[技术]Arizona眼睛模型 [复制链接]

简介 2(5wFc  
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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。 n1y#gC  
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模型 [k@D}p x  
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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。 @-kzSm  
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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. =XQ3sk6U  
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光源 3yr{B Xn  
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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。 V F6OC4 K  
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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。 1^}()H62}  
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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。 _AI2\e  
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视网膜的散射 WE|L{  
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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。 .{5)$w>  
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注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 +]I;C  
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脚本 H",yVD  
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内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： O
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如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 ?tqTG2!(  
余下的脚本计算与屈光度有关的所有参数。 Jc`LUJT  
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分析 kVkV~  
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屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 ukS@8/eJ  
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脚本代码 kL*Q})  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used.
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Dim entity As T_ENTITY [p}J=1S  
Dim op As T_OPERATION 8@6:UR.)  
Dim mat As T_MODELMATERIAL zoC/Hm  
Dim A As Double yHr/i
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Dim pupilDiam As Double b'Mg  
Dim eID As Long W>wE8? _,  
Dim parID As Long ;]Y.2 J  
Dim count As Integer Ywr^uy1V,/  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double zhHQJcQ.  
Dim tlens As Double, nlens As Double g@MTKqs  
Dim curv As Double, conic As Double >W.Pg`'D  
Dim ok As Long pL-p  
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Sub Main >/1.VT\E  
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    '用户输入对话框 9y.C])(2  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 1@CI7j  
        TextBox 220,21,40,21,.TextBox1 'default: 0 !rTh+F*  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 cQ*:U@  
        OKButton 40,91,90,21 L)8;96  
        CancelButton 190,91,90,21 Wf0ui1@  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 :#d$[:r#  
        TextBox 220,49,40,21,.TextBox2 'default: 4 6dC!&leNi  
    End Dialog ^tc@bsUF  
    Dim dlg As UserDialog !x;T2l  
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    ok = Dialog (dlg) 8*>6+"w  
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    If ok=0 Then    'cancel button was pressed A-ir   
        Print "Execution cancelled." FT`y3~
 
        End +r4US or  
    End If
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    'Assign accommodation and pupil diameter & use defaults if field left empty <wj2:Z0  
    If dlg.TextBox1 = "" Then jY87NHg  
        A = 0           'Default accommodation KkJcHU  
    Else
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        A = CDbl(dlg.TextBox1) 6M+~{9(S  
    End If J>!p^|S{  
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    If dlg.TextBox2 = "" Then `j_R ?mY  
        pupilDiam = 4   'Default pupil diameter =2J+}ac  
    Else ?P{C=Td2z  
        pupilDiam = CDbl(dlg.TextBox2) #vLDNR  
    End If X*$ 7g;  
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    Print " " *v l_3S5_  
    Print "Accommodation = " & A & " Diopters" t(p  
    Print "Pupil Diameter = " & pupilDiam & " mm" =Q3Go8b4HJ  
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    ' Calculate new parameters with accommodation +vDT^|2SF  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness gqZ7Pro.  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens F[RhuNa&'W  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens -Ah\a0z  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens 7D9R^\K  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens i
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    tlens = 3.767 + 0.04*A                  'Lens thickness f=}u;^  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction <0v'IHlZ8  
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    'Adjust parameters to account for accommodation gJvc<]W8!  
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    '************************************************************************* rUx%2O|qu  
    'Aqueous thickness (Position of Lens) 3i35F.=X,  
    '************************************************************************* cf0em!  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) c{||l+B  
    GetCustomElement eID, entity {'>X6:  
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    parID = FindFullName( "Geometry.Arizona Eye" ) ~;bwfp_  
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    ' Delete any shift(s) in z 1D=M
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    count = 0 Q6Jb]>g\H  
    While GetOperationCount(eID)>count LT'#0dCC  
        GetOperation eID, count, op IQ2<Pinv  
        If op.Type="ShiftZ" Then Pvbw
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            DeleteOperation eID,count .!)7x3|$[  
            count=count-1 HV>|f'45  
        End If  "thfd"-  
        count=count+1 Z;WqKIM#  
    Wend 1(On.Y=   
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    'Set new shift in P3lNns3  
    op.Type = "ShiftZ" 2eyvY|:Q>  
    op.val1 = taq "GZhr[AW  
    op.parent = parID Z(xn-  
    AddOperation eID, op Eptsxyz{  
    Print "Set aqueous humor thickness = " & taq-0.55 Ix1ec^?f  
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    '************************************************************************* W=F?+KgL  
    'Radius and conic constant of anterior lens ]*):2%f  
    '************************************************************************* ?;^_%XSQ*  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) gK#aC[  
    GetConic eID, entity, curv, conic )o9CFhFB  
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    SetConic eID, entity, 1/Rant, CCant w :^b3@gd  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant G V0q?  
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    '************************************************************************* Yng9_w9Y  
    'Radius and conic constant of posterior lens $R7d*\(G  
    '************************************************************************* DPy"FQYZb  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) %9Ulgs8=  
    GetConic eID, entity, curv, conic .bL{fBTT~  
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    SetConic eID, entity, 1/Rpost, CCpost .lTGFeJqZ4  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost ?P"ht  
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    '************************************************************************* o Q{gh$6*  
    'Lens thickness (Position of posterior lens surface) VZ_4B *D  
    '************************************************************************* Y*J`Wf(w  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) wW!*"z  
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    ' Delete any z-shift(s) (qB$I\  
    count = 0 173/A=]  
    While GetOperationCount(eID)>count p1X lni%=  
        GetOperation eID, count, op ,JVD ;u  
        If op.Type="ShiftZ" Then >@ge[MuS  
            DeleteOperation eID,count <V>vDno\  
            count=count-1 n%"s_W'E  
        End If W P.6ea7k  
        count=count+1 of{wZU\J+9  
    Wend rBgLj,/`U/  
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    'Set new z-shift nM}X1^PiK"  
    op.Type = "ShiftZ" |? r,W~9`  
    op.val1 = tlens UN,@K9  
    op.parent = parID 2
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    AddOperation eID, op V=E9*$b]  
    Print "Set lens thickness = " & tlens z,DEBRT+  
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    '************************************************************************* .&}}ro48
  
