[技术]Arizona眼睛模型 [复制链接]

简介 LZ&CGV"Z-  
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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。 3)0*hq&83  

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模型 l`$f@'k  
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模型的定义如表1种所示，由半径、圆锥常数、折射率、阿贝数、到下一面的距离等一系列表面组成。一些参数由屈光度（A）来决定。 qLYv=h$,  
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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. %t+V8A  
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光源 Kq!n`@  
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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。 5-u=ZB%p  
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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。 j1d#\  
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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。 }3[ [ONA  
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视网膜的散射 :syR4A WM  
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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。 u4+VG5.rhT  
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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。 @RaMO#  
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脚本 kP;Rts8JD  
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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： PVtQ&m$y  
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如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 _bMs~%?~/  
余下的脚本计算与屈光度有关的所有参数。 >/'WU79TYE  
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分析 ![Jxh,f  
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屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 -@#AQ\  
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脚本代码 }:hdAZ+z  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. V@Po}  
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Dim entity As T_ENTITY
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Dim op As T_OPERATION @8_K^3-~e  
Dim mat As T_MODELMATERIAL iWtWT1n8n  
Dim A As Double 7x1jpQ-  
Dim pupilDiam As Double 14^t{  
Dim eID As Long V25u'.'v  
Dim parID As Long IPT}JX'  
Dim count As Integer OK2wxf  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double x3M`l|  
Dim tlens As Double, nlens As Double 74Kl!A  
Dim curv As Double, conic As Double beIEy(rA  
Dim ok As Long ?SQT;C3j(  
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Sub Main da2BQ;  
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    '用户输入对话框 {(aJrSE<z  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 Crey}A/N  
        TextBox 220,21,40,21,.TextBox1 'default: 0 )T2Sw
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        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 N:&Gv'`  
        OKButton 40,91,90,21 8`*`4m  
        CancelButton 190,91,90,21 u|w[b9^r  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 E7jv  
        TextBox 220,49,40,21,.TextBox2 'default: 4  kU#$  
    End Dialog &i!.6M2  
    Dim dlg As UserDialog AalyEn&>  
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    ok = Dialog (dlg) KD#ip3  
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    If ok=0 Then    'cancel button was pressed fC81(5  
        Print "Execution cancelled." h7%<  
        End @h$7C<  
    End If jdoI)J@9H  
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    'Assign accommodation and pupil diameter & use defaults if field left empty pRYt.}/K  
    If dlg.TextBox1 = "" Then ^LnCxA&QH  
        A = 0           'Default accommodation Wk$%0xZ7  
    Else &{7%VsTB  
        A = CDbl(dlg.TextBox1) y|1-,u.$  
    End If Ejn19{  
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    If dlg.TextBox2 = "" Then DuCq16'0T  
        pupilDiam = 4   'Default pupil diameter 1o.]"~0:  
    Else /)v X|qtIY  
        pupilDiam = CDbl(dlg.TextBox2) RJSNniYr7  
    End If JZai{0se  
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    Print " " <.:B .k  
    Print "Accommodation = " & A & " Diopters" RX#:27:  
    Print "Pupil Diameter = " & pupilDiam & " mm" '{C=vW  
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    ' Calculate new parameters with accommodation "|&SC0*  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness m}8c.OJ>K`  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens g9 g &]  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens `@eQL[Z9x  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens iao_w'tJ  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens 6&h,eQ!  
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    tlens = 3.767 + 0.04*A                  'Lens thickness hXZk$a'  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction <sn^>5Ds  
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    'Adjust parameters to account for accommodation l? 7D
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    '************************************************************************* 91[(K'=&  
    'Aqueous thickness (Position of Lens) _AK-AY  
    '************************************************************************* j].XVn,  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) Lw2EA 5  
    GetCustomElement eID, entity 8BBuYY{  
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    parID = FindFullName( "Geometry.Arizona Eye" ) _sx]`3/86  
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    ' Delete any shift(s) in z >~2oQ[n  
    count = 0 T&cf6soo  
    While GetOperationCount(eID)>count C+jlIT+  
        GetOperation eID, count, op _@SC R%  
        If op.Type="ShiftZ" Then s}X2*o`,  
            DeleteOperation eID,count Pe~[qETv  
            count=count-1 T[q2quXgk  
        End If #sN]6  
        count=count+1 _-^a8F>/19  
    Wend -=@d2LY  
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    'Set new shift in ;MR8E9  
    op.Type = "ShiftZ" 9K~X}]u  
    op.val1 = taq "! m6U#^  
    op.parent = parID GK~uoz:^O  
    AddOperation eID, op G[@RZ~o4  
    Print "Set aqueous humor thickness = " & taq-0.55 S
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    '************************************************************************* V*}ft@GPD  
    'Radius and conic constant of anterior lens ?sk{(
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    '************************************************************************* /&_$+Iun  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) xo a1='  
    GetConic eID, entity, curv, conic J<yt/V]  
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    SetConic eID, entity, 1/Rant, CCant Iw~R@,  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant Xq@Bzya  
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    '************************************************************************* "A6m-xE~  
    'Radius and conic constant of posterior lens +Hgil  
    '************************************************************************* h'jc4mu0  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) n 9PYZxy  
    GetConic eID, entity, curv, conic QV)>+6\  
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    SetConic eID, entity, 1/Rpost, CCpost u5;;s@{Ye4  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost ;G.5.q[A  
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    '************************************************************************* X6*4IE  
    'Lens thickness (Position of posterior lens surface) 9kHVWDf  
    '************************************************************************* ~t^ Umx"Ew  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) ,sI<AFI  
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    ' Delete any z-shift(s) Ql"kJ_F!br  
    count = 0 oq${}n<  
    While GetOperationCount(eID)>count 4a}[&zm(5  
        GetOperation eID, count, op KW-GVe%8f  
        If op.Type="ShiftZ" Then |W_;L6)  
            DeleteOperation eID,count 2,aH1Xbex  
            count=count-1 o=J-Ju
 
