[技术]Arizona眼睛模型 [复制链接]

简介 Y:VM5r)  
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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。 Lvc*L6  
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模型 Z\{WBUR;4t  
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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。 6yF4%Sz9  
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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. -)?~5Z   
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光源 ;=Bf&hY&  
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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。 HF5aU:M  
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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。 m7e$Z  
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在往下看是内置的脚本用来修改屈光度，使其为4（250mm），光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 -2tX
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视网膜的散射 s i
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在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 ZH`6>:  
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注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 ,US~p_M!  
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脚本 e
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内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： PQvq$|q  
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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。 N!"GwH  
余下的脚本计算与屈光度有关的所有参数。 1w+&Y;d|  
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分析 ',6QL4qV/  
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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。 `
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脚本代码 vo uQ.utl  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. \D
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Dim entity As T_ENTITY WqY:XE+?\  
Dim op As T_OPERATION yKOf]m>#  
Dim mat As T_MODELMATERIAL U`:#+8h-}  
Dim A As Double dm.?-u;C  
Dim pupilDiam As Double z=>]E1'RL  
Dim eID As Long A0O$B7ylQ  
Dim parID As Long j^iH[pN] \  
Dim count As Integer N_q7ip%z  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double >S5D-
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Dim tlens As Double, nlens As Double !j%)nU  
Dim curv As Double, conic As Double }%
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Dim ok As Long s.C-II?e  
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Sub Main $hn_4$
 
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    '用户输入对话框 cdzzS?$)  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 <LZvG IMl  
        TextBox 220,21,40,21,.TextBox1 'default: 0 %>xW_5;Z  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 m++VW0Y>  
        OKButton 40,91,90,21 mN3%;$ND7  
        CancelButton 190,91,90,21 wOHK dQ'  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 V}pw ,2s  
        TextBox 220,49,40,21,.TextBox2 'default: 4 ,UWO+B]  
    End Dialog nsw.\(#  
    Dim dlg As UserDialog a2Q9tt>Q  
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    ok = Dialog (dlg) a_QO)  
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    If ok=0 Then    'cancel button was pressed b*dRNu  
        Print "Execution cancelled." WF*2^iWJ  
        End N[aK#o,  
    End If (.%:Q0i1  
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    'Assign accommodation and pupil diameter & use defaults if field left empty y7d)[d*Mz  
    If dlg.TextBox1 = "" Then !p&M,6  
        A = 0           'Default accommodation L\y,7@1%AT  
    Else 3iH
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        A = CDbl(dlg.TextBox1) ,W*<e-  
    End If s(Kf%ZoE  
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    If dlg.TextBox2 = "" Then _Mq@58q'  
        pupilDiam = 4   'Default pupil diameter 2c8,H29  
    Else :Nc~rOC_  
        pupilDiam = CDbl(dlg.TextBox2) u"pn'H  
    End If m'aw`?  
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    Print " " /,E%)K;  
    Print "Accommodation = " & A & " Diopters" (X>r_4W$  
    Print "Pupil Diameter = " & pupilDiam & " mm" oPzt1Y  
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    ' Calculate new parameters with accommodation cQ
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    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness rU.e
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens /MQd[03]  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens Q9%N>h9  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens CzNSJVE5  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens _6=6 b!hD  
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    tlens = 3.767 + 0.04*A                  'Lens thickness TKRu^KH9  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction 0p Lb<&  
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    'Adjust parameters to account for accommodation 20%xD e  
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    '************************************************************************* Q*mPU=<  
    'Aqueous thickness (Position of Lens) & r\z9!
 
