[技术]Arizona眼睛模型 [复制链接]

简介 +].Zs<  
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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。 FBR]) h'Z  
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模型 mo$`a6[h<  
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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。 4}4K6y<q  
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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. ^hpdre"  
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光源 mihR *8p  
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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。 G
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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。 TT'sO[N[  
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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。 @F+zME   
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视网膜的散射 J`&*r;""V  
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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。 O,&nCxB]  
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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。 aCq ) hR  
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脚本 N3_rqRd^  
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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： l(o#N'!j4  
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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。 ku@sQn  
余下的脚本计算与屈光度有关的所有参数。 j~|pSu.<  
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分析 6`ZHFe
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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。 'zEmg}  
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脚本代码 {0&'XA=j  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. &YSjwRr  
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Dim entity As T_ENTITY [&tN(K
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Dim op As T_OPERATION z'FpP  
Dim mat As T_MODELMATERIAL aBBTcN%'  
Dim A As Double Rxg^vM*  
Dim pupilDiam As Double nB;yS<  
Dim eID As Long bJ~@ k,'  
Dim parID As Long _(qU%B  
Dim count As Integer 4RLuv?,)~  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double 6X2~30pdE  
Dim tlens As Double, nlens As Double 'b?Px}  
Dim curv As Double, conic As Double a2'si}'3  
Dim ok As Long 8Pkw'.r  
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Sub Main 6N6}3J5  
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    '用户输入对话框 &Z.zem?n  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 W)RCo}f  
        TextBox 220,21,40,21,.TextBox1 'default: 0 lY.{v]
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        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 CDNh9`  
        OKButton 40,91,90,21 5._=m"
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        CancelButton 190,91,90,21 da'7* &/  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 55mDLiA  
        TextBox 220,49,40,21,.TextBox2 'default: 4 T6P9Icv?@7  
    End Dialog \Q CH.~]  
    Dim dlg As UserDialog
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    ok = Dialog (dlg) -W#-m'Lvu  
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    If ok=0 Then    'cancel button was pressed /C'dW  
        Print "Execution cancelled." 8[z<gxP`?  
        End OdZLJt?g  
    End If Po~u-5  
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    'Assign accommodation and pupil diameter & use defaults if field left empty q=_&izmE'7  
    If dlg.TextBox1 = "" Then 1L4-hYtCj  
        A = 0           'Default accommodation 2tEA8F~k  
    Else 3;N+5*-  
        A = CDbl(dlg.TextBox1) /+11`B0
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    End If -F]0Py8(  
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    If dlg.TextBox2 = "" Then !6yyX}%o  
        pupilDiam = 4   'Default pupil diameter S7I8BS[*v  
    Else _olhCLIR-  
        pupilDiam = CDbl(dlg.TextBox2) Ot^<:\<`G  
    End If 4X()D {uR  
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    Print " " 0cpI2  
    Print "Accommodation = " & A & " Diopters" EYsf<8cl  
    Print "Pupil Diameter = " & pupilDiam & " mm"
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    ' Calculate new parameters with accommodation ?>\JX  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness ,.g9HO/R1  

