[技术]Arizona眼睛模型 [复制链接]

简介 <Z:Fnp
 
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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。 D&C83^m  
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模型 S9@2-Oc  
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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。 N{<9Njmm  
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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. M"l<::z  
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光源 ~V`F5B  
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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[
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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。 \7elqX`.yY  
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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。 vOnhJN  
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视网膜的散射 "H"4]m1Wc  
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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。 g*a|QBj%  
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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。 b$O1I[o  
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脚本 ]%I}hjJ  
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内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： GL-r;  
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如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 stcbM  
余下的脚本计算与屈光度有关的所有参数。 )cUFb:D*"  
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分析 %"{jNC?  
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屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 :^92B?q  
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脚本代码 uU;]/  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. yL.Z{w
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Dim entity As T_ENTITY +D&aE$<  
Dim op As T_OPERATION ImZ!8#  
Dim mat As T_MODELMATERIAL nPh|rW=  
Dim A As Double W2 p&LP  
Dim pupilDiam As Double yWkg4  
Dim eID As Long {T2=bK~  
Dim parID As Long Kp.d#W_TX
 
Dim count As Integer J=@D]I*3  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double kH9P(`;Vq  
Dim tlens As Double, nlens As Double XzV:q!e-  
Dim curv As Double, conic As Double ,rZp(moj  
Dim ok As Long 2zQ62t}  
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Sub Main R-\a3q  
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    '用户输入对话框 20Rj Rd  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 LH_rc  
        TextBox 220,21,40,21,.TextBox1 'default: 0 U 4Sxr  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 N~] 4,~  
        OKButton 40,91,90,21 G:k]tZ*`  
        CancelButton 190,91,90,21 jXu)%<  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 Fu;\t 0  
        TextBox 220,49,40,21,.TextBox2 'default: 4 m?4L
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    End Dialog dd&n>A3O=  
    Dim dlg As UserDialog ?^l{t4  
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    ok = Dialog (dlg) E!_mXjlPc  
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    If ok=0 Then    'cancel button was pressed KbP( ;  
        Print "Execution cancelled." 5UU1HC;C  
        End g$P<`.  
    End If :e|[gEA  
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    'Assign accommodation and pupil diameter & use defaults if field left empty F )|0U~  
    If dlg.TextBox1 = "" Then S(nZ]QEG  
        A = 0           'Default accommodation rr;p;  
    Else +&j&es  
        A = CDbl(dlg.TextBox1) Q3OGU}F  
    End If m.|__L  
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    If dlg.TextBox2 = "" Then 6~#$bp^-  
        pupilDiam = 4   'Default pupil diameter qT}AY.O%^  
    Else %DqPRl.Gu  
        pupilDiam = CDbl(dlg.TextBox2) RD1N@sHDKc  
    End If [@RJ2q$  
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    Print " " q[rBu9  
    Print "Accommodation = " & A & " Diopters" g~#HiBgWq[  
    Print "Pupil Diameter = " & pupilDiam & " mm" G5K_e:i  
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    ' Calculate new parameters with accommodation A"$UU6Z4  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness 1_Ag:>#X  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens bm Hl\?  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens n@ rphJb  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens -kZOve|5  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens [
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    tlens = 3.767 + 0.04*A                  'Lens thickness D%k`udz<  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction L4wKG&  
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    'Adjust parameters to account for accommodation 4Z"JC9As  
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    '************************************************************************* )C0dN>Gb  
    'Aqueous thickness (Position of Lens) fsr0E=nV  
    '************************************************************************* k%[pZ5.!  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) R,'` A.Kk  
    GetCustomElement eID, entity a*fUMhIi  
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    parID = FindFullName( "Geometry.Arizona Eye" ) x<-n}VK\  
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    ' Delete any shift(s) in z y66V&#`,e0  
    count = 0 pMfP3G7V  
    While GetOperationCount(eID)>count EP;TfWc}1  
        GetOperation eID, count, op 9iWs'M  
        If op.Type="ShiftZ" Then G"
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            DeleteOperation eID,count 5m e|dvk  
            count=count-1 :vqfWK6mv  
        End If .S{Q }S  
        count=count+1 @aX$}  
    Wend k8~/lE.Wy  
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    'Set new shift in }/{G  
    op.Type = "ShiftZ" HRPNZ!B  
    op.val1 = taq 5V{ B,T  
    op.parent = parID GG KD8'j]  
    AddOperation eID, op in/ITy-  
    Print "Set aqueous humor thickness = " & taq-0.55 W%)uKQha  
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    '************************************************************************* s?j` _B  
    'Radius and conic constant of anterior lens e{8j(` (;#  
    '************************************************************************* ATdK)gG  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) ~sd+ch*  
    GetConic eID, entity, curv, conic f"8!uE*;  
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    SetConic eID, entity, 1/Rant, CCant @n-[bN  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant "gR W91 T  
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    '************************************************************************* <`~zKFUQ[  
    'Radius and conic constant of posterior lens ;g0p`wV  
    '************************************************************************* 5tIM@,.I/  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) j#`d%eQ~J  
    GetConic eID, entity, curv, conic K1F,M9 0]  
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    SetConic eID, entity, 1/Rpost, CCpost ^YpA@`n  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost ?-"%
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    '************************************************************************* 6"d^4L?  
    'Lens thickness (Position of posterior lens surface) 8, >YB+Hb  
    '************************************************************************* .>K):|Opv  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) '_~X(izc  
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    ' Delete any z-shift(s) k]vrqjn Q  
    count = 0 m}x&]">9  
    While GetOperationCount(eID)>count 2(, `9  
        GetOperation eID, count, op  QTN _Z#'  
        If op.Type="ShiftZ" Then w_gPX0N}3n  
            DeleteOperation eID,count k#4%d1O}  
            count=count-1
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        End If XYKWOrkQqa  
        count=count+1 y5XHJUTu  
    Wend &*}NN5Sv  
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    'Set new z-shift J|orvnkK  
    op.Type = "ShiftZ" o4)^U t+  
    op.val1 = tlens {L!w/IeX  
    op.parent = parID yMQuM:d  
    AddOperation eID, op N}Ol`@@#h  
    Print "Set lens thickness = " & tlens x,sMa*vd  
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    '************************************************************************* x4PH-f-7  
    'Lens index of refraction blwdcdh  
    '************************************************************************* 
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    eID = FindMaterial( "Lens" ) d2Z kchf  
    GetModelMaterial eID, mat iK*2 Z$`lw  
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    mat.Nd = nlens X(-e-:B4;  
    SetModelMaterial eID, mat G;n'c7BV  
    Print "Set lens index of refraction = " & nlens ~zklrBn&  
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    '*************************************************************************
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    'Pupil diameter KfU4#2}
 
