[技术]Arizona眼睛模型 [复制链接]

简介 5jS8{d0  
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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。 8`4Z%;1  
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模型 )8244;  
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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。 ^CtA@4  
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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. `N,q~@gL  
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光源 _w\A=6=q|  
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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。 N-Jp; D  
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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。 6k%Lc4W  
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视网膜的散射 VBe.&b8  
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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。 rgOc+[X  
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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。 ^o@N.+`&<  
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脚本 \dzHG/e  
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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： }+wvZq +c  
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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。 bWe_<'N  
余下的脚本计算与屈光度有关的所有参数。
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分析 &LD=Zp%  
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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。 pm 4"Q!K  
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脚本代码 x%WL!Lo  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. A/%
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Dim entity As T_ENTITY ?;dfA/  
Dim op As T_OPERATION Up/s)8$.  
Dim mat As T_MODELMATERIAL eInx\/  
Dim A As Double km(Mv  
Dim pupilDiam As Double hj_%'kk-A  
Dim eID As Long R;{y]1u  
Dim parID As Long 9AGf4tuy  
Dim count As Integer Y4 <  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double ,8vqzI  
Dim tlens As Double, nlens As Double -x)zyq6  
Dim curv As Double, conic As Double yL#bZ9W }  
Dim ok As Long #w *]`5 T  
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Sub Main MBO3y&\S4  
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    '用户输入对话框 zxV,v*L)  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 e_6-+l!f  
        TextBox 220,21,40,21,.TextBox1 'default: 0 dg?[gD8!4&  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 n.
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        OKButton 40,91,90,21 IQ`#M~:  
        CancelButton 190,91,90,21 a+--2+~=  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 <A_LZi  
        TextBox 220,49,40,21,.TextBox2 'default: 4 EC]b]'._  
    End Dialog j1yW{  
    Dim dlg As UserDialog )U~,q>H+ %  
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    ok = Dialog (dlg) *_aeK~du.  
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    If ok=0 Then    'cancel button was pressed 6]/LrM,23  
        Print "Execution cancelled." YXdd=F  
        End %O!~!'
 
    End If k70o=}  
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    'Assign accommodation and pupil diameter & use defaults if field left empty &f:"p*=a\  
    If dlg.TextBox1 = "" Then C_RxJWka  
        A = 0           'Default accommodation ^F*G  
    Else |?tUUT!`t  
        A = CDbl(dlg.TextBox1) dCF!.  
    End If :ziV3jRM  
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    If dlg.TextBox2 = "" Then -j6&W`  
        pupilDiam = 4   'Default pupil diameter {5$.:Y  
    Else ]4$t'wI.  
        pupilDiam = CDbl(dlg.TextBox2) %B,>6 `[  
    End If 8w:A""  
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    Print " " bw@"MF{  
    Print "Accommodation = " & A & " Diopters" i"#36CVT~  
    Print "Pupil Diameter = " & pupilDiam & " mm" }! jk  
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    ' Calculate new parameters with accommodation aMxg6\8  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness '\&t3?;  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens h7}D//~p  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens <vP{U  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens S#kA$yO  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens Nan@SuKY  
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    tlens = 3.767 + 0.04*A                  'Lens thickness i#uc  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction th$?#4SbR  
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    'Adjust parameters to account for accommodation B.e3IM0  
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    '************************************************************************* l"I G;qO.  
    'Aqueous thickness (Position of Lens)
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    '************************************************************************* 0Y%u[i/  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) $50/wb6s  
    GetCustomElement eID, entity |KV|x^fJ  
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    parID = FindFullName( "Geometry.Arizona Eye" ) Rh[%UNl  
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    ' Delete any shift(s) in z |>/T*zk<  
    count = 0 +A 4};]W|  
    While GetOperationCount(eID)>count $jpAnZR- /  
        GetOperation eID, count, op W?`%it5  
        If op.Type="ShiftZ" Then n<}t\<LG^c  
            DeleteOperation eID,count |f:1Br  
            count=count-1 k>2tC<  
        End If j9V*f HK  
        count=count+1 R-L*N$@!  
