[技术]Arizona眼睛模型 [复制链接]

简介 Wm!lWQu7  
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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。 j}}:&>;  
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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。 "|<6bA  
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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. |L|)r)t  
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光源 P6q`i<  
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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=?2{c}U  
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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。 mHc
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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。 e_m
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视网膜的散射 7g@P$e]  
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在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 ={_.}   
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注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 S-)mv'Al'F  
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脚本 O7r<6(q(  
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内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： UG)J4ZX  
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如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 ERSo&8  
余下的脚本计算与屈光度有关的所有参数。 YbS$D  
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分析 BGAqg=nDV  
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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。 ]WLQ q4q  
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脚本代码 UuDT=_1Sh  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. _"BYnPq@wb  
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Dim entity As T_ENTITY aDJ\%  
Dim op As T_OPERATION f5)4H  
Dim mat As T_MODELMATERIAL WH`E=p^x4  
Dim A As Double ,SEC~)L  
Dim pupilDiam As Double $|0_[~0-n  
Dim eID As Long <PBrW#:'  
Dim parID As Long 3&*_5<t\X  
Dim count As Integer Z+jgFl 4  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double ^a9v5hu  
Dim tlens As Double, nlens As Double X6_m&~}15  
Dim curv As Double, conic As Double %<^B\|d'?  
Dim ok As Long UsT+o  
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Sub Main \etuIFQ#U  
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    '用户输入对话框 ^T}6oUd  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 Q)"L8v v  
        TextBox 220,21,40,21,.TextBox1 'default: 0 `o7m)T')  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 y\}39Z(]  
        OKButton 40,91,90,21 S<RJ46  
        CancelButton 190,91,90,21 We^!(G  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 ] r8 hMv  
        TextBox 220,49,40,21,.TextBox2 'default: 4 R-xWZRl>  
    End Dialog o+U]=q*|)$  
    Dim dlg As UserDialog V{51wnxT  
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    ok = Dialog (dlg) AEj
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    If ok=0 Then    'cancel button was pressed JryCL]  
        Print "Execution cancelled." L%D:gy9o  
        End 5o2W[<%v  
    End If aBV{Xr~#(  
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    'Assign accommodation and pupil diameter & use defaults if field left empty .gmNE$d  
    If dlg.TextBox1 = "" Then P%Fkd3e+  
        A = 0           'Default accommodation @S3G>i  
    Else x50,4J%J'r  
        A = CDbl(dlg.TextBox1) C^uH]WO  
    End If ~=W|I:@  
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    If dlg.TextBox2 = "" Then ,TuDG*Y
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        pupilDiam = 4   'Default pupil diameter &w{""'  
    Else zE"ME*ou  
        pupilDiam = CDbl(dlg.TextBox2) cE7xNZ;Bh  
    End If e}qG_*  
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    Print " " oH/6  
    Print "Accommodation = " & A & " Diopters" <|= UrG  
    Print "Pupil Diameter = " & pupilDiam & " mm" 7%aaqQ1T  
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    ' Calculate new parameters with accommodation x"kc:F  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness kj(Ko{  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens w6F'rsko]  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens Qz*!jwg  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens chjXsq#Q^  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens %vPs38Fks  
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    tlens = 3.767 + 0.04*A                  'Lens thickness E|u#W3-:  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction TV$Pl[m  
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    'Adjust parameters to account for accommodation LQVa,'  
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    '************************************************************************* |1d;0*HIgX  
    'Aqueous thickness (Position of Lens) a`.]
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    '************************************************************************* S4RvWTtQV  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) 0i}4T:J@`  
    GetCustomElement eID, entity Rpit>  
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    parID = FindFullName( "Geometry.Arizona Eye" ) G([8Q8B4+  
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    ' Delete any shift(s) in z N>z<v\
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    count = 0 v,t&t9}/  
    While GetOperationCount(eID)>count !,}W|(P)  
        GetOperation eID, count, op [n/'JeG5  
        If op.Type="ShiftZ" Then )zK`*Fa az  
            DeleteOperation eID,count C`F*00M{  
            count=count-1 +hdD*}qauC  
        End If *hI  
        count=count+1 ` aTkIo:ms  
    Wend Jd_w:H.  
