[技术]Arizona眼睛模型 [复制链接]

简介 j8M}
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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。 t2BkQ8vr  
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模型 p W:[Q\rSj  
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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。 R5X<8(4p  
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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. 58mzh
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光源 F04`MY"  
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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。 -qs.'o ;2  
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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。 D(~6h,=m  
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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。 ?T$i  
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视网膜的散射 {tu* =
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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。 6.Ef
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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。 G+m|A*[>  
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脚本 C(}9  
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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： WT'P[RU2  
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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。 .oaW#f}0P  
余下的脚本计算与屈光度有关的所有参数。 -66|Y  
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分析 Ea!}r|~]0  
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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。 xb8fV*RO8A  
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脚本代码 fa\<![8LAU  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. 6x*ImhQ.J  
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Dim entity As T_ENTITY 7Ar4:iNvX  
Dim op As T_OPERATION 87~. |nu  
Dim mat As T_MODELMATERIAL *3S,XMS{O  
Dim A As Double e<~uU9 lg1  
Dim pupilDiam As Double (LL4V 3)  
Dim eID As Long `9a%}PVQ-  
Dim parID As Long mEz&:A  
Dim count As Integer fU>"d>6!S  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double PS`)6yn{_  
Dim tlens As Double, nlens As Double #4%,09+  
Dim curv As Double, conic As Double A[htG\A` 0  
Dim ok As Long Y_Ej-u+>{  
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Sub Main 4xtbP\=
 
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    '用户输入对话框 uO,90g[C/R  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 NZ7a^xT_)  
        TextBox 220,21,40,21,.TextBox1 'default: 0 @L{HT8utK3  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 1
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        OKButton 40,91,90,21 &IXr*I  
        CancelButton 190,91,90,21 p*#SSR9<  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 c{|soc[#  
        TextBox 220,49,40,21,.TextBox2 'default: 4 2NIK0%6  
    End Dialog ~u,g5  
    Dim dlg As UserDialog Xw9,O8}C7  
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    ok = Dialog (dlg) 6M+~{9(S  
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    If ok=0 Then    'cancel button was pressed ;[gv-H  
        Print "Execution cancelled." Gxm+5q  
        End N7+K$)3  
    End If h-lMrI)U?h  
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    'Assign accommodation and pupil diameter & use defaults if field left empty 'qQDM_+  
    If dlg.TextBox1 = "" Then C(e!cOG  
        A = 0           'Default accommodation ;)"r^M)):  
    Else '~liDz*O   
        A = CDbl(dlg.TextBox1) 7D9R^\K  
    End If (t<i?>p  
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    If dlg.TextBox2 = "" Then PJO;[: .I  
        pupilDiam = 4   'Default pupil diameter >4LX!^V"  
    Else =E4nNL
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        pupilDiam = CDbl(dlg.TextBox2) ^h^j:!76j  
    End If ,1^)JshZ~  
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    Print " " PcDPRX!@  
    Print "Accommodation = " & A & " Diopters" 7@+0E2'  
    Print "Pupil Diameter = " & pupilDiam & " mm" w<\N-J|m  
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    ' Calculate new parameters with accommodation "TN}=^A\F  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness A{&Etu(K  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens [}P|OCW  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens Y*w<~m  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens "GZhr[AW  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens ~a/yLI"'g  
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    tlens = 3.767 + 0.04*A                  'Lens thickness Mz
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction Hej0l^  
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    'Adjust parameters to account for accommodation |6_<4lmTxF  
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    '************************************************************************* __3Cjo^6&  
    'Aqueous thickness (Position of Lens) 5%tIAbGW  
    '************************************************************************* BMFpkK9|  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) V4VTP]'n  
    GetCustomElement eID, entity @X1>Wv|[  
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    parID = FindFullName( "Geometry.Arizona Eye" ) 0B3*\ H}5  
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    ' Delete any shift(s) in z kw=+"U  
    count = 0 3fM  
    While GetOperationCount(eID)>count \Sm.]=br  
        GetOperation eID, count, op 3R4-MK  
        If op.Type="ShiftZ" Then !^`ZHJ-3>;  
            DeleteOperation eID,count b?H
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            count=count-1 /i^b;?/1  
        End If aEX+M57k~  
        count=count+1 xx9qi^  
    Wend x#Hq74H,  
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    'Set new shift in
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    op.Type = "ShiftZ" v?d~H`L  
    op.val1 = taq  D&N5)   
    op.parent = parID Is?0q@  
    AddOperation eID, op <VgnrqF6:  
    Print "Set aqueous humor thickness = " & taq-0.55 `wk#5[Y_  
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    '************************************************************************* 7,Z%rqf\)  
    'Radius and conic constant of anterior lens *,pG4kh!  
    '************************************************************************* CS6,mX  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) HjV83S;  
    GetConic eID, entity, curv, conic *qKwu?]?>  
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    SetConic eID, entity, 1/Rant, CCant j.ANBE96>  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant LFg<j1Gk`  
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    '************************************************************************* N:gS]OI*  
    'Radius and conic constant of posterior lens JJ7-$h'0q  
    '************************************************************************* ("H:T?4Qs  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) d \0K3=h  
    GetConic eID, entity, curv, conic @c7 On)sy  
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    SetConic eID, entity, 1/Rpost, CCpost jC;XY!d6  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost m,)Re8W-  
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    '************************************************************************* W&Fa8  
    'Lens thickness (Position of posterior lens surface) y . AN0  
    '************************************************************************* =EV8~hMyqh  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) b/ ~&M+)  
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    ' Delete any z-shift(s) 6,cyi|s  
    count = 0 kiqq_`66  
    While GetOperationCount(eID)>count @R`OAdy  
        GetOperation eID, count, op G0a
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        If op.Type="ShiftZ" Then Z$6W)~;,
 
