[技术]Arizona眼睛模型 [复制链接]

简介 2[;~@n1P  
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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。 &YcOmI/MM  
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模型 pp@B]We  
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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。 T--%UZD]W  
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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. I!Z"X&  
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光源 3<xDxj0<  
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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。 rlA/eQrS  
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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。 x$bUd 9  
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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。 x}nBUq:  
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视网膜的散射 M0~%[nX  
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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~8WYz  
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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。 P tLWFO  
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脚本 1YJ?Y  
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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： Z/:F)c,x  
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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。 -4sKB>b  
余下的脚本计算与屈光度有关的所有参数。 rhy-o?  
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分析 _@!vF,Wcf  
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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。 JO0o@M5H  
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脚本代码 W dD889\  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. m7g*zu2#  
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Dim entity As T_ENTITY aEvbGo  
Dim op As T_OPERATION yDK
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Dim mat As T_MODELMATERIAL r6'dEa  
Dim A As Double 1=C12  
Dim pupilDiam As Double NWvIwt{  
Dim eID As Long !?0C(VL(:  
Dim parID As Long n#b{  
Dim count As Integer k]5tU\;Yw  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double ~{tO8 ]  
Dim tlens As Double, nlens As Double ){w{#  
Dim curv As Double, conic As Double #jrlNg4(  
Dim ok As Long _^#eO`4"  
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Sub Main (0b\%;}  
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    '用户输入对话框 < $e#o H  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 ]!"w?-h Si  
        TextBox 220,21,40,21,.TextBox1 'default: 0 ufIv
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        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 4n6AK
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        OKButton 40,91,90,21 ,++HiYOG}e  
        CancelButton 190,91,90,21 #f24a?n|  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 k}H7bZug  
        TextBox 220,49,40,21,.TextBox2 'default: 4 zpT^:Ag  
    End Dialog bUm%#a  
    Dim dlg As UserDialog P>iZgv  
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    ok = Dialog (dlg) ]zaTX?F:  
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    If ok=0 Then    'cancel button was pressed I V#
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        Print "Execution cancelled." sV,Yz3E<u$  
        End $Y_S`#c@i  
    End If `x/i1^/_@  
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    'Assign accommodation and pupil diameter & use defaults if field left empty = NZgbl  
    If dlg.TextBox1 = "" Then V&:x+swt  
        A = 0           'Default accommodation qS@3:R  
    Else MWA,3I\.  
        A = CDbl(dlg.TextBox1) %K|f,w=m  
    End If k+-?b(z)$  
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    If dlg.TextBox2 = "" Then ajk}&`Wj"  
        pupilDiam = 4   'Default pupil diameter AZc=Bbh  
    Else *cXq=/s  
        pupilDiam = CDbl(dlg.TextBox2) XdCP!iq*8  
    End If X/2GTU7?  
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    Print " " 2A~o)7JaZ  
    Print "Accommodation = " & A & " Diopters" r/'!#7dLG-  
    Print "Pupil Diameter = " & pupilDiam & " mm" }i"[5:  
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    ' Calculate new parameters with accommodation 4x[_lsj  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness /7#e  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens R)JH D7 1  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens Hq::F
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens GWuKDq  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens AJEbiP  
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    tlens = 3.767 + 0.04*A                  'Lens thickness C}mhnU@  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction hxMRmH[f:  
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    'Adjust parameters to account for accommodation #W)m({}  
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    '************************************************************************* C_Q3
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    'Aqueous thickness (Position of Lens) CdRJ@Lf  
    '************************************************************************* PY7H0\S)  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) __9FQ{Ra  
    GetCustomElement eID, entity x6R M)rr  
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    parID = FindFullName( "Geometry.Arizona Eye" ) ?j/FYi  
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    ' Delete any shift(s) in z W..*!UGl  
    count = 0 LEPLoF3,  
    While GetOperationCount(eID)>count @ !su7  
        GetOperation eID, count, op Wjl2S+Cc  
        If op.Type="ShiftZ" Then 9!X3Cv|+L  
            DeleteOperation eID,count H%Gz"  
            count=count-1 G$TO'C
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        End If Z[*unIk  
        count=count+1 oFP8s[B  
    Wend *:xOenI  
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    'Set new shift in YT+b{   
    op.Type = "ShiftZ" */IiL%g4u  
    op.val1 = taq XjL3Ar*  
    op.parent = parID @!dIa1Q"  
    AddOperation eID, op S=) c7t?a  
    Print "Set aqueous humor thickness = " & taq-0.55 Up?RN%gq  
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    '************************************************************************* [G$#jUt/O  
    'Radius and conic constant of anterior lens G1jj:]1  
    '************************************************************************* Wx]Xa]-  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) f}2}Ta  
    GetConic eID, entity, curv, conic 2mzn{S)nV  
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    SetConic eID, entity, 1/Rant, CCant vc"!3x-G*  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant kqih`E9P7B  

