[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 0}dpK $.  
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。 LC!bIm5'  
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模型 ?p8_AL'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。 ,UdVNA  
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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. 0h7r&t%YsV  
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光源 7EO_5/cY  
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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。 0>Z_*U~6  
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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。 e6RPIg  
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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。 TBU&6M>{3  
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视网膜的散射 \6*I'|5d  
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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。 ,7K`[  
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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。 \.#>=!Ie  
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脚本 Pw!MS5=r  

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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： :1KpGj*F  
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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。 s(q_ o
 
余下的脚本计算与屈光度有关的所有参数。 t"/q]G5  
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分析 pgZXJ  
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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。 l}sjD[2  
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脚本代码 _8UDT^?8,  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. 2'MZ s]??w  
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Dim entity As T_ENTITY !9P';p}2  
Dim op As T_OPERATION ^V Zk+'4  
Dim mat As T_MODELMATERIAL GD_hhDyD  
Dim A As Double F,)%?<!I  
Dim pupilDiam As Double EV@X*| w  
Dim eID As Long N `F~n%N  
Dim parID As Long |02gupqqi  
Dim count As Integer GKc`xIQ  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double dP]\Jo=Yh  
Dim tlens As Double, nlens As Double =CVBBuVy  
Dim curv As Double, conic As Double \%N!5>cZ{  
Dim ok As Long g:Xhw$x9  
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Sub Main R)ITy!z  
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    '用户输入对话框 74k dsgQf  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 G.dTvLv  
        TextBox 220,21,40,21,.TextBox1 'default: 0 +8d1|cB"  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 3/W'V,5G6  
        OKButton 40,91,90,21 Opc ZU{4b  
        CancelButton 190,91,90,21 0-yp,G  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 z]`k#O%%)  
        TextBox 220,49,40,21,.TextBox2 'default: 4 g0Gf6o>2  
    End Dialog $#pPZ  
    Dim dlg As UserDialog l &5QZI0I  
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    ok = Dialog (dlg) 0+;bh {Eu  
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    If ok=0 Then    'cancel button was pressed ,a]?S^:y]  
        Print "Execution cancelled." rb+j*5Es  
        End v4c[(&  
    End If n'kG] Q  
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    'Assign accommodation and pupil diameter & use defaults if field left empty w\i\Wp,FP  
    If dlg.TextBox1 = "" Then E
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        A = 0           'Default accommodation (
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    Else yS(fILV  
        A = CDbl(dlg.TextBox1) G5aieD.#  
    End If dS!:JO27  
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    If dlg.TextBox2 = "" Then @H7d_S  
        pupilDiam = 4   'Default pupil diameter _zn.K&I-*k  
    Else Xi,CV[L\  
        pupilDiam = CDbl(dlg.TextBox2) D"rK(  
    End If S:oi<F  
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    Print " " QoIT*!  
    Print "Accommodation = " & A & " Diopters" 6GSI"M6s  
    Print "Pupil Diameter = " & pupilDiam & " mm" se>8Z4  
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    ' Calculate new parameters with accommodation ^
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    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness v}O30wE  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens xLWwYK  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens -$jEfi4I  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens vAh6+K.e  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens p&bROuw<T  

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    tlens = 3.767 + 0.04*A                  'Lens thickness ]#l/2V1  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction wKYZa# u  
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    'Adjust parameters to account for accommodation `W:%mJd9  
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    '************************************************************************* gVv>9W('  
    'Aqueous thickness (Position of Lens) )Sg~[WxDv  
    '************************************************************************* `V]5sE]G
 