            DeleteOperation eID,count p/SJt0  
            count=count-1 V{c n1Af  
        End If NV*
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        count=count+1 W;Fcp  
    Wend =Z%&jul  
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    'Set new z-shift FDpNM\SR1l  
    op.Type = "ShiftZ" :c<C;.  
    op.val1 = tlens vgsu~(L;  
    op.parent = parID ~TurYvf  
    AddOperation eID, op \s+<
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    Print "Set lens thickness = " & tlens d]w*fn  
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    '************************************************************************* /5zzzaj{  
    'Lens index of refraction S(/@.gI:f  
    '************************************************************************* uw;s](~E  
    eID = FindMaterial( "Lens" ) /AW6XyMD_  
    GetModelMaterial eID, mat %qN8uQx  
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    mat.Nd = nlens .RoO6:T6  
    SetModelMaterial eID, mat [o>/2  
    Print "Set lens index of refraction = " & nlens 5.5dB2w  
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    '************************************************************************* 574
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    'Pupil diameter {s_0[>  
    '************************************************************************* Yo(8mtYU  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) <}.)kg${O  
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    'Adjust pupil diameter (trimming volume inner hole) /`2VJw  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" zgVplp  
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    ' Adjust pupil location to just in front of the lens cCWOGd  
    parID = FindFullName( "Geometry.Arizona Eye" ) H$\?D+xlf  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) t_P1a0Zu  
    count = 0 5F&i/8Ib  
    While GetOperationCount(eID)>count 0#<
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        GetOperation eID, count, op h_y<A@[P}  
        If op.Type="ShiftZ" Then 'KyT]OObS  
            DeleteOperation eID,count ~x>IN1Vci  
            count=count-1 /A##Yv!biR  
        End If :UFf6T?  
        count=count+1 7+=j]+O  
    Wend l\MiG Na  
    op.Type = "ShiftZ" Ig$5Ui  
    op.val1 = taq-0.01 zA-?x1th&  
    op.parent = parID 7_q"%xH  
    AddOperation eID, op @A$%baH0  
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    Print "Set pupil diameter = " & pupilDiam G++kUo<  
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    'Update AZ Eye subassembly Description [iL2c=_  
    eID = FindFullName( "Geometry.Arizona Eye" ) +R#*eo;o7  
    GetEntity eID, entity S7N54X2JwL  
    entity.Description = "Accommodation = " & A & "D"  FcfN]!  
    SetEntity eID, entity /[{?zS{  
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    Update F!aYK2  
    Print "DONE!" e(!a~{(kq%  
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End Sub wl(}F^:/`  
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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： '7_'s1  
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Accommodation = 4 Diopters XV+BSW7}  
Pupil Diameter = 4 mm fI"`[cA"]  
Set aqueous humor thickness = 2.81 TR ]lP<m  
Set anterior lens radius = 10.4 and conic constant = -2.375869 W>1\f0'  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 5|H?L@_9  
Set lens thickness = 3.927 t'[vN~I'  
Set lens index of refraction = 1.42672 =YPWt>\a}  
Set pupil diameter = 4 -U;s,>\)  
DONE! M5P63=1+