[技术]Arizona眼睛模型 [复制链接]

简介 xR;z!Tg)  
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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。 GYonb)F  
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模型 {"0n^
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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。 ZJQkZ_9@2  
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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. akQb%Wq  
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光源 hP/uS%X   
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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。 z.W1Za  
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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。 M+4S>Sjw  
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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。 HPK}Z|Vl  
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视网膜的散射 DE?@8k  
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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。 [{J1b  
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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。 *JaFt@ x  
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脚本 _"'-fl98*  
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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： [92bGR{  
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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。 ,qlFk|A|  
余下的脚本计算与屈光度有关的所有参数。 5gPAX $jH  
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分析 iainl@3Qj  
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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。 5?|P
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脚本代码 g/,O51f'  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. ~#[ ZuMO?  
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Dim entity As T_ENTITY '?!2h'  
Dim op As T_OPERATION bRAf!<3  
Dim mat As T_MODELMATERIAL wmPpE_{  
Dim A As Double ^F1zkIE  
Dim pupilDiam As Double o=(>#iVM  
Dim eID As Long Bb/aeLv  
Dim parID As Long @i:_JOl  
Dim count As Integer i@d@~M7/  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double |zL.PS  
Dim tlens As Double, nlens As Double |&%l @X6  
Dim curv As Double, conic As Double ?)5M3lV3k  
Dim ok As Long r,dxW5v.  
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Sub Main DSHpM/7  
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    '用户输入对话框 Yui:=GgUrr  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 }c,}+{q
 
        TextBox 220,21,40,21,.TextBox1 'default: 0 cjO,#W0&f  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 `+/[0B=.  
        OKButton 40,91,90,21 VVje|T^{Z  
        CancelButton 190,91,90,21 P6 G/J-  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 -nT+!3A8  
        TextBox 220,49,40,21,.TextBox2 'default: 4 G8?<(.pi@  
    End Dialog Q-&]Vg  
    Dim dlg As UserDialog `0Q:d'  
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    ok = Dialog (dlg) ^ihXM]1{G  
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    If ok=0 Then    'cancel button was pressed "$8<\k$LGT  
        Print "Execution cancelled." tg5jS]O  
        End LGCL*Qbsg  
    End If .< vg[  
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    'Assign accommodation and pupil diameter & use defaults if field left empty ^NLKX5Q  
    If dlg.TextBox1 = "" Then h?YjG^'9  
        A = 0           'Default accommodation o-Idr{  
    Else {nOK*7+"  
        A = CDbl(dlg.TextBox1) NI s4v(!  
    End If cCV"(Oo[H|  
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    If dlg.TextBox2 = "" Then UmgLH Cz  
        pupilDiam = 4   'Default pupil diameter NV-9C$<n2!  
    Else TzL40="F  
        pupilDiam = CDbl(dlg.TextBox2) ::T<de7  
    End If d8RpL{9\7  
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    Print " " L kq>>?T=  
    Print "Accommodation = " & A & " Diopters" c8"I]Qc7  
    Print "Pupil Diameter = " & pupilDiam & " mm" j*:pW;)^  
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    ' Calculate new parameters with accommodation UXk8nH  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness 5!ReW39c;  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens rw\4KI@ L  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens }Rux<=cd|  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens j'J*QK&Q  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens MM8)yCI  
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    tlens = 3.767 + 0.04*A                  'Lens thickness YKc{P"'/|  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction N~ozyIP,  
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    'Adjust parameters to account for accommodation !yI)3;$*  
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    '************************************************************************* 3CHte*NL=  
    'Aqueous thickness (Position of Lens) G\NCEE'A  
    '************************************************************************* w9PY^U.Y3e  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) y14@9<~9  
    GetCustomElement eID, entity (_08?cN  
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    parID = FindFullName( "Geometry.Arizona Eye" ) aBC[(}Pb]  
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    ' Delete any shift(s) in z 6e*b;{d  
    count = 0 2$ rq  
    While GetOperationCount(eID)>count L
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        GetOperation eID, count, op tj&A@\/  
        If op.Type="ShiftZ" Then 5nn*)vK {  
            DeleteOperation eID,count o_N02l4J)  
            count=count-1 -/qrEKQ0U?  
        End If dCK-"#T!  
        count=count+1 ^9RBG#ud  
    Wend C/Z"W@7#;  
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    'Set new shift in *3K"Kc2  
    op.Type = "ShiftZ" Mww]l[1'EL  
    op.val1 = taq D/Wuan?yPN  
    op.parent = parID +J4t0x  
    AddOperation eID, op u~kwNN9t3  
    Print "Set aqueous humor thickness = " & taq-0.55 o|W? a#_\  
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    '************************************************************************* F1=+<]!  
    'Radius and conic constant of anterior lens GT.^u#r  
    '************************************************************************* >`uSNY"tO  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) 8#Z5-",iw  
    GetConic eID, entity, curv, conic Dn3~8  
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    SetConic eID, entity, 1/Rant, CCant M5V1j(URE  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant $OD5t5eTsM  
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    '************************************************************************* z Y|g#V-  
    'Radius and conic constant of posterior lens z)~!G~J]  
    '************************************************************************* 3$cF)5Vf  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) a=FRJQ8S  
    GetConic eID, entity, curv, conic zOOX>3^  
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    SetConic eID, entity, 1/Rpost, CCpost lRr-S%  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost Q ?t  
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    '************************************************************************* ]t3"0  
    'Lens thickness (Position of posterior lens surface) Mg$9'a"[\
 
