[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 @dKf]&h%%  
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。 !9cPNIi  
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模型 ^yZSCrPGI  
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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。 F"#*8P  
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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. %7wzGtM]ps  
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光源 8A]q!To  
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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。 61wG:  
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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。 kV%y%l(6  
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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。 s"F,=]HQ!G  
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视网膜的散射 GuDD7~qxY  
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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。 2p.+C35c=j  

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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。 |8+rUFkU8  
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脚本 1:V/['|*g)  
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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：
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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。 aq**w?l  
余下的脚本计算与屈光度有关的所有参数。 fP*C*4#X  
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分析 qo![#s  
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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。 ~.SU$  
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脚本代码 E_*T0&P.P  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. 6n4S$a  
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Dim entity As T_ENTITY !2,.C+,  
Dim op As T_OPERATION <m\TZQBD  
Dim mat As T_MODELMATERIAL &$ 9bC't6  
Dim A As Double s@9#hjv2  
Dim pupilDiam As Double P=g+6-1  
Dim eID As Long $x<-PN  
Dim parID As Long (9h{6rc=I  
Dim count As Integer w%"q=V  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double yw^,@'  
Dim tlens As Double, nlens As Double }?$Mh)  
Dim curv As Double, conic As Double riQ?'!a7  
Dim ok As Long ![Y$[l  
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Sub Main ~'Hwszpb  
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    '用户输入对话框 4cL=f  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 34:=A0z  
        TextBox 220,21,40,21,.TextBox1 'default: 0 dDTt_B  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 w-m2N-"='  
        OKButton 40,91,90,21 QX/`s3N  
        CancelButton 190,91,90,21 U^S0H(>  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 xr-scdh2  
        TextBox 220,49,40,21,.TextBox2 'default: 4 P#]jPW  
    End Dialog jKs8i$q  
    Dim dlg As UserDialog v?t+%|dzA  
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    ok = Dialog (dlg) gqamGLK  
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    If ok=0 Then    'cancel button was pressed }s9J+m  
        Print "Execution cancelled." O\z%6:'M  
        End SJmri]4K  
    End If @A%`\Ea%   
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    'Assign accommodation and pupil diameter & use defaults if field left empty jLU)S)  
    If dlg.TextBox1 = "" Then XPSWAp)  
        A = 0           'Default accommodation IB<ihk
  
    Else "O{sdVS  
        A = CDbl(dlg.TextBox1) G"(!5+DLy  
    End If ?6
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    If dlg.TextBox2 = "" Then mE1*F'0a  
        pupilDiam = 4   'Default pupil diameter 
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    Else -`JY] H  
        pupilDiam = CDbl(dlg.TextBox2) 0!T $Ef  
    End If Yp$lc^)c>  
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    Print " " ]H*=Z:riu  
    Print "Accommodation = " & A & " Diopters" +Y+kx"8  
    Print "Pupil Diameter = " & pupilDiam & " mm" {WChD&v  
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    ' Calculate new parameters with accommodation a7ty&[\  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness ] N8V?.|:  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens Z~ (QV0}  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens 8^~]Ym:  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens P^z)]K#sw  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens )Lq FZ~B  
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    tlens = 3.767 + 0.04*A                  'Lens thickness bk2vce&  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction sj1x>  
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    'Adjust parameters to account for accommodation `Bx CTwc  
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    '************************************************************************* I[/u5V_b'  
    'Aqueous thickness (Position of Lens) l?d*g&  
    '************************************************************************* 6[i-Tl  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) "Y6f.rB  
    GetCustomElement eID, entity sSxra!tv4  
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    parID = FindFullName( "Geometry.Arizona Eye" ) *Co+UJjT  
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    ' Delete any shift(s) in z {|50&]m  
    count = 0 !^%b|=[  
    While GetOperationCount(eID)>count :'03*A_[  
        GetOperation eID, count, op k&*=:y}  
        If op.Type="ShiftZ" Then MZ.Jk
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            DeleteOperation eID,count N6eY-`4y  
            count=count-1 Ngr7E  
        End If z\a#"2(G.  
