[技术]Arizona眼睛模型 [复制链接]

简介 y4aSf2   
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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。 -LL49P6  
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模型 #C1u~db  
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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。 YEoQIR  
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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. n?*Fr sZ  
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光源 7/lXy3B4  
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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。 1u&}Lq(  
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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。 / %}Xiqlrd  
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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。 Jrd:6
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视网膜的散射 RiC1lCE  
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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。 p\66`\\l  
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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。 hER]%)#r  
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脚本 X
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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： ?4Z`^uy  
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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。 /1ZRjf^  
余下的脚本计算与屈光度有关的所有参数。 L=4%MyZ.e  
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分析 f0+)%gO{  
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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。 U:xY~>  
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脚本代码 {\3ZmF  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. \^O&){q(9  
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Dim entity As T_ENTITY {%W'Zx  
Dim op As T_OPERATION rEEoR'c6  
Dim mat As T_MODELMATERIAL <7-:flQz~  
Dim A As Double IzPnbnS}  
Dim pupilDiam As Double D?ojx
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Dim eID As Long Fd!Np7xw  
Dim parID As Long (/TYET_H  
Dim count As Integer  [@YeQ{  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double M?mPi 3  
Dim tlens As Double, nlens As Double / i[F  
Dim curv As Double, conic As Double wWjZXsOd  
Dim ok As Long [?z`XY_-  
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Sub Main o9I=zAGjy  
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    '用户输入对话框 a=n*}.  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 ,*_=w^;Rr  
        TextBox 220,21,40,21,.TextBox1 'default: 0 MYyV{W*T>  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 fS9TDy  
        OKButton 40,91,90,21 WUnz  
        CancelButton 190,91,90,21 >@?!-Fy5  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 Fo\* Cr9D  
        TextBox 220,49,40,21,.TextBox2 'default: 4 VZhtx)  
    End Dialog
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    Dim dlg As UserDialog >Pa&f20Hp  

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    ok = Dialog (dlg) _{$eOwB  
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    If ok=0 Then    'cancel button was pressed hO8~Rg   
        Print "Execution cancelled." 'Lm\ r+$F  
        End O^/z7,  
    End If )wT@`p"4  
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    'Assign accommodation and pupil diameter & use defaults if field left empty ;5S'?fj  
    If dlg.TextBox1 = "" Then :Y4m3|  
        A = 0           'Default accommodation |.]sL0;4Z  
    Else 2h=QJgpCG  
        A = CDbl(dlg.TextBox1) oUSv)G.zb  
    End If M/<>'%sj  
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    If dlg.TextBox2 = "" Then ::<v; `l  
        pupilDiam = 4   'Default pupil diameter +"P!es\q  
    Else vca]yK<u  
        pupilDiam = CDbl(dlg.TextBox2) ylTX  
    End If M%{,?
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    Print " " P]h-**O  
    Print "Accommodation = " & A & " Diopters" 8&q[jxI@8  
    Print "Pupil Diameter = " & pupilDiam & " mm" PCqE9B)l  
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    ' Calculate new parameters with accommodation 7&O0  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness *WzvPl$e  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens ,M?K3lG\g[  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens n?a?U:  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens %p; 'l  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens f3;.+hJ])  
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    tlens = 3.767 + 0.04*A                  'Lens thickness q0sdL86  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction eN,6p'&  
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    'Adjust parameters to account for accommodation H{1'OC  
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    '************************************************************************* BmhIKXE{*  
    'Aqueous thickness (Position of Lens) GS)4,.  
    '************************************************************************* XbaUmCuh  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) fk5$z0/  
    GetCustomElement eID, entity Fo.p}j+>  
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    parID = FindFullName( "Geometry.Arizona Eye" ) (qyT,K8  
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    ' Delete any shift(s) in z Oaj$Z- f  
    count = 0 3'jH,17lWV  
    While GetOperationCount(eID)>count OAiSE`  
        GetOperation eID, count, op v\ <4y P  
        If op.Type="ShiftZ" Then -hU1wX%U  
            DeleteOperation eID,count *S= c0  
            count=count-1 %=*nJvYS  
        End If wSPwa,)7s  
        count=count+1 Ljs4^vy<J  
    Wend ;N?raz2mEi  
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    'Set new shift in .~AQxsGH  
    op.Type = "ShiftZ" Va-.  