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    '************************************************************************* $T3_~7N  
    'Radius and conic constant of posterior lens qA)YYg/G  
    '************************************************************************* -)(=~|,Pq/  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) ,V!"4T,Z  
    GetConic eID, entity, curv, conic !@Qk=Xkg  
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    SetConic eID, entity, 1/Rpost, CCpost q]OIP"yv  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost _x(hlHFk  
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    '************************************************************************* .%n_{ab1  
    'Lens thickness (Position of posterior lens surface) [pTdeg;QE  
    '************************************************************************* Hj r'C?[  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) ,L-/7}"VHA  
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    ' Delete any z-shift(s) oH6zlmqG"  
    count = 0 7mYcO3{5{  
    While GetOperationCount(eID)>count KJQ8Yhq  
        GetOperation eID, count, op lFt!  
        If op.Type="ShiftZ" Then 9#U]?^DJ@  
            DeleteOperation eID,count nu+K N,3R"  
            count=count-1 `.pEI q^  
        End If aXj UDu7  
        count=count+1 wJ2cAX;"  
    Wend &v .S_Ym  
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    'Set new z-shift bdstxjJ`  
    op.Type = "ShiftZ" jw{N#QDh  
    op.val1 = tlens QD!NV*  
    op.parent = parID M}[Q2v\  
    AddOperation eID, op }nPt[77U_7  
    Print "Set lens thickness = " & tlens \u`P(fI!K%  
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    '************************************************************************* D%o(HS\E  
    'Lens index of refraction -&7?!<f
 
    '************************************************************************* VI4mEq,V  
    eID = FindMaterial( "Lens" ) UZs '[pm)  
    GetModelMaterial eID, mat ho{%7\  
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    mat.Nd = nlens y%%VJ}'X!  
    SetModelMaterial eID, mat H(.9tuA  
    Print "Set lens index of refraction = " & nlens #3 E"Ame  
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    '************************************************************************* 7I w^  
    'Pupil diameter TfZM0Wz  
    '************************************************************************* eG(YORkR  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) Sc{&h8KMTb  
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    'Adjust pupil diameter (trimming volume inner hole) X8Z) W?vu  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" H.l0kBeG  
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    ' Adjust pupil location to just in front of the lens ! N2uJ?t  
    parID = FindFullName( "Geometry.Arizona Eye" ) aB~k8]q.  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) s3A(`heoq  
    count = 0 f91]0B`C  
    While GetOperationCount(eID)>count 
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        GetOperation eID, count, op V z  
        If op.Type="ShiftZ" Then }bw^p.ci  
            DeleteOperation eID,count =Ks&m4  
            count=count-1 Ux',ma1JK  
        End If $rj:K)P  
        count=count+1 WDxcV%  
    Wend `m(ZX\W]  
    op.Type = "ShiftZ" )XonFI  
    op.val1 = taq-0.01 'Y2$9qy-L  
    op.parent = parID c$[2tZ  
    AddOperation eID, op ASi2;Q_{_  
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    Print "Set pupil diameter = " & pupilDiam c}OveR$'&  
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    'Update AZ Eye subassembly Description \,NT5>  
    eID = FindFullName( "Geometry.Arizona Eye" ) BKTTta1mY  
    GetEntity eID, entity Cw:|(`
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    entity.Description = "Accommodation = " & A & "D" yx?oxDJg  
    SetEntity eID, entity e^q^AP+*  
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    Update L>/$l(
 
    Print "DONE!" &#C&0f8PnD  
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End Sub y'
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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： HHw&BNQG  
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Accommodation = 4 Diopters X n0HJ^
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Pupil Diameter = 4 mm oNXYBeu+  
Set aqueous humor thickness = 2.81 C\"C12n{  
Set anterior lens radius = 10.4 and conic constant = -2.375869 Oq<3&*  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 lv]U)p  
Set lens thickness = 3.927 v,Kum<oi?  
Set lens index of refraction = 1.42672 !2AD/dtt  
Set pupil diameter = 4 AiR#:r  
DONE! 6%t6u3