[技术]Arizona眼睛模型 [复制链接]

简介 NX?6 (lO,  
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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。 ro18%'RRI  
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模型 M0woJt[&  
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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。 VaTA|=[;  
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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. OQ4rJ#b  
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光源 /B5rWJ2AS  
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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。 phy:G
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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。 }XRRM:B|)(  
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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。 }\vw>iHPX@  
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视网膜的散射 aTE;Gy,W  
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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。 &M2fcw?  
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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。 gr4JaV  
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脚本 -@/!u9l  
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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： ;%O>=m'4  
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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。 ]?~[!&h  
余下的脚本计算与屈光度有关的所有参数。 zO3}c3D~q  
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分析 laaoIL^  
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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。 QE`u~  
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脚本代码 )Z63 cr/  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. '! ~s=  
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Dim entity As T_ENTITY kj'  
Dim op As T_OPERATION  q #X[oVq  
Dim mat As T_MODELMATERIAL 0
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Dim A As Double q ?m<9`  
Dim pupilDiam As Double P@Av/r  
Dim eID As Long M.KXDD#O  
Dim parID As Long L$=a,$  
Dim count As Integer ?^{Ey[)'(  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double C<N7zMwT  
Dim tlens As Double, nlens As Double tMr$N[@r  
Dim curv As Double, conic As Double NucLf6  
Dim ok As Long =}[m_rp&  
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Sub Main Z4tc3e  
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    '用户输入对话框 K2-nP2Go?  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 );fPir?+  
        TextBox 220,21,40,21,.TextBox1 'default: 0 j4Y] 8  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1  A}n7A   
        OKButton 40,91,90,21 Y,d|b V*FH  
        CancelButton 190,91,90,21 o.>Yj)U  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 PsI{y&.  
        TextBox 220,49,40,21,.TextBox2 'default: 4 kI/%|L%6D  
    End Dialog (.~'\@  
    Dim dlg As UserDialog ~D!Y] SK  
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    ok = Dialog (dlg) QjyJmW("Z  
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    If ok=0 Then    'cancel button was pressed P:c'W?  
        Print "Execution cancelled." Owm2/  
        End k1;Jkq~  
    End If q%wF=<W  
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    'Assign accommodation and pupil diameter & use defaults if field left empty d4A3DTW  
    If dlg.TextBox1 = "" Then /G#W/Q  
        A = 0           'Default accommodation /V!gF+L  
    Else Bt"*a=t;  
        A = CDbl(dlg.TextBox1) .;NoKO7)  
    End If X*rB`M7,  
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    If dlg.TextBox2 = "" Then )LE#SGJP  
        pupilDiam = 4   'Default pupil diameter T1fX[R ^\  
    Else R|dSjEs  
        pupilDiam = CDbl(dlg.TextBox2) 
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    End If +yI
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    Print " " 8!Q0:4Vb  
    Print "Accommodation = " & A & " Diopters" kl9<l*  
    Print "Pupil Diameter = " & pupilDiam & " mm" (JeRJ4  
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    ' Calculate new parameters with accommodation ]\oE}7K%r  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness nokMS  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens [NguQ]B.  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens )\,hc$<=m  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens &6@e9ff0  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens 4L[-[{2  
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    tlens = 3.767 + 0.04*A                  'Lens thickness v9vY#W  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction )lB*] n`Z]  
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    'Adjust parameters to account for accommodation 8:t1%O$  
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    '************************************************************************* 8:4`q9  
    'Aqueous thickness (Position of Lens) ^W
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    '************************************************************************* zd#/zUPI  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) cLCzLNyKl  
    GetCustomElement eID, entity 9A1w5|X  
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    parID = FindFullName( "Geometry.Arizona Eye" ) 1dX)l  
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    ' Delete any shift(s) in z NpF}~$2  
    count = 0 Gz
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    While GetOperationCount(eID)>count XP_V  
        GetOperation eID, count, op a+{95"4  
        If op.Type="ShiftZ" Then ppo\cy;  
            DeleteOperation eID,count B=J/HiwV)  