    Wend J%Cn  
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    'Set new shift in TA2?Ia;@xV  
    op.Type = "ShiftZ" &!kD81?Mm  
    op.val1 = taq _iJ8*v8A  
    op.parent = parID \Ax[/J2aO  
    AddOperation eID, op mbij& 0  
    Print "Set aqueous humor thickness = " & taq-0.55 {^Y0kvnd  
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    '************************************************************************* Y(qyuS3h~*  
    'Radius and conic constant of anterior lens pb\W7G  
    '************************************************************************* u?ALZxj?  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) 5Tl3k=o}  
    GetConic eID, entity, curv, conic bv%A;  
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    SetConic eID, entity, 1/Rant, CCant p$qpC$F  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant >+9f{FP 9  
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    '************************************************************************* 1ymq7F(2  
    'Radius and conic constant of posterior lens w9Eb\An  
    '************************************************************************* f vAF0 a  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) _o'3v=5T  
    GetConic eID, entity, curv, conic =;) M+"  
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    SetConic eID, entity, 1/Rpost, CCpost Y$@?Y/rhR  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost _&U5 u  
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    '************************************************************************* RPXkf
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    'Lens thickness (Position of posterior lens surface) rA"><pH  
    '************************************************************************* @CxXkR  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) i uNBw]  
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    ' Delete any z-shift(s) -F]0Py8(  
    count = 0 )|Ho"VEmg  
    While GetOperationCount(eID)>count zvDg1p  
        GetOperation eID, count, op SWrt4G  
        If op.Type="ShiftZ" Then qv+8wJ((  
            DeleteOperation eID,count hj8S".A_  
            count=count-1 "!fvEE  
        End If ^2|G0d@.:  
        count=count+1 {m<NPtp910  
    Wend .5t|FJ]`$  
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    'Set new z-shift ThvVLK  
    op.Type = "ShiftZ" aDae0$lc.S  
    op.val1 = tlens f19~B[a  
    op.parent = parID
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    AddOperation eID, op %+1;iuDL  
    Print "Set lens thickness = " & tlens x+X^K_*  
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    '************************************************************************* )=PmHUd  
    'Lens index of refraction 0Xke2
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    '************************************************************************* U,Duq^l~s  
    eID = FindMaterial( "Lens" ) ,pg\5b  
    GetModelMaterial eID, mat +RuPfw{z  
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    mat.Nd = nlens r=`]L-}V  
    SetModelMaterial eID, mat t!u{sr{j=  
    Print "Set lens index of refraction = " & nlens ]xYm@%>6  
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    '************************************************************************* Gp PlO]  
    'Pupil diameter knPo"GQW  
    '************************************************************************* uPp9
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    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) Hf ]w  
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    'Adjust pupil diameter (trimming volume inner hole) V&j |St[  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" gOE3x^X*{  
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    ' Adjust pupil location to just in front of the lens jDaWmy<ha  
    parID = FindFullName( "Geometry.Arizona Eye" ) og! d  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) tR;? o,T  
    count = 0 0D\b;ju<  
    While GetOperationCount(eID)>count 3=SN;cn  
        GetOperation eID, count, op W$l%= /  
        If op.Type="ShiftZ" Then <gdKuoY  
            DeleteOperation eID,count !aVwmd'9  
            count=count-1 HLPnbI-+  
        End If IO(Y_7  
        count=count+1 X5M{No>z  
    Wend w^.^XK4v.  
    op.Type = "ShiftZ" 5T,In+~Kd  
    op.val1 = taq-0.01 HifU65"8  
    op.parent = parID )RQX1("O  
    AddOperation eID, op S!/N lSr<  
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    Print "Set pupil diameter = " & pupilDiam @aA1=9-L  
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    'Update AZ Eye subassembly Description Tt0:rQ.  
    eID = FindFullName( "Geometry.Arizona Eye" ) R m{\ R  
    GetEntity eID, entity xEA%UFB.!G  
    entity.Description = "Accommodation = " & A & "D" \mBH6GS  
    SetEntity eID, entity Sb9In_* 0  
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    Update HfF4BQxm  
    Print "DONE!" kRyt|ryWh  
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End Sub )ny,vcU]  
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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： 7=o
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Accommodation = 4 Diopters bwo{ Lw~  
Pupil Diameter = 4 mm CD]2a@j{  
Set aqueous humor thickness = 2.81 d^&F%)AT  
Set anterior lens radius = 10.4 and conic constant = -2.375869 iz2I4 _N  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 BBub'  
Set lens thickness = 3.927 I& `>6=)  
Set lens index of refraction = 1.42672 "/EE$eU  
Set pupil diameter = 4 a-`OE"  
DONE! `f@VX :aL}