[技术]Arizona眼睛模型 [复制链接]

简介 8L1oh
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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。 kZ=s'QRgL  
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模型 ^`D=GF^tX  
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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。 sk|=% }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. d;+[i  
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光源 W<<9y  
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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。 b,IocD6v;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。 P5gN#G  
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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。 Eaqca{%/^  
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视网膜的散射 Ap$y%6  
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在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 .6~`Ubr}E  
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注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 tV/Z)fpyH  
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脚本 s9oO%e<  
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内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： 9,]5v+  
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如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 B[9 (FRX  
余下的脚本计算与屈光度有关的所有参数。 cubUq5  
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分析 KTEZ4K^o=  
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屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 nNmsr=y5  
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脚本代码 H UWxPIu  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. EC6k{y}bA  
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Dim entity As T_ENTITY q*)+K9LRk  
Dim op As T_OPERATION _KD5T4FZR  
Dim mat As T_MODELMATERIAL ~svO*o Wa  
Dim A As Double 5y4u5Tm-%  
Dim pupilDiam As Double 
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Dim eID As Long (5$ZvXx?}  
Dim parID As Long  8%RI7Mg  
Dim count As Integer N{d@^Yj  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double j*;N\;iL!*  
Dim tlens As Double, nlens As Double W0cgI9=9  
Dim curv As Double, conic As Double VK3it3FI>3  
Dim ok As Long kJ)gP2E  
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Sub Main DW(~Qdk  
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    '用户输入对话框 r(2R<A  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 G"y.Z2$  
        TextBox 220,21,40,21,.TextBox1 'default: 0 SJgY  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 /OGA$eP  
        OKButton 40,91,90,21 v$w++3H  
        CancelButton 190,91,90,21 "zZIS6j  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 l+y-Fo@  
        TextBox 220,49,40,21,.TextBox2 'default: 4 Rn+4DcR  
    End Dialog l)+:4N?iVv  
    Dim dlg As UserDialog sNU}n<J-  
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    ok = Dialog (dlg) yy(A(}  
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    If ok=0 Then    'cancel button was pressed _ :^7a3I  
        Print "Execution cancelled." $1*3!}_0  
        End }{],GHCjQ  
    End If gY9\o#)
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    'Assign accommodation and pupil diameter & use defaults if field left empty t"s5\;IJ  
    If dlg.TextBox1 = "" Then ^~L}<]  
        A = 0           'Default accommodation u@.>WHQN  
    Else $(HjI \%l^  
        A = CDbl(dlg.TextBox1) ,|To#umym>  
    End If q'(z #h,cv  
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    If dlg.TextBox2 = "" Then 6/mF2&&g  
        pupilDiam = 4   'Default pupil diameter So4nJ><p  
    Else B/eaqJ  
        pupilDiam = CDbl(dlg.TextBox2) GHN3PEJ>  
    End If &:#m&,tQ  
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    Print " " ,-rB=|w  
    Print "Accommodation = " & A & " Diopters" =3ADT$YHd  
    Print "Pupil Diameter = " & pupilDiam & " mm" !Ua&0s%  
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    ' Calculate new parameters with accommodation %AR^+*Nu  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness >#N[GrJAE  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens V_a)jJ  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens m4/}Jx
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens VO`"<  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens ; Zq/eiB  
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    tlens = 3.767 + 0.04*A                  'Lens thickness YBSl-G'  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction \{PNwF?  
