[技术]Arizona眼睛模型 [复制链接]

简介 9K Ih}Q@P  
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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。 ~ifq_Ag.  
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模型 jF Bq>  
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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。 gTH1FR8$y  
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在FRED中使用0屈光度来创建的，光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. .%U~ r2Y(  
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光源 e\%QHoi>u  
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多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 J= ia  
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除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处，并增加了pre-propagation distance= -8。尽管光线在光瞳处创建，规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射，而不是在光瞳处入射。 PC.$&x4w1  
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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。 -,TBUWg  
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视网膜的散射 2GqPS  
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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。 vk5pnCM^3  
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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。 /quf'CV}  
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脚本 [9BlP  
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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： 9(ZzwkD'>  
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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。 JV36@DVQ  
余下的脚本计算与屈光度有关的所有参数。 ,*E%D_  
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分析 :54|Z5h|  
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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。 thipfS  
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脚本代码 g~FB&U4c  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. sx*1D9s_  
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Dim entity As T_ENTITY L9Fx Lw41  
Dim op As T_OPERATION l2VO=RDiW  
Dim mat As T_MODELMATERIAL EOtrrfT&  
Dim A As Double gW/H#T,  
Dim pupilDiam As Double 4 3]6J]!)  
Dim eID As Long *uA?}XEfi  
Dim parID As Long ^}/YGAA  
Dim count As Integer a(x[+ El  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double Y0s^9?*  
Dim tlens As Double, nlens As Double ;jX_e(T3m  
Dim curv As Double, conic As Double vbDw
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Dim ok As Long JO :m: M  
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Sub Main /rvXCA)j  
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    '用户输入对话框 P2`ks[u+i  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 <i]%T~\Af)  
        TextBox 220,21,40,21,.TextBox1 'default: 0 lz{>c.Ll[  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 KO)<Zh  
        OKButton 40,91,90,21 B{)Du :)  
        CancelButton 190,91,90,21 x-tA{
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        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 O])/kS`  
        TextBox 220,49,40,21,.TextBox2 'default: 4 PDD` eK}Fj  
    End Dialog CvbY2_>Nh  
    Dim dlg As UserDialog /jj!DO#  
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    ok = Dialog (dlg) Qbv)(&i#~  
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    If ok=0 Then    'cancel button was pressed p-*BB_J"  
        Print "Execution cancelled." M\`6H8aLn  
        End |I OTW=>  
    End If 3g-}k  
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    'Assign accommodation and pupil diameter & use defaults if field left empty V{d"cs>9  
    If dlg.TextBox1 = "" Then i3e|j(Gs4  
        A = 0           'Default accommodation >$R-:>~zN  
    Else P92:}" )*>  
        A = CDbl(dlg.TextBox1) "H G:by  
    End If 5~rs55W  
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    If dlg.TextBox2 = "" Then nF=Ig-NX^  
        pupilDiam = 4   'Default pupil diameter /f#rN_4  
    Else H.>KYiv+  
        pupilDiam = CDbl(dlg.TextBox2) l" sR\`~  
    End If 0 ?2#SM  
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    Print " " %'g/4I  
    Print "Accommodation = " & A & " Diopters" i^QcW!X&  
    Print "Pupil Diameter = " & pupilDiam & " mm" 8\I(a]kM`  
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    ' Calculate new parameters with accommodation l  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness U{ahA  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens Wq,UxMz  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens pkk0?$l",  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens pAa{,,Qc  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens |=h>3Z=r!  
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    tlens = 3.767 + 0.04*A                  'Lens thickness E* lqCh  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction mS%D" e  
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    'Adjust parameters to account for accommodation OKf/[hyu  
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    '************************************************************************* ;c;;cJc!  
