[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 '$pT:4EuGq  
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。 In^MZ)?  
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模型 v'Ce|.;  
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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。 B3K!>lz  
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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. GY<E
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光源 `bu3S}m7  
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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。 ~R/w~Kc!/A  
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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。 j)ZvlRi,  
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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。 pxjN\q  
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视网膜的散射 j}XTa[  
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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。 *6 -;iT8  
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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。 %AW5\ EX  
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脚本 fl _k5Q'&p  
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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： yveyAsN`B  
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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。 58zs%
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余下的脚本计算与屈光度有关的所有参数。
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分析 PbxuD*LQ.  
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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。 MbLG8T:y  
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脚本代码 y@]4xLB]  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. &N1C"Eov?  
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Dim entity As T_ENTITY SF+ ^dPwj  
Dim op As T_OPERATION ONJW*!(  
Dim mat As T_MODELMATERIAL SFoF]U09
 
Dim A As Double hKtOh  
Dim pupilDiam As Double b0X*+q  
Dim eID As Long %(;jx  
Dim parID As Long /-z_"G  
Dim count As Integer @iB**zR/  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double Na: M1Uhb  
Dim tlens As Double, nlens As Double ]_I<-}?;  
Dim curv As Double, conic As Double V\ch0i 1  
Dim ok As Long q_>DX,A  
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Sub Main AKx\U?ei7  
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    '用户输入对话框 ;hF>iw  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1  s=#IoNh  
        TextBox 220,21,40,21,.TextBox1 'default: 0 $m:}{:LDCf  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 =sRd5aMs  
        OKButton 40,91,90,21 a8M.EFa:  
        CancelButton 190,91,90,21 *{W5QEa  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 9 U1)sPH;  
        TextBox 220,49,40,21,.TextBox2 'default: 4 n4YEu\*  
    End Dialog C yC<{D+  
    Dim dlg As UserDialog j^KM  
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    ok = Dialog (dlg) -qfd)A6]  
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    If ok=0 Then    'cancel button was pressed FePJ8  
        Print "Execution cancelled." ~U*2h =]  
        End 8"wA8l.  
    End If c}Jy'F7&f  
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    'Assign accommodation and pupil diameter & use defaults if field left empty /r@P\_  
    If dlg.TextBox1 = "" Then eC9~ wc  
        A = 0           'Default accommodation Mp75L5  
    Else YV-2es+Bd  
        A = CDbl(dlg.TextBox1) aFo%B; 8m  
    End If n$y1kD  
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    If dlg.TextBox2 = "" Then Q9K Gf;  
        pupilDiam = 4   'Default pupil diameter `h$6MFC/g  
    Else i3: sV5  
        pupilDiam = CDbl(dlg.TextBox2) r!Eo8C  
    End If )
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    Print " " %P_\7YBC>  
    Print "Accommodation = " & A & " Diopters" =%Ut&6}sQ  
    Print "Pupil Diameter = " & pupilDiam & " mm" {x
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    ' Calculate new parameters with accommodation .^@+$}   
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness 4}580mBc  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens ksDG8^9>]  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens Uo^s]H#:  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens "4g1I<  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens RfN5X}&A  
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    tlens = 3.767 + 0.04*A                  'Lens thickness \Zoo9Wy  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction -rH4/Iby  
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    'Adjust parameters to account for accommodation 2:p2u1Q O  
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    '************************************************************************* pe,c  
    'Aqueous thickness (Position of Lens) DX$`\PA  
    '************************************************************************* I_pA)P*Q(6  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) 42z9N\ f  
    GetCustomElement eID, entity k%In   
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    parID = FindFullName( "Geometry.Arizona Eye" ) G#dpSNV
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    ' Delete any shift(s) in z "45BOw&72G  
    count = 0 qh.c#t  
    While GetOperationCount(eID)>count {GWcw<g.B  
        GetOperation eID, count, op sE/9~L  
        If op.Type="ShiftZ" Then iZSjT"l^  
            DeleteOperation eID,count SI;G|uO;/  
            count=count-1 &-cI|  
        End If \Z+v\5nmO  
        count=count+1 9s*Lzi[}  
    Wend <wE2ly&x  
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    'Set new shift in cK-!Evv  
    op.Type = "ShiftZ" ,{oP`4\Lm  
    op.val1 = taq `M7){  
    op.parent = parID ^f`#8G7(  
    AddOperation eID, op -3 W4  
    Print "Set aqueous humor thickness = " & taq-0.55 l}O`cC
 
