[技术]Arizona眼睛模型 [复制链接]

简介 ~'{VaYk]v  
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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。 D-D#`  
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模型 #G~wE*VR$  
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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。 f}blB?e  
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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. 23k)X"5  
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光源 E4Zxv*  
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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。 '}CN?f|.  
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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。 ;t~*F#p(!  
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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。 0}D-KvjyP  
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视网膜的散射 C$t.C rxx  
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在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 [bsXF#  
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注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 r(]98a]o~  
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脚本 _TrZ'iL}T  
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内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： B_!wutV@  
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如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 "~_$T@^k>  
余下的脚本计算与屈光度有关的所有参数。 3Fgz)*Gu]  
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分析 WejyYqr34-  
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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。 gt~9"I  
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脚本代码 'frWu6]< 4  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. 7&h\l6}Yh  
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Dim entity As T_ENTITY (VfwLo>#  
Dim op As T_OPERATION -Sx0qi'%  
Dim mat As T_MODELMATERIAL l
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Dim A As Double Nd
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Dim pupilDiam As Double eU`
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Dim eID As Long )4@M`8  
Dim parID As Long &ycjSBK  
Dim count As Integer Kq$:\B)<c  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double j,\tejl1  
Dim tlens As Double, nlens As Double Wa(W&]  
Dim curv As Double, conic As Double KuIkul9^%  
Dim ok As Long [?A&xqO3  
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Sub Main =n)JJS94  
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    '用户输入对话框 AbL5 !'  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 w8G7Jy  
        TextBox 220,21,40,21,.TextBox1 'default: 0 :wFb5"  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 ejP,29  
        OKButton 40,91,90,21 1]"D%U=  
        CancelButton 190,91,90,21 H3!,d`D.N  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 pi|\0lH6W  
        TextBox 220,49,40,21,.TextBox2 'default: 4 52da]BW<  
    End Dialog ,<7"K&  
    Dim dlg As UserDialog f+{c1fb>s  
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    ok = Dialog (dlg) 2=jd;2~  

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    If ok=0 Then    'cancel button was pressed hT.4t,wa8  
        Print "Execution cancelled." f;e_04K  
        End )ZQHa7V  
    End If JtSuD>H`"  
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    'Assign accommodation and pupil diameter & use defaults if field left empty S4;wa6  
    If dlg.TextBox1 = "" Then i:C.8hmAE  
        A = 0           'Default accommodation  -PcS(  
    Else -FQC9~rR;g  
        A = CDbl(dlg.TextBox1) %=laY_y G  
    End If W,xi>5k  
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    If dlg.TextBox2 = "" Then r3n=<l!Jr  
        pupilDiam = 4   'Default pupil diameter =9kj? u~  
    Else es.jh  
        pupilDiam = CDbl(dlg.TextBox2) s;vWR^Ll  
    End If P h9Hg'  
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    Print " " kEp.0wL'  
    Print "Accommodation = " & A & " Diopters" ,h3269
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    Print "Pupil Diameter = " & pupilDiam & " mm" OG0r4^6Ly  
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    ' Calculate new parameters with accommodation K#_~ !C4L  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness b{Z^)u2X  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens m"96:v  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens WAtg  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens jjJc1p0  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens xnJjCEZ  
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    tlens = 3.767 + 0.04*A                  'Lens thickness C!oS=qK?]  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction }wvwZ`5t  
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    'Adjust parameters to account for accommodation *LY~l  
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    '************************************************************************* 8 m%>:}o  
    'Aqueous thickness (Position of Lens) h$E\2lsE  
    '************************************************************************* kWzuz#  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) ap Fs UsE  
    GetCustomElement eID, entity yw;ghP;  
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    parID = FindFullName( "Geometry.Arizona Eye" ) "6NFe!/Y$*  
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    ' Delete any shift(s) in z 4^d+l.F  
    count = 0 1x~%Ydy  
    While GetOperationCount(eID)>count b:N^Fe
 
