[技术]Arizona眼睛模型 [复制链接]

简介 lcV<MDS  
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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。 wM[~2C=vx  
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模型 NA,CZ  
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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。 A8A~!2V  
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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. >u%]6_[  
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光源 fFjH "2WD  
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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。 jEXW  
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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。 7kKy\W  
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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。
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视网膜的散射 U}Hwto`R  
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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。

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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。 YJxw 'U >P  
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脚本 4;`Bj:.  
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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： ZV}X'qGaq  
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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。 TaJB4zB  
余下的脚本计算与屈光度有关的所有参数。 6pE :A@  
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分析 c':ezEaC  
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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。 #0b&^QL  
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脚本代码 nA>sHy  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. vtJV"h?e"3  
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Dim entity As T_ENTITY 8|twV35  
Dim op As T_OPERATION h!&sNzX  
Dim mat As T_MODELMATERIAL V's:>;  
Dim A As Double yj@tV2  
Dim pupilDiam As Double T)7TyE|"2g  
Dim eID As Long V%
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Dim parID As Long k6IG+:s  
Dim count As Integer dEM?~?  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double u}9fj  
Dim tlens As Double, nlens As Double ghk5rl$   
Dim curv As Double, conic As Double  H'RL62!  
Dim ok As Long !rxp?V n -  
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Sub Main tqOi x/  
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    '用户输入对话框 z*~YLT&  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 k7_I$<YDj  
        TextBox 220,21,40,21,.TextBox1 'default: 0 F>|9 52  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 V'Y
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        OKButton 40,91,90,21 c)C5KaiPG  
        CancelButton 190,91,90,21 b`cYpcs  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 yeD_j/  
        TextBox 220,49,40,21,.TextBox2 'default: 4 fUag1d  
    End Dialog >',y  
    Dim dlg As UserDialog YTY%#"  
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    ok = Dialog (dlg) [UPNd!sy  
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    If ok=0 Then    'cancel button was pressed .")b?#K  
        Print "Execution cancelled." OsW"CF2  
        End EiV=RdL  
    End If 5{>0eFzG  
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    'Assign accommodation and pupil diameter & use defaults if field left empty j~ym<-[{a  
    If dlg.TextBox1 = "" Then &B-[oqC?  
        A = 0           'Default accommodation G=M]
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    Else m>Ux`Gp+  
        A = CDbl(dlg.TextBox1) sz09+4h#  
    End If AfWl6a?T8:  
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    If dlg.TextBox2 = "" Then 9rj('F&1  
        pupilDiam = 4   'Default pupil diameter }(i(Ar-  
    Else c]Un
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        pupilDiam = CDbl(dlg.TextBox2) G_oX5:J*  
    End If C@dGWAG  
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    Print " " }X1.Wt=?  
    Print "Accommodation = " & A & " Diopters" *M!kA65'  
    Print "Pupil Diameter = " & pupilDiam & " mm" <A~GW 'HB  
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    ' Calculate new parameters with accommodation UC9{m252  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness 6c\DJD  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens SfI*bJo>V  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens \ZnN D1A  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens Fn,k!q  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens :4;S"p  
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    tlens = 3.767 + 0.04*A                  'Lens thickness ?R?Grw)`H  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction 2,AaP*,  
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    'Adjust parameters to account for accommodation G*\sdBW!k  
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    '************************************************************************* F!CAitxd  
    'Aqueous thickness (Position of Lens) @%B4;c  
    '************************************************************************* Ex,JB +  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) ,+-?Zv 2  
    GetCustomElement eID, entity '0Zm#g  
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    parID = FindFullName( "Geometry.Arizona Eye" ) w`#fH  
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    ' Delete any shift(s) in z rA#s  
    count = 0 zUQe0Gc.b^  
    While GetOperationCount(eID)>count v' 0!=r  
        GetOperation eID, count, op *]!l%Uf
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        If op.Type="ShiftZ" Then fOW_
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            DeleteOperation eID,count F"BL#g66  
