[技术]Arizona眼睛模型 [复制链接]

简介 ~ya@ YP]';  
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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。 " 3tk"#.#  
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模型 12LGWhDp  
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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。 ,~*pPhQ8m  
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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. [ XBVES8  
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光源 %4^NX@1jV  
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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。 AQjf\i  
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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。 p(fL' J  
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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。 2g HRfTF  
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视网膜的散射 yn|U<Hxl~H  
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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。 o2R&s@%0@B  
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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。 :=?od 0]W  
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脚本 Xk`'m[  
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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： e/R$Sfj
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如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 Ma^}7D /  
余下的脚本计算与屈光度有关的所有参数。 ,m[#<}xXA  
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分析 ImsyyeY]  
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屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 JnPwqIF1  
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脚本代码 l,ic-Y1  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. R c  
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Dim entity As T_ENTITY KZ 4G"  
Dim op As T_OPERATION t
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Dim mat As T_MODELMATERIAL D-Q54"^3  
Dim A As Double @me ( pnD  
Dim pupilDiam As Double ^?S 
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Dim eID As Long Cuc+9  
Dim parID As Long 9`cj9zz7  
Dim count As Integer
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Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double gg@Ew4L&  
Dim tlens As Double, nlens As Double (l}nwyh5  
Dim curv As Double, conic As Double o3Z<tI8-V  
Dim ok As Long E=]$nE]b  
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Sub Main 4F,RlKHBl  
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    '用户输入对话框 ^zKP5nzL  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 \RmU6(;IQ  
        TextBox 220,21,40,21,.TextBox1 'default: 0 nG7E j#1  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 q3ebps9^  
        OKButton 40,91,90,21 qRCUkw} fs  
        CancelButton 190,91,90,21 T1c&3  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 3w
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        TextBox 220,49,40,21,.TextBox2 'default: 4 Z9zsvg  
    End Dialog P.3kcZ   
    Dim dlg As UserDialog +kx#"L:  
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    ok = Dialog (dlg) QJ,~K&?  
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    If ok=0 Then    'cancel button was pressed b$Q#Fv&P  
        Print "Execution cancelled." ?3do-tTp  
        End nQ;M@k&9eV  
    End If NW~`oc)NS  
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    'Assign accommodation and pupil diameter & use defaults if field left empty 8xx2+  
    If dlg.TextBox1 = "" Then F@1Eg
  
        A = 0           'Default accommodation ;eC8| Xz  
    Else M<ba+Qn$  
        A = CDbl(dlg.TextBox1) <AB({(  
    End If QxiAC>%K  
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    If dlg.TextBox2 = "" Then LDdgI  
        pupilDiam = 4   'Default pupil diameter J )UCy;Y  
    Else K}tC8D  
        pupilDiam = CDbl(dlg.TextBox2) C:RA(
  
    End If jBJ|%KM  
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    Print " " R2y~+tko?
 
