[技术]Arizona眼睛模型 [复制链接]

简介 ysl#Rwt/2  
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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。 kWy@wPqms  
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模型 `wU['{=  
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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。 ,d&3IhYhD  
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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. (Z[c7  
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光源 zUZET'Bm9  
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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。 QjG/H0*mP  
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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。 )T^wc:  
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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。 d;wq@e  
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视网膜的散射 >~Tn%u<  
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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。 yRl  
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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。 92A9gY
  
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脚本 -T{2R:\{  
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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： K<`Z@f3'w  
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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。 ) 5$?e  
余下的脚本计算与屈光度有关的所有参数。 oQu>Qr{Zp  
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分析 L3xN#W;m7  
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屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 -)')PV_+  
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脚本代码 tp7$t#  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. 3e1-w$z&S  
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Dim entity As T_ENTITY <4vCx  
Dim op As T_OPERATION HB'9&  
Dim mat As T_MODELMATERIAL DgW@v[#BK=  
Dim A As Double gH'hA'  
Dim pupilDiam As Double [R%*C9Y d  
Dim eID As Long !3k-' ),z&  
Dim parID As Long ``:[Jr&  
Dim count As Integer K|-m6!C!7  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double ]k7%p>c=B  
Dim tlens As Double, nlens As Double U), HrI>;  
Dim curv As Double, conic As Double M80Q6K  
Dim ok As Long WH1" HO  
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Sub Main M57<e`m  
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    '用户输入对话框 9cP{u$  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 `P !idg*  
        TextBox 220,21,40,21,.TextBox1 'default: 0 *9kg\#  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 O)VcW/  
        OKButton 40,91,90,21 O$m &!J  
        CancelButton 190,91,90,21 xi "3NF%=  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 Kd+E]$F_OH  
        TextBox 220,49,40,21,.TextBox2 'default: 4 sfn^R+x4,9  
    End Dialog ~B"HI+:\L  
    Dim dlg As UserDialog np6G~0Y`  
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    ok = Dialog (dlg) mR@d4(:J?  
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    If ok=0 Then    'cancel button was pressed !0Nf`iCQ(  
        Print "Execution cancelled." (ub(0 h0j  
        End
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    End If uE9,N$\L_  
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    'Assign accommodation and pupil diameter & use defaults if field left empty 0'pB7^y  
    If dlg.TextBox1 = "" Then a_5s'Dh  
        A = 0           'Default accommodation ?i#x13  
    Else /Z^a,%1  
        A = CDbl(dlg.TextBox1) L@AFt)U  
    End If l_
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    If dlg.TextBox2 = "" Then r.#r!.6 q  
        pupilDiam = 4   'Default pupil diameter *.>@  
    Else -;_"Y]#  
        pupilDiam = CDbl(dlg.TextBox2) ;2
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    End If bs~P  
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    Print " " ,IboPh&Q78  
    Print "Accommodation = " & A & " Diopters" IMqe(  
    Print "Pupil Diameter = " & pupilDiam & " mm" /}U)|6-B  
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    ' Calculate new parameters with accommodation #9]2Uixq[  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness =&UE67eK,  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens [=jZP,b&),  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens eu$VKLY*  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens ]i`Q+q[  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens TCyev[(  
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    tlens = 3.767 + 0.04*A                  'Lens thickness '{ =F/q  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction =Vs?=|r  
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    'Adjust parameters to account for accommodation Oz-/0;1n  
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    '************************************************************************* *'8q?R?7g  
    'Aqueous thickness (Position of Lens) &57~i=A 3  
    '************************************************************************* GZrN,M  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) \X*y~)+K`  
    GetCustomElement eID, entity }9\6!GY0  
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    parID = FindFullName( "Geometry.Arizona Eye" ) w@,p`  
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    ' Delete any shift(s) in z aanS^t0  
    count = 0 QlMLWi  
    While GetOperationCount(eID)>count fG>3gS6&  
        GetOperation eID, count, op 8TB|Y  
        If op.Type="ShiftZ" Then J{\Uw].|0  
            DeleteOperation eID,count GV1Ol^  
            count=count-1 )GG9
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        End If N80ogio_Tk  
        count=count+1 )YEAk@h@  
    Wend +:jonN9d  
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    'Set new shift in v4|TQ8!wR  
    op.Type = "ShiftZ" I[K4/91  
    op.val1 = taq au50%sA~  
    op.parent = parID v^o`+~i  
    AddOperation eID, op fWEQ vQ  
    Print "Set aqueous humor thickness = " & taq-0.55 %zGv+H?  