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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens %+1;iuDL  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens x+X^K_*  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens )=PmHUd  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens `akbzHOM  
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    tlens = 3.767 + 0.04*A                  'Lens thickness AzfYw'^&9  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction ?)60JWOJ1  
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    'Adjust parameters to account for accommodation bSKe@4C  
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    '************************************************************************* ,^>WCG  
    'Aqueous thickness (Position of Lens) 1Ar6hA  
    '************************************************************************* ,)CRozC\}K  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) Hy_}e"  
    GetCustomElement eID, entity fG^#G/n2  
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    parID = FindFullName( "Geometry.Arizona Eye" ) 9T#JlV  
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    ' Delete any shift(s) in z Za&.sg3RG  
    count = 0 B F,rZZL  
    While GetOperationCount(eID)>count 
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        GetOperation eID, count, op =N+Ou5D  
        If op.Type="ShiftZ" Then o C5}[cYD`  
            DeleteOperation eID,count #fb <\!iza  
            count=count-1 fuwv,[
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        End If neHozmm|  
        count=count+1 $_5@NOZ,M  
    Wend ,IODV`L  
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    'Set new shift in Vd'KN2Jm  
    op.Type = "ShiftZ" UT^-!L LB]  
    op.val1 = taq |.s#m^"  
    op.parent = parID K?4/x4p@  
    AddOperation eID, op Dn}Wsd=  
    Print "Set aqueous humor thickness = " & taq-0.55 e2onR~Cf  
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    '************************************************************************* 77:s=)   
    'Radius and conic constant of anterior lens nhUL{ER  
    '************************************************************************* oQkY@)3.w  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) F$;vPAxbK"  
    GetConic eID, entity, curv, conic 1o;*`  
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    SetConic eID, entity, 1/Rant, CCant p PF]&:&-b  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant 0>E0}AvkT  
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    '*************************************************************************  h,D6MP  
    'Radius and conic constant of posterior lens s`bC?wr5h  
    '************************************************************************* xyoh B#'W  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) /pa8>_,~  
    GetConic eID, entity, curv, conic [\j@_YYd  
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    SetConic eID, entity, 1/Rpost, CCpost T%Vg0Y)P;  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost wR"4slY_%  
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    '************************************************************************* m-~eCFc  
    'Lens thickness (Position of posterior lens surface) ()E:gqQ  
    '************************************************************************* 7jb{E+DrG  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) 
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    ' Delete any z-shift(s) n(mS  
    count = 0 pY3N7&m\:  
    While GetOperationCount(eID)>count eBK s-2r  
        GetOperation eID, count, op gAx8r-` `  
        If op.Type="ShiftZ" Then "dKYJ&$  
            DeleteOperation eID,count . k6)  
            count=count-1 )P{I<TBI;  
        End If UL/|!(s  
        count=count+1 yqg&dq  
    Wend HzO6hb{jJO  
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    'Set new z-shift !eoN  
    op.Type = "ShiftZ" ^UF]%qqOn  
    op.val1 = tlens M!=WBw8Y]a  
    op.parent = parID 2C@hjw(
 
    AddOperation eID, op [_3Rhp:  
    Print "Set lens thickness = " & tlens [\hk_(}  
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    '************************************************************************* $RQ7rL3g{  
    'Lens index of refraction u5f+%!p  
    '************************************************************************* 5(/
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    eID = FindMaterial( "Lens" ) oCLs"L-r{  
    GetModelMaterial eID, mat =5P_xQx  
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    mat.Nd = nlens ."m6zq  
    SetModelMaterial eID, mat !;SpQ28  
    Print "Set lens index of refraction = " & nlens eQk ~YA]K  
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    '************************************************************************* zS Yh ?NB5  
    'Pupil diameter ZCQ7xQD  
    '************************************************************************* 7'[C+/:  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) HQ%-e5Q  
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    'Adjust pupil diameter (trimming volume inner hole) (D'Z
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" n6gYZd  
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    ' Adjust pupil location to just in front of the lens mT.p-C  
    parID = FindFullName( "Geometry.Arizona Eye" ) Fj9/@pe1  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) p}KZ#"Q  
    count = 0 _tR%7%3*  
    While GetOperationCount(eID)>count &jgpeFiiC  
        GetOperation eID, count, op @:@0}]%z9  
        If op.Type="ShiftZ" Then *G^n<p$"  
            DeleteOperation eID,count l`2X'sw[/  
            count=count-1 eNlE]W,=  
        End If 6 ^X$;  
        count=count+1 5/Ng!bW  
    Wend <zN  
    op.Type = "ShiftZ" =*.Nt*;;  
    op.val1 = taq-0.01 V1KWi^  
    op.parent = parID 47_4`rzy;  
    AddOperation eID, op dbkccO}WB  
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    Print "Set pupil diameter = " & pupilDiam DBl.bgf  
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    'Update AZ Eye subassembly Description L<>;E  
    eID = FindFullName( "Geometry.Arizona Eye" ) 'sJ=h0d_[V  
    GetEntity eID, entity 'Y+AU#1~H  
    entity.Description = "Accommodation = " & A & "D" Wh%qvV6]  
    SetEntity eID, entity y D.S"  
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    Update 09"C&X~  
    Print "DONE!" R@``MC0  
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End Sub B&0^3iKFi  
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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： rE"`q1b#  
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Accommodation = 4 Diopters ]GYO`,  
Pupil Diameter = 4 mm &I.UEF2,  
Set aqueous humor thickness = 2.81 -6MgC9]  
Set anterior lens radius = 10.4 and conic constant = -2.375869 OpY2Z7_  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 XM3N>OR.  
Set lens thickness = 3.927 <ns[( Q  
Set lens index of refraction = 1.42672 4KE"r F  
Set pupil diameter = 4 1
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DONE! 2O {@W +Mt