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    'Set new shift in 8>.l4:`  
    op.Type = "ShiftZ" 1 h(oty2p  
    op.val1 = taq $YvT* T$_  
    op.parent = parID eto3dJ!R  
    AddOperation eID, op @DgJxY|  
    Print "Set aqueous humor thickness = " & taq-0.55 J{$+\  
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    '************************************************************************* V$u~}]z  
    'Radius and conic constant of anterior lens uLV@D r   
    '************************************************************************* 
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    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) M/GQQG;  
    GetConic eID, entity, curv, conic J%']t$AR  
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    SetConic eID, entity, 1/Rant, CCant )/FB73!  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant W69 -,w/  
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    '************************************************************************* 0-~Y[X"9.  
    'Radius and conic constant of posterior lens %V-\|cw   
    '************************************************************************* [Af&K22M(X  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) V6l*!R  
    GetConic eID, entity, curv, conic iTgGf  
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    SetConic eID, entity, 1/Rpost, CCpost L
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    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost 5Cxh>,k  
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    '************************************************************************* @xR7>-$0p  
    'Lens thickness (Position of posterior lens surface) m7X&"0X  
    '************************************************************************* $ wGDk
  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) <,qJ%kc  
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    ' Delete any z-shift(s) e*_8B2da  
    count = 0 'Im7^!-d  
    While GetOperationCount(eID)>count zmkqqiDp_  
        GetOperation eID, count, op `j*&F8}  
        If op.Type="ShiftZ" Then Ms5m.lX  
            DeleteOperation eID,count Z;shFMu  
            count=count-1 Bb[%?~ E!  
        End If Lv@JfN"O  
        count=count+1 BQ
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    Wend lTe}[@(  
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    'Set new z-shift g~_cYy  
    op.Type = "ShiftZ" |D)NPN&  
    op.val1 = tlens 2UY0:ye  
    op.parent = parID ]bO{001y,  
    AddOperation eID, op lJ@2N$w  
    Print "Set lens thickness = " & tlens ($*bwqp]}  
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    '************************************************************************* Be+'&+  
    'Lens index of refraction !cnunLc`  
    '************************************************************************* <{m!.9g9  
    eID = FindMaterial( "Lens" ) ey<u  
    GetModelMaterial eID, mat ,Iq+v  
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    mat.Nd = nlens k$kq|  
    SetModelMaterial eID, mat 2%0zPflT  
    Print "Set lens index of refraction = " & nlens r$=MBeT  
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    '************************************************************************* lZCvH1&"  
    'Pupil diameter \{J gjd  
    '************************************************************************* i'J.c4  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) Ixm<wKwW#  
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    'Adjust pupil diameter (trimming volume inner hole) (8o~ XL  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" ~Kda#=  
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    ' Adjust pupil location to just in front of the lens |Hg)!5EJ  
    parID = FindFullName( "Geometry.Arizona Eye" ) 9F)v=  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) !q~s-~d^  
    count = 0 {'Nvs_{6  
    While GetOperationCount(eID)>count # 'G/&&<  
        GetOperation eID, count, op 2D`@$)KL  
        If op.Type="ShiftZ" Then )c5M;/s  
            DeleteOperation eID,count !zLd,`  
            count=count-1 r=4'6!  
        End If o%h"gbvMY!  
        count=count+1 JC`|GaUy  
    Wend ]O',Ei^  
    op.Type = "ShiftZ" 6FG h=~{3,  
    op.val1 = taq-0.01 L?&+*|VxI  
    op.parent = parID CJg &  
    AddOperation eID, op iZ#dS}VlJ  
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    Print "Set pupil diameter = " & pupilDiam /S1EQ%_  
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    'Update AZ Eye subassembly Description '#xxjhF^  
    eID = FindFullName( "Geometry.Arizona Eye" ) `x$d8(1J`#  
    GetEntity eID, entity &0SGAJlec  
    entity.Description = "Accommodation = " & A & "D" t5N@z  
    SetEntity eID, entity *3WK:0  
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    Update -h^FSW($-R  
    Print "DONE!" n[n0iz1-  
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End Sub 4;Z`u.1  
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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： %]nYv#K  
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Accommodation = 4 Diopters >8Zz<S&z  
Pupil Diameter = 4 mm )5gcLD/zI  
Set aqueous humor thickness = 2.81 K@U"^ `G2  
Set anterior lens radius = 10.4 and conic constant = -2.375869 </tiNc  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 -"u}lCz>  
Set lens thickness = 3.927 _I
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Set lens index of refraction = 1.42672 [J\5DctX;c  
Set pupil diameter = 4 !1+L0,I6  
DONE!  dKDtj: