[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 I4UsDs*BD  
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。 u%1JdEWZd  
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模型 Ic&YiATj  
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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。 -y3[\zNe  
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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. Qn-nO_JL  
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光源 Kg /,  
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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。 }&s
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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。 [{&OcEf  
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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。 9j-;-`$S  
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视网膜的散射 LRS,bl3}/  
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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。 )S#?'gt*  
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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。 !g|[A7<|  
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脚本 {`>pigo  
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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： ?a?4;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。 N?A}WW#  
余下的脚本计算与屈光度有关的所有参数。 W55kR.X6M  
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分析 ~~p)_  
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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。 G#E8xA"{/  
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脚本代码 tpgD{BY^wJ  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. U:PtRSdn!b  
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Dim entity As T_ENTITY o?#-Tkb  
Dim op As T_OPERATION V-63   
Dim mat As T_MODELMATERIAL $}0\sj%  
Dim A As Double [8acan+ 2l  
Dim pupilDiam As Double ]\ZmK0q<:  
Dim eID As Long ^ZBTd5t#  
Dim parID As Long a'>n'Y~E  
Dim count As Integer (8NE'd8  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double 3_{rXtT)'  
Dim tlens As Double, nlens As Double H5jk#
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Dim curv As Double, conic As Double j:^gmZ;J  
Dim ok As Long l @E {K|
 
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Sub Main 6mxzE3?G  
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    '用户输入对话框 CRNt5T>qH  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 T*(mi{[T  
        TextBox 220,21,40,21,.TextBox1 'default: 0 >LVGNicQ  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 diK
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        OKButton 40,91,90,21 /f=31<+MtF  
        CancelButton 190,91,90,21 .lSoC`HE  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 nH+wU;M  
        TextBox 220,49,40,21,.TextBox2 'default: 4 I&% Z*H  
    End Dialog g-/ }*ml  
    Dim dlg As UserDialog _.m|Ml,`{  
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    ok = Dialog (dlg) og4mLoLA  
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    If ok=0 Then    'cancel button was pressed !bn=b>+  
        Print "Execution cancelled." sP>-k7K
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        End <(45(6fQ  
    End If +z~bH!$2  
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    'Assign accommodation and pupil diameter & use defaults if field left empty .W\x{h  
    If dlg.TextBox1 = "" Then p$Floubh]  
        A = 0           'Default accommodation I 6L3M\+-  
    Else e=[@HVr   
        A = CDbl(dlg.TextBox1) ^--8 cLB n  
    End If ;[:IC^9fv  
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    If dlg.TextBox2 = "" Then !R[~Z7b6  
        pupilDiam = 4   'Default pupil diameter Vf$$
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    Else qtz~Y~h|>  
        pupilDiam = CDbl(dlg.TextBox2) srS)"Jt  
    End If AO(zl*4  
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    Print " " 
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    Print "Accommodation = " & A & " Diopters" bUuQ"!>ppu  
    Print "Pupil Diameter = " & pupilDiam & " mm" NjO_Y t  
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    ' Calculate new parameters with accommodation @E"lN  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness j.\0p-,  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens Wo5%@C#M  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens \9R=fA18  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens 1c*;Lr.K  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens 4)p ID`  
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    tlens = 3.767 + 0.04*A                  'Lens thickness ]\/"-Y#4Q  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction cG1iO:  
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    'Adjust parameters to account for accommodation
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    '************************************************************************* UMK9[Iy$<M  
    'Aqueous thickness (Position of Lens) DbYnd%k*4  
    '************************************************************************* bicbCC6kC  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) #@E:|^$1y  
    GetCustomElement eID, entity I*n]8c  
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    parID = FindFullName( "Geometry.Arizona Eye" ) mA^3?yj  
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    ' Delete any shift(s) in z 4hkyq>c}  
    count = 0 .S]*A b  
    While GetOperationCount(eID)>count hd`jf97*  
        GetOperation eID, count, op jrX`_Y  
        If op.Type="ShiftZ" Then #JN4K>_4  
            DeleteOperation eID,count /bLL!nD=^  
            count=count-1 0#~k)>(7lR  
        End If f6{.Uq%SGp  
        count=count+1 7W>(T8K X\  
    Wend Uz%ynH  
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    'Set new shift in }[(v(1j='~  
    op.Type = "ShiftZ"  6NSSuK3  
    op.val1 = taq 8EBd`kiq  
    op.parent = parID wn\R|'Rdz  
    AddOperation eID, op sj6LrE=1  
    Print "Set aqueous humor thickness = " & taq-0.55 s}bLA>~Ta  
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    '************************************************************************* ;jBS:k?  
