[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 
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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。 =_Rd0,  
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模型 <*P1Sd.  
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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。 xmDwoLU  
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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. 65v'/m!ys  
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光源 G)Y!aX  
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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。 iKwVYL
 
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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。 m\yO/9{h1  
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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]QkZg2?Yn  
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视网膜的散射 PLD!BD  
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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。 N@}U;x}  
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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。 `Oi@7/oT  
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脚本 yAOC<d9 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： ?~!h N,h  
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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。 x{rt\OT  
余下的脚本计算与屈光度有关的所有参数。 04s N4C  
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分析 M
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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。 #r1x0s40D  
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脚本代码 k@w&$M{tPF  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. z, OMR`W  
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Dim entity As T_ENTITY "783F:mPh  
Dim op As T_OPERATION B7#;tCf  
Dim mat As T_MODELMATERIAL Uc4r  
Dim A As Double !MbRI  
Dim pupilDiam As Double ' |4XyU=  
Dim eID As Long '@$?A>.cj  
Dim parID As Long F?UL0Q|uv  
Dim count As Integer oR+Fn}mG  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double p'H5yg3h  
Dim tlens As Double, nlens As Double 7l?=$q>k"  
Dim curv As Double, conic As Double ?}W:DGudZ  
Dim ok As Long w(vf>L6(
 
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Sub Main |Oo WGVc  
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    '用户输入对话框 8'zwyd3  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 @FQ@*XD  
        TextBox 220,21,40,21,.TextBox1 'default: 0 9U+^8,5  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 2-$R@ SVy  
        OKButton 40,91,90,21 ]|-y[iu  
        CancelButton 190,91,90,21 ^0r@",  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 Cnn,$R=/s  
        TextBox 220,49,40,21,.TextBox2 'default: 4 9Vp$A$7M  
    End Dialog "DUL} "5T  
    Dim dlg As UserDialog ddw!FH2W (  
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    ok = Dialog (dlg) +'[iyHBJ  
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    If ok=0 Then    'cancel button was pressed a1?Y7(alPU  
        Print "Execution cancelled." jildi
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        End b7\nCRY  
    End If Sna7r~j  
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    'Assign accommodation and pupil diameter & use defaults if field left empty poM VB{U  
    If dlg.TextBox1 = "" Then nF7Ozxm#  
        A = 0           'Default accommodation 5^%FEZ&Sp  
    Else ^D!UF(H  
        A = CDbl(dlg.TextBox1) ^fRA$t  
    End If r1,RloyZS  
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    If dlg.TextBox2 = "" Then {~Phc 2z  
        pupilDiam = 4   'Default pupil diameter J H6\;G6  
    Else $[IuEdc/  
        pupilDiam = CDbl(dlg.TextBox2) IuRKj8J)o  
    End If e\\ I,  
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    Print " " w@hm>6j  
    Print "Accommodation = " & A & " Diopters"  M*%iMz  
    Print "Pupil Diameter = " & pupilDiam & " mm" qF>}"m  
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    ' Calculate new parameters with accommodation 9HWtdJ+^C=  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness %h3CQk  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens =T9QmEBm  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens YrA#NTB_o  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens iQ:]1H s  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens ~Q5L)}8N  
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    tlens = 3.767 + 0.04*A                  'Lens thickness `NrxoU=  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction CmM K\R.  
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    'Adjust parameters to account for accommodation k|1/gd5  
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    '************************************************************************* gaVWfG  
    'Aqueous thickness (Position of Lens) 9=Y-w s  
    '************************************************************************* .#P'NF(5#  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) {73Z$w1%  
    GetCustomElement eID, entity @MTm8E6au  

