[技术]Arizona眼睛模型 [复制链接]

简介 8@Zg@>,  
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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。 iV h^;  
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模型 \8Mn[G9TL  
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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。 YCv)DW;  
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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. (G:A^z  
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光源 }ll&qb
 
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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。 Yt]tRqrh;T  
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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。 "gm[q."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。 lSMv9:N  
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视网膜的散射 U3Fa.bC6}  
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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。 w_c)iJ  
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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。 *QKxrg  
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脚本 3.i$lp`t  
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内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： A -C.Bi;/  
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如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 #Hn<4g"AjM  
余下的脚本计算与屈光度有关的所有参数。 RIhu9W  
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分析 xq6 eu 9  
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屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 <z'Pj7c[  
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脚本代码 csh@C ckC8  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. =`MxgK +  
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Dim entity As T_ENTITY :Dt]sE_d  
Dim op As T_OPERATION oI\Lepl*  
Dim mat As T_MODELMATERIAL EZ,Tc;f=  
Dim A As Double CP]nk0  
Dim pupilDiam As Double =3h?!$#?  
Dim eID As Long 1K*`i(  
Dim parID As Long Kw%to9eh)  
Dim count As Integer :d AC:h  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double F"-u8in`
 
Dim tlens As Double, nlens As Double :P2{^0$  
Dim curv As Double, conic As Double f|v5itO2  
Dim ok As Long c-jE1y<  
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Sub Main 539fB,  
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    '用户输入对话框 Y>J$OA:  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 dguN<yS-E  
        TextBox 220,21,40,21,.TextBox1 'default: 0 0?$jC-@k:  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 mm dQ\\  
        OKButton 40,91,90,21 C vOH*K'  
        CancelButton 190,91,90,21 )%+7"7.  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 =(==aP  
        TextBox 220,49,40,21,.TextBox2 'default: 4 whW%c8  
    End Dialog #+"1">l  
    Dim dlg As UserDialog +L\Dh.Ir  
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    ok = Dialog (dlg) 1zcaI^e#  
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    If ok=0 Then    'cancel button was pressed e0"80"D  
        Print "Execution cancelled." 1!S*z^LGl  
        End h@2YQgw`  
    End If 9cIKi#Bl  
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    'Assign accommodation and pupil diameter & use defaults if field left empty 5y~Srb?2  
    If dlg.TextBox1 = "" Then &cpqn2Z  
        A = 0           'Default accommodation CcJ%;.V,T  
    Else , 3&DA  
        A = CDbl(dlg.TextBox1) p 2>
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    End If TWeup6k  
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    If dlg.TextBox2 = "" Then V[;^{,;  
        pupilDiam = 4   'Default pupil diameter $=9g,39
 
