[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 }>w  
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。 QO7:iSZJ  
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模型 ],YYFU}  
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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。 xI: 'Hk1  
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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. BXo|CITso  
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光源 e87- B1`  
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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。 N &[,nUd  
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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。 2E2}|: ||&  
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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。 =b!J)]  
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视网膜的散射 lZM3Q58?\  
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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。 ]kkBgjQbS  
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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。 6eT'[Umx  
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脚本 T#n1@FgC  
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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： kr(<Y|  
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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。 cN WcNMm  
余下的脚本计算与屈光度有关的所有参数。 6#)Jl  
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分析 cvUut^CdK  
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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。 J`q}Ry;  
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脚本代码 P$3=i`X!nw  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. gXu^"  
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Dim entity As T_ENTITY :Jeo_}e 0  
Dim op As T_OPERATION f5aF6FBH  
Dim mat As T_MODELMATERIAL $}nh[@  
Dim A As Double x$n~f:1Y  
Dim pupilDiam As Double =~hsKBt*  
Dim eID As Long c',:@2R  
Dim parID As Long +^*5${g;@H  
Dim count As Integer {@V3?pG?p  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double )@,90Vhh  
Dim tlens As Double, nlens As Double t@(9ga(  
Dim curv As Double, conic As Double l#b|@4:I  
Dim ok As Long WBr:|F+~s  
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Sub Main )[^y t0%  
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    '用户输入对话框 S\9t4Ki_'  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 {OO*iZ.O  
        TextBox 220,21,40,21,.TextBox1 'default: 0 E69:bQ94u  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 -R&E,X7N  
        OKButton 40,91,90,21 N^\2 _T  
        CancelButton 190,91,90,21 +YkW[a\4  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 A mI>m  
        TextBox 220,49,40,21,.TextBox2 'default: 4 0+}EA[  
    End Dialog (Pv`L  
    Dim dlg As UserDialog {N!E5*$Tr  
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    ok = Dialog (dlg) >gk z4.*  
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    If ok=0 Then    'cancel button was pressed ;8*XOC;[  
        Print "Execution cancelled." ,-(T"Ph<  
        End _8Nw D_"  
    End If UzgA26;  
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    'Assign accommodation and pupil diameter & use defaults if field left empty ;&Bna#~B  
    If dlg.TextBox1 = "" Then 1BQ0M{&  
        A = 0           'Default accommodation c62dorDqy  
    Else xF( bS+(o  
        A = CDbl(dlg.TextBox1) A*8m8Sh$  
    End If e1 x^PT  
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    If dlg.TextBox2 = "" Then fJN*s  
        pupilDiam = 4   'Default pupil diameter O^9CV*]!n  
    Else iq"ob8.  
        pupilDiam = CDbl(dlg.TextBox2) E X%6''ys  
    End If TB7>s~)47E  
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    Print " " 4_PCqEp)  
    Print "Accommodation = " & A & " Diopters" Ih.rC>)rx  
    Print "Pupil Diameter = " & pupilDiam & " mm" *16<M)7  
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    ' Calculate new parameters with accommodation qWsylC23  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness z Yw;q3"  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens O: ,$%  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens eV"!/A2:N5  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens `|$'g^eCL  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens E7Ibp79}N  
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    tlens = 3.767 + 0.04*A                  'Lens thickness 9G0D3F  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction AXwaVLEBQ  
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    'Adjust parameters to account for accommodation 3&'2aW  
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    '************************************************************************* hd+]Ok7"  
    'Aqueous thickness (Position of Lens) #/Ruz'H1>  
    '************************************************************************* wV(AT$  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) $
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    GetCustomElement eID, entity
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    parID = FindFullName( "Geometry.Arizona Eye" ) a1Hz3y~S/  
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    ' Delete any shift(s) in z UuU/c-.  
