[技术]Arizona眼睛模型 [复制链接]

简介 !~04^(  
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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。 Wd_bDZQ  
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模型 z!)_'A  
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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。 Z*.fSmT8)  
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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. { >{|3  
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光源 l^:m!SA_  
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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。 -_ .f&l8  
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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。 x6* {@J&5*  
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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。 @j`_)Y\
 
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视网膜的散射 49bzHEqZ  
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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。 sVZb[|zSri  
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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。 Ra'0 ^4t  
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脚本 HDIB GG~  
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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： sT[)r]`T  
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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。 XrYMv WT  
余下的脚本计算与屈光度有关的所有参数。  02Ur'|  
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分析 >T%Jlj3ZG  
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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。 i5?)E7-  
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脚本代码 5z~Ji77!  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. VQZ3&]o  
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Dim entity As T_ENTITY =   
Dim op As T_OPERATION ;DL|%-%;$r  
Dim mat As T_MODELMATERIAL ?1xBhKq  
Dim A As Double n&iWYECz  
Dim pupilDiam As Double 6dV@.(][a  
Dim eID As Long o{4ya jt  
Dim parID As Long l,1}1{k&  
Dim count As Integer *qAF
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Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double )F0_V 4  
Dim tlens As Double, nlens As Double >MUwT$szs  
Dim curv As Double, conic As Double `. /[/z-g  
Dim ok As Long [@"H2#CQ  
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Sub Main r62x*?/  
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    '用户输入对话框 79~,KFct  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 >a%NC'~rc  
        TextBox 220,21,40,21,.TextBox1 'default: 0 UG s <<  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 ~=Z&l  
        OKButton 40,91,90,21 0Tp?ED_  
        CancelButton 190,91,90,21 O4@Ki4f3A%  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 G-G!c2o  
        TextBox 220,49,40,21,.TextBox2 'default: 4 "z69jxXo  
    End Dialog xp7,0'(;  
    Dim dlg As UserDialog iVd*62$@$  
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    ok = Dialog (dlg) T$06D
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    If ok=0 Then    'cancel button was pressed MfJk`-%~  
        Print "Execution cancelled." +>.plvZhu  
        End X;w1@4!  
    End If % rdW:  
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    'Assign accommodation and pupil diameter & use defaults if field left empty ?#qA>:2,  
    If dlg.TextBox1 = "" Then @~ N:F~  
        A = 0           'Default accommodation UY5ia4_D  
    Else ~B:Lai4"  
        A = CDbl(dlg.TextBox1) F] +t/
 