    Else Yn
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        pupilDiam = CDbl(dlg.TextBox2) `C&@
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    End If ii5dTimRJ  
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    Print " " &SW~4{n:  
    Print "Accommodation = " & A & " Diopters" K'c[r0Ew  
    Print "Pupil Diameter = " & pupilDiam & " mm" 3E-dhSz:i  
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    ' Calculate new parameters with accommodation m4on<5s/  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness fzJ^`  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens 0K(&EpVE  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens adtgNwg  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens .)c+gyaQ  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens szs.B|3X@*  
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    tlens = 3.767 + 0.04*A                  'Lens thickness GUps\:ss  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction !!<H*9]+W;  
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    'Adjust parameters to account for accommodation &a
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    '************************************************************************* ?&JKq^9\I  
    'Aqueous thickness (Position of Lens) cB6LJ}R  
    '************************************************************************* Gm[XnUR7V  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) BC)1FxsGf  
    GetCustomElement eID, entity IP!`;?T=  
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    parID = FindFullName( "Geometry.Arizona Eye" ) i<M F8$  
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    ' Delete any shift(s) in z @Yw>s9X  
    count = 0 6Zx)L|B  
    While GetOperationCount(eID)>count wz{&0-md*'  
        GetOperation eID, count, op 2-%9k)KH  
        If op.Type="ShiftZ" Then !}hG|Y6s  
            DeleteOperation eID,count avY<~-44B  
            count=count-1 ig^x%!;  
        End If 8'Iei78Ov  
        count=count+1 1oI2  
    Wend :j`4nXm  
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    'Set new shift in I&f!>y?,Z  
    op.Type = "ShiftZ" !>:]k?$b  
    op.val1 = taq *{(tg~2'(  
    op.parent = parID L5wR4Ue)  
    AddOperation eID, op p^s:s-"f\  
    Print "Set aqueous humor thickness = " & taq-0.55 M7=|N:/_  
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    '************************************************************************* y9~:[jB  
    'Radius and conic constant of anterior lens K(AZD&D  
    '************************************************************************* 6J <.i  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) Ud_0{%@  
    GetConic eID, entity, curv, conic {$I1(DYN  
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    SetConic eID, entity, 1/Rant, CCant 'yR\%#s6  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant t4UL|fI  
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    '************************************************************************* :)F0~Q  
    'Radius and conic constant of posterior lens |#sY(1  
    '************************************************************************* U^kk0OT^  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) ),lE8A{ H  
    GetConic eID, entity, curv, conic k54b@U52 h  
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    SetConic eID, entity, 1/Rpost, CCpost 825 QS`  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost y;fnC5Q  
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    '************************************************************************* WO*dO9O  
    'Lens thickness (Position of posterior lens surface) NbK67p:  
    '************************************************************************* lL,0IfC,  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) $XcuU sG  
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    ' Delete any z-shift(s) _e "  
    count = 0 xmejoOF  
    While GetOperationCount(eID)>count fs2y$HN  
        GetOperation eID, count, op 5Vr#>W  
        If op.Type="ShiftZ" Then esd9N'.Q*  
            DeleteOperation eID,count bUe6f,8,  
            count=count-1 ^*F'[!. p  
        End If C?]+(
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        count=count+1 QtLd(& !v  
    Wend %>1C($^  
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    'Set new z-shift QC(ce)Y  
    op.Type = "ShiftZ" e\}'i-  
    op.val1 = tlens HE-ErEtGB  
    op.parent = parID MADt$_  
    AddOperation eID, op dB8 e  
    Print "Set lens thickness = " & tlens (Ft#6oK"  
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    '************************************************************************* e"ClG/M_XS  
    'Lens index of refraction >0cg  
    '************************************************************************* ^xq)Q?[{  
    eID = FindMaterial( "Lens" ) L$?YbQo7  
    GetModelMaterial eID, mat d~y]7h|  
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    mat.Nd = nlens QEP|%$:i  
    SetModelMaterial eID, mat 8-9<r  
    Print "Set lens index of refraction = " & nlens ;".]W;I*O  
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    '************************************************************************* ,qIut|C*  
    'Pupil diameter cK75Chsu  
    '************************************************************************* $Zj3#l:rK  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) " t,ZO  
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    'Adjust pupil diameter (trimming volume inner hole) 9 xFX"_J  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" 58]t iP"  
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    ' Adjust pupil location to just in front of the lens ooj^Z%9P  
    parID = FindFullName( "Geometry.Arizona Eye" ) E0eZal],  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) 1n#{c5T  
    count = 0 mzcxq:uZ5  
    While GetOperationCount(eID)>count Y r8gKhv W  
        GetOperation eID, count, op Fu65VLKh  
        If op.Type="ShiftZ" Then 8O0]h
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            DeleteOperation eID,count c#a>> V  
            count=count-1 2,p= %  
        End If |9mGX9q  
        count=count+1 @1V?94T1  
    Wend nM`pnR_  
    op.Type = "ShiftZ" `rpmh7*WV  
    op.val1 = taq-0.01 ?$=Ml$  
    op.parent = parID FZN}T{<  
    AddOperation eID, op B~%SB/eu  
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    Print "Set pupil diameter = " & pupilDiam >(W\Eh{J  
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    'Update AZ Eye subassembly Description ZSn6JV'g  
    eID = FindFullName( "Geometry.Arizona Eye" ) e*39/B0S  
    GetEntity eID, entity 1r<'&f5  
    entity.Description = "Accommodation = " & A & "D" SA~oGgk=P  
    SetEntity eID, entity 4TcW%  
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    Update 7 ;x to =  
    Print "DONE!" ;eMb$px  
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End Sub /Tp>aW%}"  
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如果屈光度是4，光瞳直径是4，则会输出如下数据： 1Ch0O__2L  
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Accommodation = 4 Diopters ,1i
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Pupil Diameter = 4 mm lht :%Ts$  
Set aqueous humor thickness = 2.81 !lI1jb"
 
Set anterior lens radius = 10.4 and conic constant = -2.375869 !uhh_3RH  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 :(i=> ~O  
Set lens thickness = 3.927 Zc=#Y  
Set lens index of refraction = 1.42672 hho\e 8  
Set pupil diameter = 4 Pa/2])w  
DONE! SKJ'6*6