[技术]Arizona眼睛模型 [复制链接]

简介 CNefk$/cR  
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人眼光学模型可用来设计眼科用设备，光学系统注定了要与人眼一起使用。本文演示了这样一个模型：Arizona眼睛模型，在Jim Schwiegerling教授的书中有详细描述：《Field Guide to Visual and Ophthalmic Optics》。AZ眼睛模型达到了基于平均临床数据所决定的轴上和轴外像差等级。FRED文件包含了此眼睛模型及几个用来分析它的光源，并包括一个基于想要的屈光度来调整模型的内嵌脚本。 xy]O8>b  
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模型 mpug#i6q  
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模型的定义如表1种所示，由半径、圆锥常数、折射率、阿贝数、到下一面的距离等一系列表面组成。一些参数由屈光度（A）来决定。 [9${4=Kq  
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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. Ba@~:  
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光源 T2MC`s|`  
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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。 dazNwn  
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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。 m2\\!C]f  
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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。 ZK8)FmT_<O  
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视网膜的散射 l.o/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。 T0tX%_6`  
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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。 =G:Krc8w@  
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脚本 *'-4%7C`1  
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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： IQPu%n{0v  
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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。 H54RA6$>  
余下的脚本计算与屈光度有关的所有参数。 wHj1+W  
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分析 _
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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。 >K9Ia4I,  
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脚本代码 $Q/@5f'T`9  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. v0\l~_|H  
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Dim entity As T_ENTITY Wk0E7Pr  
Dim op As T_OPERATION qLmzA@Cv  
Dim mat As T_MODELMATERIAL { LvD\4h"  
Dim A As Double r%.k,FzGZY  
Dim pupilDiam As Double }=/zG!+  
Dim eID As Long W#F9Qw  
Dim parID As Long ?XHQdN3e  
Dim count As Integer D5lQ0_IeW  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double eM<N?9s  
Dim tlens As Double, nlens As Double cW:y^(Xii  
Dim curv As Double, conic As Double >9{?&#]x  
Dim ok As Long GOc   
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Sub Main Me.I>7c  
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    '用户输入对话框 pN[WYM?[  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 ^X96yj'?  
        TextBox 220,21,40,21,.TextBox1 'default: 0 SboHo({5VA  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 1C<cwd;9  
        OKButton 40,91,90,21 f!x9%  
        CancelButton 190,91,90,21 1B4Qj`:+0  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 x(Bt[=,K3  
        TextBox 220,49,40,21,.TextBox2 'default: 4 6$R9Y.s>Z  
    End Dialog /f#b;qa,  
    Dim dlg As UserDialog ;ek*2Lh  
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    ok = Dialog (dlg) eN=jWUoCh  
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    If ok=0 Then    'cancel button was pressed '#+&?6p  
        Print "Execution cancelled." Z mJ<h&  
        End OXEEpoU?V  
    End If p3M!H2W  
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    'Assign accommodation and pupil diameter & use defaults if field left empty %zcA|SefP  
    If dlg.TextBox1 = "" Then VE+H! ob A  
        A = 0           'Default accommodation h$02#(RHJ  
    Else izl6L  
        A = CDbl(dlg.TextBox1) ' h7Faj  
    End If RrMEDMhk6  
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    If dlg.TextBox2 = "" Then 0fOhCxtL@  
        pupilDiam = 4   'Default pupil diameter }X)vktE+|  
    Else cXb*d|-|N  
        pupilDiam = CDbl(dlg.TextBox2) 1@|+l!rYF  
    End If 4,)9@-|0R  
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    Print " " X!]v4ma`  
    Print "Accommodation = " & A & " Diopters" (7R?T}  
    Print "Pupil Diameter = " & pupilDiam & " mm" -Uo11'{  
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    ' Calculate new parameters with accommodation qfDG.Zee#  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness 8c9HJ9vk  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens &r1(1<  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens b >D  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens Jy(G A  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens yx]9rD1cz  
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    tlens = 3.767 + 0.04*A                  'Lens thickness ZwUBeyxS=c  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction i7#4&r  
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    'Adjust parameters to account for accommodation L8`v  
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    '************************************************************************* ^^b'tP1>  
    'Aqueous thickness (Position of Lens) ~Gfytn9x.;  
    '************************************************************************* 1B;2 ~2X  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) eh9?GUr5  
    GetCustomElement eID, entity R;OPY?EeW  