        GetOperation eID, count, op ?b!CV   
        If op.Type="ShiftZ" Then bBkm] 
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            DeleteOperation eID,count [W^6u7~  
            count=count-1 \>*MMe  
        End If 'Qm` A=  
        count=count+1 u=p ;A1oy  
    Wend aukk|/3Ih  
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    'Set new shift in 2ApDpH`fiJ  
    op.Type = "ShiftZ" +-Z"H)  
    op.val1 = taq *u|lmALs  
    op.parent = parID Cfv L)f  
    AddOperation eID, op v#Cz&j  
    Print "Set aqueous humor thickness = " & taq-0.55 {-xi0
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    '************************************************************************* t9Enk!@  
    'Radius and conic constant of anterior lens ikEWY_1Y  
    '************************************************************************* ua]\xBWx  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) 5}.,"Fbr  
    GetConic eID, entity, curv, conic )LXoey!aZ  
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    SetConic eID, entity, 1/Rant, CCant "E@NZ*"u  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant KuIt[oM  
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    '************************************************************************* 1kB'sc3N
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    'Radius and conic constant of posterior lens Yv#J`b@y  
    '************************************************************************* ]y1$
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    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) s)=!2AY  
    GetConic eID, entity, curv, conic l>3M|js@/  
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    SetConic eID, entity, 1/Rpost, CCpost mhHA!:Y  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost Z^/z  
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    '************************************************************************* dCf'\@<<  
    'Lens thickness (Position of posterior lens surface) D\45l  
    '************************************************************************* H{ n>KZ]\  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) I2t-D1X  
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    ' Delete any z-shift(s) B|]t\(~$[  
    count = 0 7AGZu?1]M  
    While GetOperationCount(eID)>count [M7iJcwt  
        GetOperation eID, count, op pz*/4  
        If op.Type="ShiftZ" Then Jf%!I  
            DeleteOperation eID,count dvg;  
            count=count-1 mr{k>Un\  
        End If ;w>3,ub(0  
        count=count+1 hQg,#r(JE4  
    Wend ~cO?S2!W  
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    'Set new z-shift OEy:#9<'  
    op.Type = "ShiftZ" _g^K$+F'}  
    op.val1 = tlens {a+Fx}W
 
    op.parent = parID 2R_opbw  
    AddOperation eID, op K]H"qG.K  
    Print "Set lens thickness = " & tlens 3<KZ.hr  
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    '************************************************************************* \jF" nl  
    'Lens index of refraction KV^:sxU  
    '************************************************************************* 7})!>p )  
    eID = FindMaterial( "Lens" ) IEIxjek  
    GetModelMaterial eID, mat .v #0cQX+.  
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    mat.Nd = nlens V:,3OLL*  
    SetModelMaterial eID, mat ,%)WT>  
    Print "Set lens index of refraction = " & nlens WQIM2_=M  
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    '************************************************************************* eu}:Wg2  
    'Pupil diameter ?j&~vy= T  
    '************************************************************************* ?FY@fO?es  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) 26('V `N  
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    'Adjust pupil diameter (trimming volume inner hole) -tK;RQYax  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" m5'__<  
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    ' Adjust pupil location to just in front of the lens )<}VP&:X  
    parID = FindFullName( "Geometry.Arizona Eye" ) .=b +O~  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) XqE55Jclp  
    count = 0 >PTu*6Z  
    While GetOperationCount(eID)>count d 40'3]/{  
        GetOperation eID, count, op T|BY00Sz`  
        If op.Type="ShiftZ" Then IJ #v"! D  
            DeleteOperation eID,count cOZajC<G  
            count=count-1 \J3v>&m<7  
        End If ys.!S.k+  
        count=count+1 %`s9yRk9>E  
    Wend dp//p)B>  
    op.Type = "ShiftZ" \fM!^  
    op.val1 = taq-0.01 V%
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    op.parent = parID 5EV8zf  
    AddOperation eID, op e$/Zb`k  
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    Print "Set pupil diameter = " & pupilDiam W"}*Q-8W  
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    'Update AZ Eye subassembly Description soQv?4  
    eID = FindFullName( "Geometry.Arizona Eye" ) H,4,~lv|  
    GetEntity eID, entity K&Wv.}=V  
    entity.Description = "Accommodation = " & A & "D" e~2*>5\:  
    SetEntity eID, entity  ZZFI\o  
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    Update M*T# 5  
    Print "DONE!" *2m&?,nJ  
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End Sub v;F+fOo  
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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： 0R%uVJG  
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Accommodation = 4 Diopters 7"CH\*%  
Pupil Diameter = 4 mm ! 4^L $  
Set aqueous humor thickness = 2.81 q2j}64o_S  
Set anterior lens radius = 10.4 and conic constant = -2.375869 @=zBF'<.9  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 Kj<<&_B.H  
Set lens thickness = 3.927 [%)B%h`XGf  
Set lens index of refraction = 1.42672 {;z L[AgCg  
Set pupil diameter = 4 ae(]9VW  
DONE! @SQ*/sw (c