            count=count-1 OgBZoTT  
        End If @X*r5hjc  
        count=count+1 h;sdm/  
    Wend B|n<{g[-cM  
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    'Set new shift in  <IL$8a  
    op.Type = "ShiftZ" FR@##i$  
    op.val1 = taq B|+t
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    op.parent = parID wXxk+DV@  
    AddOperation eID, op 4>xv7  
    Print "Set aqueous humor thickness = " & taq-0.55 haMt2S2_B:  
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    '************************************************************************* rC!~4xj-  
    'Radius and conic constant of anterior lens SgocHpyg  
    '************************************************************************* Oy/+uw^  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) 0q ^dpM  
    GetConic eID, entity, curv, conic <sq@[\l}a  
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    SetConic eID, entity, 1/Rant, CCant 1p9+c~4l:  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant #.n%$r  
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    '************************************************************************* t'0dyQ%u  
    'Radius and conic constant of posterior lens U4@W{P02  
    '************************************************************************* _GK3]F0  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) 5=--+8[ bV  
    GetConic eID, entity, curv, conic ;{Kx$Yt+  
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    SetConic eID, entity, 1/Rpost, CCpost 13nXvYo'  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost W!BIz&SY:-  
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    '************************************************************************* zbDM+;  
    'Lens thickness (Position of posterior lens surface) yy6?16@  
    '************************************************************************* `?ijKZ}y5  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) *!*J5/b  
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    ' Delete any z-shift(s) @gZ<!g/vza  
    count = 0 C,xM)V^a  
    While GetOperationCount(eID)>count 0FV?By  
        GetOperation eID, count, op f}cz_"o4  
        If op.Type="ShiftZ" Then d?/?VooU  
            DeleteOperation eID,count 75V?K  
            count=count-1 2$O@T]  
        End If Bld$<uU  
        count=count+1 $3Ct@}=n  
    Wend 6Q._zk  
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    'Set new z-shift ^{T3lQvt  
    op.Type = "ShiftZ" LA.xLU3  
    op.val1 = tlens r%g?.4o*b  
    op.parent = parID ''f07R  
    AddOperation eID, op Uaho.(_GP  
    Print "Set lens thickness = " & tlens N'nqVYTU  
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    '************************************************************************* )k8=< =s  
    'Lens index of refraction |6pNe T[  
    '************************************************************************* 0pS|t/h0  
    eID = FindMaterial( "Lens" ) c2z%|\q  
    GetModelMaterial eID, mat Oop;Y^gG}  
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    mat.Nd = nlens bV#U&)|  
    SetModelMaterial eID, mat ^ )Lh5   
    Print "Set lens index of refraction = " & nlens K`nI$l7hg  
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    '************************************************************************* iTt"Ik'  
    'Pupil diameter >a;^=5E  
    '************************************************************************* *JX)q  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) [UVxtMJ  
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    'Adjust pupil diameter (trimming volume inner hole) tj ,*-).4%  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" $Gs&' yR  
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    ' Adjust pupil location to just in front of the lens Ey77]\  
    parID = FindFullName( "Geometry.Arizona Eye" ) .-;K$'YG  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) *=1;HN3  
    count = 0 R<gC,eV<=  
    While GetOperationCount(eID)>count u:pdY'`"#  
        GetOperation eID, count, op %:n1S]Vr  
        If op.Type="ShiftZ" Then *Rv e
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            DeleteOperation eID,count ?=]`X=g6  
            count=count-1 sD$ \!7:b  
        End If 3,bA&c3  
        count=count+1 FX"%  
    Wend ,P ?TYk  
    op.Type = "ShiftZ" N7%+n*Z  
    op.val1 = taq-0.01 :z^ps0  
    op.parent = parID oW-Tw@D  
    AddOperation eID, op @.gT&H
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    Print "Set pupil diameter = " & pupilDiam "aN<3
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    'Update AZ Eye subassembly Description aTs5^Kh')  
    eID = FindFullName( "Geometry.Arizona Eye" ) V#1_jxP)Q  
    GetEntity eID, entity Hw5\~!FX  
    entity.Description = "Accommodation = " & A & "D" K6kPNi  
    SetEntity eID, entity e_+`%A+-  
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    Update zh'TR$+\hO  
    Print "DONE!" e| (jv<~r  
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End Sub +15j^ Az  
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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： PG9won5_  
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Accommodation = 4 Diopters p8
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Pupil Diameter = 4 mm -9/YS  
Set aqueous humor thickness = 2.81 iYA06~d  
Set anterior lens radius = 10.4 and conic constant = -2.375869 -8qLshQ  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 GEw
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Set lens thickness = 3.927 %4cUa| =?  
Set lens index of refraction = 1.42672 @QtJ/("&WC  
Set pupil diameter = 4 EuqmA7s8A  
DONE! c6s*u%+},