[技术]Arizona眼睛模型 [复制链接]

简介 )N7Y^CN~  
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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。 mt,OniU=Q  
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模型 X!9 B2w  
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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。 b[o"7^H  
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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. q,93nhs "  
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光源 ,*7 (%k^`  
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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。 ?~hHGf\^b6  
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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。 +yk24 `>  
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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。 ykV 5  
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视网膜的散射  SL#0kc0x  
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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。 =kJ,%\E`  
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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。 Yu)NO\3&  
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脚本 wt!nMQ  
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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： 5=v}W:^v.  
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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。 !F A]  
余下的脚本计算与屈光度有关的所有参数。 YQHw1  
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分析 Z4S!NDMm~  
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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。 ++6`sMJ  
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脚本代码 3RYpJAH  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. o
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Dim entity As T_ENTITY H`1{_  
Dim op As T_OPERATION V@zg}C|e  
Dim mat As T_MODELMATERIAL ^l9N48]|?  
Dim A As Double _ba>19csq%  
Dim pupilDiam As Double fVF2-Rh=  
Dim eID As Long _jLL_GD  
Dim parID As Long 6$kqa
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Dim count As Integer #gRM i)(F  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double `Aw^H!  
Dim tlens As Double, nlens As Double GFeQ%l`7F  
Dim curv As Double, conic As Double -:|?h{q?u  
Dim ok As Long $*e2YQdLo  
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Sub Main iII=;:p  
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    '用户输入对话框 9^oKtkoDZ  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 @;*Ksy@1O  
        TextBox 220,21,40,21,.TextBox1 'default: 0 LAB=Vp1y3[  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 #Y

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        OKButton 40,91,90,21 {:6r;TB  
        CancelButton 190,91,90,21 i,>khc  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 j[`j9mM8  
        TextBox 220,49,40,21,.TextBox2 'default: 4 7gf05Z'=  
    End Dialog %zG;Q@  
    Dim dlg As UserDialog hs^zTZ_  
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    ok = Dialog (dlg) ]^h]t~  
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    If ok=0 Then    'cancel button was pressed Xe$I7iKD  
        Print "Execution cancelled." >V-A;S:  
        End zk$FkbX  
    End If 1oR7iD^  
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    'Assign accommodation and pupil diameter & use defaults if field left empty [k.tWA,&  
    If dlg.TextBox1 = "" Then |iakz|])  
        A = 0           'Default accommodation [xSF6  
    Else ) i;1*jK  
        A = CDbl(dlg.TextBox1) u+Y\6~
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    End If q]T1dz?  
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    If dlg.TextBox2 = "" Then nV"~-On  
        pupilDiam = 4   'Default pupil diameter A,JmX  
    Else [w0QZyUn  
        pupilDiam = CDbl(dlg.TextBox2) '))0Lh l  
    End If k.uH~S_  
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    Print " " n&$j0k  
    Print "Accommodation = " & A & " Diopters" Ro\8ZXUQa  
    Print "Pupil Diameter = " & pupilDiam & " mm" o} J&E{Tk  
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    ' Calculate new parameters with accommodation '~5LY!H(pT  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness T1ut"
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens &v56#lG  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens '*K:  lx  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens Oxm>c[R  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens ``,fodA8  
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    tlens = 3.767 + 0.04*A                  'Lens thickness ]OM"ZG/^  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction SWH2  
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    'Adjust parameters to account for accommodation k Z?=AXu  
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    '************************************************************************* H=<S 9M  
    'Aqueous thickness (Position of Lens) :0Bq^G"ge  
    '************************************************************************* PY{ G [  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) m4**~xfC  
    GetCustomElement eID, entity \d6C%S!  
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    parID = FindFullName( "Geometry.Arizona Eye" ) I4'5P}1yp  
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    ' Delete any shift(s) in z qyZ" %Kz  
    count = 0 ( Z619w  
    While GetOperationCount(eID)>count FEW14U'O  
        GetOperation eID, count, op qU+t/C.  
