[技术]Arizona眼睛模型 [复制链接]

简介 w)Q0_2p.  
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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。 -F<Wd/Xse  
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模型 vJ'2@f$  
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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"~P/\jP  
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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. k~jP'aD  
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光源 xO&eRy?%  
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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。 ;*:Pw?'  
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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。 =5kY6%E7c  

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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。 w-Da~[J  
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视网膜的散射 =Ur}~w&H8  
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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。 `/EGyN6X  
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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。 %F-ZN^R  
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脚本 K':K{ee>  
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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： i`dCG[  
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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。 il:$sd  
余下的脚本计算与屈光度有关的所有参数。 (^u1~1E 5  
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分析 L1Iz<>  
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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。 v?& -xH-S  
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脚本代码
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. ^(|vsFz
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Dim entity As T_ENTITY W!?7D0q  
Dim op As T_OPERATION #m{UrTC  
Dim mat As T_MODELMATERIAL rld67'KcE  
Dim A As Double b0Kc^uj5  
Dim pupilDiam As Double +YqZ((  
Dim eID As Long 11<KpxKpk  
Dim parID As Long {`K m_<Te!  
Dim count As Integer DsT>3  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double ~ ; -! n;  
Dim tlens As Double, nlens As Double YEj8S5"Su\  
Dim curv As Double, conic As Double }RwSp!}C  
Dim ok As Long V??dYB(  
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Sub Main yjhf   
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    '用户输入对话框 rfNm&!K  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 IuNi
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        TextBox 220,21,40,21,.TextBox1 'default: 0 UmQ?rS8d  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 /4vG3  
        OKButton 40,91,90,21 *g[^.Sg  
        CancelButton 190,91,90,21 +eX@U;J,g  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 _c,'>aH=  
        TextBox 220,49,40,21,.TextBox2 'default: 4 o9F/y=.r=  
    End Dialog [BT/~6ovrZ  
    Dim dlg As UserDialog /ew Ukc8,  
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    ok = Dialog (dlg) z&{5;A}Q@  
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    If ok=0 Then    'cancel button was pressed []A%<EI7  
        Print "Execution cancelled." OnK~
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        End !kE-_dY6)  
    End If /yZQ\{=  
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    'Assign accommodation and pupil diameter & use defaults if field left empty _h":>  
    If dlg.TextBox1 = "" Then }b0; 0j  
        A = 0           'Default accommodation \l.-eu'O  
    Else %"af748!+D  
        A = CDbl(dlg.TextBox1) U )l,'y2  
    End If R8T]2?Q1  
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    If dlg.TextBox2 = "" Then cdG|
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        pupilDiam = 4   'Default pupil diameter ##EYH1P]  
    Else $pFo Rv  
        pupilDiam = CDbl(dlg.TextBox2) 7g(F#T?;'  
    End If ODC8D>Z
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    Print " " Ldl5zc  
    Print "Accommodation = " & A & " Diopters" Ns[ym>x#2  
    Print "Pupil Diameter = " & pupilDiam & " mm" [fKUyIY_  
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    ' Calculate new parameters with accommodation 'I /aboDB  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness N1}={yF.fQ  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens Jte#ZnP  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens =n' 4?W@  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens }-o{ASC#  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens BYo/57&:  
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    tlens = 3.767 + 0.04*A                  'Lens thickness ^+m+zd_  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction I~9hx*!%%  
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    'Adjust parameters to account for accommodation NM6Teu_
  
