[技术]Arizona眼睛模型 [复制链接]

简介 Z4G%Ve[  
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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。 ~Q=;L>Qd  
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模型 D'[:35z  
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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。 ,]\cf  
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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. ue3 ].:  
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光源 #qVvh3#g  
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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。 :V6 [_VaF  
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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。 \V'fB5  
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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_us!Sn  
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视网膜的散射 r1q'+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。 #:=c)[G8  
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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。 r=.@APZB  
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脚本 :BR_
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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： w8S pt  
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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。 #/I+[|=[O  
余下的脚本计算与屈光度有关的所有参数。 D4"<suU|.  
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分析 N (\n$bpTt  
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屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 U`N?<zm<oO  
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脚本代码 f3,LX]zKA  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. | J'k9W"  
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Dim entity As T_ENTITY U*N{H$ACuR  
Dim op As T_OPERATION l %zbx"%x  
Dim mat As T_MODELMATERIAL 3 u=\d)eq  
Dim A As Double G$_)X%Vb I  
Dim pupilDiam As Double Qd~7OH4Lp  
Dim eID As Long "Cvr("'O  
Dim parID As Long 5KbPpKpd  
Dim count As Integer r9-ayp#pC  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double _)LXD,LA  
Dim tlens As Double, nlens As Double &B:L9^  
Dim curv As Double, conic As Double 3P75:v  
Dim ok As Long !iHC++D  
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Sub Main Mx0~^l
 
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    '用户输入对话框 ~f[;(?39xZ  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 3J8>r|u;1'  
        TextBox 220,21,40,21,.TextBox1 'default: 0 ,|8aDL?
 