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    'Adjust parameters to account for accommodation C{Blqf3V0  
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    '************************************************************************* &(O06QL  
    'Aqueous thickness (Position of Lens) 8wF#e\Va0  
    '************************************************************************* D<nxr~pQ  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) S;}qLjT  
    GetCustomElement eID, entity v.`+I-\.z)  
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    parID = FindFullName( "Geometry.Arizona Eye" ) 3Xdn62[&  
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    ' Delete any shift(s) in z g@E&uyM  
    count = 0 !Z/$}xxj  
    While GetOperationCount(eID)>count sb'p-Mj  
        GetOperation eID, count, op aIu2>  
        If op.Type="ShiftZ" Then *ro.mQ_  
            DeleteOperation eID,count 0$2={s4ze  
            count=count-1 ahp1!=Z-=  
        End If z~.9@[LG]  
        count=count+1 @)z*BmP  
    Wend fq Y1ggL  
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    'Set new shift in &s-VSu7  
    op.Type = "ShiftZ" 8_iHVc;<  
    op.val1 = taq d;g-3Pf  
    op.parent = parID T~:_}J  
    AddOperation eID, op I*c;hfu  
    Print "Set aqueous humor thickness = " & taq-0.55 Mdky^;qq3;  
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    '************************************************************************* MF|*AB|E  
    'Radius and conic constant of anterior lens ~'[jBn)  
    '************************************************************************* [|
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    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) {]M>Y%j48  
    GetConic eID, entity, curv, conic B"[{]GP BY  
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    SetConic eID, entity, 1/Rant, CCant FF@`+T  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant > Z++^YVE  
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    '************************************************************************* ^^ j/  
    'Radius and conic constant of posterior lens fKYKW?g;)Z  
    '************************************************************************* -eq=4N=s  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) xSOoIsL[  
    GetConic eID, entity, curv, conic u
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    SetConic eID, entity, 1/Rpost, CCpost Z^+a*^w~{  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost tnL."^%A2I  
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    '************************************************************************* 2*YP"R
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    'Lens thickness (Position of posterior lens surface) ?.j,Bq5At  
    '************************************************************************* *JS"(. '(  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) (n}%a6M  
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    ' Delete any z-shift(s) xiJz`KD&  
    count = 0 c&A]p
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    While GetOperationCount(eID)>count I1~G$)w#  
        GetOperation eID, count, op EaCZx  
        If op.Type="ShiftZ" Then &*ZC0V3  
            DeleteOperation eID,count .f+9 A>  
            count=count-1 Hp*gv/0  
        End If Z]p8IH%~92  
        count=count+1 3f,u}1npa*  
    Wend >eu `!8  
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    'Set new z-shift L-MiaKcL  
    op.Type = "ShiftZ" G ;jF9i  
    op.val1 = tlens 5{HtJ?sKc5  
    op.parent = parID -P*xyI  
    AddOperation eID, op F[(6*/46x  
    Print "Set lens thickness = " & tlens !rz)bd
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    '************************************************************************* 5(KG=EHj_  
    'Lens index of refraction 6l<1A$BQ  
    '************************************************************************* EuLXtq  
    eID = FindMaterial( "Lens" ) G
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    GetModelMaterial eID, mat oAC^4-Ld  
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    mat.Nd = nlens yX3PUO9  
    SetModelMaterial eID, mat 6,a%&1_  
    Print "Set lens index of refraction = " & nlens %OuX`w=  
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    '************************************************************************* _>;&-e  
    'Pupil diameter 2[XltjO  
    '************************************************************************* ,v|CombIc.  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) FSFFk~  
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    'Adjust pupil diameter (trimming volume inner hole)  JUmw$u  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" H'D#s;SlR  
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    ' Adjust pupil location to just in front of the lens pEY>A_F  
    parID = FindFullName( "Geometry.Arizona Eye" ) +tPx0>p;  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) m\/>C|f\  
    count = 0 P_v0))n{  
    While GetOperationCount(eID)>count w<v1N  
        GetOperation eID, count, op <&KLo>B^  
        If op.Type="ShiftZ" Then r+SEw ;  
            DeleteOperation eID,count 5DmCxg  
            count=count-1 >pN;J)H  
        End If ?VU
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        count=count+1 ip<15;Z  
    Wend IU7$%6<Y  
    op.Type = "ShiftZ" 56"#Syj  
    op.val1 = taq-0.01 fm[_@L% x  
    op.parent = parID VjC*(6<Gj  
    AddOperation eID, op 4t,zHR6W  
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    Print "Set pupil diameter = " & pupilDiam U.HoFf+HN  
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    'Update AZ Eye subassembly Description P\Ai|"=&]  
    eID = FindFullName( "Geometry.Arizona Eye" ) @Q/x&BV  
    GetEntity eID, entity f2`P8$U)R  
    entity.Description = "Accommodation = " & A & "D" w9/nVu  
    SetEntity eID, entity ^).WW  
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    Update /A%om|+Gq  
    Print "DONE!" 1 ,#{X3  
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End Sub @TdQZZ}G\x  
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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： V h Z=,m  
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Accommodation = 4 Diopters }Q47_]5  
Pupil Diameter = 4 mm eo>/  
Set aqueous humor thickness = 2.81 TP{>O%b  
Set anterior lens radius = 10.4 and conic constant = -2.375869 R)
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Set posterior lens radius = -4.424557 and conic constant = -3.081019 MMd0O X)P  
Set lens thickness = 3.927 YtV |e|aD  
Set lens index of refraction = 1.42672 }pbBo2  
Set pupil diameter = 4 T@%;0Ro~  
DONE! q"{Up