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    parID = FindFullName( "Geometry.Arizona Eye" ) 6!O~:\`DJ  
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    ' Delete any shift(s) in z A@+pv
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    count = 0 ~`(#sjr6KR  
    While GetOperationCount(eID)>count "4|D"|wI)  
        GetOperation eID, count, op o|$l+TC  
        If op.Type="ShiftZ" Then j$siCsF  
            DeleteOperation eID,count *JUP~/Nr  
            count=count-1 <OCy  
        End If b v~"_)C  
        count=count+1 cd#@"&r  
    Wend vEk jd#  
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    'Set new shift in ma,H<0R  
    op.Type = "ShiftZ" C8%q?.nH=  
    op.val1 = taq pq*W;6(-  
    op.parent = parID 0
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    AddOperation eID, op ;i@,TU  
    Print "Set aqueous humor thickness = " & taq-0.55 ilHZx2k  
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    '************************************************************************* LW 8LD|@  
    'Radius and conic constant of anterior lens ~A(fn
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    '************************************************************************* l`4hWs\I  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) _f8Wa u# "  
    GetConic eID, entity, curv, conic p<: b
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    SetConic eID, entity, 1/Rant, CCant '1_CMr  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant \ym3YwP4/:  
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    '************************************************************************* K1Snag  
    'Radius and conic constant of posterior lens _?]bd-E  
    '************************************************************************* 8XIG<Nc  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) ;*Ldnj;B  
    GetConic eID, entity, curv, conic gi#bU  
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    SetConic eID, entity, 1/Rpost, CCpost ]
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    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost | U)  
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    '************************************************************************* 7j| ^ZuI+  
    'Lens thickness (Position of posterior lens surface) ZxFRE#y~2  
    '************************************************************************* t2uX+1F  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) )!z<q}i5  
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    ' Delete any z-shift(s) V(3^ev/  
    count = 0 T)?:
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    While GetOperationCount(eID)>count MH7 n@.t  
        GetOperation eID, count, op "
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        If op.Type="ShiftZ" Then <[Oe.0SGu  
            DeleteOperation eID,count H]As2$[  
            count=count-1 !tJQ75Hwv  
        End If 1fUg  
        count=count+1 (?4m0Sn>#h  
    Wend 0}H7Xdkp  
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    'Set new z-shift |C"(K-do  
    op.Type = "ShiftZ" (dmLEt  
    op.val1 = tlens &y_Ya%Z3*e  
    op.parent = parID "sh*,K5x|  
    AddOperation eID, op `Y]t*` e|  
    Print "Set lens thickness = " & tlens [}:;B$,  
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    '************************************************************************* )}w2'(!X8  
    'Lens index of refraction ?TTtGbvU  
    '************************************************************************* t$~CLq5ad  
    eID = FindMaterial( "Lens" ) m'HAt~  
    GetModelMaterial eID, mat _[F(8Qx"  
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    mat.Nd = nlens bji5X')~#  
    SetModelMaterial eID, mat [>--U)/  
    Print "Set lens index of refraction = " & nlens 69< <pm,m  
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    '************************************************************************* <OgwA$abl%  
    'Pupil diameter Ql>bsr}  
    '************************************************************************* P! cfe@;<4  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) /vgEDw  
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    'Adjust pupil diameter (trimming volume inner hole) 0MpZdJ  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" R` g'WaDk  
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    ' Adjust pupil location to just in front of the lens _\&vA5-  
    parID = FindFullName( "Geometry.Arizona Eye" ) 2nra@  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) wCQ.?*7-9Q  
    count = 0  GY`mF1b  
    While GetOperationCount(eID)>count xQUs
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        GetOperation eID, count, op 2P,%}Ms  
        If op.Type="ShiftZ" Then d)>b/0CZ  
            DeleteOperation eID,count u~c75Mk_v  
            count=count-1 kF]sy8u]  
        End If f?JP=j  
        count=count+1 mY=Q#nG  
    Wend 8yCt(ms  
    op.Type = "ShiftZ" _w}l,   
    op.val1 = taq-0.01 MD98N{+[|  
    op.parent = parID mP*Ct6628n  
    AddOperation eID, op #nq$^H  
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    Print "Set pupil diameter = " & pupilDiam 9QP-~V{$  
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    'Update AZ Eye subassembly Description 6L<Y   
    eID = FindFullName( "Geometry.Arizona Eye" ) u_HCXpP!Q  
    GetEntity eID, entity ]A=yj@o$xN  
    entity.Description = "Accommodation = " & A & "D" w%1-_;.aU6  
    SetEntity eID, entity
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    Update d%Ls'[Y^_0  
    Print "DONE!" 3p1U,B}  
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End Sub b9;w3Ba  
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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： HT:V;?"  
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Accommodation = 4 Diopters ;RK;kdZ  
Pupil Diameter = 4 mm i&TWIl8  
Set aqueous humor thickness = 2.81 XvSng"f.  
Set anterior lens radius = 10.4 and conic constant = -2.375869 ?WP*At0  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 gb{8SG5ac  
Set lens thickness = 3.927 lFtH;h,==v  
Set lens index of refraction = 1.42672 G\z5Ue*  
Set pupil diameter = 4 dOT7;@  
DONE! 4_P6P  
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