[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 }.O2xZ;}]'  
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。 !L+*.k:  
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模型 Pm6/sO  
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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。 T&I*8 R~  
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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. Jeyy Z=  
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光源 `(<XdlOj  
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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。 LZV  

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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。 W\o(f W  
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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。 $$2\qN -  
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视网膜的散射 B5aFt ;Vj  
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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。 l2U"4d!o  
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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。 &!vJ3:  
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脚本 |S|0'C*  
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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： 1+v&SU  
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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)g=Lew  
余下的脚本计算与屈光度有关的所有参数。 >_(Xb%w  
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分析 r4k=i
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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。 \:]Clvc  
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脚本代码 rlmzbIuI9  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. k{(R.gLZG  
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Dim entity As T_ENTITY )4>M<BO  
Dim op As T_OPERATION (wU<Kpt?J  
Dim mat As T_MODELMATERIAL sxIvL7jl  
Dim A As Double RiqYC3Ka  
Dim pupilDiam As Double :#1{c^i%3  
Dim eID As Long %bgjJ`  
Dim parID As Long m.e+S,i  
Dim count As Integer a7s
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Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double x7)j?2  
Dim tlens As Double, nlens As Double 'd4I/  
Dim curv As Double, conic As Double htX;"R&  
Dim ok As Long 6z=h0,Y}  
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Sub Main ggtGecKm  
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    '用户输入对话框 VTQ V]>|  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 {I0b%>r=  
        TextBox 220,21,40,21,.TextBox1 'default: 0 8+K=3=05#U  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 ~sT/t1Rp  
        OKButton 40,91,90,21 Jn3cU  
        CancelButton 190,91,90,21 'NHtCs=F   
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 g"aWt% P  
        TextBox 220,49,40,21,.TextBox2 'default: 4 <qjNX-|  
    End Dialog jA_wOR7$  
    Dim dlg As UserDialog JoeU J3N  
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    ok = Dialog (dlg) s\i:;`l:=5  
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    If ok=0 Then    'cancel button was pressed "&;8U.  
        Print "Execution cancelled." I
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        End )@+lfIE(l  
    End If 4.il4Qqy}i  
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    'Assign accommodation and pupil diameter & use defaults if field left empty ?}|l )  
    If dlg.TextBox1 = "" Then h!.#r*vV  
        A = 0           'Default accommodation kHLpa/A  
    Else ,p2BB"^_i  
        A = CDbl(dlg.TextBox1) !l
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    End If 8axz`2`  
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    If dlg.TextBox2 = "" Then o zg%-  
        pupilDiam = 4   'Default pupil diameter 0kC}qru'  
    Else Mx?]7tI  
        pupilDiam = CDbl(dlg.TextBox2) xS.Rpx/8  
    End If l{q$[/J~)  
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    Print " " %B9iby8)1  
    Print "Accommodation = " & A & " Diopters" :sO^b*e /  
    Print "Pupil Diameter = " & pupilDiam & " mm" }xhat,9  
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    ' Calculate new parameters with accommodation E.~;  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness 0zH^yx:ma  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens w&&uk[Gh/a  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens w
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens CbPCj.MH  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens ]MI>"hn  
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    tlens = 3.767 + 0.04*A                  'Lens thickness jvfVB'Tmr  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction Mou@G3  
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    'Adjust parameters to account for accommodation -^A
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    '************************************************************************* F\pw0^K;N  
    'Aqueous thickness (Position of Lens) }mGOEG|F2  
    '************************************************************************* 9{OH%bF  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) r]!<iw  
    GetCustomElement eID, entity O[nl#$w  
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    parID = FindFullName( "Geometry.Arizona Eye" ) mX@Un9k  
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    ' Delete any shift(s) in z e[`E-br^  
    count = 0 <9za!.(zu  
    While GetOperationCount(eID)>count ]J=S\  
        GetOperation eID, count, op M:m-iX  
        If op.Type="ShiftZ" Then $`nKq4Y   
            DeleteOperation eID,count sOyWsXd+R'  
            count=count-1 8 I'1~d%$  
        End If |.bp  
        count=count+1 d<*4)MRN  
    Wend .3;bUJ1  
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    'Set new shift in R=D\VIu,Z  
    op.Type = "ShiftZ" 3J\NkaSR  
    op.val1 = taq ]mU,y$IQ  
    op.parent = parID >.R6\>N%  
    AddOperation eID, op xx}R6VKU.  
