[技术]Arizona眼睛模型 [复制链接]

简介 p 2>
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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。 u2E}DhV  
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模型 \S_o{0ZY}  
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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。 OTj J'  
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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. [BTOs4f  
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光源 [9C{\t  
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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。 ;S?ei>Q  
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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。 S}3?  
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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。 c$8M}q:X  
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视网膜的散射 tiPZ.a~k  
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在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 V4ybrUWK  
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注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 c=f;3N  
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脚本
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内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： ncpNesB  
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如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 Y^QG\6q  
余下的脚本计算与屈光度有关的所有参数。 }_oQg_-7e  
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分析 .naSK`J,`  
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屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 &&7&/   
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脚本代码 hz+c]K  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. >W6?!ue_  
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Dim entity As T_ENTITY `Krk<G  
Dim op As T_OPERATION zym6b@+jN  
Dim mat As T_MODELMATERIAL MDoV84Fh  
Dim A As Double :pLaxWus!  
Dim pupilDiam As Double 7.tIf <^$P  
Dim eID As Long O jH"qi  
Dim parID As Long K}vYE7n:  
Dim count As Integer _2WW0  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double 6GoQJ  
Dim tlens As Double, nlens As Double )T@?.J`  
Dim curv As Double, conic As Double ?(Xy 2%v  
Dim ok As Long \s6VOR/  
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Sub Main '>GPk5Nq77  
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    '用户输入对话框 w&*oWI$i  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 A&{eC C  
        TextBox 220,21,40,21,.TextBox1 'default: 0 pp+z5  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 ^;[^L=}8$  
        OKButton 40,91,90,21 UlPhW~F)  
        CancelButton 190,91,90,21 _FCg5F2U  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 XHm6K1mGZ  
        TextBox 220,49,40,21,.TextBox2 'default: 4 [&)*jc16  
    End Dialog A]MX^eY  
    Dim dlg As UserDialog IeAi'  
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    ok = Dialog (dlg) &
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    If ok=0 Then    'cancel button was pressed h>A~yDT[  
        Print "Execution cancelled." xmejoOF  
        End jxZ_-1  
    End If LCqWL1  
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    'Assign accommodation and pupil diameter & use defaults if field left empty =3=8oFx8  
    If dlg.TextBox1 = "" Then e 3TKg  
        A = 0           'Default accommodation 19i=kdH  
    Else 71Y3.1+  
        A = CDbl(dlg.TextBox1) Bqw/\Lxwlf  
    End If -HRa6  
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    If dlg.TextBox2 = "" Then M %!O)r#Pn  
        pupilDiam = 4   'Default pupil diameter Ah;`0Hz;  
    Else zor  
        pupilDiam = CDbl(dlg.TextBox2) f.:0T&%G  
    End If PJAM_K;  
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    Print " " =00sB  
    Print "Accommodation = " & A & " Diopters" lr=quWDY  
    Print "Pupil Diameter = " & pupilDiam & " mm" ITZ}$=   
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    ' Calculate new parameters with accommodation 2>)::9e4  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness <1<0odB  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens yY!@FGsA  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens :/6u*HwZh  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens juMHc$d17  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens }x:}9iphF  
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    tlens = 3.767 + 0.04*A                  'Lens thickness 4+Y9":<  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction Ci?
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    'Adjust parameters to account for accommodation |5*:ThC[  
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    '************************************************************************* 7|<-rjz^  
    'Aqueous thickness (Position of Lens) n66b(6"mO2  
    '************************************************************************* [jTZxH<  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) ooj^Z%9P  
    GetCustomElement eID, entity ootkf=  
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    parID = FindFullName( "Geometry.Arizona Eye" ) *rC%nmJwk!  
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    ' Delete any shift(s) in z .]/k#Hv  
    count = 0 %V92q0XW  
    While GetOperationCount(eID)>count W7w*VD|  
        GetOperation eID, count, op Fyc":{Jd  
        If op.Type="ShiftZ" Then V5+|H1=  
            DeleteOperation eID,count k>#-NPU$  
            count=count-1 d6A+pa'2  
        End If |%j7Es  
        count=count+1 &&Otj-n5  
    Wend @e+qe9A|  
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    'Set new shift in ! ~+mf^D  
    op.Type = "ShiftZ" FB O_B  
    op.val1 = taq bK|nxL  
    op.parent = parID ZSn6JV'g  
    AddOperation eID, op hne}G._b  
    Print "Set aqueous humor thickness = " & taq-0.55 J74kK#uF=  
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    '************************************************************************* fjHd"!)3  
    'Radius and conic constant of anterior lens #^w8Y'{?  
