[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 pEc|h*p8  
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。 >^cP]gGY  
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模型 taS2b#6\+  
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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。 Cu5fp.OS7  
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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. _j$"fg  
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光源 TU6e,G|t  
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多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。
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除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处，并增加了pre-propagation distance= -8。尽管光线在光瞳处创建，规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射，而不是在光瞳处入射。 .\r=1HZ3  
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在往下看是内置的脚本用来修改屈光度，使其为4（250mm），光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 q^:>sfd  
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视网膜的散射 S6k R o^2  
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在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 3V)ef$Y0  
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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。 {WBe(dc_%  
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脚本 o!R.QI^2VT  
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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： *QKxrg  
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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。 ew13qpt)<L  
余下的脚本计算与屈光度有关的所有参数。 [HRry2#s  
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分析 KCBA`N8  
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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。  Dno]N  
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脚本代码 M =/+q  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. ,9A1p06  
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Dim entity As T_ENTITY 2XX-  
Dim op As T_OPERATION @AB}r1E2  
Dim mat As T_MODELMATERIAL |wxAdPe  
Dim A As Double COc,  
Dim pupilDiam As Double 1>c^-"#e^  
Dim eID As Long zIzL7oD  
Dim parID As Long <<FBT`Y[  
Dim count As Integer 9QXBz=Fnf  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double QZh#&Qf;  
Dim tlens As Double, nlens As Double \CU-a`n  
Dim curv As Double, conic As Double 5cUz^ >  
Dim ok As Long Z|#G+$"QV  
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Sub Main 'bQjJRq!  
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    '用户输入对话框  *Cj<Vy  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 DqJzsk'd3  
        TextBox 220,21,40,21,.TextBox1 'default: 0 <eh<4_<qF  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 .)g7s? K  
        OKButton 40,91,90,21 L^FQ|?*  
        CancelButton 190,91,90,21 <WiyM[ep  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 oypF0?!m  
        TextBox 220,49,40,21,.TextBox2 'default: 4 WHy r;m3)  
    End Dialog HhZ>/5'(  
    Dim dlg As UserDialog :!QT ,  
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    ok = Dialog (dlg) [*K.9}+G_  
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    If ok=0 Then    'cancel button was pressed grxlGS~Q  
        Print "Execution cancelled." +zg3/C4 S  
        End 1>=]lMW  
    End If adtgNwg  
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    'Assign accommodation and pupil diameter & use defaults if field left empty L2Fi/UWM  
    If dlg.TextBox1 = "" Then ^2`*1el  
        A = 0           'Default accommodation u#+Is4Vh  
    Else NtG^t}V  
        A = CDbl(dlg.TextBox1) 0i>>CvAl}  
    End If `sLD>@m  
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    If dlg.TextBox2 = "" Then )@],0yL  
        pupilDiam = 4   'Default pupil diameter UE-1p  
    Else W.c>("gC  
        pupilDiam = CDbl(dlg.TextBox2) 5i-VnG  
    End If h,ipQ>  
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    Print " " 98*C/=^TH{  
    Print "Accommodation = " & A & " Diopters" Ae* 6&R4  
    Print "Pupil Diameter = " & pupilDiam & " mm" D$Ao-6QE W  
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    ' Calculate new parameters with accommodation ?&D.b$  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness MxqIB(5k  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens dN@C)5pm5`  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens t{e}3}LEd  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens $U"pdf  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens L\q-Z..  
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    tlens = 3.767 + 0.04*A                  'Lens thickness eMtQa;Lc9o  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction ]]T,;|B
 