    Print "Accommodation = " & A & " Diopters" 
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    Print "Pupil Diameter = " & pupilDiam & " mm" ^\w!D{Y7Q  
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    ' Calculate new parameters with accommodation ^`fqK4<  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness @UW*o&pGqL  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens 5$c*r$t_RK  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens w5q'M  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens nw=:+?  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens gCaxZ~o  
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    tlens = 3.767 + 0.04*A                  'Lens thickness B dxV [SF  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction {$'oKJy*  
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    'Adjust parameters to account for accommodation 8YO` TgW  
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    '************************************************************************* uOb}R   
    'Aqueous thickness (Position of Lens) y>& s;  
    '************************************************************************* Duq.`XO  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) #./8inbG  
    GetCustomElement eID, entity 7%i6zP/a  
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    parID = FindFullName( "Geometry.Arizona Eye" ) O
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    ' Delete any shift(s) in z wcW}Sv[r  
    count = 0 59k-,lyU,  
    While GetOperationCount(eID)>count <'vtnz  
        GetOperation eID, count, op 0|FQIhVuY  
        If op.Type="ShiftZ" Then +uMK_ds~  
            DeleteOperation eID,count +g%
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            count=count-1 'Xg9MS&  
        End If ^o Q^/v~  
        count=count+1 *[tLwl.  
    Wend F*=}}H/  
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    'Set new shift in |],ocAN{  
    op.Type = "ShiftZ" % r0AhWv  
    op.val1 = taq 5/i]Jni  
    op.parent = parID wZ/b;%I!  
    AddOperation eID, op ig4mj47wJ  
    Print "Set aqueous humor thickness = " & taq-0.55 'V}4_3#q  
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    '************************************************************************* jWh}cM=  
    'Radius and conic constant of anterior lens XVYj X  
    '************************************************************************* .%_=(C<E  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) Yn8aTg[J  
    GetConic eID, entity, curv, conic s^GE>rf  
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    SetConic eID, entity, 1/Rant, CCant k9iB-=X?4s  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant E 7"`D\*  
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    '************************************************************************* d?4-"9Y  
    'Radius and conic constant of posterior lens +EM^  
    '************************************************************************* B{cb'\C  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) I->4Q&3  
    GetConic eID, entity, curv, conic "K#zY~>L  
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    SetConic eID, entity, 1/Rpost, CCpost sF p% T4j  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost {Zf 9} !qF  
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    '************************************************************************* N6!$V7oT  
    'Lens thickness (Position of posterior lens surface) Hs(U|BXU  
    '************************************************************************* ^4{"h  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) pSS8 %r%S'  
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    ' Delete any z-shift(s) aaFt=7(K  
    count = 0 ?Z"<&ts
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    While GetOperationCount(eID)>count %Su,  
        GetOperation eID, count, op ,\D*=5  
        If op.Type="ShiftZ" Then pFwhvw  
            DeleteOperation eID,count `h$^=84  
            count=count-1 NSQ#\:3:S  
        End If a VIh|v  
        count=count+1 Wh1'?#  
    Wend OLyl.#J  
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    'Set new z-shift | gP%8nh'C  
    op.Type = "ShiftZ" G*rlU  
    op.val1 = tlens !Bn,f2  
    op.parent = parID ;<nQl,2N  
    AddOperation eID, op T7j,%ay9  
    Print "Set lens thickness = " & tlens ,=`iQl3(y/  
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    '************************************************************************* S/xCX!  
    'Lens index of refraction ,2lH*=m;  
    '************************************************************************* Ep1p>s^  
    eID = FindMaterial( "Lens" ) w*B4>FYg  
    GetModelMaterial eID, mat ?m dGMf)  
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    mat.Nd = nlens %q_b\K  
    SetModelMaterial eID, mat 5DnX8t+d  
    Print "Set lens index of refraction = " & nlens Ys@G0}\3G  
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    '************************************************************************* [M&.'X  
    'Pupil diameter eTZ2f  
    '************************************************************************* jQ9i<-zc  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) */A ~lR|  
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    'Adjust pupil diameter (trimming volume inner hole) 70yM]C^  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" Yo[Pu< zR  
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    ' Adjust pupil location to just in front of the lens QLOcgU^  
    parID = FindFullName( "Geometry.Arizona Eye" ) =Bb/Y`Q  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) {qL}:ha?  
    count = 0 8&UwnEk<  
    While GetOperationCount(eID)>count s!WI:E7  
        GetOperation eID, count, op l$3YJ.n|s~  
        If op.Type="ShiftZ" Then "wj-Qgz  
            DeleteOperation eID,count n+:}pD  
            count=count-1 Wt
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        End If 1eMz"@Q9  
        count=count+1 hO0g3^  
    Wend tW}At  
    op.Type = "ShiftZ" 6tv-PgZ  
    op.val1 = taq-0.01 m!_*Q  
    op.parent = parID vDcYz,  
    AddOperation eID, op -1c{Jo  
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    Print "Set pupil diameter = " & pupilDiam !TeI Jm/l  
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    'Update AZ Eye subassembly Description _Sn45h@"  
    eID = FindFullName( "Geometry.Arizona Eye" ) tLo_lLn*~%  
    GetEntity eID, entity J0,;F9<C#X  
    entity.Description = "Accommodation = " & A & "D" .l
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    SetEntity eID, entity qotWWe#  
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    Update d.t$VRO  
    Print "DONE!" 10W6wIqK  
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End Sub v5dLjy5
 
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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： D%!GY1wdn  
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Accommodation = 4 Diopters [ %6(1$Ih  
Pupil Diameter = 4 mm -mY,nMDb  
Set aqueous humor thickness = 2.81 ;T*o RS  
Set anterior lens radius = 10.4 and conic constant = -2.375869 k`h#.B J  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 Ji7<UJ30x  
Set lens thickness = 3.927 YK%rTbB(  
Set lens index of refraction = 1.42672 6gTc)rhRT  
Set pupil diameter = 4 ^b^}6L'Z  
DONE! i:\|G^h