[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 aP
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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。 2*l/3VW  
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模型 paE[rS\  
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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。 `MN4uC  
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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. :g=qz~2Xk  
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光源 sW'AjI  
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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。 WH@,kH@  
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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。 @&3EJ1  
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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}K"24`=  
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视网膜的散射 J~zUp(>K  
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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。
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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。 PI:4m%[  
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脚本
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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： ~"&|W'he[  
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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。 b_#m}yZ6  
余下的脚本计算与屈光度有关的所有参数。 %Ycy{`  
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分析 t?x<g<PJ4  
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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。 :bu/^mW[  
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脚本代码 vMi;+6'n>  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. a}B
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Dim entity As T_ENTITY \Fbv
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Dim op As T_OPERATION 1R{!]uh  
Dim mat As T_MODELMATERIAL z0p*Z&  
Dim A As Double /ivJsPH  
Dim pupilDiam As Double hl7bzKO*w  
Dim eID As Long pMx*F@&nU  
Dim parID As Long uGf@  
Dim count As Integer h5{'Q$Erl  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double G_3O]BMKd)  
Dim tlens As Double, nlens As Double */)c?)"  
Dim curv As Double, conic As Double !*
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Dim ok As Long fo*2:?K&  
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Sub Main [fya)}  
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    '用户输入对话框 (lBCO?`fx  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 dUeN*Nq&(,  
        TextBox 220,21,40,21,.TextBox1 'default: 0 E"\<s3  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 DkY4MH?  
        OKButton 40,91,90,21 q1$N>;&  
        CancelButton 190,91,90,21 ]_mb7X>  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1  N_kMK  
        TextBox 220,49,40,21,.TextBox2 'default: 4 ??
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    End Dialog :t"^6xt  
    Dim dlg As UserDialog (Du@ S  
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    ok = Dialog (dlg) F'={q{2wH  
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    If ok=0 Then    'cancel button was pressed Gv!2f  
        Print "Execution cancelled." ]^. _z  
        End =1FRFZI!j  
    End If I+%[d^,  
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    'Assign accommodation and pupil diameter & use defaults if field left empty U8s2|G;K  
    If dlg.TextBox1 = "" Then $B2J T9  
        A = 0           'Default accommodation fIx+ILs  
    Else "(3[+W{|  
        A = CDbl(dlg.TextBox1) !hA-_  
    End If & TCkpS  
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    If dlg.TextBox2 = "" Then =J
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        pupilDiam = 4   'Default pupil diameter D
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    Else WA<v9#m  
        pupilDiam = CDbl(dlg.TextBox2) ?(@ 7r_j  
    End If G*?8MTP8![  
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    Print " " lF<]8m%F  
    Print "Accommodation = " & A & " Diopters" `[y^ :mj  
    Print "Pupil Diameter = " & pupilDiam & " mm" wm+};L&_  
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    ' Calculate new parameters with accommodation j"8ZM{aO  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness $f$SNx)),  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens k90YV(  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens BwN0!lsF3  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens WJ]T\DI  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens :p1u(hflS  
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    tlens = 3.767 + 0.04*A                  'Lens thickness ,5P0S0*{  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction M:=J^0  
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    'Adjust parameters to account for accommodation 8v6(qBK  
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    '************************************************************************* dUD[e,?  
    'Aqueous thickness (Position of Lens) h,(26 y/s  
    '************************************************************************* 3#n_?-  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) xf'V{9*  
    GetCustomElement eID, entity Ex.yU{|c  
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    parID = FindFullName( "Geometry.Arizona Eye" ) nd`1m[7MNu  
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    ' Delete any shift(s) in z p .%]Q*8  
    count = 0 Ml`:UrU  
    While GetOperationCount(eID)>count  >^O7  
        GetOperation eID, count, op Q*GN`07@?d  
        If op.Type="ShiftZ" Then H
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            DeleteOperation eID,count iR HQ:Y!  
            count=count-1 RV1coC.g4x  
        End If 7:e{;iG  
        count=count+1 xPdG*OcX!  
    Wend `T1  
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    'Set new shift in XjBW9a  
    op.Type = "ShiftZ" C;v.S5x  
    op.val1 = taq &L3M]  
    op.parent = parID a1+oj7  
    AddOperation eID, op AI2~Jp  
    Print "Set aqueous humor thickness = " & taq-0.55 IM*y|UHt  
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    '************************************************************************* 2bz2KB5>  
    'Radius and conic constant of anterior lens V(}:=eK  
    '************************************************************************* PhLn8jNti  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) &*o=I|pQ  
    GetConic eID, entity, curv, conic y4yhF8E>;U  
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    SetConic eID, entity, 1/Rant, CCant +tB=OwU%0  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant rDtY[  
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    '************************************************************************* C-xr"]#]  
    'Radius and conic constant of posterior lens *9 {PEx  
    '************************************************************************* O}gV`q;  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) &{5,:%PXw  
    GetConic eID, entity, curv, conic 5#6|j?_a  
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    SetConic eID, entity, 1/Rpost, CCpost Fk
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    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost H;is/  
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    '************************************************************************* XE
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    'Lens thickness (Position of posterior lens surface) /|w6:;$;mn  
    '************************************************************************* oE@a'*.\  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) 3qgS&js 7  
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    ' Delete any z-shift(s) m<G,[Yc  
    count = 0 ?Rb9|`6  
    While GetOperationCount(eID)>count 2F
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        GetOperation eID, count, op PxX4[ P  
        If op.Type="ShiftZ" Then 2F;y;l%  
            DeleteOperation eID,count q~Hn-5H4Q  
            count=count-1 .D~;u-%|F  
        End If z9f-.72"X  
        count=count+1 ~i= _J3'  
    Wend R>|{N9  
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    'Set new z-shift .N;=\C
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    op.Type = "ShiftZ" @)F)S7  
    op.val1 = tlens 299H$$WS,Z  
    op.parent = parID Xfc-UP|}  
    AddOperation eID, op `?H]h"{7Q  
    Print "Set lens thickness = " & tlens 2y\E[jA  
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    '************************************************************************* J`Q>3]wL  
    'Lens index of refraction &N9 a<w8+  
    '************************************************************************* Y;eZ9|Ht9  
    eID = FindMaterial( "Lens" ) ^
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    GetModelMaterial eID, mat p>,|50|  
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    mat.Nd = nlens Wb,KjtX
 