    '************************************************************************* JiGS[tR  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) UC!"1)~mt`  
    GetConic eID, entity, curv, conic 
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    SetConic eID, entity, 1/Rant, CCant u9{Z*w3L7  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant (n2=.9k!  
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    '************************************************************************* I}\`l+  
    'Radius and conic constant of posterior lens FwDEYG  
    '************************************************************************* (!T\[6  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) z[0t%]7l  
    GetConic eID, entity, curv, conic ;RW5XnVx  
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    SetConic eID, entity, 1/Rpost, CCpost ^F-AZP /5F  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost V""3#Tw  
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    '************************************************************************* Suk;##I  
    'Lens thickness (Position of posterior lens surface) TWU1@5?Ct  
    '************************************************************************* -9(nsaV  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) LHq*E`  
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    ' Delete any z-shift(s) )>!y7/3  
    count = 0 s+a#x(7{  
    While GetOperationCount(eID)>count 2MDY nMy  
        GetOperation eID, count, op e_llW(*l8^  
        If op.Type="ShiftZ" Then +\Je B/F  
            DeleteOperation eID,count }QJ6"s  
            count=count-1 /+f3jy:d  
        End If 1P/4,D@  
        count=count+1 1
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    Wend m[A$Sp_"-h  
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    'Set new z-shift P,7beHjf  
    op.Type = "ShiftZ" q
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    op.val1 = tlens ExSy/^4f  
    op.parent = parID -7m7.>/M  
    AddOperation eID, op 2bTM0-  
    Print "Set lens thickness = " & tlens 7/FF}d  
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    '************************************************************************* z_87;y;=  
    'Lens index of refraction 0y=lf+xA*  
    '************************************************************************* z?(QM:  
    eID = FindMaterial( "Lens" ) D__*?frWpW  
    GetModelMaterial eID, mat Xl/2-'4  
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    mat.Nd = nlens -nk0Q_7N  
    SetModelMaterial eID, mat  -to3I  
    Print "Set lens index of refraction = " & nlens }z_7?dn/  
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    '************************************************************************* n#)kvr  
    'Pupil diameter g y1i%  
    '************************************************************************* Cx ;n#dn*  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) t<znz
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    'Adjust pupil diameter (trimming volume inner hole) Med0O~T%  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" 3!u:*ibt  
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    ' Adjust pupil location to just in front of the lens \yY2 mr  
    parID = FindFullName( "Geometry.Arizona Eye" ) .q9i10C  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) 8#15*'Y  
    count = 0 /@]@Tz@'  
    While GetOperationCount(eID)>count q%MLj./?[  
        GetOperation eID, count, op W.  p'T}2  
        If op.Type="ShiftZ" Then o`\@Yq$.  
            DeleteOperation eID,count \_3#%%z  
            count=count-1 TRQH{O\O  
        End If x%,!px3s  
        count=count+1 /w:~!3Aj0+  
    Wend i UW.$1l  
    op.Type = "ShiftZ" JAI;7  
    op.val1 = taq-0.01 D,, x<JG|  
    op.parent = parID R5MY\^H/A  
    AddOperation eID, op b "5WsJ:'#  
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    Print "Set pupil diameter = " & pupilDiam 0vcM+}rw  
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    'Update AZ Eye subassembly Description U,GY']J  
    eID = FindFullName( "Geometry.Arizona Eye" ) |&H(skF_  
    GetEntity eID, entity r#/Bz5Jb*  
    entity.Description = "Accommodation = " & A & "D" of?0 y-LT%  
    SetEntity eID, entity *]* D^'  
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    Update d]QCk&XU  
    Print "DONE!" O@? *5  
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End Sub Ss#UX_DT_  
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如果屈光度是4，光瞳直径是4，则会输出如下数据： Y(P<9m:  
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Accommodation = 4 Diopters 1IV R4:a  
Pupil Diameter = 4 mm g+M& _n  
Set aqueous humor thickness = 2.81 o|7 h  
Set anterior lens radius = 10.4 and conic constant = -2.375869 }A'Ro/n  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 O,?aVgY  
Set lens thickness = 3.927 dSIZsapH  
Set lens index of refraction = 1.42672 E>O1dPZcM  
Set pupil diameter = 4 -87]$ ax  
DONE! =hB0p^a