[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 &C 9hT  
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。 @^{Hq6_`  
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模型 b 2gng}  
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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。 ~9X^3.nI  
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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. rpNb.  
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光源 ?gH[la  
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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。 fFQ|dE;cF  
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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。 ]#!uke Q  
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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  
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视网膜的散射 [KDxB>R<{  
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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。 SV7;B?e%Y  
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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。 w5FIHYl6B  
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脚本 $l.*;h*  
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内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： dFg>uo  
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如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 A40DbD\^ad  
余下的脚本计算与屈光度有关的所有参数。 qGk+4 yC  
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分析 ,H7X_KbFD4  
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屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 C6+ 5G-Z  
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脚本代码 2+]5}'M  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. DE13x*2  
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Dim entity As T_ENTITY 1]xk:u4LA  
Dim op As T_OPERATION 5eAZfe%H  
Dim mat As T_MODELMATERIAL DP_b9o \5  
Dim A As Double r6<;bO(  
Dim pupilDiam As Double (P>nA3:UXB  
Dim eID As Long ct+F\:e  
Dim parID As Long G?Et$r7:R  
Dim count As Integer "1o{mvCkR  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double gC7!cn  
Dim tlens As Double, nlens As Double iUkUo x  
Dim curv As Double, conic As Double kBUkE-~  
Dim ok As Long lg^'/8^f  
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Sub Main n,T &n  
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    '用户输入对话框 HcRw9,I'  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 :UwBs  
        TextBox 220,21,40,21,.TextBox1 'default: 0 oZ{,IZ45  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 q` S ~w  
        OKButton 40,91,90,21 hY}Q|-|  
        CancelButton 190,91,90,21 5SFr E`  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 xj5TnE9^  
        TextBox 220,49,40,21,.TextBox2 'default: 4 'h$:~C  
    End Dialog ?;~!C2Zs  
    Dim dlg As UserDialog +'F;\E  
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    ok = Dialog (dlg) xd?=#d  
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    If ok=0 Then    'cancel button was pressed Qt u;
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        Print "Execution cancelled." (l5p_x  
        End (Ypy}  
    End If -jQ*r$iRE  
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    'Assign accommodation and pupil diameter & use defaults if field left empty L: $ `8  
    If dlg.TextBox1 = "" Then Mo/R+\u+Y  
        A = 0           'Default accommodation ]($ \7+  
    Else r3V1l
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        A = CDbl(dlg.TextBox1) e;i 6C%DB  
    End If }L0 [Jo:  
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    If dlg.TextBox2 = "" Then fY]"_P  
        pupilDiam = 4   'Default pupil diameter # epP~J_f  
    Else fW= N  
        pupilDiam = CDbl(dlg.TextBox2) .0dGS  
    End If  \? /'
 
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    Print " " w_"d&eYdg0  
    Print "Accommodation = " & A & " Diopters" j"Jf|Hq $  
    Print "Pupil Diameter = " & pupilDiam & " mm" $f@YQN=  
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    ' Calculate new parameters with accommodation =r]l"T  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness ):N#X<b':  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens )\])?q61  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens @x `X|>&  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens c0wLc,)G  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens l]G iz&  
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    tlens = 3.767 + 0.04*A                  'Lens thickness 8#!g;`~ D  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction tR51Pw  
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    'Adjust parameters to account for accommodation B=KrJ{&!  
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    '************************************************************************* ")KqPD6k  
    'Aqueous thickness (Position of Lens) V u")%(ix  
    '************************************************************************* s.4+5
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    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) A=kOSq 4Q  
    GetCustomElement eID, entity ?22U0UF  
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    parID = FindFullName( "Geometry.Arizona Eye" ) aEdA'>  
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    ' Delete any shift(s) in z :]:)c8!6  
    count = 0 nlpEkq  
    While GetOperationCount(eID)>count pZ8J\4+  
        GetOperation eID, count, op [~Ky{:@)[  
        If op.Type="ShiftZ" Then @QTw9,pS  
            DeleteOperation eID,count +iQ@J+k  
            count=count-1 7"eK<qJ  
        End If s(py7{ ^K  
        count=count+1 )bM,>x  
    Wend p2Khfl6-  

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    'Set new shift in 4T3Z9KD!8  
    op.Type = "ShiftZ" yKhI&  
    op.val1 = taq W=HvMD  
    op.parent = parID \k5"&]I3  
    AddOperation eID, op +a39 !j 1_  
    Print "Set aqueous humor thickness = " & taq-0.55 R'sNMWM  
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    '************************************************************************* NC
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    'Radius and conic constant of anterior lens N!ihj:,  
    '************************************************************************* eL~xS: VT  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) JPF6zzl)  
    GetConic eID, entity, curv, conic g8cBb5(L  
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    SetConic eID, entity, 1/Rant, CCant wU|@fm"  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant zG$5g^J  
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    '************************************************************************* w71YA#cg  
    'Radius and conic constant of posterior lens c2NB@T9'v  
    '************************************************************************* gy@=)R/~  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) CN
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    GetConic eID, entity, curv, conic TC-Vzk G|  
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    SetConic eID, entity, 1/Rpost, CCpost 
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    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost |\dv$`_T  
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    '************************************************************************* .v(GVkE}  
    'Lens thickness (Position of posterior lens surface) YzjRD:  
    '************************************************************************* -+{[.U<1jk  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) tTBDb  
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    ' Delete any z-shift(s) N ;=zo-8  
    count = 0 2*Qi4%s#  
    While GetOperationCount(eID)>count 5IUdA?  
