[技术]Arizona眼睛模型 [复制链接]

简介 TZ?Os4+  
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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。 wYZT D*A2h  
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模型 3/X-Cr+d  
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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。 B\Xh3l]+j  
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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. :w@F?:C  
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光源 nD7|8,
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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。 ]JOephX2R  
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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。 !X^Hi=aV  
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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。 b9!.-^<8y  
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视网膜的散射 wZ#Rlv,3Wa  
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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。 Ab/j(xr=  
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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。 F8H'^3`b`U  
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脚本 0
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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： "< v\M85&  
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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。 \i!Son.<  
余下的脚本计算与屈光度有关的所有参数。
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分析 Ur^j$B}  
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屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 LOr|k8t
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脚本代码 IS BV%^la|  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. m 41t(i  
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Dim entity As T_ENTITY NBjeHtT  
Dim op As T_OPERATION AVG>_$<  
Dim mat As T_MODELMATERIAL t|V0x3X  
Dim A As Double C9qJP^F  
Dim pupilDiam As Double MxOD8TDF4  
Dim eID As Long +E/y ~s  
Dim parID As Long 'xnnLCm.
 
Dim count As Integer S_v(S^x6  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double /-4$7qd  
Dim tlens As Double, nlens As Double *f5l=lDOB  
Dim curv As Double, conic As Double &.Q8Mi aT  
Dim ok As Long [3N[i(Wlk  
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Sub Main u=r`t(Z1H  
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    '用户输入对话框 2 -Xdoxw  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 )zq.4  
        TextBox 220,21,40,21,.TextBox1 'default: 0 K=?VDN  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 ar.AL
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        OKButton 40,91,90,21 W2Luz;(U  
        CancelButton 190,91,90,21 ?m0IehI  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 5\F
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        TextBox 220,49,40,21,.TextBox2 'default: 4 cCY/gEv  
    End Dialog 4f^C\i+q  
    Dim dlg As UserDialog K-eY|n  
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    ok = Dialog (dlg) >u0w.3r#  
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    If ok=0 Then    'cancel button was pressed M2@b
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        Print "Execution cancelled." C+{l7QT$t  
        End 93O;+Z5J  
    End If !}KqB8;  
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    'Assign accommodation and pupil diameter & use defaults if field left empty in-C/m#  
    If dlg.TextBox1 = "" Then }-@4vl x$  
        A = 0           'Default accommodation DJ@|QQ  
    Else ;heHefbvvd  
        A = CDbl(dlg.TextBox1) =Z G:x<Hg  
    End If p?X02 >yA  
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    If dlg.TextBox2 = "" Then 9\;|x  
        pupilDiam = 4   'Default pupil diameter ILw
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    Else v$wBxCY  
        pupilDiam = CDbl(dlg.TextBox2) ?=;qK{)37  
    End If ^pnG0(9  
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    Print " " 27F~(!n  
    Print "Accommodation = " & A & " Diopters" :-`7Q\c}  
    Print "Pupil Diameter = " & pupilDiam & " mm" *e#<n_%R  
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    ' Calculate new parameters with accommodation o*g|m.SjL  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness h*B|fy4K9U  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens ~z5R{;Nbz|  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens ]rN5Ao}2  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens X+k}2HvNG  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens qmy%J  
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    tlens = 3.767 + 0.04*A                  'Lens thickness ]iNEw9  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction sOCs
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    'Adjust parameters to account for accommodation t*<#<a  
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    '************************************************************************* COzyG.R.  
    'Aqueous thickness (Position of Lens) jjM\.KL]  
    '************************************************************************* 8vSse  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) >>i@r@  
    GetCustomElement eID, entity bI)u/  
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    parID = FindFullName( "Geometry.Arizona Eye" ) ^u}L;`L  
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    ' Delete any shift(s) in z 5}$b0<em~  
    count = 0 E37<"(;  
    While GetOperationCount(eID)>count K_?W\Yg   
        GetOperation eID, count, op |t iUej  
        If op.Type="ShiftZ" Then ~9)"!  
            DeleteOperation eID,count ps .]N   
            count=count-1 #rO8Kf  
        End If &!aAO(g  
        count=count+1 [[d(jV=*  
    Wend l!}:|N Yh!  