    'Lens index of refraction 7CwG(c/5  
    '************************************************************************* -V4@BKI8  
    eID = FindMaterial( "Lens" ) >rYP}k  
    GetModelMaterial eID, mat UyK|KL  
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    mat.Nd = nlens ;QgJw2G  
    SetModelMaterial eID, mat Is?0q@  
    Print "Set lens index of refraction = " & nlens i~l0XjQbs  
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    '************************************************************************* Kw-E%7gh4c  
    'Pupil diameter t0}3QGf;c  
    '************************************************************************* >@y5R^B`  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) N,Y<mX  
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    'Adjust pupil diameter (trimming volume inner hole) $&lS7}  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" f4X?\eGT  
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    ' Adjust pupil location to just in front of the lens ?~u"w OH'  
    parID = FindFullName( "Geometry.Arizona Eye" ) '+'
  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) P9Rq'u  
    count = 0 my*UN_]  
    While GetOperationCount(eID)>count m0un=>{  
        GetOperation eID, count, op *"1]NAz+  
        If op.Type="ShiftZ" Then l'-iIbKX  
            DeleteOperation eID,count =%$ _)=}J  
            count=count-1 N}\$i&Vi  
        End If VA2%2g2n{  
        count=count+1 F(@|p]3*  
    Wend >JC.qjA  
    op.Type = "ShiftZ" 2eb :(D7Cq  
    op.val1 = taq-0.01 t{84ioJ"$  
    op.parent = parID ^qV*W1|0  
    AddOperation eID, op d [K56wbpx  
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    Print "Set pupil diameter = " & pupilDiam IVEvu3  
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    'Update AZ Eye subassembly Description 1z[WJ}$u  
    eID = FindFullName( "Geometry.Arizona Eye" ) T<p>:$vo  
    GetEntity eID, entity Zf(ucAhL  
    entity.Description = "Accommodation = " & A & "D" Ig5J_Z
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    SetEntity eID, entity D~2,0K  
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    Update O^sgUT1O  
    Print "DONE!" N}.h_~6  
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End Sub )`;?%
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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： SU H^]4>  
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Accommodation = 4 Diopters YZ/mTQn_D  
Pupil Diameter = 4 mm e|Lh~sVq  
Set aqueous humor thickness = 2.81 ~_^nWT*BV  
Set anterior lens radius = 10.4 and conic constant = -2.375869 5_=&U-? H  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 _Se>X=  
Set lens thickness = 3.927 EeL~`$f  
Set lens index of refraction = 1.42672 e2/[`k=7-  
Set pupil diameter = 4 w3,QT}WvY  
DONE! kiqq_`66