    'Radius and conic constant of anterior lens  SWyJ`  
    '************************************************************************* uavyms^  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) bgkBgugZhX  
    GetConic eID, entity, curv, conic N1"bH~  
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    SetConic eID, entity, 1/Rant, CCant }'Ph^ %ox  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant o'8%5M@  
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    '************************************************************************* zjzEmX  
    'Radius and conic constant of posterior lens Fl}!3k>c  
    '************************************************************************* G2b"R{i/,  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) ja(ZJ[<`  
    GetConic eID, entity, curv, conic j]aIJbi  
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    SetConic eID, entity, 1/Rpost, CCpost b~(S;1NS'  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost IYa(B+nB)  
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    '************************************************************************* fUZCP*7>  
    'Lens thickness (Position of posterior lens surface) MPF({Pnx7  
    '************************************************************************* +fq\K]  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) ,fo7. h4{  
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    ' Delete any z-shift(s) v9(N}hoP  
    count = 0 bfkFk  
    While GetOperationCount(eID)>count -OnKvpeI  
        GetOperation eID, count, op ?~cO\(TY["  
        If op.Type="ShiftZ" Then `
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            DeleteOperation eID,count qOa*JA`  
            count=count-1 w{N8Y~O  
        End If 9fOE.  
        count=count+1 L=P8;Gj)  
    Wend ^==Tv+T9U  
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    'Set new z-shift ?v'CuWS  
    op.Type = "ShiftZ" CIRMAX  
    op.val1 = tlens IoV"t
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    op.parent = parID 5glEV`.je  
    AddOperation eID, op e)3Mg^  
    Print "Set lens thickness = " & tlens G;USVF-'K  
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    '************************************************************************* ZT`" {#L  
    'Lens index of refraction p0}Yo8?OW  
    '************************************************************************* ,'sDauFn  
    eID = FindMaterial( "Lens" ) MYR\W*B'b  
    GetModelMaterial eID, mat h]IoH0/  
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    mat.Nd = nlens A;f)`i0l,  
    SetModelMaterial eID, mat S&;)F|-q  
    Print "Set lens index of refraction = " & nlens $#wi2Ve=6b  
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    '************************************************************************* a FWTm,)  
    'Pupil diameter ::3[H$  
    '************************************************************************* 4`7~~:W!M5  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) ETR7%0$r  
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    'Adjust pupil diameter (trimming volume inner hole) &v9"lR=_k  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" ^}:0\;|N  
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    ' Adjust pupil location to just in front of the lens {xP-p"?p  
    parID = FindFullName( "Geometry.Arizona Eye" ) jP<6Q|5F  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) E;"VI2F  
    count = 0 u!fZ>kS  
    While GetOperationCount(eID)>count W&m3"~BJ  
        GetOperation eID, count, op mXsSOAD<  
        If op.Type="ShiftZ" Then x_l8&RIB*  
            DeleteOperation eID,count w[G-=>;  
            count=count-1 #kJ8 qN  
        End If R1.Yx?  
        count=count+1 ]n$ v ^  
    Wend rERtOgi  
    op.Type = "ShiftZ" Lf{pTxKr  
    op.val1 = taq-0.01 CM`Q((  
    op.parent = parID kpk ^Uw%f  
    AddOperation eID, op r8A'8g4cM  
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    Print "Set pupil diameter = " & pupilDiam TBHd)BhI.  
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    'Update AZ Eye subassembly Description ol_&epG;ST  
    eID = FindFullName( "Geometry.Arizona Eye" ) K5(T7S  
    GetEntity eID, entity -7EwZRS@9  
    entity.Description = "Accommodation = " & A & "D" 472'P  
    SetEntity eID, entity P)ne^_   
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    Update [y<s]C6E  
    Print "DONE!" ]0{,P !  
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End Sub Exat_ L'
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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： ]!@!q
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Accommodation = 4 Diopters ubsx NCqD  
Pupil Diameter = 4 mm XU}" h&>  
Set aqueous humor thickness = 2.81 UG6\OgkL+  
Set anterior lens radius = 10.4 and conic constant = -2.375869 #O'g*]j  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 O /h1ew  
Set lens thickness = 3.927 BpF}H^V-  
Set lens index of refraction = 1.42672 EE qlsH  
Set pupil diameter = 4 9Lqz:4}  
DONE! [c99m:*+  
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