[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 P'OvwA  
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。 0=3)`v{S@  
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模型 -grf7w^  
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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。 J??AU0vh  
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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. \ m~?yq8H  
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光源 ]<f(@]R/d  
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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。 ap}p?r  
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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。 Cn3_D  
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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。 $N)G:=M!s  
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视网膜的散射 v>} +->f  
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在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 '^_u5Y]  
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注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 70c]|5  
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脚本 @Uez2?  
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内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： mg'q-G`\<  
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如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 l}z<q  
余下的脚本计算与屈光度有关的所有参数。 Bxm,?=h  
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分析 nL:&G'd  
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屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 Kt_oo[ey{  
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脚本代码 sh$-}1 ;  

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Option Explicit     'Remove this to enable non-dimensioned variables to be used. ?N<My&E  
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Dim entity As T_ENTITY 2@zduL'do_  
Dim op As T_OPERATION /]TNEU,K  
Dim mat As T_MODELMATERIAL h4pS~/  
Dim A As Double c 3QgX4vq  
Dim pupilDiam As Double !'jq.RawP  
Dim eID As Long CjQO5  
Dim parID As Long 'V:Q :  
Dim count As Integer K?^;|m-  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double n(F!t,S1i  
Dim tlens As Double, nlens As Double @N>7+ 4  
Dim curv As Double, conic As Double .zO2g8(VR  
Dim ok As Long d+JK")$9C  
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Sub Main
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    '用户输入对话框 >D,Oav  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 15g!Q *v  
        TextBox 220,21,40,21,.TextBox1 'default: 0 !wy _3a
 
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 M5`v^>  
        OKButton 40,91,90,21 "<ZV'z  
        CancelButton 190,91,90,21 gpV4qDXV  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 [A-_?#cZ  
        TextBox 220,49,40,21,.TextBox2 'default: 4 nj[TTndJt  
    End Dialog Yr9'2.%Q  
    Dim dlg As UserDialog JtL>mH  
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    ok = Dialog (dlg) 2Xt4Rqk$  
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    If ok=0 Then    'cancel button was pressed (u,)v_Oo]a  
        Print "Execution cancelled." 7AqgX0)  
        End x>#{C,Fi  
    End If ]" 'yf;g  
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    'Assign accommodation and pupil diameter & use defaults if field left empty Lzh8-d=HQ  
    If dlg.TextBox1 = "" Then w+br)  
        A = 0           'Default accommodation .G8`Ut Z  
    Else )0"Q h  
        A = CDbl(dlg.TextBox1) cbzA`b'Mg  
    End If k"N>pjgd$  
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    If dlg.TextBox2 = "" Then sU_K^=6*  
        pupilDiam = 4   'Default pupil diameter PF{uaKWk  
    Else w$}q`k'  
        pupilDiam = CDbl(dlg.TextBox2) /7AHd ;  
    End If > G\0Z[<v,  
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    Print " " @Kpm&vd(  
    Print "Accommodation = " & A & " Diopters" sf> E  
    Print "Pupil Diameter = " & pupilDiam & " mm" KYFKH+d>m  
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    ' Calculate new parameters with accommodation UUt"8]@[  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness 2.q Zs8&  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens `0d0T~  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens /UCBoQ$/]  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens uF7vba$  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens O=0p}{3l  
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    tlens = 3.767 + 0.04*A                  'Lens thickness Y 6a`{'  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction r&u1-%%9[  
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    'Adjust parameters to account for accommodation q*hn5K*  
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    '************************************************************************* t~+M>Fjm?d  
    'Aqueous thickness (Position of Lens) =M\yh,s!  
    '************************************************************************* fv;Q*; oC&  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) ,1-%C)  
    GetCustomElement eID, entity 14,)JZN  
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    parID = FindFullName( "Geometry.Arizona Eye" ) (m/:B=K  
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    ' Delete any shift(s) in z Hv/C40
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    count = 0 r:QLU]   
    While GetOperationCount(eID)>count A4j,]hOD  
        GetOperation eID, count, op |~9rak,  
        If op.Type="ShiftZ" Then vXJs.)D7  
            DeleteOperation eID,count dwA"QVp{  
            count=count-1 zEQ]5>mG  
        End If mF6-f#t>H+  
        count=count+1 /X}1%p  
    Wend ql?w6qFs]  
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    'Set new shift in bmT%?it  
    op.Type = "ShiftZ" 5wK==hZ  
    op.val1 = taq N_%@_$3G]  
    op.parent = parID 4H