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    '************************************************************************* c,D'Hl6(%  
    'Radius and conic constant of anterior lens `Z@wWs  
    '************************************************************************* |LNXu  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) zG@!(  
    GetConic eID, entity, curv, conic (|6qN  
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    SetConic eID, entity, 1/Rant, CCant ZVGw
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    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant H/, tE0ZV  
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    '************************************************************************* ?QuFRl,ZJ  
    'Radius and conic constant of posterior lens 1:>RQPXcWv  
    '************************************************************************* *Lh0E/5  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) [j!0R'T  
    GetConic eID, entity, curv, conic 9*2hBNp+  
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    SetConic eID, entity, 1/Rpost, CCpost V_ ]4UE  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost %^5$=w  
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    '************************************************************************* 9J|YP}%  
    'Lens thickness (Position of posterior lens surface) =  Oq;  
    '************************************************************************* 6u.b?_u  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) ,LMme}FFeb  
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    ' Delete any z-shift(s) K^w9@&g6  
    count = 0 #g|j;{P  
    While GetOperationCount(eID)>count T@RzY2tz  
        GetOperation eID, count, op }pTj8Tr  
        If op.Type="ShiftZ" Then Ha/\&Z(  
            DeleteOperation eID,count FF_$)%YUp  
            count=count-1 NFa ;  
        End If i#-Jl7V[a  
        count=count+1 w"BTu-I  
    Wend )5&m:R9  
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    'Set new z-shift c:$:j,i}  
    op.Type = "ShiftZ" 6F(
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    op.val1 = tlens &U,f~KJ  
    op.parent = parID Y^!40XjrD  
    AddOperation eID, op sZbzY^P  
    Print "Set lens thickness = " & tlens i5wA=K_  
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    '************************************************************************* B!N807  
    'Lens index of refraction yNT2kB'  
    '************************************************************************* DQ9s57VxC!  
    eID = FindMaterial( "Lens" ) j)]'kg  
    GetModelMaterial eID, mat I;|Ai
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    mat.Nd = nlens &6:,2W&s  
    SetModelMaterial eID, mat I|ULf  
    Print "Set lens index of refraction = " & nlens a-}%R  
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    '************************************************************************* 2+P3Sii  
    'Pupil diameter '~f@p~P  
    '************************************************************************* P0Jd6"sS"  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) ~
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    'Adjust pupil diameter (trimming volume inner hole) -'0AV,{Z  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" \=_8G:1  
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    ' Adjust pupil location to just in front of the lens 3Mcz9exY  
    parID = FindFullName( "Geometry.Arizona Eye" ) lxmS.C
  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) *c%@f<R~  
    count = 0 n=SZ8R
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    While GetOperationCount(eID)>count Y5NbY02E  
        GetOperation eID, count, op 6vjB;uS[  
        If op.Type="ShiftZ" Then .J@[v  
            DeleteOperation eID,count j(BS;J$i  
            count=count-1 !Q3Snu=  
        End If -#o+x Jj  
        count=count+1 T7T!v  
    Wend [!q&r(-K  
    op.Type = "ShiftZ" qB39\j  
    op.val1 = taq-0.01 *~cs8<.!1  
    op.parent = parID X|QCa@Foe  
    AddOperation eID, op G9
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    Print "Set pupil diameter = " & pupilDiam StDmJ]  
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    'Update AZ Eye subassembly Description W@C56fCa  
    eID = FindFullName( "Geometry.Arizona Eye" ) 0;H6b=  
    GetEntity eID, entity u20b+c4  
    entity.Description = "Accommodation = " & A & "D" 6uXW`/lvX  
    SetEntity eID, entity ^sOm7S{  
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    Update r:5Ve&~  
    Print "DONE!" g Oj5c
 
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End Sub +7Lco"\w<  
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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： XH *tChf<  
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Accommodation = 4 Diopters Riw7<j  
Pupil Diameter = 4 mm UjDF  
Set aqueous humor thickness = 2.81 5An0DV5  
Set anterior lens radius = 10.4 and conic constant = -2.375869 NslA/"*  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 UvZ@"El  
Set lens thickness = 3.927 mCt>s9a)H  
Set lens index of refraction = 1.42672 P{Z71a5  
Set pupil diameter = 4 ?R]y}6P$  
DONE! =.X?LWKY  
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