    '************************************************************************* 's?Fip  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) Fc~w`~tv  
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    ' Delete any z-shift(s) g8"7wf`0k  
    count = 0 0Y2^}u@5  
    While GetOperationCount(eID)>count !y`e,(E  
        GetOperation eID, count, op '[
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        If op.Type="ShiftZ" Then )''wu\7A)'  
            DeleteOperation eID,count ,<^HB+{Wo  
            count=count-1 B,833Azi  
        End If HJR<d&l;p  
        count=count+1 cvA\C_  
    Wend ek)(pJ(+#  
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    'Set new z-shift rb'GveW[  
    op.Type = "ShiftZ" \ZR
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    op.val1 = tlens ZD%_PgiT  
    op.parent = parID YXVJJd$U  
    AddOperation eID, op 'kvFU_
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    Print "Set lens thickness = " & tlens eF^"{a3b  
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    '************************************************************************* U]0)$OH5e  
    'Lens index of refraction Q;O)>K  
    '************************************************************************* |S:!+[  
    eID = FindMaterial( "Lens" ) M%s$F@  
    GetModelMaterial eID, mat aX)./  
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    mat.Nd = nlens KBR0p&MN  
    SetModelMaterial eID, mat sC_UalOC_  
    Print "Set lens index of refraction = " & nlens <]^;/2.B  
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    '************************************************************************* @:9fS  
    'Pupil diameter rDX'oP:  
    '************************************************************************* BemkCj
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    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) .Pes{uHg  
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    'Adjust pupil diameter (trimming volume inner hole) aiZo{j<6  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" (TNY2Ke2 8  
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    ' Adjust pupil location to just in front of the lens !5%5]9'n@*  
    parID = FindFullName( "Geometry.Arizona Eye" ) %Rep6=K*$  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) h+~df(S.  
    count = 0 :n9xH  
    While GetOperationCount(eID)>count yCCw<?  
        GetOperation eID, count, op $7&l6~sMQ  
        If op.Type="ShiftZ" Then !LIfeL.4h  
            DeleteOperation eID,count YB B$uGA  
            count=count-1 rk,1am:cg  
        End If )YMlFzYr  
        count=count+1 w;@25= |  
    Wend rgdQR^!l6  
    op.Type = "ShiftZ" E<CxKY9  
    op.val1 = taq-0.01 L\m!8o4  
    op.parent = parID TDFO9%2c  
    AddOperation eID, op ~8xh0TSi  
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    Print "Set pupil diameter = " & pupilDiam iSr`fQw#  
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    'Update AZ Eye subassembly Description RmWfV  
    eID = FindFullName( "Geometry.Arizona Eye" ) Wx?&igh  
    GetEntity eID, entity 'uf2 nUo  
    entity.Description = "Accommodation = " & A & "D" c Z6p^  
    SetEntity eID, entity Sm$j:xw<  
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    Update #W@% K9  
    Print "DONE!"
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End Sub 0^}'+t,lc  
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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： XK%W^a*x
 
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Accommodation = 4 Diopters 2rO)qjiH  
Pupil Diameter = 4 mm 7mn,{2  
Set aqueous humor thickness = 2.81 6I&j cHH  
Set anterior lens radius = 10.4 and conic constant = -2.375869 ;Lsjh#  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 x\`RW3 K  
Set lens thickness = 3.927 n4WSV  
Set lens index of refraction = 1.42672 w.
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Set pupil diameter = 4 0ck&kpL:9  
DONE! nGx ~)T