    '************************************************************************* $c-h'o  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) RLypWjMx$
 
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    'Adjust pupil diameter (trimming volume inner hole) )`RF2Y-A7  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" G`9\v
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    ' Adjust pupil location to just in front of the lens }+[H~8)5  
    parID = FindFullName( "Geometry.Arizona Eye" ) 4:\s.Z{!3  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) 8oSndfV  
    count = 0 +\FTR  
    While GetOperationCount(eID)>count `.z;.&x  
        GetOperation eID, count, op 8&6h()  
        If op.Type="ShiftZ" Then \*}JdEHB  
            DeleteOperation eID,count :X>%6Xj?RV  
            count=count-1 >EFjyhVE  
        End If ]Dm'J%P0}  
        count=count+1 p
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    Wend `~Eo;'(+^  
    op.Type = "ShiftZ" *p;Fwj]  
    op.val1 = taq-0.01 5oQy $Y  
    op.parent = parID r5qp[Ss3F  
    AddOperation eID, op =J0X{Ovn4z  
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    Print "Set pupil diameter = " & pupilDiam \UI7H1XDH  
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    'Update AZ Eye subassembly Description 7|6uY  
    eID = FindFullName( "Geometry.Arizona Eye" ) @O}%sjC1  
    GetEntity eID, entity od{b]HvgS  
    entity.Description = "Accommodation = " & A & "D" xrX^";}j  
    SetEntity eID, entity \ajy%$;$}  
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    Update >Vr+\c  
    Print "DONE!" ]/!#
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End Sub SxLu<  
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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： 75~>[JM  
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Accommodation = 4 Diopters .P\wE";  
Pupil Diameter = 4 mm <syMrXk)R(  
Set aqueous humor thickness = 2.81 +0mU)4n/  
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 XVjs0/5b  
Set lens thickness = 3.927 >3V{I'^^-  
Set lens index of refraction = 1.42672 4l+"J:,  
Set pupil diameter = 4 Bk&ry)`gD  
DONE! OD!b*Iy|