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    AddOperation eID, op }&v}S6T  
    Print "Set aqueous humor thickness = " & taq-0.55 \mb4leg5  
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    '************************************************************************* &9e  
    'Radius and conic constant of anterior lens X@~/.H5  
    '************************************************************************* pMU\f  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) dle\}Sy=  
    GetConic eID, entity, curv, conic a~2Jf @I3  
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    SetConic eID, entity, 1/Rant, CCant O"\4[HE^  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant o$@/@r  
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    '************************************************************************* $QiMA,  
    'Radius and conic constant of posterior lens B>u`%Ry&  
    '************************************************************************* -@AhJY.  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) tB;PGk_6  
    GetConic eID, entity, curv, conic h7]+#U]mi
 
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    SetConic eID, entity, 1/Rpost, CCpost f1NHW|_j  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost |gkNhxzB  
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    '************************************************************************* g$Tsht(rHD  
    'Lens thickness (Position of posterior lens surface) u>fs yn9c  
    '************************************************************************* \>$zxC_  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) ww|fqx?  
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    ' Delete any z-shift(s) dV$[O`F*b  
    count = 0 *)[fGxz \  
    While GetOperationCount(eID)>count 3]S*p ErY  
        GetOperation eID, count, op oyVT  
        If op.Type="ShiftZ" Then QMMpB{FZ`o  
            DeleteOperation eID,count uGAQt9$>_  
            count=count-1 TTG=7x:3  
        End If F-kjv\  
        count=count+1 -~z@W3\  
    Wend ?g1eW q&  
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    'Set new z-shift Y
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    op.Type = "ShiftZ" %LnLB  
    op.val1 = tlens B1X&O d  
    op.parent = parID X -1r$.
  
    AddOperation eID, op WD4"ft  
    Print "Set lens thickness = " & tlens zd_N' :6  
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    '************************************************************************* MTt8O+J?P~  
    'Lens index of refraction C.4(8~Y=~  
    '************************************************************************* wQW`Er3w  
    eID = FindMaterial( "Lens" ) Bc!<!  
    GetModelMaterial eID, mat Gd!_9S`68  
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    mat.Nd = nlens pg5W`
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    SetModelMaterial eID, mat ~{DJ,(N"n  
    Print "Set lens index of refraction = " & nlens Dp['U
  
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    '************************************************************************* W,8Uu1X =  
    'Pupil diameter x`?>j$  
    '************************************************************************* +PPQ"#1pS  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) Z7wl~Hk  
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    'Adjust pupil diameter (trimming volume inner hole) ](I||JJa9f  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" M_0f{  
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    ' Adjust pupil location to just in front of the lens tF[)Y#  
    parID = FindFullName( "Geometry.Arizona Eye" ) `C_qqf  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) Na`> pH  
    count = 0 ~F@p}u8TV  
    While GetOperationCount(eID)>count v$\<L|  
        GetOperation eID, count, op S/Ic=  
        If op.Type="ShiftZ" Then KrP?*yk  
            DeleteOperation eID,count !0pK8k&MG  
            count=count-1 RaLV@>jPm  
        End If xd `MEOY  
        count=count+1 UNSXr`9  
    Wend 8(ZQM01;  
    op.Type = "ShiftZ" h@JX?LzZS  
    op.val1 = taq-0.01 -[N9"Z,  
    op.parent = parID (k+*0.T&?  
    AddOperation eID, op FzOWM7+\  
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    Print "Set pupil diameter = " & pupilDiam ,e|"p[z~T  
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    'Update AZ Eye subassembly Description Z=$-S(>J  
    eID = FindFullName( "Geometry.Arizona Eye" ) 0"j:-1  
    GetEntity eID, entity FD!8
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    entity.Description = "Accommodation = " & A & "D" ;\|GU@K{hC  
    SetEntity eID, entity $S>bcsAy  
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    Update ;k0Jl0[}  
    Print "DONE!" m*1  
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End Sub hrJ(][8  
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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： J e|  
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Accommodation = 4 Diopters C ]B P}MY<  
Pupil Diameter = 4 mm %yc-D]P/  
Set aqueous humor thickness = 2.81 7L:Eg  
Set anterior lens radius = 10.4 and conic constant = -2.375869 QiA}0q3]0  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 5'DY)s-K  
Set lens thickness = 3.927 ~u!V_su]GY  
Set lens index of refraction = 1.42672 IlO,Ql  
Set pupil diameter = 4 S;t`C~l
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DONE! M^OYQf  
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