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) 3
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    GetCustomElement eID, entity kabnVVn~  
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    parID = FindFullName( "Geometry.Arizona Eye" ) BJB^m|b)  
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    ' Delete any shift(s) in z o( RG-$  
    count = 0 O[s{ Gk'>  
    While GetOperationCount(eID)>count 1+qw$T  
        GetOperation eID, count, op PMh^(j[  
        If op.Type="ShiftZ" Then 9XyYHi  
            DeleteOperation eID,count %?uc><&?e  
            count=count-1 36
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        End If KJ=6n%6  
        count=count+1 X;B\Kj`n  
    Wend sCis4gX.]  
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    'Set new shift in V_RTI.3p  
    op.Type = "ShiftZ" #Jn_c0  
    op.val1 = taq *-q"3D`  
    op.parent = parID i;jw\ed  
    AddOperation eID, op OK6]e3UO  
    Print "Set aqueous humor thickness = " & taq-0.55 v:o({Y 1Aq  
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    '************************************************************************* W?aI|U1  
    'Radius and conic constant of anterior lens pUq1|)g  
    '************************************************************************* 04'~ta(t  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) (TwnkXrR,  
    GetConic eID, entity, curv, conic `m?c;,\  
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    SetConic eID, entity, 1/Rant, CCant x&9hI  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant ,:
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    '************************************************************************* HA`@7I  
    'Radius and conic constant of posterior lens U,gti,IX^  
    '************************************************************************* x2z;6)  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) Y"Ql!5=  
    GetConic eID, entity, curv, conic zG9Y!
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    SetConic eID, entity, 1/Rpost, CCpost J6%AH?Mt  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost /D^"X 4!"  
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    '************************************************************************* s#DaKPC  
    'Lens thickness (Position of posterior lens surface) k
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    '************************************************************************* ?jt}*q>X]  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) y^Kph# F"  
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    ' Delete any z-shift(s) WxJf{=-  
    count = 0 X 9%'|(tL  
    While GetOperationCount(eID)>count 80&.JP.
 
        GetOperation eID, count, op ]Xf% ,iu  
        If op.Type="ShiftZ" Then t|<NI+H(e  
            DeleteOperation eID,count ^#1.l=s  
            count=count-1 &jczO-R^  
        End If 0=q;@OIf  
        count=count+1 9D}/\jM  
    Wend DUe&r,(4O  
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    'Set new z-shift E}_[QEY;Y  
    op.Type = "ShiftZ" wm")[!h)v  
    op.val1 = tlens RJH,  
    op.parent = parID bY2 C]r(n  
    AddOperation eID, op p!V>XY'N^  
    Print "Set lens thickness = " & tlens pdb1GDl0q  
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    '************************************************************************* ^*= 85iyo  
    'Lens index of refraction Ty@=yA17  
    '************************************************************************* H:JLAK  
    eID = FindMaterial( "Lens" ) <0.$'M~E  
    GetModelMaterial eID, mat bo=ZM9  
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    mat.Nd = nlens J3b4cxm  
    SetModelMaterial eID, mat 1b>C
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    Print "Set lens index of refraction = " & nlens ph|ZG6:
  
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    '************************************************************************* ,chf~-d  
    'Pupil diameter lhYn5d)DV  
    '************************************************************************* !epgTN  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) o{kbc5_  
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    'Adjust pupil diameter (trimming volume inner hole) M4LktR-[  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" !lmWb-v%36  
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    ' Adjust pupil location to just in front of the lens x/
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    parID = FindFullName( "Geometry.Arizona Eye" ) ;C/bJEgdd  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) PS" .R
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    count = 0 ]43bere  
    While GetOperationCount(eID)>count "$5\,  
        GetOperation eID, count, op JH]K/sC>  
        If op.Type="ShiftZ" Then Lx U={Y0  
            DeleteOperation eID,count rspayO<]3  
            count=count-1 "?
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        End If OAZ#|U   
        count=count+1 [rOaM$3|  
    Wend 0i8hI6d  
    op.Type = "ShiftZ" 6Bm9?eU0  
    op.val1 = taq-0.01 X7|.T0{=x  
    op.parent = parID ,C
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    AddOperation eID, op 1GE|Wd
  
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    Print "Set pupil diameter = " & pupilDiam V5GkP1L  
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    'Update AZ Eye subassembly Description dYojm1MQ  
    eID = FindFullName( "Geometry.Arizona Eye" ) \H5Jk$*  
    GetEntity eID, entity N 6O8Wn  
    entity.Description = "Accommodation = " & A & "D" F X1ZG!  
    SetEntity eID, entity } i)$n(A)K  
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    Update QI!i  
    Print "DONE!" h#Ce_,o  
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End Sub ;ggy5?>Qu  
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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： zyN (4  
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Accommodation = 4 Diopters 3@O0^v-  
Pupil Diameter = 4 mm L$Z(+6m5  
Set aqueous humor thickness = 2.81 OalP1Gy
 
Set anterior lens radius = 10.4 and conic constant = -2.375869 )3muPMaY  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 DcV<y-`'1  
Set lens thickness = 3.927 c8QnN:n  
Set lens index of refraction = 1.42672 XqR{.jF.  
Set pupil diameter = 4 26:evid  
DONE! 2Q$\KRE  
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