        count=count+1 gs'(px  
    Wend eG<
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    'Set new shift in Y,{Xv  
    op.Type = "ShiftZ" 4IVCTz[  
    op.val1 = taq Q[ IaA"  
    op.parent = parID My)/d]a  
    AddOperation eID, op 9tJiIr8i  
    Print "Set aqueous humor thickness = " & taq-0.55 ^K8Ey#T  
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    '*************************************************************************
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    'Radius and conic constant of anterior lens dS-
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    '************************************************************************* qzXch["So  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) d)LifsD)  
    GetConic eID, entity, curv, conic 7yKadM~)  
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    SetConic eID, entity, 1/Rant, CCant Pm-@ZZ~  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant <X:7$v6T|  
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    '************************************************************************* (%".=x-  
    'Radius and conic constant of posterior lens tH$Z_(5  
    '************************************************************************* l+@NjZGm<  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) >-Jutr<I"~  
    GetConic eID, entity, curv, conic m}k rG  
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    SetConic eID, entity, 1/Rpost, CCpost yB&s2J  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost I-^Y$6-  
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    '************************************************************************* Rv }e+5F  
    'Lens thickness (Position of posterior lens surface) \ ^_3Yw  
    '************************************************************************* `6'fX[j5  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) \S _ycn  
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    ' Delete any z-shift(s) YOqBIbp~&)  
    count = 0 U:p<pTnMR  
    While GetOperationCount(eID)>count XvWUJ6M  
        GetOperation eID, count, op wPOQy~:  
        If op.Type="ShiftZ" Then zUWu5JI  
            DeleteOperation eID,count ^+I{*0{/[  
            count=count-1 , j7&(V~  
        End If b:oB $E  
        count=count+1 v#F
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    Wend *?cE]U6;  
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    'Set new z-shift %kUIIHV}  
    op.Type = "ShiftZ" nF]lSg&]X  
    op.val1 = tlens ^2=11  
    op.parent = parID [+UF]m%W  
    AddOperation eID, op Ft'?43J  
    Print "Set lens thickness = " & tlens *1|&uE&_R  
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    '************************************************************************* 3nMXfh/  
    'Lens index of refraction ?!KqDI  
    '************************************************************************* }}@xx&  
    eID = FindMaterial( "Lens" ) cE'MSB  
    GetModelMaterial eID, mat Cjdw@v0;  
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    mat.Nd = nlens It&$R`k  
    SetModelMaterial eID, mat !;>j(xc  
    Print "Set lens index of refraction = " & nlens e2~&I`ct  
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    '************************************************************************* [WW3'= e^  
    'Pupil diameter sk6C/ '0:  
    '************************************************************************* P`0}( '"U  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) v25]}9/C  
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    'Adjust pupil diameter (trimming volume inner hole) )cxLpTr  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" _NA[g:DZ&O  
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    ' Adjust pupil location to just in front of the lens UU~S{!*+L  
    parID = FindFullName( "Geometry.Arizona Eye" ) S}WQ~e  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) e'Njl?>3  
    count = 0 teIUSB[  
    While GetOperationCount(eID)>count ):-\TVz~  
        GetOperation eID, count, op Wb4+U;C^!'  
        If op.Type="ShiftZ" Then 8iQ8s;@S&>  
            DeleteOperation eID,count _HjS!(lMk  
            count=count-1 Xy0*1$IS]  
        End If p,0J $L  
        count=count+1 h)7hk*I  
    Wend [TRHcz n  
    op.Type = "ShiftZ" ai0am  
    op.val1 = taq-0.01 d.>Zn?u4L  
    op.parent = parID &V"9[0  
    AddOperation eID, op \\}tD@V"  
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    Print "Set pupil diameter = " & pupilDiam :Aq==N_/
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    'Update AZ Eye subassembly Description {{N*/E^  
    eID = FindFullName( "Geometry.Arizona Eye" ) _!_%A
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    GetEntity eID, entity  vf}.)  
    entity.Description = "Accommodation = " & A & "D" <l>o6K  
    SetEntity eID, entity Y~,ZBl,  
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    Update LlbRr.wL  
    Print "DONE!" x:dI:G  
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End Sub 3;v%78[&P  
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如果屈光度是4，光瞳直径是4，则会输出如下数据： t:$^iUrx  
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Accommodation = 4 Diopters pd%h5|*n;  
Pupil Diameter = 4 mm A*b>@>2  
Set aqueous humor thickness = 2.81 mLGbwm'K  
Set anterior lens radius = 10.4 and conic constant = -2.375869 9S<g2v  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 D^dos`L0b  
Set lens thickness = 3.927 U]Pl` =SL  
Set lens index of refraction = 1.42672 o!$O+%4  
Set pupil diameter = 4 ']Z1nb  
DONE! lD+f{GR  
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