[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。 W$}2 $}r0U  
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模型 j;_E0j#  
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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。 *P12d  
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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. /Zz[vf
 
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光源 pfMmDl5|  
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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。 4SkCV  
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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。 }.A \;FDyj  
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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。 L>`inrpz=w  
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视网膜的散射 $B )jSxSy  
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在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 e=i9l  
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注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 @i>4k  
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脚本 _o6Zj1p  
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内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： 0[-@<w ^j  
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如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 &*qAB)**  
余下的脚本计算与屈光度有关的所有参数。 {u$<-W-&  
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分析 {%v{iE>  
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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。 5Kkp1K$M  
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脚本代码 jGn2QL  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. $*+`;PG-  
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Dim entity As T_ENTITY f!}e*oX  
Dim op As T_OPERATION Uclta  
Dim mat As T_MODELMATERIAL M
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Dim A As Double ^4 ~ V/  
Dim pupilDiam As Double 6$5SS#  
Dim eID As Long %xN91j["  
Dim parID As Long o+T,O+i  
Dim count As Integer 0PJ7o#}_{@  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double jY$3   
Dim tlens As Double, nlens As Double DP &*P/
  
Dim curv As Double, conic As Double oN.#q$\` k  
Dim ok As Long ;TCT%j`^o  
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Sub Main hODq&9!  
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    '用户输入对话框 C<q@C!A  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 QzD8 jk#  
        TextBox 220,21,40,21,.TextBox1 'default: 0 ]= 9^wS  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 \r&9PkHWo  
        OKButton 40,91,90,21 b[my5Ol  
        CancelButton 190,91,90,21 f5vsxP)Y[  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 'n7Ld6%1  
        TextBox 220,49,40,21,.TextBox2 'default: 4 `j(-y`fo  
    End Dialog e-YMFJtoK}  
    Dim dlg As UserDialog \']_y\  
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    ok = Dialog (dlg) c~n:xblv  
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    If ok=0 Then    'cancel button was pressed Xs$UpQo   
        Print "Execution cancelled." '>dx~v %  
        End gP>`DPgb^  
    End If R}0!F2  
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    'Assign accommodation and pupil diameter & use defaults if field left empty ~|=goHmm[  
    If dlg.TextBox1 = "" Then PG'+vl  
        A = 0           'Default accommodation ,&rHBNS  
    Else hH=}<@z   
        A = CDbl(dlg.TextBox1) \WZ]'o6  
    End If MI|anM  
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    If dlg.TextBox2 = "" Then 0tp3mYd  
        pupilDiam = 4   'Default pupil diameter |eFce/  
    Else sB%QqFRP  
        pupilDiam = CDbl(dlg.TextBox2) t(5PKD#~Dc  
    End If oC1Nfc+  
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    Print " " #'oGtFCd`  
    Print "Accommodation = " & A & " Diopters" #@K %Mx  
    Print "Pupil Diameter = " & pupilDiam & " mm" GGkU$qp2~  
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    ' Calculate new parameters with accommodation yDe#,|-p  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness z3Q#Wmv2  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens NaYr$`  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens }ujl2uhM  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens @_C?M5v  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens <~R{U>zO  
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    tlens = 3.767 + 0.04*A                  'Lens thickness 5BB:.  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction _!Ir|j.A  
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    'Adjust parameters to account for accommodation b*W01ist  
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    '************************************************************************* T6fm`uL&L  
    'Aqueous thickness (Position of Lens) ])H[>.?K  
    '************************************************************************* Q,<V)  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) }+ZZO0  
    GetCustomElement eID, entity {<y.G1<.  
