[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 )1fQhdO}x  
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。 -Ez|  
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模型 b=|&0B$E  
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模型的定义如表1种所示，由半径、圆锥常数、折射率、阿贝数、到下一面的距离等一系列表面组成。一些参数由屈光度（A）来决定。 7-o=E=  
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在FRED中使用0屈光度来创建的，光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. @>9
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光源 R^B2J+O  
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多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 |O4A+S  
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除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处，并增加了pre-propagation distance= -8。尽管光线在光瞳处创建，规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射，而不是在光瞳处入射。 <,E*,&0W  
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在往下看是内置的脚本用来修改屈光度，使其为4（250mm），光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 g Go  
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视网膜的散射 7 YK+TGmU^  
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在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 ]F@md(J  
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注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 ]JD$f
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脚本 } )e`0)  
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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： \9}5}X_x.  
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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。 bY2Mw8e%  
余下的脚本计算与屈光度有关的所有参数。 !n{c#HfG  
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分析 <=inogf  
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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。 @}?D<O8#"#  
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脚本代码 q],R6GcVr  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. ,\M_q">npc  
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Dim entity As T_ENTITY hX_p5a1t  
Dim op As T_OPERATION {@#L'i|  
Dim mat As T_MODELMATERIAL 84!4Vz^  
Dim A As Double {T.Vu]L80  
Dim pupilDiam As Double zrew:5*uZ  
Dim eID As Long U959=e  
Dim parID As Long cA%U  
Dim count As Integer VjqdKQeVq  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double BLH=:zb5  
Dim tlens As Double, nlens As Double U(N$6{i_  
Dim curv As Double, conic As Double IA^)`l
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Dim ok As Long .O#lab`:2  
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Sub Main 4LjSDgA  
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    '用户输入对话框 5)zB/Ta<  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 fE*I
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        TextBox 220,21,40,21,.TextBox1 'default: 0 W`'|&7~  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 iy82QNe  
        OKButton 40,91,90,21 mG~y8nUtp  
        CancelButton 190,91,90,21 XC1lo4|  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 +7/*y}.U  
        TextBox 220,49,40,21,.TextBox2 'default: 4 iFCH$!  
    End Dialog &&]!+fTZ\(  
    Dim dlg As UserDialog |2<f<k/UT  
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    ok = Dialog (dlg) G r|@CZq  
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    If ok=0 Then    'cancel button was pressed N`Xnoehu  
        Print "Execution cancelled." /V<`L  
        End C9H11g7{  
    End If 4_%FSW8-  
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    'Assign accommodation and pupil diameter & use defaults if field left empty gwaC?tf[  
    If dlg.TextBox1 = "" Then ePRMv  
        A = 0           'Default accommodation ba9<(0`  
    Else !;*2*WuO;  
        A = CDbl(dlg.TextBox1) U9o*6`"o  
    End If m90R8 V  
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    If dlg.TextBox2 = "" Then 6&QTVdK'O  
        pupilDiam = 4   'Default pupil diameter *z"1MU  
    Else q7 oR9  
        pupilDiam = CDbl(dlg.TextBox2) .&x?`pER  
    End If :ZfUjqRE  
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    Print " " ptcLJ]+)  
    Print "Accommodation = " & A & " Diopters" :/[YY?pg-  
    Print "Pupil Diameter = " & pupilDiam & " mm" quGPk)c  
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    ' Calculate new parameters with accommodation T7,Gf({  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness ~`>26BWQz  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens
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    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens FJ%R3N\  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens b)hOz
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    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens 7x7r!rSe,  
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    tlens = 3.767 + 0.04*A                  'Lens thickness yFU2'pB  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction v6P~XK}G  
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    'Adjust parameters to account for accommodation uU ?37V
 
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    '************************************************************************* 'oiD#\t4  
    'Aqueous thickness (Position of Lens) g.Caapy  
    '************************************************************************* x$5nLS2.  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) )47j8jL  
    GetCustomElement eID, entity LJNie*  
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    parID = FindFullName( "Geometry.Arizona Eye" ) mf]( 3ZL  
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    ' Delete any shift(s) in z d[RWkk5  
    count = 0 >,"D9!  