        If op.Type="ShiftZ" Then 1#C4;3i,  
            DeleteOperation eID,count ,kiv>{  
            count=count-1 (uXL^oja  
        End If YJ^] u}  
        count=count+1 gR&Q3jlIV  
    Wend 'H3^e}   
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    'Set new shift in 0@[$lv;OS  
    op.Type = "ShiftZ" 6^V=?~a&z  
    op.val1 = taq eX?OYDDC0j  
    op.parent = parID \MA+f~)9  
    AddOperation eID, op I&2c&yO  
    Print "Set aqueous humor thickness = " & taq-0.55 !02`t4Zc-  
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    '************************************************************************* ^&B@Uw5{  
    'Radius and conic constant of anterior lens ojafy}  
    '************************************************************************* Ghu#XJB?  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) V_R@o3kv
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    GetConic eID, entity, curv, conic 44gPCW,u  
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    SetConic eID, entity, 1/Rant, CCant 35A|BD)q  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant .t{MIC  
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    '************************************************************************* }{,^@xdyW  
    'Radius and conic constant of posterior lens ; ^*}#Xd  
    '************************************************************************* u#Pa7_zBj]  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) bk[
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    GetConic eID, entity, curv, conic Z 6t56"u  
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    SetConic eID, entity, 1/Rpost, CCpost VEH&&@d  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost cL-[ZvyVX  
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    '************************************************************************* |EIng0a  
    'Lens thickness (Position of posterior lens surface) TCN8a/@z  
    '************************************************************************* ?[VM6- &  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) e|NG"
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    ' Delete any z-shift(s) g%ndvdb m  
    count = 0 BTlk Etm  
    While GetOperationCount(eID)>count F<ZYh  
        GetOperation eID, count, op c%^7!FSg  
        If op.Type="ShiftZ" Then hjU::m,WX  
            DeleteOperation eID,count bh
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            count=count-1 4qphA9i1  
        End If 5/q}`T9i%7  
        count=count+1 i#&z2h-b  
    Wend \(3y7D  
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    'Set new z-shift Htay-PB }  
    op.Type = "ShiftZ" gD0eFTN  
    op.val1 = tlens l3KVW5-!gS  
    op.parent = parID GSY(  
    AddOperation eID, op N@;?CKU  
    Print "Set lens thickness = " & tlens !!qK=V|>  
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    '************************************************************************* 8&;UO{  
    'Lens index of refraction }elc `jj  
    '************************************************************************* ;5wn67'  
    eID = FindMaterial( "Lens" ) #c!*</  
    GetModelMaterial eID, mat z(o,m3@v  
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    mat.Nd = nlens 'WMh8)  
    SetModelMaterial eID, mat 8a&:6Zuo  
    Print "Set lens index of refraction = " & nlens jLy  
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    '************************************************************************* zUDg&-J3  
    'Pupil diameter x"eRJii?  
    '************************************************************************* Okgv!Nt8)A  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) cO-7ke  
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    'Adjust pupil diameter (trimming volume inner hole) zqd@EF6/bz  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" V @rI`~$  
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    ' Adjust pupil location to just in front of the lens @(
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    parID = FindFullName( "Geometry.Arizona Eye" ) y9_V  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) -Btk 3  
    count = 0 Z<U6<{b  
    While GetOperationCount(eID)>count OHv[#xGuV?  
        GetOperation eID, count, op 9*$t!r{B@  
        If op.Type="ShiftZ" Then 3NZK*!@'  
            DeleteOperation eID,count M])ZK  
            count=count-1 3sc+3-TF  
        End If J%8(kWQ|  
        count=count+1 ::o lN  
    Wend wWgWWXGT}  
    op.Type = "ShiftZ" k2E0/ @f{k  
    op.val1 = taq-0.01 :WC2Ax7$2  
    op.parent = parID )js)2L~  
    AddOperation eID, op -VZ-<\uH  
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    Print "Set pupil diameter = " & pupilDiam Ytgcs( /$  
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    'Update AZ Eye subassembly Description >82@Q^O  
    eID = FindFullName( "Geometry.Arizona Eye" ) %el"BSB  
    GetEntity eID, entity [vge56h  
    entity.Description = "Accommodation = " & A & "D" |].pDwgt  
    SetEntity eID, entity 85lCj-cs  
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    Update ]d55m/(   
    Print "DONE!" QS0:@.}$E)  
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End Sub I6~pV@h^=  
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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： $ oTdfb  
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Accommodation = 4 Diopters 4f@o m
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Pupil Diameter = 4 mm r$5i Wu  
Set aqueous humor thickness = 2.81 Y_}mYvJW  
Set anterior lens radius = 10.4 and conic constant = -2.375869 U93}-){m  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 _4TH4~cY  
Set lens thickness = 3.927 ktI/3Mb@  
Set lens index of refraction = 1.42672 -g)9R%>
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Set pupil diameter = 4 A2^\q>_#  
DONE! W8Q|$ZJ88F