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    'Set new shift in Ch$*Gm19Z  
    op.Type = "ShiftZ" 4'4\,o  
    op.val1 = taq 3kcTE&1^  
    op.parent = parID CC\*?BKj"  
    AddOperation eID, op n+lOb  
    Print "Set aqueous humor thickness = " & taq-0.55 :l7U>~ o  
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    '************************************************************************* ;,i]w"*  
    'Radius and conic constant of anterior lens 'TH15r@  
    '************************************************************************* a22Mufl  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) r<F hY  
    GetConic eID, entity, curv, conic -/{4Jf Wf  
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    SetConic eID, entity, 1/Rant, CCant mWR4|1(  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant 9% l%  
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    '************************************************************************* :1t~[-h^  
    'Radius and conic constant of posterior lens Q#h 9n]5  
    '************************************************************************* '>$]{
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    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) Y]]}*8  
    GetConic eID, entity, curv, conic ]EwVpvTw  
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    SetConic eID, entity, 1/Rpost, CCpost >5s6u`\  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost `wF8k{Pb  
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    '************************************************************************* A)%A!  
    'Lens thickness (Position of posterior lens surface) ?4H i-  
    '************************************************************************* 2I*;A5$N1  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) /Q~gU<  
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    ' Delete any z-shift(s) z
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    count = 0 pv^O"Bs  
    While GetOperationCount(eID)>count '*\|;l#1  
        GetOperation eID, count, op "#(T  
        If op.Type="ShiftZ" Then ;<G=M2  
            DeleteOperation eID,count *tm0R>?!  
            count=count-1 Y0D}g3`  
        End If PJcwH6m  
        count=count+1 r$]HIvJD  
    Wend 22f`LoM  
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    'Set new z-shift )(y)A[  
    op.Type = "ShiftZ" uV 7BK+[O  
    op.val1 = tlens /-bO!RTwf  
    op.parent = parID <dW]\h?)  
    AddOperation eID, op rvr-XGK36\  
    Print "Set lens thickness = " & tlens (@iMLuewK  
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    '************************************************************************* n_3O-X(  
    'Lens index of refraction 1"pw  
    '************************************************************************* o] mD
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    eID = FindMaterial( "Lens" ) :n /@z4#  
    GetModelMaterial eID, mat ChCrL[2  
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    mat.Nd = nlens B<C*  
    SetModelMaterial eID, mat Duc#$YfGm  
    Print "Set lens index of refraction = " & nlens * S=\
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    '************************************************************************* i;!H!-sM  
    'Pupil diameter IpP~Uz  
    '************************************************************************* ^h{)Gf,+\  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) 'Ysx=  
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    'Adjust pupil diameter (trimming volume inner hole) sg+uBCGB  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" >Wz;ySEz  
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    ' Adjust pupil location to just in front of the lens B/` !K  
    parID = FindFullName( "Geometry.Arizona Eye" ) It{;SKeo  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) ^5=B`aich  
    count = 0 5Kkdo!z  
    While GetOperationCount(eID)>count 7EXI6jGJ|  
        GetOperation eID, count, op b$Vz2Fzx  
        If op.Type="ShiftZ" Then o1<_
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            DeleteOperation eID,count }g4 M2|  
            count=count-1 %'[&U#-  
        End If f%V4pzOc"  
        count=count+1 A'2w>8  
    Wend .nyfYa+  
    op.Type = "ShiftZ" Nj?/J47?,  
    op.val1 = taq-0.01 WD1G&5XP  
    op.parent = parID +zy=50,   
    AddOperation eID, op S{Er?0wm.R  
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    Print "Set pupil diameter = " & pupilDiam rD*sl}  
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    'Update AZ Eye subassembly Description [ :zO}
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    eID = FindFullName( "Geometry.Arizona Eye" ) j\m_o% 4  
    GetEntity eID, entity P{u0ftyX}  
    entity.Description = "Accommodation = " & A & "D" d9q(xZ5  
    SetEntity eID, entity v'e[GB0  
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    Update hcyM6:}  
    Print "DONE!" 7e<c$t#H  
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End Sub z`\F@pX%wC  
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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： zD<or&6  
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Accommodation = 4 Diopters VqS#waNrx  
Pupil Diameter = 4 mm AZmb!}m+d  
Set aqueous humor thickness = 2.81 9D4NX<_  
Set anterior lens radius = 10.4 and conic constant = -2.375869 HQB(*  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 &\Amn?Iq  
Set lens thickness = 3.927 ;s52{>&F]  
Set lens index of refraction = 1.42672 ~{Mn{  
Set pupil diameter = 4 I}t#%/'YA  
DONE! !tp1:'KG