[技术]Arizona眼睛模型 [复制链接]

简介 'b[O-6v  
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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。 7F2:'3SQ  
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模型
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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。 U![$7k>,pr  
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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. <)_#6)z:  
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光源 @qWClr{`  
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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。 2t0VbAO1{  
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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。 ^?q
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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 Jz*}=  
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视网膜的散射 8t7r^[T  
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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。 < uV@/fn<  
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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。 z)eNM}cF  
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脚本 ;<cCT!A  
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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： ^4[QX -_2  
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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。 l r~>!O  
余下的脚本计算与屈光度有关的所有参数。 'Vhnio;qC  
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分析 rc`Il{~k  
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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。 ^|!\IzDp  
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脚本代码 6@d/k.3p  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. &u) qw}  
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Dim entity As T_ENTITY SM<qb0
 
Dim op As T_OPERATION r$LU$F  
Dim mat As T_MODELMATERIAL f?@M"p@T  
Dim A As Double -O@/S9]S)  
Dim pupilDiam As Double '1G0YfG}n  
Dim eID As Long ~jWpD7px  
Dim parID As Long mndEB!b  
Dim count As Integer 6Tq2WZ}<'  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double Ghe@m6|D  
Dim tlens As Double, nlens As Double ILHn~d IC  
Dim curv As Double, conic As Double l`:-B'WM  
Dim ok As Long kWbY&]ZO  
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Sub Main #S|On[Q!  
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    '用户输入对话框 0zjGL7  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 1"1ElH  
        TextBox 220,21,40,21,.TextBox1 'default: 0 On+0@hh  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 zHW&i~  
        OKButton 40,91,90,21 PhmtCp0-7-  
        CancelButton 190,91,90,21 iZ(p]0aP7  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 (+
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        TextBox 220,49,40,21,.TextBox2 'default: 4 g(F2IpUm/  
    End Dialog a uve&y"R  
    Dim dlg As UserDialog %VrMlG4hx  
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    ok = Dialog (dlg) You~ 6d6Om  
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    If ok=0 Then    'cancel button was pressed D6P/39}W  
        Print "Execution cancelled." NVDv
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        End 368H6 Jj  
    End If od3b,Q  
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    'Assign accommodation and pupil diameter & use defaults if field left empty NE@P8pQ>  
    If dlg.TextBox1 = "" Then 7. eiM!7g  
        A = 0           'Default accommodation ><)fK5x  
    Else u3PM 7z!~  
        A = CDbl(dlg.TextBox1) ]mi)x63^  
    End If 7{[i)  
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    If dlg.TextBox2 = "" Then (8GA;:G7G  
        pupilDiam = 4   'Default pupil diameter )U2%kmt  
    Else \@7 4I7  
        pupilDiam = CDbl(dlg.TextBox2) DEenvS`,P  
    End If w< |Lx#L}  
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    Print " " rT{2  
    Print "Accommodation = " & A & " Diopters" K$ |!IXs  
    Print "Pupil Diameter = " & pupilDiam & " mm" t`x_@pr  
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    ' Calculate new parameters with accommodation PO0/C q)  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness Sr6?^>A@t  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens ,j[1!*Z_[  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens .wuRT>4G)G  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens fR lJ`\ t  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens p,2H8I){  
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    tlens = 3.767 + 0.04*A                  'Lens thickness ze#ncnMo  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction 
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    'Adjust parameters to account for accommodation |Fzt| \  
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    '************************************************************************* { *Wc`ZBY  
    'Aqueous thickness (Position of Lens) zm^5WH  
    '************************************************************************* _jk+$`[9PL  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) l8N5}!N  
    GetCustomElement eID, entity ^|%7}=e  
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    parID = FindFullName( "Geometry.Arizona Eye" ) W o$UV  
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    ' Delete any shift(s) in z "I45=nf  
    count = 0 > ,P,{"  
    While GetOperationCount(eID)>count x@<!#d+  
        GetOperation eID, count, op )$E'2|Gm/  
        If op.Type="ShiftZ" Then ?B:],aztf  
            DeleteOperation eID,count lJBZ0  
            count=count-1 ;UWp0d%  