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    parID = FindFullName( "Geometry.Arizona Eye" ) 'n'>+W:  
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    ' Delete any shift(s) in z mh3S?Uc  
    count = 0 /
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    While GetOperationCount(eID)>count O*~,
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        GetOperation eID, count, op gzs\C{4D  
        If op.Type="ShiftZ" Then "6jt$-?  
            DeleteOperation eID,count zH]oAu=H  
            count=count-1 Tx.N#,T|  
        End If ;I4vPh5Q  
        count=count+1 So1
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    Wend *)E${\1'<  
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    'Set new shift in .y s_'F-]0  
    op.Type = "ShiftZ" !yd B,S  
    op.val1 = taq |]< 3cW+  
    op.parent = parID
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    AddOperation eID, op R%jOgZG  
    Print "Set aqueous humor thickness = " & taq-0.55 ga +, P  
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    '************************************************************************* -qP)L;n  
    'Radius and conic constant of anterior lens &Gt{9#  
    '************************************************************************* j.&dH
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    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) _.JQ h
 
    GetConic eID, entity, curv, conic 3'z$@;Ev+  
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    SetConic eID, entity, 1/Rant, CCant ~0p8joOH  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant Jw
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    '************************************************************************* hju^x8 ,=m  
    'Radius and conic constant of posterior lens U"r*kO%  
    '************************************************************************* u !BU^@P  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) Y+"1'W  
    GetConic eID, entity, curv, conic G=cRdiy`C  
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    SetConic eID, entity, 1/Rpost, CCpost PLz{EQ[cV  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost hQ|mow@Zmz  
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    '************************************************************************* %tVU Rj  
    'Lens thickness (Position of posterior lens surface) AY52j  
    '************************************************************************* |?88EG@05  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) Tksv7*5$  
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    ' Delete any z-shift(s) q9
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    count = 0 !gkr?yhE  
    While GetOperationCount(eID)>count +v B}E  
        GetOperation eID, count, op 3 `_/h' ~  
        If op.Type="ShiftZ" Then  qraXAQ  
            DeleteOperation eID,count 'UX^]  
            count=count-1 B!+c74  
        End If R[m-jUL  
        count=count+1 ?$/::uo  
    Wend 7rdmj[vu  
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    'Set new z-shift )xcjQkb  
    op.Type = "ShiftZ" ;T
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    op.val1 = tlens $[X][[  
    op.parent = parID )|=1;L  
    AddOperation eID, op ^|MS2'  
    Print "Set lens thickness = " & tlens G u`xJ  
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    '************************************************************************* +<\LY(o  
    'Lens index of refraction kqeEm{I  
    '************************************************************************* xdO3koE:  
    eID = FindMaterial( "Lens" ) ->I.D?p  
    GetModelMaterial eID, mat Cj>HMB}  
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    mat.Nd = nlens NV
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    SetModelMaterial eID, mat G `|7NL   
    Print "Set lens index of refraction = " & nlens --]blP7  
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    '************************************************************************* {gzQ/|}#z-  
    'Pupil diameter mPA)G,^  
    '************************************************************************* )cH\i91  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) XgxO:"B  
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    'Adjust pupil diameter (trimming volume inner hole) 807+|Ol[  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" +^9^)Ur|  
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    ' Adjust pupil location to just in front of the lens H{=]94  
    parID = FindFullName( "Geometry.Arizona Eye" ) Pjh;;k|V  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) DQ0S]:tC  
    count = 0 [lIX&!T"  
    While GetOperationCount(eID)>count g}`g>&l5  
        GetOperation eID, count, op /5E0'y,|P  
        If op.Type="ShiftZ" Then pS8\B  
            DeleteOperation eID,count f8
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            count=count-1 YAXd   
        End If {eU>E/SQ  
        count=count+1 #eYYu2ND  
    Wend ;X+0,K3c  
    op.Type = "ShiftZ" ;^:8F  
    op.val1 = taq-0.01 &7'=t6  
    op.parent = parID i@:^b_  
    AddOperation eID, op V(cU/Aia^  
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    Print "Set pupil diameter = " & pupilDiam Q7u|^Gu,5  
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    'Update AZ Eye subassembly Description O$z"`'&j#  
    eID = FindFullName( "Geometry.Arizona Eye" ) \X %#-y  
    GetEntity eID, entity ;ZB=@@l(  
    entity.Description = "Accommodation = " & A & "D" DvhFCA}z  
    SetEntity eID, entity f IV"U  
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    Update $-DW+|p.?^  
    Print "DONE!" g Nz  
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End Sub 8/2Wq~&  
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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： .;31G0<w2  
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Accommodation = 4 Diopters e|C2/U-  
Pupil Diameter = 4 mm )T '?"guh`  
Set aqueous humor thickness = 2.81 X%-"b`  
Set anterior lens radius = 10.4 and conic constant = -2.375869 >CG;df<~  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 {31X  
Set lens thickness = 3.927 /7B3z}rd  
Set lens index of refraction = 1.42672 1f3g5y'z5  
Set pupil diameter = 4 zk }SEt-  
DONE! 8r}tf3xMCM