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    parID = FindFullName( "Geometry.Arizona Eye" ) IH$ZPux  
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    ' Delete any shift(s) in z H&E3RU>`  
    count = 0 #Zt(g(T  
    While GetOperationCount(eID)>count ;{f4E)t 7  
        GetOperation eID, count, op ERz{, >
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        If op.Type="ShiftZ" Then ^QTtCt^:  
            DeleteOperation eID,count yHjuT+/wM,  
            count=count-1 |.Vs
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        End If o2e gNTG  
        count=count+1 `T(T]^C98  
    Wend +jN%w{^=  
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    'Set new shift in  "DsL$D2e  
    op.Type = "ShiftZ" y;xY74Nq  
    op.val1 = taq )H|cri~D  
    op.parent = parID wC`+^>WFo  
    AddOperation eID, op Dwg_#GSr  
    Print "Set aqueous humor thickness = " & taq-0.55 l[u=_uaYl  
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    '************************************************************************* >dYN@cB$}  
    'Radius and conic constant of anterior lens {?hpW+1,#  
    '************************************************************************* m*H' Cb  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) } za"rU  
    GetConic eID, entity, curv, conic 9U]j@*QN  
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    SetConic eID, entity, 1/Rant, CCant K0C3s  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant s>c0K@ADO  
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    '************************************************************************* >Pf\"%*  
    'Radius and conic constant of posterior lens wjc&S'[  
    '************************************************************************* M~,N~ N1  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) gUHx(Fi[4  
    GetConic eID, entity, curv, conic iWp 6^g  
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    SetConic eID, entity, 1/Rpost, CCpost @M&qH[tK-A  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost N97
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    '************************************************************************* _(:<l YaY  
    'Lens thickness (Position of posterior lens surface) r2G38/K  
    '************************************************************************* B<\HK:%{  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) nN5fP<H2x  
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    ' Delete any z-shift(s) fprP$MbI  
    count = 0 FL E3LH  
    While GetOperationCount(eID)>count 7Xf52\7n  
        GetOperation eID, count, op ODNZLCB~t  
        If op.Type="ShiftZ" Then 4=qZ Z>[t  
            DeleteOperation eID,count ?4cj
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            count=count-1 P"%f8C~r  
        End If o1Nfn'!3/>  
        count=count+1 oe<DP7e  
    Wend 9:,ZG4s  
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    'Set new z-shift 0)rayzv  
    op.Type = "ShiftZ" RmRPR<vGW  
    op.val1 = tlens qT~a`ou:  
    op.parent = parID 6_g:2=6S  
    AddOperation eID, op #7['M;_  
    Print "Set lens thickness = " & tlens ;cf
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    '************************************************************************* 2{<o1x,Ym  
    'Lens index of refraction 'Y0h w  
    '************************************************************************* -car>hQq  
    eID = FindMaterial( "Lens" ) ?azcWf z0  
    GetModelMaterial eID, mat qPBOt;N  
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    mat.Nd = nlens >Og|*g  
    SetModelMaterial eID, mat ,ygUy]  
    Print "Set lens index of refraction = " & nlens x;{Hd;<YF  
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    '************************************************************************* L%jIU<?Z7  
    'Pupil diameter !<>*|a  
    '************************************************************************* {5]c\_.  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) `BVXF#sb  
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    'Adjust pupil diameter (trimming volume inner hole) 4W#DLi
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder"
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    ' Adjust pupil location to just in front of the lens //'&a-%$^  
    parID = FindFullName( "Geometry.Arizona Eye" ) +ZOK
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    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) ,b4o
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    count = 0 WK0:3q(P  
    While GetOperationCount(eID)>count Vh?RlIUA  
        GetOperation eID, count, op -Fq`#"  
        If op.Type="ShiftZ" Then X;n09 L`CB  
            DeleteOperation eID,count +)LCYDRV7  
            count=count-1 09qfnQG  
        End If BA[ uO3\4  
        count=count+1 &\%\"Zh  
    Wend q@g#DP+C  
    op.Type = "ShiftZ" 6-z(34&N  
    op.val1 = taq-0.01 )-0+O=v  
    op.parent = parID 0SQrz$y  
    AddOperation eID, op udXzsY9Ng  
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    Print "Set pupil diameter = " & pupilDiam <4n"LJ9  
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    'Update AZ Eye subassembly Description e_"m\e#N  
    eID = FindFullName( "Geometry.Arizona Eye" ) 1nw\?r2  
    GetEntity eID, entity NeJ->x,  
    entity.Description = "Accommodation = " & A & "D" --EDr>'D5P  
    SetEntity eID, entity $6(a6!  
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    Update ?GlXxx=eV  
    Print "DONE!" 9c
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End Sub XhA tf@n  
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如果屈光度是4，光瞳直径是4，则会输出如下数据： hw.>HT|.N  
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Accommodation = 4 Diopters zk"8mTg  
Pupil Diameter = 4 mm !FDd5CS  
Set aqueous humor thickness = 2.81 P*H0Hwn;  
Set anterior lens radius = 10.4 and conic constant = -2.375869 TyjZ  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 k>\v]&|T`  
Set lens thickness = 3.927 :t<S  
Set lens index of refraction = 1.42672 fs?H  
Set pupil diameter = 4 a#k7 aOT0  
DONE! 4$WR8