        End If @GUlw[vi  
        count=count+1 txE=AOY5  
    Wend DK)T2{:  
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    'Set new z-shift ,2YZB*6h{  
    op.Type = "ShiftZ" 3{$
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    op.val1 = tlens (qglD  
    op.parent = parID '_d4[Olu  
    AddOperation eID, op Yw] 7@  
    Print "Set lens thickness = " & tlens v%:VV*MxF  
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    '************************************************************************* i/j53towe  
    'Lens index of refraction -M/j&<;LW  
    '************************************************************************* wU6sU]P  
    eID = FindMaterial( "Lens" ) Z_W
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    GetModelMaterial eID, mat Q2/65$nW  
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    mat.Nd = nlens m/z,MT74*J  
    SetModelMaterial eID, mat mG"xo^1_H  
    Print "Set lens index of refraction = " & nlens H2H`7 +I,  
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    '************************************************************************* _j+!Fd  
    'Pupil diameter !O,Sq/=.  
    '************************************************************************* K!]a+M]>  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" )  ^M{,{bG  
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    'Adjust pupil diameter (trimming volume inner hole) `78Bv>[A  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" {j=`  
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    ' Adjust pupil location to just in front of the lens Xu8I8nAwl  
    parID = FindFullName( "Geometry.Arizona Eye" ) tI1OmhNN  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) ~wa6S?  
    count = 0 *,mI=1  
    While GetOperationCount(eID)>count ~:{05W  
        GetOperation eID, count, op /a'1W/^2  
        If op.Type="ShiftZ" Then J$Z=`=]t+  
            DeleteOperation eID,count s3HVX'  
            count=count-1 Wl |5EY  
        End If B*N1)J\5  
        count=count+1 [% C,&h5  
    Wend +? h}e  
    op.Type = "ShiftZ" ;h\T7pwwb  
    op.val1 = taq-0.01 =A.$~9P  
    op.parent = parID 8LbwEKl  
    AddOperation eID, op ;eN ^'/4A  
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    Print "Set pupil diameter = " & pupilDiam &E_a0*)e  
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    'Update AZ Eye subassembly Description Pg%9hejf3  
    eID = FindFullName( "Geometry.Arizona Eye" ) X/yq<_ g  
    GetEntity eID, entity f<NR6],}  
    entity.Description = "Accommodation = " & A & "D" H/c (m|KK  
    SetEntity eID, entity Zz0e4C  
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    Update g w" \pD  
    Print "DONE!" GC{M"q|_  
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End Sub gv''A"  
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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： pFvu,Q"  
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Accommodation = 4 Diopters q`VL i  
Pupil Diameter = 4 mm "j@\a)a  
Set aqueous humor thickness = 2.81 Ax;=Zh<DAv  
Set anterior lens radius = 10.4 and conic constant = -2.375869 l~6K}g?  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 )th[fUC(  
Set lens thickness = 3.927 "9wD|wsz  
Set lens index of refraction = 1.42672 5o#JHD  
Set pupil diameter = 4 1^!SuAA@  
DONE! T$I_nxh[)L