[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 A4]s~Ur  
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。 -^ C=]Medl  
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模型 H Tz  
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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。 bk\yCt06y;  
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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. Zw~
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光源 5Fz.Y}  
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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。 dzkw$m^@^  
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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。 \~5C7^_  
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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。 +EAT:,  
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视网膜的散射 Dxk+P!!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。 <2nZ&M4/s{  
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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。 [S@}T zE  
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脚本 ~M(5Ho  
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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： yu;SH[{Wi  
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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。 E[^ {w  
余下的脚本计算与屈光度有关的所有参数。 gp-T"l  
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分析 UG<79"\i  
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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。  PTS]7  
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脚本代码 L.=w?%:H=  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. qSejLh6  
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Dim entity As T_ENTITY 8#
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Dim op As T_OPERATION 1LY8Ma]E  
Dim mat As T_MODELMATERIAL WW@d:R  
Dim A As Double l)-Mq@V  
Dim pupilDiam As Double :>81BuMvg  
Dim eID As Long H-p
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Dim parID As Long h},oF!,  
Dim count As Integer _e7-zg$/  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double ')N{wSM9Ft  
Dim tlens As Double, nlens As Double `.2hjO  
Dim curv As Double, conic As Double O0PJ6:9P  
Dim ok As Long jp+_@S>  
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Sub Main :ZDMNhUl &  
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    '用户输入对话框 "+uNmUUnm  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 TH&
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        TextBox 220,21,40,21,.TextBox1 'default: 0 DSxUdEK6  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 "3F;cCDv]  
        OKButton 40,91,90,21 }Up.)
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        CancelButton 190,91,90,21 g`>og^7g  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 ! <WBCclX  
        TextBox 220,49,40,21,.TextBox2 'default: 4 |/ }\6L]  
    End Dialog 1h7+@#<:a  
    Dim dlg As UserDialog 9GdB#k6W`  
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    ok = Dialog (dlg) j(#%tIv  
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    If ok=0 Then    'cancel button was pressed ejXMKPE;  
        Print "Execution cancelled." aTzDew  
        End gLsU:aeCT  
    End If [\Qr. 2  
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    'Assign accommodation and pupil diameter & use defaults if field left empty g-vg6@6  
    If dlg.TextBox1 = "" Then $t-n'Qh^2  
        A = 0           'Default accommodation S.|FL%;  
    Else j'p1q  
        A = CDbl(dlg.TextBox1) (.3'=n|kE  
    End If MEiRj]t  
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    If dlg.TextBox2 = "" Then !q"CV  
        pupilDiam = 4   'Default pupil diameter @$eT~ C  
    Else [hRU&z;W  
        pupilDiam = CDbl(dlg.TextBox2)
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    End If y/c%+Ca/  
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    Print " " rp7W }P+uU  
    Print "Accommodation = " & A & " Diopters" XUV!C7  
    Print "Pupil Diameter = " & pupilDiam & " mm" gBk5wk_j|  
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    ' Calculate new parameters with accommodation VK3it3FI>3  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness kJ)gP2E  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens "'Z- UV  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens nkeI60  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens ]|:uU  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens =sOo:s
 
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    tlens = 3.767 + 0.04*A                  'Lens thickness 9j|gdfb%ml  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction \0FT!} L  
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    'Adjust parameters to account for accommodation 'q%%m/,VPQ  
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    '************************************************************************* F:37MUQi  
    'Aqueous thickness (Position of Lens) BC\S/5~k  
    '************************************************************************* gd^Js1Z  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) X21dX`eMN  
    GetCustomElement eID, entity s.jO<{  
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    parID = FindFullName( "Geometry.Arizona Eye" ) 7uI#L}y  
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    ' Delete any shift(s) in z PQj<[rY
 
    count = 0 #%S0PL"x U  
    While GetOperationCount(eID)>count PoD^`()FR{  
        GetOperation eID, count, op QYT
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        If op.Type="ShiftZ" Then 3 EYiQ`  
            DeleteOperation eID,count (%<'A  
            count=count-1 FEm=w2  
        End If ^lO76Dz~a  
        count=count+1 So4nJ><p  
    Wend ulXnq`  
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    'Set new shift in &:#m&,tQ  
    op.Type = "ShiftZ" ;6DnId2Zh  
    op.val1 = taq WtX>Qu|  
    op.parent = parID &/ouW'oP  
    AddOperation eID, op NW.XA! =E)  
    Print "Set aqueous humor thickness = " & taq-0.55 #o[\Dwu  
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    '************************************************************************* h[=nx^  
    'Radius and conic constant of anterior lens YL5>V$i  
    '************************************************************************* .RRlUWu  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) p#H]\P'  
    GetConic eID, entity, curv, conic 68x}w Ae  
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    SetConic eID, entity, 1/Rant, CCant uu}-"/<~7  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant YBSl-G'  
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    '************************************************************************* \{PNwF?  