    count = 0 X) V7bVW  
    While GetOperationCount(eID)>count <,"4k&0Q>V  
        GetOperation eID, count, op zh\p  
        If op.Type="ShiftZ" Then M=OCzgj  
            DeleteOperation eID,count 8S\RN&T$  
            count=count-1 ,57$N&w  
        End If f-Jbs`(+  
        count=count+1 ,7W:fwdR  
    Wend ~#R9i^Y  
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    'Set new shift in ? B@&#E!/f  
    op.Type = "ShiftZ" : [q0S@  
    op.val1 = taq Mi+H#xx16  
    op.parent = parID e  ^Ds  
    AddOperation eID, op Mp~y0e  
    Print "Set aqueous humor thickness = " & taq-0.55 `K*b?:0lp  
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    '************************************************************************* ~vHk
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    'Radius and conic constant of anterior lens cvnB!$eji  
    '************************************************************************* O*[{z)M.  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) F/p,j0S  
    GetConic eID, entity, curv, conic /kgeV4]zR  
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    SetConic eID, entity, 1/Rant, CCant y}FZD?"  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant u:&o}[  
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    '************************************************************************* {Z> M  
    'Radius and conic constant of posterior lens ^Dg<Ki  
    '************************************************************************* ]5}=^  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) u7fK1
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    GetConic eID, entity, curv, conic W3r?7!~  
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    SetConic eID, entity, 1/Rpost, CCpost nOb?-rR  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost qH>`}/,P  
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    '************************************************************************* xe4Oxo  
    'Lens thickness (Position of posterior lens surface) hA}~es=c  
    '************************************************************************* Ml?~ |_  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) /P:.qtT(  
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    ' Delete any z-shift(s) x}TS  
    count = 0 =-KMb`xT  
    While GetOperationCount(eID)>count fpWg R4__  
        GetOperation eID, count, op !}f1`/   
        If op.Type="ShiftZ" Then ~
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            DeleteOperation eID,count {sVY`}p|  
            count=count-1 p5\]5bb  
        End If t23'x0l  
        count=count+1 l[Q:}y  
    Wend +k\Uf*wh  
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    'Set new z-shift 1PH:\0}  
    op.Type = "ShiftZ" <eN_1NTH_  
    op.val1 = tlens oVvc?P  
    op.parent = parID r%@Lej5+  
    AddOperation eID, op "{D6J809  
    Print "Set lens thickness = " & tlens \Q~8?p+  
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    '************************************************************************* 2I/xJ+  
    'Lens index of refraction kDvc" ,SD#  
    '************************************************************************* 5U`ZbG  
    eID = FindMaterial( "Lens" ) =,y |00l  
    GetModelMaterial eID, mat JyLa#\ R  
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    mat.Nd = nlens n">u mM;Eh  
    SetModelMaterial eID, mat 1Xu?(2;NF  
    Print "Set lens index of refraction = " & nlens q h/F  
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    '************************************************************************* E/M_lvQ
 
    'Pupil diameter A4C+5R  
    '************************************************************************* x5}'7
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    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) Byl^?5  
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    'Adjust pupil diameter (trimming volume inner hole) Tm}rH]F&  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" cH' iA.  
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    ' Adjust pupil location to just in front of the lens o?L'Pg  
    parID = FindFullName( "Geometry.Arizona Eye" ) N|N3x7=gs  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) {7u[1[L1  
    count = 0 S$)*&46g  
    While GetOperationCount(eID)>count $rIoHxh. y  
        GetOperation eID, count, op 3@+b}9s8  
        If op.Type="ShiftZ" Then ]aP=Ks%  
            DeleteOperation eID,count K 0gI):  
            count=count-1 ]i(-I <`  
        End If SIO&rrT.  
        count=count+1 Y8M]Lwj  
    Wend *IgE
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    op.Type = "ShiftZ" |-sPLU&s%  
    op.val1 = taq-0.01 Zl 9aDg  
    op.parent = parID E)Gw0]G  
    AddOperation eID, op j',W 64  
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    Print "Set pupil diameter = " & pupilDiam W} WI; cI  
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    'Update AZ Eye subassembly Description `&\Q +W  
    eID = FindFullName( "Geometry.Arizona Eye" ) T134ZXqqz  
    GetEntity eID, entity 8fA_p}wp  
    entity.Description = "Accommodation = " & A & "D" Z^ }mp@j>  
    SetEntity eID, entity f}g\D#`]/  
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    Update Uc/+gz Z;  
    Print "DONE!" 4tL<q_  
    
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End Sub J+rC
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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： l/;X?g5+  
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Accommodation = 4 Diopters UOQEk22  
Pupil Diameter = 4 mm ;iDPn2?6?x  
Set aqueous humor thickness = 2.81 pv|Pm  
Set anterior lens radius = 10.4 and conic constant = -2.375869 NM ]bgpP  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 93t9^9  
Set lens thickness = 3.927 dJ"iEb|4  
Set lens index of refraction = 1.42672 %$%&m1Y  
Set pupil diameter = 4 h-iJlm  
DONE! +`3!I  
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