    op.val1 = taq n4A#T#D!t3  
    op.parent = parID E``\Jre@  
    AddOperation eID, op '7yVvd  
    Print "Set aqueous humor thickness = " & taq-0.55 L (@".{T  
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    '************************************************************************* bNh~=[E  
    'Radius and conic constant of anterior lens ^
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    '************************************************************************* /r?EY&9G  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) :8LK}TY7  
    GetConic eID, entity, curv, conic d>gN3}tT  
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    SetConic eID, entity, 1/Rant, CCant  %G>  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant "QLp%B,A  
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    '************************************************************************* cMZ-  
    'Radius and conic constant of posterior lens ]yV,lp  
    '************************************************************************* m#|h22^H  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) DP6>fzsl  
    GetConic eID, entity, curv, conic @3_."-
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    SetConic eID, entity, 1/Rpost, CCpost $,8}3R5}  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost >k9W+mk  
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    '************************************************************************* ojbms>a  
    'Lens thickness (Position of posterior lens surface) q c DJ  
    '************************************************************************* EHH+)mlo  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) XJ6=Hg4_O  
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    ' Delete any z-shift(s)
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    count = 0 XFi!=|F  
    While GetOperationCount(eID)>count jn._4TQ*}  
        GetOperation eID, count, op i:n1Di1~E  
        If op.Type="ShiftZ" Then Lt2<3DB  
            DeleteOperation eID,count c+N\uG4  
            count=count-1 8c<OX!  
        End If >p>B-m  
        count=count+1 a+ s%9l  
    Wend W.7XShwd*2  
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    'Set new z-shift 4YyVh.x  
    op.Type = "ShiftZ" get$r5  
    op.val1 = tlens O`TM}  
    op.parent = parID RCY}JH>}  
    AddOperation eID, op 19*
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    Print "Set lens thickness = " & tlens k~=W1R%  
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    '************************************************************************* h:Hpz  
    'Lens index of refraction k*|WI$  
    '************************************************************************* >vZ^D  
    eID = FindMaterial( "Lens" ) r%FfJM@!  
    GetModelMaterial eID, mat ^+u/Lw&  
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    mat.Nd = nlens ;G4g;YHy|  
    SetModelMaterial eID, mat 1+9}Xnxb  
    Print "Set lens index of refraction = " & nlens i _YJq;(  
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    '*************************************************************************
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    'Pupil diameter iu'At7  
    '************************************************************************* Lem:z
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    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) g;\_MbfP  
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    'Adjust pupil diameter (trimming volume inner hole) R:, |xz  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" gn6@x  
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    ' Adjust pupil location to just in front of the lens ~vw$Rnotz  
    parID = FindFullName( "Geometry.Arizona Eye" ) L%31>)8  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) O=\`q6l  
    count = 0 9k3RC}dEr  
    While GetOperationCount(eID)>count v 0D@`C  
        GetOperation eID, count, op >L,Pw1Y0W[  
        If op.Type="ShiftZ" Then N6w!V]b  
            DeleteOperation eID,count I0v4TjHH  
            count=count-1 4N_iHe5U  
        End If de,4Ms!%  
        count=count+1 N&]_U%#Q  
    Wend *5q_fO  
    op.Type = "ShiftZ" r%vO^8FQ  
    op.val1 = taq-0.01 x?n13C  
    op.parent = parID WNo<0|X  
    AddOperation eID, op L /V;;  
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    Print "Set pupil diameter = " & pupilDiam Y%#r&de  
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    'Update AZ Eye subassembly Description P"<,@Mn  
    eID = FindFullName( "Geometry.Arizona Eye" ) YTV|]xpR  
    GetEntity eID, entity e8Vt
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    entity.Description = "Accommodation = " & A & "D" A?ij  
    SetEntity eID, entity y/OPN<=*  
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    Update Bw4 _hlm  
    Print "DONE!" #GIjU1-  
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End Sub C#:L.qK  
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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： y9X1X{  
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Accommodation = 4 Diopters 1wt(pkNk  
Pupil Diameter = 4 mm ]=jpqxlx  
Set aqueous humor thickness = 2.81 &0JCZ/e  
Set anterior lens radius = 10.4 and conic constant = -2.375869 f/tJ>^N5  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 }D*5PV%d  
Set lens thickness = 3.927 *Fm#Qek  
Set lens index of refraction = 1.42672 eWU@@$9  
Set pupil diameter = 4 zi= gOm  
DONE! ["SD'