[技术]Arizona眼睛模型 [复制链接]

简介 dtZE67KS  

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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。 E5</h"1  
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模型 PLX>-7@  
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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。 y7/F_{  

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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. ICC%,$C~l  
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光源 Jrxz'9qRG  
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多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 h6~$/`&]b  
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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。 -' g*^  
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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。 rV6/Tdy  
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视网膜的散射 "ZwKk G  
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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。 !-<p,z  
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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。 #Tw@wfaq)  
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脚本 qz?mh4Oh  
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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： AN!s{7V3  
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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。 ,R%q}IH#  
余下的脚本计算与屈光度有关的所有参数。 SZaS;hhhHu  
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分析 $odso;Hn  
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屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 wLc4Dm*V  
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脚本代码 .*m>\>Gsgw  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. <sK4#!K  
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Dim entity As T_ENTITY #@<9S{F  
Dim op As T_OPERATION `x%'jPP1^  
Dim mat As T_MODELMATERIAL Z}$TKO*u  
Dim A As Double BauU{:Sh  
Dim pupilDiam As Double F*"}aP$  
Dim eID As Long okbQ<{9  
Dim parID As Long 7}M2bH} \K  
Dim count As Integer /|* Y2ETOr  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double 93Co}@Y;Y+  
Dim tlens As Double, nlens As Double '>r7V  
Dim curv As Double, conic As Double i3rH'B-I.  
Dim ok As Long Fu!RhsW5j  
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Sub Main &=VDASEu  
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    '用户输入对话框 qkiI/nH3  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 _/i4MtM  
        TextBox 220,21,40,21,.TextBox1 'default: 0 'Lu__NfN  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 tH-C8Qxy  
        OKButton 40,91,90,21 X5j1`t,  
        CancelButton 190,91,90,21 yUpgoX(6  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 Q ]}Hd-  
        TextBox 220,49,40,21,.TextBox2 'default: 4 M5 <@~V/[  
    End Dialog EK4d_L]I  
    Dim dlg As UserDialog yu;P +G  
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    ok = Dialog (dlg) 6I%5Q4Ll  
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    If ok=0 Then    'cancel button was pressed #{?qNl8F*J  
        Print "Execution cancelled." 'FDef#P<  
        End v%q0OX>9X"  
    End If gHo?[pS%y  
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    'Assign accommodation and pupil diameter & use defaults if field left empty 1fpQLaT  
    If dlg.TextBox1 = "" Then V,cBk  
        A = 0           'Default accommodation Evedc*z~P  
    Else =>_\fNy  
        A = CDbl(dlg.TextBox1) lhqg$lb  
    End If C#Na&m  
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    If dlg.TextBox2 = "" Then INJEsz  
        pupilDiam = 4   'Default pupil diameter PpAu!2lt9  
    Else MRdduPrM%$  
        pupilDiam = CDbl(dlg.TextBox2) 2.l:O2<  
    End If @0/+_2MH-  
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    Print " " |&zz,
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    Print "Accommodation = " & A & " Diopters" MB]<Dyj,  
    Print "Pupil Diameter = " & pupilDiam & " mm" *-8&[D0  
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    ' Calculate new parameters with accommodation fTK3,s1=  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness UWd=!h^dt  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens wY[+ZT  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens 7t0er'VC  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens toBHkiuD  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens 'Wmx)0)  
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    tlens = 3.767 + 0.04*A                  'Lens thickness v@ lM3_rbO  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction +l<5#pazx  
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    'Adjust parameters to account for accommodation k@k&}N0{  
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    '************************************************************************* 8|l\EVV6  
    'Aqueous thickness (Position of Lens) paCV!tP  
    '************************************************************************* P*3BB>FO   
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) 1cpiHZa  
    GetCustomElement eID, entity qKr8)}h  
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    parID = FindFullName( "Geometry.Arizona Eye" ) h7lDHIQf  
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    ' Delete any shift(s) in z e#$]Y?,  
    count = 0 ;;6uw\6 O  
    While GetOperationCount(eID)>count -z)n?(pftm  
        GetOperation eID, count, op $QN"wL||  
        If op.Type="ShiftZ" Then 8 Hg+H=?  
            DeleteOperation eID,count "&G/T ?4  
            count=count-1 Bg x'9p/  
        End If TJ6*t!'*X  
        count=count+1 r\'A i6  
    Wend M_/7D|xl/T  
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    'Set new shift in \/zq7j  
    op.Type = "ShiftZ" keL&b/@  
    op.val1 = taq v$?+MNks  
    op.parent = parID mwHB(7YS,  
    AddOperation eID, op jaII r06  
    Print "Set aqueous humor thickness = " & taq-0.55 PNgY>=Y  
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    '************************************************************************* <Tzrj1"Q3  
    'Radius and conic constant of anterior lens 0zmE>/O+
 