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    '************************************************************************* l59\Lo:  
    'Radius and conic constant of anterior lens AeEdqX)  
    '************************************************************************* (,o@/ -o  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) JGvhw,g  
    GetConic eID, entity, curv, conic d]sqj\Q57  
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    SetConic eID, entity, 1/Rant, CCant L)U*dY  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant GP4!t~"1  
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    '************************************************************************* dYD;Z<l  
    'Radius and conic constant of posterior lens T$u
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    '************************************************************************* dI%jR&.e;  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) ; ,sNRES3  
    GetConic eID, entity, curv, conic n5"oXpcIx  
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    SetConic eID, entity, 1/Rpost, CCpost %JSRC<,a  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost H:hM(m0?q  
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    '************************************************************************* n7;jME/!  
    'Lens thickness (Position of posterior lens surface) l9|K,YVW  
    '************************************************************************* {~9HJDcM  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) O0'|\:my  
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    ' Delete any z-shift(s) !$1qnsz  
    count = 0 AC <2.i_  
    While GetOperationCount(eID)>count QpQ2hNf  
        GetOperation eID, count, op +jF|8  
        If op.Type="ShiftZ" Then P,m+^,  
            DeleteOperation eID,count B6&[_cht  
            count=count-1 ?F]P=S:x  
        End If z6J12tu  
        count=count+1 6 L4\UTr  
    Wend XZ.D<T"  
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    'Set new z-shift lq53 xT  
    op.Type = "ShiftZ" `.JW_F)1  
    op.val1 = tlens fgL"\d}  
    op.parent = parID -E6av|c,F  
    AddOperation eID, op >H;m[  
    Print "Set lens thickness = " & tlens 46)[F0,$r  
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    '************************************************************************* ) q'D9x9  
    'Lens index of refraction nHbi{,3  
    '************************************************************************* wxK71OH  
    eID = FindMaterial( "Lens" ) %Bm{ctf#)  
    GetModelMaterial eID, mat +-;
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    mat.Nd = nlens lU Zj  
    SetModelMaterial eID, mat NVkYm+J#  
    Print "Set lens index of refraction = " & nlens ZMMx)}hS  
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    '************************************************************************* cu?6\@cD  
    'Pupil diameter }*9F`=%F  
    '************************************************************************* rU9")4sQ  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) Wx3DWY;  
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    'Adjust pupil diameter (trimming volume inner hole) <`Fl I
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" cu5}(  
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    ' Adjust pupil location to just in front of the lens *
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    parID = FindFullName( "Geometry.Arizona Eye" ) 3v3cK1K@oE  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) Y{e,I-"{  
    count = 0 y=\&z&3$  
    While GetOperationCount(eID)>count 9HN&M*}  
        GetOperation eID, count, op 2l V`UIa  
        If op.Type="ShiftZ" Then @+M1M2@Xz  
            DeleteOperation eID,count ]6v7iuvI  
            count=count-1 :n~Mg{j3  
        End If Z-CA9&4Uh  
        count=count+1 3`SH-"{j%  
    Wend /o$6"~t  
    op.Type = "ShiftZ" 8Wtr,%82  
    op.val1 = taq-0.01 /J-.K*xKt  
    op.parent = parID +ah4 K(+3  
    AddOperation eID, op l8+1{6xP  
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    Print "Set pupil diameter = " & pupilDiam @~$=96^  
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    'Update AZ Eye subassembly Description >(n/  
    eID = FindFullName( "Geometry.Arizona Eye" ) z<A8S=s6n  
    GetEntity eID, entity W=S^t_F  
    entity.Description = "Accommodation = " & A & "D" GfP'  
    SetEntity eID, entity EqD@o  
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    Update F\;l)  
    Print "DONE!" |,n(9Ix  
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End Sub #]i^L;u1A  
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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： $M-"az]  
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Accommodation = 4 Diopters ; 1?L  
Pupil Diameter = 4 mm E<B/5g!  
Set aqueous humor thickness = 2.81 ,{iMF (Nj  
Set anterior lens radius = 10.4 and conic constant = -2.375869 $@{d\@U  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 B[w.8e5  
Set lens thickness = 3.927 UZiL NKc  
Set lens index of refraction = 1.42672 0.!vp?  
Set pupil diameter = 4 .{;RJ:O  
DONE! :&$v.#