        End If 7e<\11uI]a  
        count=count+1 ~ePtK~,dv  
    Wend o%73M!-  
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    'Set new shift in 3+:
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    op.Type = "ShiftZ" $ 4A!Y  
    op.val1 = taq V4x6,*)e  
    op.parent = parID \&%y4=y<sE  
    AddOperation eID, op 3- 4jSN\  
    Print "Set aqueous humor thickness = " & taq-0.55 AG,;1b,:81  
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    '************************************************************************* ~2?UEv6  
    'Radius and conic constant of anterior lens %'[ pucEF  
    '************************************************************************* %{";RfSVX%  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) 0XrOOYmx  
    GetConic eID, entity, curv, conic vTYgWR,h  
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    SetConic eID, entity, 1/Rant, CCant >U')ICD~  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant 3x~AaC.j  
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    '************************************************************************* ^]?Yd)v  
    'Radius and conic constant of posterior lens 05vu{>  
    '************************************************************************* 8]0?mV8iOE  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) |0aGX]Y  
    GetConic eID, entity, curv, conic Qx !! Ttd{  
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    SetConic eID, entity, 1/Rpost, CCpost oJ)v6"j  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost .aqP=  
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    '************************************************************************* I'16-  
    'Lens thickness (Position of posterior lens surface) 7)+%;|~  
    '************************************************************************* &5;y&dh  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" )
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    ' Delete any z-shift(s) |m>n4-5QL  
    count = 0 h2Jdcr#@FF  
    While GetOperationCount(eID)>count dq$CCOC^F  
        GetOperation eID, count, op r=pb7=M#LN  
        If op.Type="ShiftZ" Then z[ N_3n  
            DeleteOperation eID,count q5(Z   
            count=count-1 FUU/=)^P$  
        End If (Qys`D   
        count=count+1 $8,/[V A  
    Wend ]gGCy '*)  
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    'Set new z-shift " ^:$7~%bA  
    op.Type = "ShiftZ" h^6Yjy  
    op.val1 = tlens B[Fuyy?  
    op.parent = parID i#y3QCNqf^  
    AddOperation eID, op -,#LTW<.  
    Print "Set lens thickness = " & tlens {^n\ r^5  
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    '************************************************************************* `mTc  
    'Lens index of refraction -#?p16qz5  
    '************************************************************************* ec` $2u  
    eID = FindMaterial( "Lens" ) ewcgg  
    GetModelMaterial eID, mat V2?&3Z)W  
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    mat.Nd = nlens ]tVXao  
    SetModelMaterial eID, mat 2i~qihx5^  
    Print "Set lens index of refraction = " & nlens g"Z X
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    '************************************************************************* J]|lCwF  
    'Pupil diameter \aO.LwYm;:  
    '************************************************************************* q#~]Hp=W5  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) |E)IJj 3  
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    'Adjust pupil diameter (trimming volume inner hole) !zNMU$p  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" h8!;RN[  
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    ' Adjust pupil location to just in front of the lens :i6k6=  
    parID = FindFullName( "Geometry.Arizona Eye" ) a/wkc*}}/  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) 5CsJghTw  
    count = 0 /U%
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    While GetOperationCount(eID)>count rn?:ut
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        GetOperation eID, count, op ZSTpA,+6  
        If op.Type="ShiftZ" Then zSiSZMP"  
            DeleteOperation eID,count vK\;CSk  
            count=count-1 ~=,|dGAa$  
        End If jF\J+:5M  
        count=count+1 1Bz'$u;  
    Wend &,Xs=Lvmq  
    op.Type = "ShiftZ" .baS mfc  
    op.val1 = taq-0.01 GBZx@B[TY  
    op.parent = parID q#RVi8('  
    AddOperation eID, op {-]/r  
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    Print "Set pupil diameter = " & pupilDiam z.[ Ok  
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    'Update AZ Eye subassembly Description
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    eID = FindFullName( "Geometry.Arizona Eye" ) [D H@>:"dd  
    GetEntity eID, entity ]AGJPuX  
    entity.Description = "Accommodation = " & A & "D" zSYWNmj&  
    SetEntity eID, entity 4>gMe3]0  
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    Update {=,?]Z+  
    Print "DONE!" D(&${Mnac  
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End Sub m//(1hWv7  
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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： q
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Accommodation = 4 Diopters 2f]9I1{  
Pupil Diameter = 4 mm 4\?I4|{pC  
Set aqueous humor thickness = 2.81 [j5^Zb&0  
Set anterior lens radius = 10.4 and conic constant = -2.375869 c(bh i  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 nYuZg6K  
Set lens thickness = 3.927 u+zq:2)H6  
Set lens index of refraction = 1.42672 flLC\  
Set pupil diameter = 4 n\ma5"n0=\  
DONE! s&lZxnIjc