    'Radius and conic constant of posterior lens +8^_D?*\n  
    '************************************************************************* C{Blqf3V0  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) <TjBd1  
    GetConic eID, entity, curv, conic 5N1 K~".  
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    SetConic eID, entity, 1/Rpost, CCpost $A?}a  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost /4C`k=>  
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    '************************************************************************* 4r*Pa(;y  
    'Lens thickness (Position of posterior lens surface) oCJbkt=  
    '************************************************************************* }aZrou3E  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) )vHi|~(  
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    ' Delete any z-shift(s) %CT!$Y'n  
    count = 0 ]p$zvMf}  
    While GetOperationCount(eID)>count $Sb@zLi)  
        GetOperation eID, count, op :QKb#4/8;  
        If op.Type="ShiftZ" Then l10-XU02  
            DeleteOperation eID,count uL>:tb  
            count=count-1 nW&$
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        End If ve%l({  
        count=count+1 m"-G6BKS  
    Wend r~[B_f!  
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    'Set new z-shift U
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    op.Type = "ShiftZ" lJj&kVHb  
    op.val1 = tlens 1NGyaI  
    op.parent = parID ITn;m  
    AddOperation eID, op _m7co :  
    Print "Set lens thickness = " & tlens 6UI>
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    '************************************************************************* ZeTL$E[E}  
    'Lens index of refraction ` @>ZGL:  
    '************************************************************************* 3k{c$x}  
    eID = FindMaterial( "Lens" ) @Mr}6x*  
    GetModelMaterial eID, mat ^;64!BaK  
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    mat.Nd = nlens \-G5l+!  
    SetModelMaterial eID, mat TF)8qHy! u  
    Print "Set lens index of refraction = " & nlens t 2G1[j!  
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    '************************************************************************* @tQ2E}psP,  
    'Pupil diameter *2#FRA#q  
    '************************************************************************* '^B3pR:  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) \6LcVik  
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    'Adjust pupil diameter (trimming volume inner hole) M1gP R  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" sZEgsrJh  
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    ' Adjust pupil location to just in front of the lens {DS\!0T-X  
    parID = FindFullName( "Geometry.Arizona Eye" ) L"9 Gc  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) ,W8au"  
    count = 0 ,0.|P`|w  
    While GetOperationCount(eID)>count 'XEK&Yi1  
        GetOperation eID, count, op aa!a&L|!  
        If op.Type="ShiftZ" Then s79q5  
            DeleteOperation eID,count -sx-7LKi  
            count=count-1 [[&)cbv  
        End If _&K\D p&@  
        count=count+1 "&Ff[O*  
    Wend Lv^a+'  
    op.Type = "ShiftZ" 9Yd-m  
    op.val1 = taq-0.01 R;.d/U|av  
    op.parent = parID 6_Fpca3L  
    AddOperation eID, op Q+HZ?V(  
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    Print "Set pupil diameter = " & pupilDiam w
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    'Update AZ Eye subassembly Description i@Vs4E[b  
    eID = FindFullName( "Geometry.Arizona Eye" ) |O%:P}6c  
    GetEntity eID, entity OM1*I
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    entity.Description = "Accommodation = " & A & "D" 17|
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    SetEntity eID, entity sb`&bA;i  
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    Update vs+We*8H  
    Print "DONE!" >QA/Mi~R  
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End Sub KxGKA  
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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： uSH>$;a  
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Accommodation = 4 Diopters bx;yHIRb  
Pupil Diameter = 4 mm >7"$}5d  
Set aqueous humor thickness = 2.81 G OH  
Set anterior lens radius = 10.4 and conic constant = -2.375869 /*AJ+K._  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 VjC*(6<Gj  
Set lens thickness = 3.927 Oi6f8*,  
Set lens index of refraction = 1.42672 7s0)3HR}  
Set pupil diameter = 4 OiYNH~hv  
DONE! mJSK; @w<O  
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