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    'Adjust parameters to account for accommodation %zN~%mJ
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    '************************************************************************* #&Rx?V  
    'Aqueous thickness (Position of Lens) Nk<H=kw+  
    '************************************************************************* xmejoOF  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) |=[._VH1  
    GetCustomElement eID, entity zd=N.  
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    parID = FindFullName( "Geometry.Arizona Eye" ) \=H+m%  
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    ' Delete any shift(s) in z g6@^n$Y  
    count = 0 2
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    While GetOperationCount(eID)>count 6 )lWuY]e  
        GetOperation eID, count, op *JO%.QNg  
        If op.Type="ShiftZ" Then 91UC>]}H  
            DeleteOperation eID,count T3t w.yh  
            count=count-1 ITZ}$=   
        End If d~y]7h|  
        count=count+1 |AS9^w  
    Wend T+>W(w i  
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    'Set new shift in ,qIut|C*  
    op.Type = "ShiftZ" SKo*8r   
    op.val1 = taq Vg7BK%  
    op.parent = parID @DlN;r?Cv  
    AddOperation eID, op 7|<-rjz^  
    Print "Set aqueous humor thickness = " & taq-0.55 ySHio;g9  
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    '************************************************************************* EE*FvI`  
    'Radius and conic constant of anterior lens ,<;.'r  
    '************************************************************************* bLO^5`6  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" )  @4>?Y=#  
    GetConic eID, entity, curv, conic 3m"9
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    SetConic eID, entity, 1/Rant, CCant |%j7Es  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant ki8Jl}dr  
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    '************************************************************************* aL/7
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    'Radius and conic constant of posterior lens j#9n.i %h  
    '************************************************************************* X`7O%HiX/`  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) p e$WSS J  
    GetConic eID, entity, curv, conic G$jw#a[L  
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    SetConic eID, entity, 1/Rpost, CCpost :Y4G^i  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost u9{Z*w3L7  
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    '************************************************************************* @Dd3mWKq  
    'Lens thickness (Position of posterior lens surface) ,DCrhk
 
    '************************************************************************* ]gVW&3ZW  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) ;eP.B/N  
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    ' Delete any z-shift(s) 1fV\84m^  
    count = 0 D}?JX5.  
    While GetOperationCount(eID)>count /[|A(,N}{  
        GetOperation eID, count, op \m+;^_;5GW  
        If op.Type="ShiftZ" Then R'aA\k-  
            DeleteOperation eID,count $lF\FC  
            count=count-1 1P/4,D@  
        End If W<H<~wf#  
        count=count+1 BSg3  
    Wend ~.Cu,>fV  
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    'Set new z-shift U zMIm  
    op.Type = "ShiftZ" CPu~^ik  
    op.val1 = tlens O_&Km[  
    op.parent = parID {y
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    AddOperation eID, op %F]:nk`  
    Print "Set lens thickness = " & tlens h\*I*I8C  
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    '************************************************************************* M;E$ ]Z9  
    'Lens index of refraction vtXZ`[D,l)  
    '************************************************************************* >>0c)uC|W  
    eID = FindMaterial( "Lens" ) 01o,9_|FL  
    GetModelMaterial eID, mat yo#fJ`  
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    mat.Nd = nlens qr?RU .W  
    SetModelMaterial eID, mat VY "i>Ae  
    Print "Set lens index of refraction = " & nlens 1lf]}V  
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    '************************************************************************* KgEfhO$W  
    'Pupil diameter :tBZu%N/N  
    '************************************************************************* SgY\h{{sP  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) z229:L6"  
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    'Adjust pupil diameter (trimming volume inner hole) 1fU~&?&-u  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" 6#1:2ZHKG  
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    ' Adjust pupil location to just in front of the lens FY<77i  
    parID = FindFullName( "Geometry.Arizona Eye" ) +U,>D+  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) VHTr;(]hk  
    count = 0 lcEin*Oc  
    While GetOperationCount(eID)>count w1 tg7^(@  
        GetOperation eID, count, op 1IV R4:a  
        If op.Type="ShiftZ" Then &Ch~$Wb^  
            DeleteOperation eID,count :*s+X$x,<  
            count=count-1 pt- 1>Ui  
        End If J1{ucFa  
        count=count+1 + +G%~)S:  
    Wend K^+}__;]  
    op.Type = "ShiftZ" [49Ae2W`  
    op.val1 = taq-0.01 IRl(H_.  
    op.parent = parID ?<-ins  
    AddOperation eID, op lF
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    Print "Set pupil diameter = " & pupilDiam X3,+aL`  
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    'Update AZ Eye subassembly Description 088"7 s  
    eID = FindFullName( "Geometry.Arizona Eye" ) XbKNH>  
    GetEntity eID, entity 'or8CGr^p  
    entity.Description = "Accommodation = " & A & "D" $yg=tWk  
    SetEntity eID, entity dt|f4XWF  
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    Update IYk^eG:;
 
    Print "DONE!" 2OQDG7#Kc  
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End Sub wx%TQ!  
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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： JOm6Zc  
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Accommodation = 4 Diopters +1j+%&).  
Pupil Diameter = 4 mm #-Ad0/  
Set aqueous humor thickness = 2.81 [#-!&>  
Set anterior lens radius = 10.4 and conic constant = -2.375869 .a *^6TC.  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 -L%2*`-L$  
Set lens thickness = 3.927 s.7s:Q`  
Set lens index of refraction = 1.42672 ,dO$R.h  
Set pupil diameter = 4 czv )D\*  
DONE! 5};$>47m  
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