[技术]Arizona眼睛模型 [复制链接]

简介 -Jt36|O  
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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。 I&`aGnr^^  
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模型 A0OA7m:~4  
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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。 ]D4lZK>H  
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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. {< EPm&q  
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光源 .osG"cS  
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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。 b1;h6AeL  
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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。 +d7Arg!m  
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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。 Z}{]/=h  
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视网膜的散射 "$D'gSoYe  
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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。 d]:G#<.  
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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。 78r0K 5=  
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脚本 o 0T1pGs'  
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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： h-RhmQA=Iz  
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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。 f/s"2r  
余下的脚本计算与屈光度有关的所有参数。 k"C
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分析 NqGSoOjIO2  
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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。 Od^Sr4C  
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脚本代码 fms(_Q:R?  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. ,I ][  
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Dim entity As T_ENTITY !dU$1:7  
Dim op As T_OPERATION 3
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Dim mat As T_MODELMATERIAL ~MXhp5PI   
Dim A As Double F_m' 9KX4E  
Dim pupilDiam As Double g<,0kl2'S  
Dim eID As Long T,jb%uPcE  
Dim parID As Long ;<thEWH;Y  
Dim count As Integer wW/q#kc  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double D6|-nl  
Dim tlens As Double, nlens As Double 8UXRM :Z"  
Dim curv As Double, conic As Double 6/?onEL9_  
Dim ok As Long pT3icy!A=  
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Sub Main zx,9x*g  
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    '用户输入对话框 A0U
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    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 Pr(@&:v:  
        TextBox 220,21,40,21,.TextBox1 'default: 0 )J0h\ky  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 awvP;F?q|  
        OKButton 40,91,90,21 GBWL0'COV  
        CancelButton 190,91,90,21 Kd58'$  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 zH6@v+gb  
        TextBox 220,49,40,21,.TextBox2 'default: 4 9j
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    End Dialog )p1~Jx(\  
    Dim dlg As UserDialog #p55/54ZI  
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    ok = Dialog (dlg) Mp>(cs  
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    If ok=0 Then    'cancel button was pressed (Nk[ys}%*  
        Print "Execution cancelled." q<!-Anc  
        End QIlZZ  
    End If a'/i/@h  
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    'Assign accommodation and pupil diameter & use defaults if field left empty &e;Qabwxva  
    If dlg.TextBox1 = "" Then I[v`)T'_{  
        A = 0           'Default accommodation FMI1[|:;  
    Else ' |B3@9<  
        A = CDbl(dlg.TextBox1) **kix  
    End If 3l41"5Fy&  
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    If dlg.TextBox2 = "" Then X-kOp9/.  
        pupilDiam = 4   'Default pupil diameter #vxq|$e  
    Else ]d@>vzCO  
        pupilDiam = CDbl(dlg.TextBox2) )RvX}y-  
    End If X?wZ7*'1  
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    Print " " s</qT6@  
    Print "Accommodation = " & A & " Diopters" z\A ),;  
    Print "Pupil Diameter = " & pupilDiam & " mm" KX
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    ' Calculate new parameters with accommodation m,!SDCq  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness 9A} *  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens .#$2,"8  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens wW1\{<hgr  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens 3B 'j?+A  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens 3^~J;U!3  
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    tlens = 3.767 + 0.04*A                  'Lens thickness 0 }od Q#  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction I4?oBq  
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    'Adjust parameters to account for accommodation ?z&%VU"  
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    '************************************************************************* =3w;<1 ?'  
    'Aqueous thickness (Position of Lens) Cp"7
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    '************************************************************************* ,&WwADZ-s  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) Cd"{7<OyM4  
    GetCustomElement eID, entity ]2qKc  
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    parID = FindFullName( "Geometry.Arizona Eye" ) >20dK
 