    While GetOperationCount(eID)>count 4=F]`Lql  
        GetOperation eID, count, op &X]=Qpl  
        If op.Type="ShiftZ" Then ;vv!qBl|@  
            DeleteOperation eID,count t1:
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            count=count-1
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        End If @maZlw1q  
        count=count+1 i9@;,4f  
    Wend 22Y!u00D  
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    'Set new shift in sPE)m_u  
    op.Type = "ShiftZ" 1^60I#Vr@  
    op.val1 = taq 27*(oT  
    op.parent = parID 'e<HPNi)  
    AddOperation eID, op jgo<#AJ/E  
    Print "Set aqueous humor thickness = " & taq-0.55 "
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    '************************************************************************* KXx@ {cv  
    'Radius and conic constant of anterior lens N+C)/EN$  
    '************************************************************************* pRiH,:\  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) {glqWFT  
    GetConic eID, entity, curv, conic "
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    SetConic eID, entity, 1/Rant, CCant T[4[/n>i  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant +Jo 3rX'`  
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    '************************************************************************* ]w_  
    'Radius and conic constant of posterior lens i!.I
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    '************************************************************************* G>[ NZE  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) \2].|Mym  
    GetConic eID, entity, curv, conic BDm88<]  
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    SetConic eID, entity, 1/Rpost, CCpost gI^L 9jE7  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost (pT(&/\8  
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    '************************************************************************* xqQ~|  
    'Lens thickness (Position of posterior lens surface) \8>  
    '************************************************************************* 2|
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) z<yNG/M1>U  
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    ' Delete any z-shift(s) B8cBQv  
    count = 0 .# !'c  
    While GetOperationCount(eID)>count *l>[`U+  
        GetOperation eID, count, op L@1,7@  
        If op.Type="ShiftZ" Then O?nPxa<  
            DeleteOperation eID,count j.=UI-&m  
            count=count-1 b(.-~c('  
        End If W9&0k+#^  
        count=count+1 [l8V<*x%S9  
    Wend Ism^hyL  
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    'Set new z-shift cX|[WT0[I  
    op.Type = "ShiftZ" 6?3
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    op.val1 = tlens p4m^ ~e  
    op.parent = parID &\J?[>EJ.  
    AddOperation eID, op T:K"  
    Print "Set lens thickness = " & tlens H4PbO/{xO  
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    '************************************************************************* >\|kJ?h  
    'Lens index of refraction @9}),hl`  
    '************************************************************************* "*Lj8C3|n  
    eID = FindMaterial( "Lens" ) *3A3>Rwu  
    GetModelMaterial eID, mat bx hPjAL  
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    mat.Nd = nlens G$?|S@I,  
    SetModelMaterial eID, mat 0[n c7)sW  
    Print "Set lens index of refraction = " & nlens Hv8SYQ|  
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    '************************************************************************* _u:>1]  
    'Pupil diameter 9">zdFC'  
    '************************************************************************* q[{:  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) .dD9&n;#^  
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    'Adjust pupil diameter (trimming volume inner hole) Wmzq  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" RL?u n}Qa  
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    ' Adjust pupil location to just in front of the lens 6B7<  
    parID = FindFullName( "Geometry.Arizona Eye" )
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    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) 38[)[{G)Hv  
    count = 0 nkCecwzr-  
    While GetOperationCount(eID)>count jrIA]K6  
        GetOperation eID, count, op I\}|Y+C$d/  
        If op.Type="ShiftZ" Then Yt
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            DeleteOperation eID,count G 6W
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            count=count-1
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        End If 7m@
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        count=count+1 c5X`_  
    Wend w- UKMW9"  
    op.Type = "ShiftZ" 3^!Hl8P7  
    op.val1 = taq-0.01 uWUR3n  
    op.parent = parID J__;.rnk  
    AddOperation eID, op }X=87ud  
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    Print "Set pupil diameter = " & pupilDiam -G8c5b[  
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    'Update AZ Eye subassembly Description .4wTjbO6  
    eID = FindFullName( "Geometry.Arizona Eye" ) uA~YRKer  
    GetEntity eID, entity -@rxiC:Q  
    entity.Description = "Accommodation = " & A & "D" dSwm|kIa  
    SetEntity eID, entity ,VAp>x+O  
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    Update kt:)W])V  
    Print "DONE!" RXBb:f  
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End Sub 3AK(dC[ri  
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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： , Hn7(^t  
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Accommodation = 4 Diopters wuKl-:S;Vs  
Pupil Diameter = 4 mm (Up'$J}  
Set aqueous humor thickness = 2.81 HzE1r+3Q@  
Set anterior lens radius = 10.4 and conic constant = -2.375869 gF3TwA
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Set posterior lens radius = -4.424557 and conic constant = -3.081019 mV<i JZh  
Set lens thickness = 3.927 , 7Xqte  
Set lens index of refraction = 1.42672 Xq|nJ|h  
Set pupil diameter = 4 (B&h;U$HAH  
DONE! UV4u.7y  
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