        GetOperation eID, count, op 7SS#V  
        If op.Type="ShiftZ" Then 6YU,>KP  
            DeleteOperation eID,count ]7}!3m  
            count=count-1 UhqTn$=fb  
        End If sJx_X8  
        count=count+1 -&D=4,#  
    Wend (1|wM+)"  
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    'Set new z-shift V\m"Hl>VIU  
    op.Type = "ShiftZ" /i8OyRpSyk  
    op.val1 = tlens >=97~a+
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    op.parent = parID Hk;;+'-  
    AddOperation eID, op 4/~x+tdc  
    Print "Set lens thickness = " & tlens ?|kbIZP(  
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    '************************************************************************* Soq#cl'll-  
    'Lens index of refraction t3<8n;'y:  
    '************************************************************************* #1U>  
    eID = FindMaterial( "Lens" ) \{`^Q+<  
    GetModelMaterial eID, mat 0e<>2AL   
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    mat.Nd = nlens ViiJDYT>E<  
    SetModelMaterial eID, mat ZeuL*c \  
    Print "Set lens index of refraction = " & nlens 7P2n{zd,  
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    '************************************************************************* qdI%v#'M  
    'Pupil diameter iS,l  
    '************************************************************************* m6[}KkW  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) Ic4#Tk20i  
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    'Adjust pupil diameter (trimming volume inner hole) f~wON>$K  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" Fn.JtIu  
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    ' Adjust pupil location to just in front of the lens h_?`ESI~  
    parID = FindFullName( "Geometry.Arizona Eye" ) ;ZUj2WxE  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) VA[EY`8  
    count = 0 T='uqKW\  
    While GetOperationCount(eID)>count h"+7cc@  
        GetOperation eID, count, op y:98}gW`n  
        If op.Type="ShiftZ" Then uCr& `  
            DeleteOperation eID,count P9yMf~  
            count=count-1 uKAI->"  
        End If LH2B*8=^2  
        count=count+1 chL1r9V)v  
    Wend 'Z~ZSu  
    op.Type = "ShiftZ" 7tlK'j'  
    op.val1 = taq-0.01 enJ;#aA  
    op.parent = parID 5h/,*p6Nje  
    AddOperation eID, op 7iv
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    Print "Set pupil diameter = " & pupilDiam 6}-No  
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    'Update AZ Eye subassembly Description }q
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    eID = FindFullName( "Geometry.Arizona Eye" ) P4Pc;8T@!  
    GetEntity eID, entity ^+D/59I  
    entity.Description = "Accommodation = " & A & "D" +o`%7r(R  
    SetEntity eID, entity 'Wnh1|z  
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    Update n5kGHL2  
    Print "DONE!" =F$?`q`  
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End Sub 3eE=>E4,  
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如果屈光度是4，光瞳直径是4，则会输出如下数据： }y6@YfV${  
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Accommodation = 4 Diopters %]}JWXof  
Pupil Diameter = 4 mm Ztmh z_u7  
Set aqueous humor thickness = 2.81 D/Ki^E  
Set anterior lens radius = 10.4 and conic constant = -2.375869  Kg';[G\  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 buX(mj:
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Set lens thickness = 3.927 |K1S(m<F  
Set lens index of refraction = 1.42672 Oq~{HJ{  
Set pupil diameter = 4 m@XX2l9:9  
DONE! 1"Oe*@`pV  
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