            count=count-1 eUs-5 L  
        End If X8b#[40:  
        count=count+1 6F ;Or  
    Wend WD;)VsP  
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    'Set new shift in 0#=W#Jl>  
    op.Type = "ShiftZ" R9=K(pOT  
    op.val1 = taq lM&UFEl-\  
    op.parent = parID c
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    AddOperation eID, op hZ o5p&b  
    Print "Set aqueous humor thickness = " & taq-0.55 bFn(w:1Q  
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    '************************************************************************* ^f0(aYWx  
    'Radius and conic constant of anterior lens U9F6d!:L7A  
    '************************************************************************* sy.:T]ZH  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) >t,
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    GetConic eID, entity, curv, conic ]+lF=kkc%  
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    SetConic eID, entity, 1/Rant, CCant gUb "3g0  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant qzlER  
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    '************************************************************************* Fva]*5  
    'Radius and conic constant of posterior lens HqRCjD  
    '************************************************************************* [k~C+FI  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) XC}1_VWs  
    GetConic eID, entity, curv, conic Xr2 Wa  
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    SetConic eID, entity, 1/Rpost, CCpost fU`T\  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost C,3T!\  
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    '************************************************************************* XJ\_V[WA  
    'Lens thickness (Position of posterior lens surface) "Y(%oJS]D  
    '************************************************************************* ;3 dM@>5[  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) g6`.qyVfz'  
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    ' Delete any z-shift(s) `{WCrw6)  
    count = 0 kw;wlFU;  
    While GetOperationCount(eID)>count v'$ykZ!Z  
        GetOperation eID, count, op YiO3<}Uf  
        If op.Type="ShiftZ" Then ^Wk0*.wg  
            DeleteOperation eID,count WSSaZ9 =  
            count=count-1 cY^Y!.,  
        End If ,`+Bs&S8  
        count=count+1 I'P.K| "R  
    Wend 3} l;  
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    'Set new z-shift wV?[3bEhM  
    op.Type = "ShiftZ" . *Z#cq0  
    op.val1 = tlens TiTYs  
    op.parent = parID " _mmR
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    AddOperation eID, op 8db6(Q~P  
    Print "Set lens thickness = " & tlens i'9eKO  
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    '************************************************************************* R,XD6'Q  
    'Lens index of refraction oX2r?.j#M  
    '************************************************************************* 4bWfx_0W  
    eID = FindMaterial( "Lens" ) [!5l0{0  
    GetModelMaterial eID, mat i /C'0  
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    mat.Nd = nlens J511AoQ{R  
    SetModelMaterial eID, mat "NlRSc#  
    Print "Set lens index of refraction = " & nlens "_Zh5 g  
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    '************************************************************************* %jpH:-8'2  
    'Pupil diameter -<_+-t  
    '************************************************************************* +)% ,G@-`  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) *:k~g].Iz  
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    'Adjust pupil diameter (trimming volume inner hole) tYF$#Nor#k  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" |:{g?4Mi  
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    ' Adjust pupil location to just in front of the lens 01'y^`\xQ  
    parID = FindFullName( "Geometry.Arizona Eye" ) ]U#JsMS  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) q=J9LQ  
    count = 0 }7otuO(pRo  
    While GetOperationCount(eID)>count g6HphRJ5s  
        GetOperation eID, count, op 5^bh.uF  
        If op.Type="ShiftZ" Then 7O]J^H+7  
            DeleteOperation eID,count Bi %Z2/  
            count=count-1 !>?4[|?n<  
        End If q|?`Gsr  
        count=count+1 `4se7{'UK`  
    Wend eUi> Mp  
    op.Type = "ShiftZ" NU BpIx&  
    op.val1 = taq-0.01 z&\Il#'\m+  
    op.parent = parID W` WLW8Qsw  
    AddOperation eID, op [%HYh7ua<  
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    Print "Set pupil diameter = " & pupilDiam XL{{7%j  
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    'Update AZ Eye subassembly Description Vf@S8H  
    eID = FindFullName( "Geometry.Arizona Eye" ) B:B0p+$I  
    GetEntity eID, entity R?1i
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    entity.Description = "Accommodation = " & A & "D" ~NTDG  
    SetEntity eID, entity {Q}!NkF1  
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    Update #JHy[!4  
    Print "DONE!" IptB.bYc  
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End Sub u<BHf@AI  
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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： V,99N'o~x  
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Accommodation = 4 Diopters z36brv<_'p  
Pupil Diameter = 4 mm R (+h)#![  
Set aqueous humor thickness = 2.81 Nv}U/$$S  
Set anterior lens radius = 10.4 and conic constant = -2.375869 Uqb
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Set posterior lens radius = -4.424557 and conic constant = -3.081019 P]~N-xdV  
Set lens thickness = 3.927 B<vvsp\X  
Set lens index of refraction = 1.42672 [,.[gWA  
Set pupil diameter = 4 KqT#zj  
DONE! s{x*~M$vt