    SetModelMaterial eID, mat ";lVa'HMZ  
    Print "Set lens index of refraction = " & nlens uh_RGM&  
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    '************************************************************************* G&SB-  
    'Pupil diameter .8g)av+  
    '************************************************************************* of~4Q{f$6  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) 2>9C-VL2  
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    'Adjust pupil diameter (trimming volume inner hole) o#)C^xlQ  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" qx(xvU9  
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    ' Adjust pupil location to just in front of the lens B4/
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    parID = FindFullName( "Geometry.Arizona Eye" ) @n/\L<]t  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) ;a!S!%.h  
    count = 0 udH7}K v  
    While GetOperationCount(eID)>count v~+(GqR=+  
        GetOperation eID, count, op A|[?#S((]  
        If op.Type="ShiftZ" Then Xq4O@V  
            DeleteOperation eID,count ldcqe$7,  
            count=count-1 G>_*djUf  
        End If ^6
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        count=count+1 PQt")[
 
    Wend u
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    op.Type = "ShiftZ" GKqm&/M*=  
    op.val1 = taq-0.01 KkyVSoD\  
    op.parent = parID :VBV&l` [  
    AddOperation eID, op JG.y,<xW  
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    Print "Set pupil diameter = " & pupilDiam bP#:Oi0v`  
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    'Update AZ Eye subassembly Description g/_5unI}u  
    eID = FindFullName( "Geometry.Arizona Eye" ) ]%SH>  
    GetEntity eID, entity |i*37r6]=  
    entity.Description = "Accommodation = " & A & "D" hag$GX'2k
 
    SetEntity eID, entity q$UJ$7=f8  
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    Update ,t744k')  
    Print "DONE!" (/YHk`v2  
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End Sub DK~xrU'  
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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_[tu!~  
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Accommodation = 4 Diopters A2FYBM`Q&D  
Pupil Diameter = 4 mm sdrfsrNvB-  
Set aqueous humor thickness = 2.81 =s{>Fsm1  
Set anterior lens radius = 10.4 and conic constant = -2.375869 3%|&I:tI  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 Jr4Ky<G_i  
Set lens thickness = 3.927 P;no?  
Set lens index of refraction = 1.42672 ;1=1:S8  
Set pupil diameter = 4 XJB)rP  
DONE! dQX6(Jj  
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