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    '************************************************************************* yT#{UA^  
    'Aqueous thickness (Position of Lens) 
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    '************************************************************************* =pznu+,  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) S9>0t0  
    GetCustomElement eID, entity zWb4([P;  
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    parID = FindFullName( "Geometry.Arizona Eye" ) sqS=qC  
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    ' Delete any shift(s) in z |-CnT:|o  
    count = 0 ?l$Nf@-  
    While GetOperationCount(eID)>count /g$G_}  
        GetOperation eID, count, op CCX8>09  
        If op.Type="ShiftZ" Then j$TwL;  
            DeleteOperation eID,count W5'3$,X9  
            count=count-1 8B#GbS K  
        End If !QT'L,_  
        count=count+1 `r_m+
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    Wend ??i4z[0M  
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    'Set new shift in h#hxOVl%x  
    op.Type = "ShiftZ" %Jf<l&K.`  
    op.val1 = taq ?^EXTU85`"  
    op.parent = parID mnID3=JF  
    AddOperation eID, op Cb_oS4vM  
    Print "Set aqueous humor thickness = " & taq-0.55 \^V`ds*.  
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    '************************************************************************* $L2%u8}8:  
    'Radius and conic constant of anterior lens .<K iMh  
    '************************************************************************* ]D!k&j~P  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) wHem5E  
    GetConic eID, entity, curv, conic PccB]  
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    SetConic eID, entity, 1/Rant, CCant hHPs&EA.p  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant NcAp_q? 4  
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    '************************************************************************* thqS*I'#g  
    'Radius and conic constant of posterior lens @Fpb-Qd"  
    '************************************************************************* :~ A%#  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) DS-fjH\  
    GetConic eID, entity, curv, conic 3F#+~^2  
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    SetConic eID, entity, 1/Rpost, CCpost D
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    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost 1H,g=Y4f%  
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    '************************************************************************* /n4pXT  
    'Lens thickness (Position of posterior lens surface) >z`,ch6~  
    '************************************************************************* cFagz* !  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) lI/0:|l  
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    ' Delete any z-shift(s) gs W0  
    count = 0 )){xlFA}  
    While GetOperationCount(eID)>count &VBd~4|p  
        GetOperation eID, count, op -[Qvg49jy  
        If op.Type="ShiftZ" Then {R^'=(YFy  
            DeleteOperation eID,count o_Si mJFK  
            count=count-1 2 /y}a#s  
        End If 8:.nEo'  
        count=count+1 ./p|?pu  
    Wend rz(0:vxwA  
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    'Set new z-shift e0;  
    op.Type = "ShiftZ" 'lS`s(  
    op.val1 = tlens <g9"Cr`  
    op.parent = parID b%t+,0s|  
    AddOperation eID, op [ "xn5lE  
    Print "Set lens thickness = " & tlens .]|Zf!>}s  
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    '************************************************************************* V5D`eX9  
    'Lens index of refraction 5=KF!?  
    '************************************************************************* wG8Wez%  
    eID = FindMaterial( "Lens" ) *wV[TKaN  
    GetModelMaterial eID, mat L"<B;u5pM  
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    mat.Nd = nlens (H?ZSeWx  
    SetModelMaterial eID, mat IB
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    Print "Set lens index of refraction = " & nlens OSzjK7:  
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    '************************************************************************* E-1"+p  
    'Pupil diameter (}:C+p 'I  
    '************************************************************************* X;!D};;M  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) xiyxrR;  
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    'Adjust pupil diameter (trimming volume inner hole) x"(9II*  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" e(1k0W4B  
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    ' Adjust pupil location to just in front of the lens mh;X~.98  
    parID = FindFullName( "Geometry.Arizona Eye" ) XtBMp=7Oa  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) iS@\ =CK  
    count = 0 e@F|NCQ.9  
    While GetOperationCount(eID)>count 5eX59:vtl  
        GetOperation eID, count, op tL0`Rvl  
        If op.Type="ShiftZ" Then S)%_weLW7  
            DeleteOperation eID,count =z:U~D  
            count=count-1 :k46S<RE  
        End If AH.9A_dG  
        count=count+1 eSl-9 ^  
    Wend p-GT`D  
    op.Type = "ShiftZ" jnoL2JR[=-  
    op.val1 = taq-0.01 !;>(ie\  
    op.parent = parID # nfI%  
    AddOperation eID, op ^ua12f  
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    Print "Set pupil diameter = " & pupilDiam X9~m8c){z  
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    'Update AZ Eye subassembly Description FQf#*  
    eID = FindFullName( "Geometry.Arizona Eye" ) bdV3v`  
    GetEntity eID, entity [V@yRWI  
    entity.Description = "Accommodation = " & A & "D" dDKqq(9(`  
    SetEntity eID, entity Rq7p29w  
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    Update 0^]t"z5f0  
    Print "DONE!" 015Owi  
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End Sub ;mO,3dV  
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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： qmmv7==  
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Accommodation = 4 Diopters q|q::q*  
Pupil Diameter = 4 mm da*9(!OV  
Set aqueous humor thickness = 2.81 '7nJb6V,0l  
Set anterior lens radius = 10.4 and conic constant = -2.375869 FU@uH U5fd  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 &]nd!N  
Set lens thickness = 3.927 
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Set lens index of refraction = 1.42672 L? ;/cO^  
Set pupil diameter = 4 \; bWh  
DONE! B-Y+F