[技术]Arizona眼睛模型 [复制链接]

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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。 -=
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模型 @)d_z
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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。 )#i@DHt=  
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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. :\[l~S  
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光源 '> ib K|  
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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。 x=cucZ  
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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。 <&m50pq  
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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。 v,iZnANZ&P  
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视网膜的散射 ,]EhDW6  
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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。 SVo?o|<  
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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。 fHd[8{;P:  
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脚本 !~|-CF0z=  
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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： qHZDo[  
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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。 (6$P/k8  
余下的脚本计算与屈光度有关的所有参数。 #_.JkY  
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分析 e' M&Eh  
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屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 ir<e^a  
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脚本代码 e ymv/  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. ,jRAVt+{N  
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Dim entity As T_ENTITY XHU$&t`7>g  
Dim op As T_OPERATION sex\dg<  
Dim mat As T_MODELMATERIAL {V/>5pz4e  
Dim A As Double [uU!\xe  
Dim pupilDiam As Double qS\#MMsTd  
Dim eID As Long e4` L8  
Dim parID As Long 3'.@aMA@  
Dim count As Integer J- S.m(  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double }T4|Kyu?  
Dim tlens As Double, nlens As Double N#l2wT  
Dim curv As Double, conic As Double 67iI wY*8'  
Dim ok As Long .yy-jf/  
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Sub Main ZMQ=D!kT  
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    '用户输入对话框 2yK">xYY@  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 Y]SF0:v!n  
        TextBox 220,21,40,21,.TextBox1 'default: 0 'O(=Pz  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 yIL=jzm`7  
        OKButton 40,91,90,21 tq59w  
        CancelButton 190,91,90,21 dLp1l2h!0  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 m}'_Poc  
        TextBox 220,49,40,21,.TextBox2 'default: 4 bqE'9GI  
    End Dialog ^;_~mq.  
    Dim dlg As UserDialog ."+lij=56  
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    ok = Dialog (dlg) B)Y[~4o  
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    If ok=0 Then    'cancel button was pressed R `tJ7MB  
        Print "Execution cancelled." 2'@m'4-N  
        End ~Y x_ 3  
    End If fF)Q;~_VA  
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    'Assign accommodation and pupil diameter & use defaults if field left empty S-Y{Vi"2  
    If dlg.TextBox1 = "" Then T2Yf7Szp  
        A = 0           'Default accommodation Z i6s0Uck  
    Else x{:U$[_  
        A = CDbl(dlg.TextBox1) n>}Y@{<]/  
    End If *Y(59J2  
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    If dlg.TextBox2 = "" Then FC1rwXL(  
        pupilDiam = 4   'Default pupil diameter ]u5TvI,C  
    Else Em(_W5 ND{  
        pupilDiam = CDbl(dlg.TextBox2) yq-~5ui  
    End If 2?~nA2+vm  
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    Print " " R0=f`;  
    Print "Accommodation = " & A & " Diopters" i%9vZ  
    Print "Pupil Diameter = " & pupilDiam & " mm" WRD z*Zf  
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    ' Calculate new parameters with accommodation =c@hE'{
 
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness  Lw\u{E@  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens ^i8,9T'=  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens G0 EXgq8  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens s^zlBvr|.  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens B!Wp=9)G  
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    tlens = 3.767 + 0.04*A                  'Lens thickness ytY\&m  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction L"'=[O~  
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    'Adjust parameters to account for accommodation :=hL}(~]  
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    '************************************************************************* h-PJC/>  
    'Aqueous thickness (Position of Lens) b;VI
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    '************************************************************************* J920A^)j!  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) nDvfb*\  
    GetCustomElement eID, entity <Z-Pc?F&(k  
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    parID = FindFullName( "Geometry.Arizona Eye" ) %$ya>0?mq  
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    ' Delete any shift(s) in z qR.FjQOvn  
    count = 0 sGY}(9ED;  
    While GetOperationCount(eID)>count %O9Wm_%  
        GetOperation eID, count, op Qp<*or@  
        If op.Type="ShiftZ" Then eI ( S)q  
            DeleteOperation eID,count `e ZDG  
            count=count-1 !U?C
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        End If H}r]j\  
        count=count+1 c$1