    End If 9HLn_|yU  
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    If dlg.TextBox2 = "" Then 5u:+hB  
        pupilDiam = 4   'Default pupil diameter ,M>W)TSH  
    Else $9y]>R  
        pupilDiam = CDbl(dlg.TextBox2) s2@N&7"u)  
    End If o2W pi  
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    Print " " s Ce7ni  
    Print "Accommodation = " & A & " Diopters" =gGK243  
    Print "Pupil Diameter = " & pupilDiam & " mm" x1/Usupi  
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    ' Calculate new parameters with accommodation l'W?X '  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness x~$P.X7(~  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens ";`ddN3  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens )3.udx  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens !#rZeDmw  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens 7V4iPx  
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    tlens = 3.767 + 0.04*A                  'Lens thickness X-3L4@T:?  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction ,ZD!Qb  
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    'Adjust parameters to account for accommodation 0+/L?J3  
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    '************************************************************************* D?}LKs[  
    'Aqueous thickness (Position of Lens) <!y_L5S|  
    '************************************************************************* /Or76kE  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) J%aW^+O  
    GetCustomElement eID, entity 3cT  
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    parID = FindFullName( "Geometry.Arizona Eye" ) UldKlQ8  
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    ' Delete any shift(s) in z *7ap[YXZ\w  
    count = 0 agBK
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    While GetOperationCount(eID)>count A!Ng@r  
        GetOperation eID, count, op xE9^4-Px*  
        If op.Type="ShiftZ" Then *B#OLx  
            DeleteOperation eID,count &VR<'^>  
            count=count-1 5irewh'R  
        End If 5;`([oX|_  
        count=count+1 klT6?'S  
    Wend \Y>^L{  
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    'Set new shift in bkmX@+Pe  
    op.Type = "ShiftZ" q1r\60M  
    op.val1 = taq `gfK#0x#  
    op.parent = parID 4yQ4lU,r  
    AddOperation eID, op j[iJo 5  
    Print "Set aqueous humor thickness = " & taq-0.55 7; TS  
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    '************************************************************************* ;f?OT7>kN  
    'Radius and conic constant of anterior lens O5_E"um  
    '************************************************************************* m(B6FPjr  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) ~>>o'H6  
    GetConic eID, entity, curv, conic Z'S>i*Ts  
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    SetConic eID, entity, 1/Rant, CCant WVy"MD  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant fN0D\Mu!)b  
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    '************************************************************************* ?B@hCd)  
    'Radius and conic constant of posterior lens J#Bz)WmR  
    '************************************************************************* #kLM=a/_NO  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) i;6\tK"!  
    GetConic eID, entity, curv, conic oWs&W  
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    SetConic eID, entity, 1/Rpost, CCpost /I[cj3}{+f  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost
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    '************************************************************************* O-|RPW}  
    'Lens thickness (Position of posterior lens surface) YV!!bI  
    '************************************************************************* %{zM> le9  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) :JW~$4  
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    ' Delete any z-shift(s) &+&^Hc  
    count = 0 s15f <sp  
    While GetOperationCount(eID)>count /V7u0y  
        GetOperation eID, count, op w\$b(HC  
        If op.Type="ShiftZ" Then ^,U&v;  
            DeleteOperation eID,count b<=K@I.=  
            count=count-1 dN\pe@#lKP  
        End If 
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        count=count+1 | @di<d@  
    Wend  [POy"O  
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    'Set new z-shift IgN,]y  
    op.Type = "ShiftZ" p,kJ#I  
    op.val1 = tlens M{~eI  
    op.parent = parID V#3VRh  
    AddOperation eID, op zYls>fbp,  
    Print "Set lens thickness = " & tlens Bm~>w`1wK  
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    '************************************************************************* fC~WuG3  
    'Lens index of refraction w`!Yr:dU  
    '************************************************************************* f3v/Y5)  
    eID = FindMaterial( "Lens" ) D+ jk0*bJ  
    GetModelMaterial eID, mat 0;k3  
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    mat.Nd = nlens 'JkK0a2D  
    SetModelMaterial eID, mat d%]7:  
    Print "Set lens index of refraction = " & nlens R^PQ`$W 'R  
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    '************************************************************************* V!ajD!00  
    'Pupil diameter 78 UT]<Q;K  
    '************************************************************************* &TK%igL  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) j$8~M  
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    'Adjust pupil diameter (trimming volume inner hole) 9oGsrClH  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" m m`:ci  
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    ' Adjust pupil location to just in front of the lens JVXBm]  
    parID = FindFullName( "Geometry.Arizona Eye" ) }>tUkXlhJ<  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) { ET+V  
    count = 0 `8'|g8,wb0  
    While GetOperationCount(eID)>count &JF^a  
        GetOperation eID, count, op B<0lif|  
        If op.Type="ShiftZ" Then DOR
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            DeleteOperation eID,count Z ,T TI>P  
            count=count-1 %/sf#8^m  
        End If nY~CAo/:  
        count=count+1 cFH,fj  
    Wend [9>1e  
    op.Type = "ShiftZ" xNm<` Y?  
    op.val1 = taq-0.01 yq&]>ox  
    op.parent = parID H:~LL0Md%  
    AddOperation eID, op +,PBhB  
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    Print "Set pupil diameter = " & pupilDiam 1miTE4;?  
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    'Update AZ Eye subassembly Description nR ,j1IUF  
    eID = FindFullName( "Geometry.Arizona Eye" ) Ad`;O+/;  
    GetEntity eID, entity w
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    entity.Description = "Accommodation = " & A & "D" g(<@r2p  
    SetEntity eID, entity Xw![}L>  
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    Update 0}w>8L7i{  
    Print "DONE!" .|o7YTcR
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End Sub o3uv"# C  
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如果屈光度是4，光瞳直径是4，则会输出如下数据： ?MN?.O9-  
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Accommodation = 4 Diopters &d6'$h:kHb  
Pupil Diameter = 4 mm ,AM6E63  
Set aqueous humor thickness = 2.81 .Mm8\].  
Set anterior lens radius = 10.4 and conic constant = -2.375869 N4$0ptz#}G  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 &z,w0FOre  
Set lens thickness = 3.927 [81k4kU  
Set lens index of refraction = 1.42672 1Z*-@%RX  
Set pupil diameter = 4 >Y[{m $-  
DONE! RAxA H