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 cJ?,\@uuP  
        OKButton 40,91,90,21 82)=#ye_P  
        CancelButton 190,91,90,21 wYFkGih  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 |ggtb\W  
        TextBox 220,49,40,21,.TextBox2 'default: 4 :Eh}]_  
    End Dialog ;9#W#/B  
    Dim dlg As UserDialog +F,])p4,]i  
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    ok = Dialog (dlg) 67H?xsk@n  
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    If ok=0 Then    'cancel button was pressed w|I5x}ZFG  
        Print "Execution cancelled." J7dHD(R8  
        End 
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    End If qfAnMBM1@  
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    'Assign accommodation and pupil diameter & use defaults if field left empty &&jQ4@m}j  
    If dlg.TextBox1 = "" Then FP y}Wc*UA  
        A = 0           'Default accommodation ,QA=)~;D  
    Else $\k)Y(&  
        A = CDbl(dlg.TextBox1) W}7U
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    End If q$H@W.f  
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    If dlg.TextBox2 = "" Then u46Z}~xfb  
        pupilDiam = 4   'Default pupil diameter jpXbFWgN  
    Else ;X+.Ag  
        pupilDiam = CDbl(dlg.TextBox2) ME)='~E  
    End If 4S+E%b|)  
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    Print " " g@t..xJ,  
    Print "Accommodation = " & A & " Diopters" AfZGI'%4[a  
    Print "Pupil Diameter = " & pupilDiam & " mm" 1NTx?JJfW  
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    ' Calculate new parameters with accommodation Mc8_D,7  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness ~ e<,GUx(]  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens HsRoiqo  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens Cnc=GTRi  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens p_zVrlVb  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens lR F5/  
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    tlens = 3.767 + 0.04*A                  'Lens thickness Z,-TMtM7  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction qauvwAMuX  
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    'Adjust parameters to account for accommodation  SN}3  
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    '************************************************************************* 5,O:"3>c  
    'Aqueous thickness (Position of Lens) K0@bh/i/^  
    '************************************************************************* hp7ni1V  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) gC%$)4-:  
    GetCustomElement eID, entity 23+JuXC6>  
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    parID = FindFullName( "Geometry.Arizona Eye" ) !6#.%"{-  
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    ' Delete any shift(s) in z zT!.5qd  
    count = 0 ?}uvpB1}  
    While GetOperationCount(eID)>count *y+K{ fM1  
        GetOperation eID, count, op 31]Vo;D  
        If op.Type="ShiftZ" Then >h9~ /  
            DeleteOperation eID,count =:TQ_>$Nc2  
            count=count-1 QD-Bt=S7l  
        End If l r~>!O  
        count=count+1 'Vhnio;qC  
    Wend ]g%HU%R-m  
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    'Set new shift in x6\^dVR}  
    op.Type = "ShiftZ" ^|!\IzDp  
    op.val1 = taq E1A5<^t  
    op.parent = parID Hg\H>Z  
    AddOperation eID, op ]r#NjP  
    Print "Set aqueous humor thickness = " & taq-0.55 IG%x(\V-e  
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    '************************************************************************* mEb`ET|  
    'Radius and conic constant of anterior lens h,/3}  
    '************************************************************************* 'I[xZu/8yg  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) ~X;sa,)L1+  
    GetConic eID, entity, curv, conic p-z!i+  
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    SetConic eID, entity, 1/Rant, CCant t?;=\%^<  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant L<Z2  
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    '************************************************************************* &Ci_wDJ  
    'Radius and conic constant of posterior lens -H5-6w$  
    '************************************************************************* o 7V&HJ[  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) {D]I[7f8Ev  
    GetConic eID, entity, curv, conic (5RZLRn  
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    SetConic eID, entity, 1/Rpost, CCpost h`tf!MD]  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost Z#GR)
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    '************************************************************************* TP`"x}ACa?  
    'Lens thickness (Position of posterior lens surface) ])zpx-  
    '************************************************************************* )_l(WF.  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) 1u* (=!  
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    ' Delete any z-shift(s) `K2vG`c  
    count = 0 a uve&y"R  
    While GetOperationCount(eID)>count %VrMlG4hx  
        GetOperation eID, count, op #hEU)G'$+  
        If op.Type="ShiftZ" Then You~ 6d6Om  
            DeleteOperation eID,count *m6*sIR  
            count=count-1 /\pUA!G)BD  
        End If NVDv
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        count=count+1 368H6 Jj  
    Wend od3b,Q  
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    'Set new z-shift $bk_%R}s  
    op.Type = "ShiftZ" uVw|jj  
    op.val1 = tlens b]WvKdq  
    op.parent = parID u3PM 7z!~  
    AddOperation eID, op t\ 9Y)d  
    Print "Set lens thickness = " & tlens hnv0Loe.IW  
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    '************************************************************************* A+hT2Ew@t}  
    'Lens index of refraction (`f)Tt=`  
    '************************************************************************* (=s%>lW|  
    eID = FindMaterial( "Lens" ) `u8=~]rblj  
    GetModelMaterial eID, mat D._7)$d  
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    mat.Nd = nlens O
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    SetModelMaterial eID, mat qh wl  
    Print "Set lens index of refraction = " & nlens j<vU[J+gx~  
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    '************************************************************************* wV{VV?h}  
    'Pupil diameter Q,\S3>1n  
    '************************************************************************* PE+{<[n  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) ~rbJtz  
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    'Adjust pupil diameter (trimming volume inner hole) jTok1k  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" ,,Vuvn  
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    ' Adjust pupil location to just in front of the lens MPJ0>Ly  
    parID = FindFullName( "Geometry.Arizona Eye" ) K`cy97  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) zS}!87r)  
    count = 0 lp]q%P  
    While GetOperationCount(eID)>count `)1qq @  
        GetOperation eID, count, op 2!Pwg0%2  
        If op.Type="ShiftZ" Then 7FP @ vng  
            DeleteOperation eID,count qo}u(pOj|  
            count=count-1 z%/<|` 7  
        End If +hMF\@  
        count=count+1 A:,V)  
    Wend #r80FVwiD  
    op.Type = "ShiftZ" 4_vJ_H-mO,  
    op.val1 = taq-0.01 El3Ayd3  
    op.parent = parID M_F4I$V4  
    AddOperation eID, op 9h^TOZK)  
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    Print "Set pupil diameter = " & pupilDiam l65Qk2<YC  
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    'Update AZ Eye subassembly Description 7Y*Q)DDy  
    eID = FindFullName( "Geometry.Arizona Eye" ) :j% B(@b  
    GetEntity eID, entity D?9EO=  
    entity.Description = "Accommodation = " & A & "D" @S Quc  
    SetEntity eID, entity X0%BE!  
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    Update 78u=Jz6  
    Print "DONE!" c}#(,<8X  
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End Sub is=|rY9$  
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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： PAy7b7m~B  
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Accommodation = 4 Diopters vjXCArS  
Pupil Diameter = 4 mm `k'Dm:*`u4  
Set aqueous humor thickness = 2.81 8HH\wu$$e  
Set anterior lens radius = 10.4 and conic constant = -2.375869 W:=CpbwENX  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 b]5S9^=LI  
Set lens thickness = 3.927 R2nDK7j  
Set lens index of refraction = 1.42672 )N]%cO(^  
Set pupil diameter = 4 Z`bo1,6>  
DONE! ju
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