    '************************************************************************* ;-~B)M_S`  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) g?goZPZB  
    GetConic eID, entity, curv, conic 8lvV4
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    SetConic eID, entity, 1/Rant, CCant gY/"cq  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant nP$Ky1y G  
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    '************************************************************************* C~,a!qY  
    'Radius and conic constant of posterior lens 5F)C  jQ  
    '************************************************************************* #Z?A2r!1  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) {FeDvhv  
    GetConic eID, entity, curv, conic a*lh)l<KV  
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    SetConic eID, entity, 1/Rpost, CCpost _.tVSVp  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost iVhJ t#_b  
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    '************************************************************************* |W,& Hl7  
    'Lens thickness (Position of posterior lens surface) e^6)Zz1\  
    '************************************************************************* P{kur} T  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) tqE6>"jD  
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    ' Delete any z-shift(s) ^ Edfv5  
    count = 0 N)uSG&S:  
    While GetOperationCount(eID)>count x nsLf?>]  
        GetOperation eID, count, op dk[!V1x4\  
        If op.Type="ShiftZ" Then }
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            DeleteOperation eID,count )B"jF>9)[  
            count=count-1 [kVS O  
        End If hZ?Rof  
        count=count+1 6iVxc|Ia  
    Wend SoW9p^HJ  
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    'Set new z-shift ?PuBa`zDE  
    op.Type = "ShiftZ" X9v.1s,  
    op.val1 = tlens $v4.sl:x  
    op.parent = parID T"{>t  
    AddOperation eID, op !#], hok8X  
    Print "Set lens thickness = " & tlens eBZXI)pPh  
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    '************************************************************************* kyR:[+je  
    'Lens index of refraction 2e+UM$  
    '************************************************************************* 2J7:\pR^  
    eID = FindMaterial( "Lens" ) jwc
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    GetModelMaterial eID, mat >K_(J/&p  
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    mat.Nd = nlens l: HTk4$0  
    SetModelMaterial eID, mat xK *b1CB  
    Print "Set lens index of refraction = " & nlens N({MP
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    '************************************************************************* sJB;3"~  
    'Pupil diameter bkOv2tZ  
    '************************************************************************* <Th6r.#?  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) u1J0$  
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    'Adjust pupil diameter (trimming volume inner hole) |^&b8  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" kvL=> A  
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    ' Adjust pupil location to just in front of the lens G,&<<2{(f;  
    parID = FindFullName( "Geometry.Arizona Eye" ) 5Yg'BkEr  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) @6Y?\Wx$w  
    count = 0 >8~.wXyoC  
    While GetOperationCount(eID)>count D$w6V  
        GetOperation eID, count, op nHM
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        If op.Type="ShiftZ" Then k :(SCHf  
            DeleteOperation eID,count #3i3G(mQ  
            count=count-1 "3X2VFwo
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        End If R{C(K(5/  
        count=count+1 Vh'P&W?[  
    Wend |B?cVc0  
    op.Type = "ShiftZ" L7n D|  
    op.val1 = taq-0.01 ;,hwZZ
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    op.parent = parID F|'>NL-=  
    AddOperation eID, op kjTduZ/3"  
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    Print "Set pupil diameter = " & pupilDiam 8r*E-akuyr  
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    'Update AZ Eye subassembly Description \ ZgE  
    eID = FindFullName( "Geometry.Arizona Eye" ) &C`Gg<  
    GetEntity eID, entity iN bIp"W  
    entity.Description = "Accommodation = " & A & "D" QE^$=\l0  
    SetEntity eID, entity 9&$y}Y  
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    Update :vmH]{R  
    Print "DONE!" 'j`=if
 
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End Sub J4k=A7^N  
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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： J9\Cm!H  
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Accommodation = 4 Diopters bZ dNi
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Pupil Diameter = 4 mm eQ$Y0qH1E  
Set aqueous humor thickness = 2.81 KI.q@zO6|  
Set anterior lens radius = 10.4 and conic constant = -2.375869 j
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Set posterior lens radius = -4.424557 and conic constant = -3.081019 b:U$x20n$  
Set lens thickness = 3.927 +jAGGv^)  
Set lens index of refraction = 1.42672 b_$4V3TA  
Set pupil diameter = 4 FI)17i$  
DONE! ^%d\qd`