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    Wend QqF<HCO  
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    'Set new shift in d9JAt-6z2  
    op.Type = "ShiftZ" |y7TYjg6  
    op.val1 = taq dlo`](5m  
    op.parent = parID "=Z=SJ1D  
    AddOperation eID, op l0G{{R0Y  
    Print "Set aqueous humor thickness = " & taq-0.55 yr+QV:oVA  
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    '************************************************************************* 6|p8_[e`  
    'Radius and conic constant of anterior lens YQD`4ND  
    '************************************************************************* <p<6!tdO  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) 0i}.l\  
    GetConic eID, entity, curv, conic n}Z%-w$K#  
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    SetConic eID, entity, 1/Rant, CCant ^JxVs 7  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant fP<==DK  
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    '************************************************************************* P>q
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    'Radius and conic constant of posterior lens 9%kO%j,3  
    '************************************************************************* tfHr'Qy BC  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) qf K gNZ  
    GetConic eID, entity, curv, conic NCg("n,jx  
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    SetConic eID, entity, 1/Rpost, CCpost F lVG,Z  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost ;LgMi5dN  
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    '************************************************************************* d0T 8Cwcb  
    'Lens thickness (Position of posterior lens surface) ?6*\M  
    '************************************************************************* 1g=T"O&=  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) Ew]&~:$Ki  
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    ' Delete any z-shift(s) X7*ossv  
    count = 0 WMKxGZg"  
    While GetOperationCount(eID)>count A]iT uu5p  
        GetOperation eID, count, op Gmu
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        If op.Type="ShiftZ" Then :{eYm|2-  
            DeleteOperation eID,count
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            count=count-1 x%)oL:ue  
        End If wy|b Hkr_  
        count=count+1 X%I@4 B7Ts  
    Wend !*DYdqQ/  
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    'Set new z-shift yz3=#  
    op.Type = "ShiftZ" 7&etnQJ{  
    op.val1 = tlens V,zFHX
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    op.parent = parID }x6)}sz7  
    AddOperation eID, op mb_6f:Qh3  
    Print "Set lens thickness = " & tlens %*q^i}5)E  
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    '************************************************************************* Z!q$d/1  
    'Lens index of refraction j<WsFVS  
    '************************************************************************* u=PLjrB~}  
    eID = FindMaterial( "Lens" ) ENA"T-p  
    GetModelMaterial eID, mat t0<RtIh9e  
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    mat.Nd = nlens Wf?[GO  
    SetModelMaterial eID, mat HXh:83  
    Print "Set lens index of refraction = " & nlens <QgpePyoN  
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    '************************************************************************* asQ^33g z  
    'Pupil diameter "\lOOp^-  
    '************************************************************************* w$]wd`N}  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) }]1C=~lC  
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    'Adjust pupil diameter (trimming volume inner hole) 8YPX8d8u  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" _`*G71PS  
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    ' Adjust pupil location to just in front of the lens D0_CDdW%7  
    parID = FindFullName( "Geometry.Arizona Eye" ) Dm?:j9o]g  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) m1K4_a)^[  
    count = 0 Z>/ *q2  
    While GetOperationCount(eID)>count _iA oNT!  
        GetOperation eID, count, op a&kt!%p:  
        If op.Type="ShiftZ" Then O<AGAD  
            DeleteOperation eID,count Z"l].\= F  
            count=count-1 xqDz*V/mD  
        End If ^\S~rW.3_  
        count=count+1 Vv`94aQTD  
    Wend 6c>:h)?  
    op.Type = "ShiftZ" bO('y@)X  
    op.val1 = taq-0.01 =~,2E;#X  
    op.parent = parID Gf!c  
    AddOperation eID, op zDm3$P=  
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    Print "Set pupil diameter = " & pupilDiam >`yRL[c;  
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    'Update AZ Eye subassembly Description 8B "^}y\0  
    eID = FindFullName( "Geometry.Arizona Eye" ) +~==qLsU  
    GetEntity eID, entity  Ew;AYZX  
    entity.Description = "Accommodation = " & A & "D" D2Q0p(#%  
    SetEntity eID, entity -`X`Ff  
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    Update ]R^xO;g'  
    Print "DONE!" Rb^G~82d?  
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End Sub AnE] kq u  
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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： 6#:V3 ;  
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Accommodation = 4 Diopters =RM]/O9  
Pupil Diameter = 4 mm YoK )fh$  
Set aqueous humor thickness = 2.81 "ChJR[4@  
Set anterior lens radius = 10.4 and conic constant = -2.375869 {EV
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Set posterior lens radius = -4.424557 and conic constant = -3.081019 cUw$F{|W  
Set lens thickness = 3.927 yr.sfPnJK  
Set lens index of refraction = 1.42672 R%9,.g<  
Set pupil diameter = 4 _Wp.s]D [  
DONE! Lv)1 )'v0