[技术]Arizona眼睛模型 [复制链接]

简介
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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。 k]yv#Pa  
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模型 %QX"oRMn0  
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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。 qQCds}<w  
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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. [};?;YN  
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光源 +<f!#4T  
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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。 !tuK.?q|l  
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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。 "IJcKoB  
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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。 @wa<nYd  
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视网膜的散射 $kn"S>jV  
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在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 h
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注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 z. xRJ  
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脚本 &A
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内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： 8:}$L)[V  
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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。 l[{Ci|4  
余下的脚本计算与屈光度有关的所有参数。 rOXh?r  
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分析 }3y Q*<  
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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。 kF7`R4Sz  
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脚本代码 0/?=FM>  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. >s"kL^  
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Dim entity As T_ENTITY Y'M}lv$sa  
Dim op As T_OPERATION |NaEXzo|qY  
Dim mat As T_MODELMATERIAL S3_QOL  
Dim A As Double ,ikn%l#cm  
Dim pupilDiam As Double p|R]/C0f  
Dim eID As Long R,[+9U|4V  
Dim parID As Long e+P|PW  
Dim count As Integer ({p@Ay  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double }J\KnaKo  
Dim tlens As Double, nlens As Double B<?fD  
Dim curv As Double, conic As Double o$bD?Zn  
Dim ok As Long "Yf?33UNZ  
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Sub Main XX'Rv
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    '用户输入对话框 >rzpYc'~w  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 5}_D
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        TextBox 220,21,40,21,.TextBox1 'default: 0 ?kM53zbT#  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 <D{_q.`vA  
        OKButton 40,91,90,21 ]e]l08  
        CancelButton 190,91,90,21 O8S"B6?$~'  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 Y4n;[nHQ(  
        TextBox 220,49,40,21,.TextBox2 'default: 4 pM7xnL4  
    End Dialog @ei:/~y3  
    Dim dlg As UserDialog OPwO`pN  
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    ok = Dialog (dlg) .6#Y-iJqc  
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    If ok=0 Then    'cancel button was pressed 9{V54ue;  
        Print "Execution cancelled." ](H vx  
        End cE0Kvqe`  
    End If @ 6{U*vs  
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    'Assign accommodation and pupil diameter & use defaults if field left empty 9Fm><,0'u  
    If dlg.TextBox1 = "" Then #3act)m  
        A = 0           'Default accommodation B#;yko  
    Else 3xz{[5<p  
        A = CDbl(dlg.TextBox1) cYMlcwS  
    End If b?FTwjV+#  
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    If dlg.TextBox2 = "" Then _jCjq   
        pupilDiam = 4   'Default pupil diameter (J^2|9r  
    Else -KG3_kE  
        pupilDiam = CDbl(dlg.TextBox2) :X;AmLf`2u  
    End If U i ~*]  
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    Print " " 
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    Print "Accommodation = " & A & " Diopters" Q.G6y,KR  
    Print "Pupil Diameter = " & pupilDiam & " mm" "|l-NUe  
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    ' Calculate new parameters with accommodation *T'>-nm]  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness L'Fy\K\  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens <C9_5Ce~  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens Hc{0O7  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens ?"[h P=3J  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens va/$dD9  
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    tlens = 3.767 + 0.04*A                  'Lens thickness SlZ>N$E  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction 4W''j[Y/  
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    'Adjust parameters to account for accommodation yS[Z%]bvU  
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    '************************************************************************* -a[]#v9  
    'Aqueous thickness (Position of Lens) IJAWG  
    '************************************************************************* R2af>R  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) fscAG\>8  
    GetCustomElement eID, entity @*gm\sU4  
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    parID = FindFullName( "Geometry.Arizona Eye" ) bNG;`VZ%  
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    ' Delete any shift(s) in z x`vIY-DS  
    count = 0 m18If  
    While GetOperationCount(eID)>count 9s-op:5  
        GetOperation eID, count, op kgvB80$4  
        If op.Type="ShiftZ" Then x_oL~~@  
            DeleteOperation eID,count /i]!=~\qFs  
            count=count-1 })R8VJ&C/  
        End If 6"Km E}  
        count=count+1 [~ sXjaL8  
    Wend u,e(5LU  
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    'Set new shift in ;y7V-sf  
    op.Type = "ShiftZ" I"]5B  
    op.val1 = taq Dm j^aFB0|  
    op.parent = parID aNpeePF)z  
    AddOperation eID, op D/w4u;E@  
    Print "Set aqueous humor thickness = " & taq-0.55 yVyh'd:Ik  
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    '************************************************************************* /]Fs3uf  
    'Radius and conic constant of anterior lens AT:T%a:G?  