    Print "Set aqueous humor thickness = " & taq-0.55 id^U%4J  
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    '************************************************************************* Q@3.0Hf|{  
    'Radius and conic constant of anterior lens K;2]c3T  
    '************************************************************************* pv;c<NQ'1  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) Q37VhScs  
    GetConic eID, entity, curv, conic >40B Fxc  
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    SetConic eID, entity, 1/Rant, CCant \!UNale  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant $s2-O!P?  
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    '************************************************************************* 7R\!'`]\M  
    'Radius and conic constant of posterior lens Xco$ yF%  
    '************************************************************************* uCK!lq-  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) ujcS>XN,1  
    GetConic eID, entity, curv, conic 5H6GZ:hp  
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    SetConic eID, entity, 1/Rpost, CCpost +n(H"I7cU  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost ;WIL?[;w  
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    '************************************************************************* D#%J||  
    'Lens thickness (Position of posterior lens surface) A!v-[AI[  
    '************************************************************************* < %Qw dEO  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) w
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    ' Delete any z-shift(s) *8p\.za1  
    count = 0 PF.sM(  
    While GetOperationCount(eID)>count u)P$xkf  
        GetOperation eID, count, op :C42yQAP  
        If op.Type="ShiftZ" Then [BhpfZNKRA  
            DeleteOperation eID,count Y6A]dk  
            count=count-1 @"9y\1u  
        End If Fm}O,=  
        count=count+1 ^&uWAQohL  
    Wend o,) p*glO  
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    'Set new z-shift +ZXGT  
    op.Type = "ShiftZ" 6\86E$f=h  
    op.val1 = tlens 6,G^iv6H  
    op.parent = parID ,Ucb)8a  
    AddOperation eID, op "!)8bTW  
    Print "Set lens thickness = " & tlens eEsEW<su  
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    '************************************************************************* :kZ2N67  
    'Lens index of refraction V`69%35*@  
    '************************************************************************* Ao96[2U6  
    eID = FindMaterial( "Lens" ) 6@2p@eYo  
    GetModelMaterial eID, mat ]CC= \<  
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    mat.Nd = nlens u\qyh9s  
    SetModelMaterial eID, mat S=aXmz<  
    Print "Set lens index of refraction = " & nlens {yyg=AMz  
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    '************************************************************************* Lu:!vTRmw  
    'Pupil diameter Cw{#(x
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    '************************************************************************* 54F([w  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) 4BEVG&Ks  
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    'Adjust pupil diameter (trimming volume inner hole) lRt8{GFy  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" 6lT'%ho}B  
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    ' Adjust pupil location to just in front of the lens `ss]\46>  
    parID = FindFullName( "Geometry.Arizona Eye" ) 6%S>~L66  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) LR)is  
    count = 0 y6*i/3  
    While GetOperationCount(eID)>count 66L*6O4  
        GetOperation eID, count, op {bETHPCf  
        If op.Type="ShiftZ" Then q/OraPAB  
            DeleteOperation eID,count r~s03g0  
            count=count-1 3C,e>zE}  
        End If OD1ns  
        count=count+1 1}jE?{V*  
    Wend ^|sxbP  
    op.Type = "ShiftZ" dN*<dz+4r  
    op.val1 = taq-0.01 2:DpnLU5  
    op.parent = parID M2xUs  
    AddOperation eID, op T[Gz  
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    Print "Set pupil diameter = " & pupilDiam {iQ<`,)Y  
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    'Update AZ Eye subassembly Description 0>e>G(4(8  
    eID = FindFullName( "Geometry.Arizona Eye" ) %!.rP  
    GetEntity eID, entity VGvOwd)E  
    entity.Description = "Accommodation = " & A & "D" S?3{G@!  
    SetEntity eID, entity a|s=d  
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    Update =kc{Q@Dk  
    Print "DONE!" Gc 8  
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End Sub rLKDeB  
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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： wUV%NZB  
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Accommodation = 4 Diopters / 9;Pbxn  
Pupil Diameter = 4 mm {W4t]Ff  
Set aqueous humor thickness = 2.81 7I44BC*R~  
Set anterior lens radius = 10.4 and conic constant = -2.375869 YJL=|v   
Set posterior lens radius = -4.424557 and conic constant = -3.081019 l|up3A3)  
Set lens thickness = 3.927 pF!vW  
Set lens index of refraction = 1.42672 aEM#V  
Set pupil diameter = 4 cXCczqabv  
DONE! RI*%\~6t?  
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