    'Aqueous thickness (Position of Lens) WrG)&&d  
    '************************************************************************* 9]7^/g*!  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) YEZ"BgUnbp  
    GetCustomElement eID, entity $hEX,  
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    parID = FindFullName( "Geometry.Arizona Eye" ) 5,mb]v0k  
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    ' Delete any shift(s) in z #[i({1`^L  
    count = 0 nKHyq\  
    While GetOperationCount(eID)>count =j}00,WH  
        GetOperation eID, count, op .79'c%3}  
        If op.Type="ShiftZ" Then |bBYJ  
            DeleteOperation eID,count IGbQ L  
            count=count-1 3F4I{L  
        End If \,_%e[g49  
        count=count+1 ~Aq UT]l  
    Wend n=yFw\w'  
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    'Set new shift in S&QZ"4jq  
    op.Type = "ShiftZ" xUeLX`73  
    op.val1 = taq +q=/}|  
    op.parent = parID 3-Ti'xM  
    AddOperation eID, op U~T/f-CT  
    Print "Set aqueous humor thickness = " & taq-0.55 w-\GrxlbX  
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    '************************************************************************* a"ht\v}1  
    'Radius and conic constant of anterior lens V= .'Db2D  
    '************************************************************************* TSD7.t)^  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) G,$jU9 f  
    GetConic eID, entity, curv, conic l$zM|Z1wR`  
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    SetConic eID, entity, 1/Rant, CCant N2x\O~7  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant hx:x5L>  
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    '************************************************************************* yCmiW %L4  
    'Radius and conic constant of posterior lens ~A6QX8a  
    '************************************************************************* yTmoEy. q  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) m"xw5aa>  
    GetConic eID, entity, curv, conic T"dEa-O  
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    SetConic eID, entity, 1/Rpost, CCpost g8B@M*JA  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost Z!ub`coV[  
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    '************************************************************************* 4wK!)Pwq  
    'Lens thickness (Position of posterior lens surface) e&wWlB![  
    '************************************************************************* _STN^   
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) n*'|7#;  
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    ' Delete any z-shift(s) >0u4>=#  
    count = 0 K72U0}$B  
    While GetOperationCount(eID)>count Y.=v!*p?}  
        GetOperation eID, count, op zf6k%  
        If op.Type="ShiftZ" Then b^FB[tZ\x  
            DeleteOperation eID,count CFn!P;.!  
            count=count-1 p+A#t~K  
        End If $0{c=r9  
        count=count+1 qL3*H\9N  
    Wend MT|}[|_  
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    'Set new z-shift ^TnBtIU-B  
    op.Type = "ShiftZ" DmPp&  
    op.val1 = tlens \J:/l|h  
    op.parent = parID ULAAY$o@5  
    AddOperation eID, op Rl-Sr  
    Print "Set lens thickness = " & tlens wD"Y
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    '************************************************************************* NCd_h<}|6F  
    'Lens index of refraction W}nD#9tL  
    '************************************************************************* tE- s/  
    eID = FindMaterial( "Lens" ) YW0UIO  
    GetModelMaterial eID, mat @ Al\:  
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    mat.Nd = nlens Svy bP&i|  
    SetModelMaterial eID, mat jsc1B  
    Print "Set lens index of refraction = " & nlens I=|b3-  
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    '************************************************************************* yp_:]RE  
    'Pupil diameter i,Yv  
    '************************************************************************* IIs'm!"Y>  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) (*BQd1Z  
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    'Adjust pupil diameter (trimming volume inner hole) &+d>xy\^/  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" CR&v z3\Q  
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    ' Adjust pupil location to just in front of the lens 3<CCC+47  
    parID = FindFullName( "Geometry.Arizona Eye" ) t|%wVj?_  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) !z$.Jcr1  
    count = 0 $9j\sZ
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    While GetOperationCount(eID)>count x{j|Tf3,G  
        GetOperation eID, count, op Kbrb;r59  
        If op.Type="ShiftZ" Then m "h{HgJd  
            DeleteOperation eID,count p,Qr9p3y  
            count=count-1 8|OsVIe%  
        End If
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        count=count+1 w?Cqe N  
    Wend 7q^osOj"  
    op.Type = "ShiftZ" :q<8:,rP  
    op.val1 = taq-0.01 V^As@P8,'(  
    op.parent = parID F/IXqj  
    AddOperation eID, op HSE9-c=  
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    Print "Set pupil diameter = " & pupilDiam C%9;~S  
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    'Update AZ Eye subassembly Description c-(,%0G0  
    eID = FindFullName( "Geometry.Arizona Eye" ) *?VbN}g2  
    GetEntity eID, entity !MOVv\@O  
    entity.Description = "Accommodation = " & A & "D" 3Gubq4r  
    SetEntity eID, entity T6*naH  
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    Update ?k CK$P  
    Print "DONE!" ba^B$$?Bo  
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End Sub 1>r7s*  
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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： imv[xBA(d  
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Accommodation = 4 Diopters n*D-01vYP  
Pupil Diameter = 4 mm /'ccFm2  
Set aqueous humor thickness = 2.81 @`^+XPK\  
Set anterior lens radius = 10.4 and conic constant = -2.375869 3Un q 9  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 J\^ZRu_K  
Set lens thickness = 3.927 .
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Set lens index of refraction = 1.42672 e)]9u$x  
Set pupil diameter = 4 r({!ejT{U  
DONE! mEyJ o|