    '************************************************************************* c?<FMb3]  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) NwT3e&u%|  
    GetCustomElement eID, entity J#:%| F%  
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    parID = FindFullName( "Geometry.Arizona Eye" ) ;z
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    ' Delete any shift(s) in z UnW,|n8  
    count = 0 o5Pq>Y2T  
    While GetOperationCount(eID)>count .f(x9|K^  
        GetOperation eID, count, op og2]B\mN4  
        If op.Type="ShiftZ" Then BszkQ>#6  
            DeleteOperation eID,count g&BF#)7C  
            count=count-1 /:U\U_j  
        End If Ae`K9  
        count=count+1 \:-; {  
    Wend n~K_|  
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    'Set new shift in (q:L_zFj>"  
    op.Type = "ShiftZ" @BW~A@8  
    op.val1 = taq Y#?Sqm(  
    op.parent = parID tgg*6lc  
    AddOperation eID, op 4
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    Print "Set aqueous humor thickness = " & taq-0.55 f>p;Jh{2fn  
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    '*************************************************************************
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    'Radius and conic constant of anterior lens WnUYZ_+e!  
    '************************************************************************* Bz7T1B&to  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) 9.1%T06$  
    GetConic eID, entity, curv, conic @Cw<wrem  
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    SetConic eID, entity, 1/Rant, CCant NbG3^(  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant tM{t'WU  
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    '************************************************************************* a#j0N5<Nl  
    'Radius and conic constant of posterior lens ir%/9=^d  
    '************************************************************************* M@s2T|bQw  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) roW8 4x  
    GetConic eID, entity, curv, conic u4#BD!W  
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    SetConic eID, entity, 1/Rpost, CCpost LA"`8  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost OU0\xx1/  
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    '************************************************************************* hua{g_  
    'Lens thickness (Position of posterior lens surface) XY0Gjo0  
    '************************************************************************* Wl::tgU  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) _j<46^  
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    ' Delete any z-shift(s) 0P%(4t$pd  
    count = 0 h7I_{v8  
    While GetOperationCount(eID)>count ]hL 1qS  
        GetOperation eID, count, op H$;K(,'  
        If op.Type="ShiftZ" Then }2V|B4  
            DeleteOperation eID,count vpOzF>O  
            count=count-1 ]}KmT"vA  
        End If rJ9a@n,  
        count=count+1 dO rgqz`e  
    Wend 4wBMBCJ;P  
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    'Set new z-shift }MXZ  
    op.Type = "ShiftZ" VJZ   
    op.val1 = tlens /g@.1z1w  
    op.parent = parID R}>Gk  
    AddOperation eID, op K^s!0[6  
    Print "Set lens thickness = " & tlens ?sp  
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    '************************************************************************* q=UKL`;C}U  
    'Lens index of refraction :
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    '************************************************************************* @x"vGYKd  
    eID = FindMaterial( "Lens" ) '$q'Wl)  
    GetModelMaterial eID, mat & UL(r  
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    mat.Nd = nlens 2$=?;~  
    SetModelMaterial eID, mat waO*CjxE:  
    Print "Set lens index of refraction = " & nlens (Dq3e9fX  
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    '************************************************************************* ^<[oKi;>  
    'Pupil diameter <iJ->$  
    '************************************************************************* $*L@ym  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) O'A''}M  
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    'Adjust pupil diameter (trimming volume inner hole) KzI$GU3  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" s26:(J [{  
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    ' Adjust pupil location to just in front of the lens EJb"/oLla  
    parID = FindFullName( "Geometry.Arizona Eye" ) sAC1Pda  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) "7Zb)Ocb  
    count = 0 Gvl-q1PVC  
    While GetOperationCount(eID)>count [1 w  
        GetOperation eID, count, op mY#[D;mUe  
        If op.Type="ShiftZ" Then zZ Oo
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            DeleteOperation eID,count FyQ  
            count=count-1 gWv/3hWWB  
        End If P0k|33;7L  
        count=count+1 u5$\E]+_  
    Wend :$dGcX}  
    op.Type = "ShiftZ" c*HS#C7'2  
    op.val1 = taq-0.01 lmQ!q>N
 
    op.parent = parID z#8GF^U:T  
    AddOperation eID, op L8/o9N1  
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    Print "Set pupil diameter = " & pupilDiam ZTMzL%i  
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    'Update AZ Eye subassembly Description HiILJyb  
    eID = FindFullName( "Geometry.Arizona Eye" ) W^60
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    GetEntity eID, entity Pm#B'N#*N|  
    entity.Description = "Accommodation = " & A & "D" Y>wpla[kUq  
    SetEntity eID, entity zp,f}  
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    Update (ZT*EFhb(  
    Print "DONE!" 4US8B=jk  
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End Sub DUM,dFIlvF  
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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： s|"V$/X(W  
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Accommodation = 4 Diopters 2RT9Q!BX{  
Pupil Diameter = 4 mm :-Ho5DHg  
Set aqueous humor thickness = 2.81 $6Nm`[V  
Set anterior lens radius = 10.4 and conic constant = -2.375869 s7D_fv4e  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 WK:~2m&y  
Set lens thickness = 3.927 2:&8FdU  
Set lens index of refraction = 1.42672 lk2F]@_kJH  
Set pupil diameter = 4 @HMt}zD  
DONE! "n7rbh3VW