l`<1Y|  
        End "wR1=&gk  
    End If QOR92}yC  
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    'Assign accommodation and pupil diameter & use defaults if field left empty XiMd|D  
    If dlg.TextBox1 = "" Then tMiy`CPh  
        A = 0           'Default accommodation ]iYO}JuX  
    Else QJy1j~9x  
        A = CDbl(dlg.TextBox1) lyD=n  
    End If _iF*BnmN  

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    If dlg.TextBox2 = "" Then Y#t9DhzFWo  
        pupilDiam = 4   'Default pupil diameter
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    Else  X`20=x  
        pupilDiam = CDbl(dlg.TextBox2) FnPn#Cv>*  
    End If w `nm}4M  
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    Print " " 7J;\&q'  
    Print "Accommodation = " & A & " Diopters" wq7h8Z}l  
    Print "Pupil Diameter = " & pupilDiam & " mm" "Q`Le{  
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    ' Calculate new parameters with accommodation gHtflS  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness L0)w~F ?m  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens y8ODoXk  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens &. MUSqo9  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens -asjBSo*D  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens 2f0mr?l)N  
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    tlens = 3.767 + 0.04*A                  'Lens thickness BJt]k7ku+  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction }X6w"  
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    'Adjust parameters to account for accommodation !>#gm7  
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    '************************************************************************* =q(?ALGc  
    'Aqueous thickness (Position of Lens) H;seT X
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    '************************************************************************* d`,z4_  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" )  Q@!XVQx4  
    GetCustomElement eID, entity ^3ai}Ei3  
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    parID = FindFullName( "Geometry.Arizona Eye" ) KF6N P  
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    ' Delete any shift(s) in z Mh2Zj  
    count = 0 A34O(fE  
    While GetOperationCount(eID)>count 5,pEJ>dDD3  
        GetOperation eID, count, op 1En:QQ4/  
        If op.Type="ShiftZ" Then :NL[NbQYt  
            DeleteOperation eID,count 0 ;].q*|#  
            count=count-1 h1)ny1;  
        End If / */"gz%  
        count=count+1 -Q/wW4dE=  
    Wend ::_
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    'Set new shift in e)y+]  
    op.Type = "ShiftZ" };
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    op.val1 = taq ->*~e~T  
    op.parent = parID r0@s3/  
    AddOperation eID, op K_n GZ/`[  
    Print "Set aqueous humor thickness = " & taq-0.55 ILx4[m7  
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    '************************************************************************* O)ose?Z  
    'Radius and conic constant of anterior lens W7c B  
    '************************************************************************* MJ$.ST  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) [%P[ x]-  
    GetConic eID, entity, curv, conic nly}ly Q/  
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    SetConic eID, entity, 1/Rant, CCant Kf6D)B 26  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant gi>W&6  
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    '************************************************************************* P @J)S ?  
    'Radius and conic constant of posterior lens H]W'mm  
    '************************************************************************* >
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    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) |&@`~OBa  
    GetConic eID, entity, curv, conic 4 aE{}jp1  
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    SetConic eID, entity, 1/Rpost, CCpost 4\ |/S@.  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost q{%~(A5*H  
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    '************************************************************************* .2U3_1dX  
    'Lens thickness (Position of posterior lens surface) ESk:$`P  
    '************************************************************************* @FZ_[CYg  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) ,hrv  
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    ' Delete any z-shift(s) D>^g2!b:  
    count = 0 DAg*  
    While GetOperationCount(eID)>count Pe-rwM  
        GetOperation eID, count, op cq5^7.  
        If op.Type="ShiftZ" Then W]Nc6B*gI  
            DeleteOperation eID,count ;" D~F  
            count=count-1 7SN61)[m  
        End If E^gN]Z"O  
        count=count+1 &*E! %57  
    Wend $BT[fJ'k  
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    'Set new z-shift ho)JY $#6  
    op.Type = "ShiftZ" i`Qa7  
    op.val1 = tlens B'mUDW8\D  
    op.parent = parID k ]T  
    AddOperation eID, op azNv(|eeJL  
    Print "Set lens thickness = " & tlens (`_fP.Ogb  
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    '************************************************************************* 2#00<t\  
    'Lens index of refraction ,`OQAJ)>  
    '************************************************************************* 2s>BNWTU  
    eID = FindMaterial( "Lens" ) DSWmQQ  
    GetModelMaterial eID, mat ,jtaTG.
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    mat.Nd = nlens 19-V;F@;  
    SetModelMaterial eID, mat 717G CL@  
    Print "Set lens index of refraction = " & nlens r&Qa;-4Pl  
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    '************************************************************************* QoZZXCU  
    'Pupil diameter :>o0zG[;f  
    '************************************************************************* FA;-D5=
 
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) ,%BDBZ  
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    'Adjust pupil diameter (trimming volume inner hole) eMdf[eS  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" /u_9uJ"-K(  
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    ' Adjust pupil location to just in front of the lens ?Bl/bY$*h  
    parID = FindFullName( "Geometry.Arizona Eye" ) ?FUK_]  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) #D%6b  
    count = 0 Mu-kvgO`L  
    While GetOperationCount(eID)>count Wv9L}@J  
        GetOperation eID, count, op &cJ?mSI  
        If op.Type="ShiftZ" Then ~'0ZW<X.  
            DeleteOperation eID,count Lz p}<B  
            count=count-1 )''V}Zn.X  
        End If q_ryW$/_  
        count=count+1 _%Ua8bR$  
    Wend =kzp$ i  
    op.Type = "ShiftZ" 3:8p="$F  
    op.val1 = taq-0.01 En#Q p3  
    op.parent = parID bBXLW}W  
    AddOperation eID, op &['x+vL9  
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    Print "Set pupil diameter = " & pupilDiam h^qZi@L  
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    'Update AZ Eye subassembly Description 3&5b!Y  
    eID = FindFullName( "Geometry.Arizona Eye" ) ZZHzC+O#^  
    GetEntity eID, entity 12hD*,A5j  
    entity.Description = "Accommodation = " & A & "D" |5:2?S2R  
    SetEntity eID, entity } XhL`%  
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    Update N
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    Print "DONE!" 6>;OVX  
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End Sub Ycq )$7p  
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如果屈光度是4，光瞳直径是4，则会输出如下数据： Lj#xZ!mQS  
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Accommodation = 4 Diopters /V`SJ"  
Pupil Diameter = 4 mm N{&Lo}6F  
Set aqueous humor thickness = 2.81 /':64#'  
Set anterior lens radius = 10.4 and conic constant = -2.375869 ($/l_F  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 S w%6-  
Set lens thickness = 3.927 NWPT89@l  
Set lens index of refraction = 1.42672 aPK:k$.  
Set pupil diameter = 4 >;Vfs{Z(q  
DONE! +kEM%z