    '************************************************************************* AFWcTz6#d  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) \:8eN}B  
    GetConic eID, entity, curv, conic @83h/Wcxd  
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    SetConic eID, entity, 1/Rant, CCant U/2g N H  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant IPU'M*|Q  
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    '************************************************************************* Oph4&Ip[w  
    'Radius and conic constant of posterior lens fn zj@_{|  
    '************************************************************************* )*I=>v.Jq  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) X3DXEeBEL  
    GetConic eID, entity, curv, conic E/<[G?  
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    SetConic eID, entity, 1/Rpost, CCpost hv'~S  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost ,#1ke  
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    '************************************************************************* 8{HeHU  
    'Lens thickness (Position of posterior lens surface) EOrWax@k$}  
    '************************************************************************* w0Fi~
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) 5#.uA_Fov  
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    ' Delete any z-shift(s) UAT46  
    count = 0 J'4{+Q_pa  
    While GetOperationCount(eID)>count GdavCwJ  
        GetOperation eID, count, op ,9q=2V[GP  
        If op.Type="ShiftZ" Then x\XgQQ]-  
            DeleteOperation eID,count N:!XtYA<  
            count=count-1 QeA)@x.p  
        End If @5H1Ni5/o@  
        count=count+1 Z&=K+P  
    Wend YNbs*i&  
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    'Set new z-shift I]>-~_  
    op.Type = "ShiftZ" lnW/T--  
    op.val1 = tlens `LnLd;Z  
    op.parent = parID .b]g#Du=  
    AddOperation eID, op YWeEvo(,=  
    Print "Set lens thickness = " & tlens <pGPuw|~I  
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    '************************************************************************* iYA06~d  
    'Lens index of refraction -8qLshQ  
    '************************************************************************* 8Uvf9,I'  
    eID = FindMaterial( "Lens" ) %4cUa| =?  
    GetModelMaterial eID, mat @QtJ/("&WC  
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    mat.Nd = nlens c6s*u%+},  
    SetModelMaterial eID, mat  r_]wa  
    Print "Set lens index of refraction = " & nlens bvn?wK  
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    '************************************************************************* ?]f+)tCMs  
    'Pupil diameter
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    '************************************************************************* 'g#Ml`cm  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) SY["(vP%#  
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    'Adjust pupil diameter (trimming volume inner hole) |!dyk<}oIu  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" pq*b"Jku1  
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    ' Adjust pupil location to just in front of the lens ^o"9f1s5  
    parID = FindFullName( "Geometry.Arizona Eye" ) Mq42^m:qe  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) [+gX6  
    count = 0 OnF+  
    While GetOperationCount(eID)>count @.T'  
        GetOperation eID, count, op WE4
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        If op.Type="ShiftZ" Then M
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            DeleteOperation eID,count eGvHU ;@  
            count=count-1 b=-<4Vu*\  
        End If Kom$i<O?48  
        count=count+1 gPe*M =iF  
    Wend zUXqTcj  
    op.Type = "ShiftZ" 6<NaME  
    op.val1 = taq-0.01 I'BoP  
    op.parent = parID BkA>':bUr  
    AddOperation eID, op B[C2uVEX:  
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    Print "Set pupil diameter = " & pupilDiam 
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    'Update AZ Eye subassembly Description 5)V J  
    eID = FindFullName( "Geometry.Arizona Eye" )  nq8mzI  
    GetEntity eID, entity I5Foh|)  
    entity.Description = "Accommodation = " & A & "D" Q0,]Q ]_  
    SetEntity eID, entity 4eYj.=I  
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    Update VGM8&J{o'  
    Print "DONE!" &B#HgWud  
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End Sub waQNX7Xdn  
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如果屈光度是4，光瞳直径是4，则会输出如下数据： gx4`pH;B\  
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Accommodation = 4 Diopters "2 ma]Ps  
Pupil Diameter = 4 mm 0+;.T1?  
Set aqueous humor thickness = 2.81 '7 6}6G%  
Set anterior lens radius = 10.4 and conic constant = -2.375869 {08UBnR  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 9HRYk13ae  
Set lens thickness = 3.927 xRP#}i:m  
Set lens index of refraction = 1.42672 f<uLbJ6  
Set pupil diameter = 4 zbx,qctYo$  
DONE! XkCbdb