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    ' Delete any shift(s) in z Pap6JR{7  
    count = 0 h )5S4)  
    While GetOperationCount(eID)>count YnU)f@b#  
        GetOperation eID, count, op ,:A;4  
        If op.Type="ShiftZ" Then |oXd4  
            DeleteOperation eID,count BB(6[V"SV  
            count=count-1 z_fjmqa?  
        End If w"s@q$}]8M  
        count=count+1 79W^;
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    Wend a~$Y;C_#<  
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    'Set new shift in 5HV+7zU5  
    op.Type = "ShiftZ" ~<n.5q%Z  
    op.val1 = taq @|DQZt  
    op.parent = parID e@ZM&iR  
    AddOperation eID, op mA+:)?e5~  
    Print "Set aqueous humor thickness = " & taq-0.55 ud$-A  
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    '************************************************************************* yW=+6@A4  
    'Radius and conic constant of anterior lens WXY'%G  
    '************************************************************************* WJnGF3G>  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) }QE*-GVv]  
    GetConic eID, entity, curv, conic X$ZVY2  
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    SetConic eID, entity, 1/Rant, CCant IUFc_uL@\  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant qGV_oa74  
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    '************************************************************************* ^F+7<$2  
    'Radius and conic constant of posterior lens " L`)^  
    '************************************************************************* \xCCJWek  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) ^x: lB>  
    GetConic eID, entity, curv, conic ~$g:  
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    SetConic eID, entity, 1/Rpost, CCpost zR^Gy"  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost Tz,9>uN  
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    '************************************************************************* sE6>JaH  
    'Lens thickness (Position of posterior lens surface)
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    '************************************************************************* "a8E
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) x1.S+:  
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    ' Delete any z-shift(s) ^U*y*l$  
    count = 0 p2i?)+z  
    While GetOperationCount(eID)>count WYUDD_m  
        GetOperation eID, count, op Q,&Li+u|  
        If op.Type="ShiftZ" Then RDp  
            DeleteOperation eID,count akzGJ3g  
            count=count-1 "+ou!YK+  
        End If WR"D7{>tw  
        count=count+1 eMJ>gXA]  
    Wend -V|"T+U  
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    'Set new z-shift rR> X<  
    op.Type = "ShiftZ" 
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    op.val1 = tlens E5bVCAz  
    op.parent = parID }|kFHodo  
    AddOperation eID, op l?U=s7s0?  
    Print "Set lens thickness = " & tlens AAevN3a#nI  
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    '************************************************************************* TmQIpeych  
    'Lens index of refraction l}))vf=i  
    '************************************************************************* GkIY2PD  
    eID = FindMaterial( "Lens" ) Hsf::K x  
    GetModelMaterial eID, mat $Iwvecn?I  
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    mat.Nd = nlens k2U*dn"9U  
    SetModelMaterial eID, mat XVYFyza;  
    Print "Set lens index of refraction = " & nlens }'$PYAf6  
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    '************************************************************************* "<!U  
    'Pupil diameter Fm
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    '************************************************************************* T }}2J/sj  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) qz-QVY,  
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    'Adjust pupil diameter (trimming volume inner hole) ~|V^IJZ22  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder"  x]+PWk  
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    ' Adjust pupil location to just in front of the lens sS>b}u+v#!  
    parID = FindFullName( "Geometry.Arizona Eye" ) A9$x8x*Lt  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) tJ\ $
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    count = 0 kJWg},-\  
    While GetOperationCount(eID)>count >NRppPqL  
        GetOperation eID, count, op iVXt@[  
        If op.Type="ShiftZ" Then HC%Hbc~S_Q  
            DeleteOperation eID,count 7zb^Z]  
            count=count-1 fK J-/{|  
        End If 8D='N`cN+  
        count=count+1 .-KI,IU
 
    Wend )/T[Cnx.Nc  
    op.Type = "ShiftZ" : uncOd.  
    op.val1 = taq-0.01 k{}> *pCU  
    op.parent = parID oJ74Mra  
    AddOperation eID, op qb>41j9_t  

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    Print "Set pupil diameter = " & pupilDiam j[G`p^ul  
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    'Update AZ Eye subassembly Description R6+)&:Ab{R  
    eID = FindFullName( "Geometry.Arizona Eye" )  Aqyw  
    GetEntity eID, entity j/O~8o&  
    entity.Description = "Accommodation = " & A & "D" :GXF=Df  
    SetEntity eID, entity =@HS  
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    Update _fHC+lwN  
    Print "DONE!" #,%bW[L<N  
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End Sub X0lPRk53(  
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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： l4bytI{63  
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Accommodation = 4 Diopters ar3L|MN  
Pupil Diameter = 4 mm XUqorE  
Set aqueous humor thickness = 2.81 (bsx|8[  
Set anterior lens radius = 10.4 and conic constant = -2.375869 m=dNJF  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 |R`"Zu`  
Set lens thickness = 3.927 f9.?+.^_  
Set lens index of refraction = 1.42672 !J$r|IX5  
Set pupil diameter = 4 sh<Q2X  
DONE! $DbnPZ2$