[技术]Arizona眼睛模型 [复制链接]

简介 d=3'?l`  
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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。 D'_Bz8H!p  
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模型 pz|'l:v^  
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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。 _.V?A*  
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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. ^%>kO,  
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光源 {b)~V3rsY  
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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。 S:bC[}  
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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。 }8K4-[\  

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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。 =aG xg57  
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视网膜的散射 Z|lU8`'5  
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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。 w'Tq3-%V  
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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。 )cJ#-M2  
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脚本 YIRZ+H<Q  
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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： X2sH
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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。 0|4%4Mt  
余下的脚本计算与屈光度有关的所有参数。 'dG%oDHX]P  
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分析 <xpph t<  
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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。  uF|3/x=  
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脚本代码 2&mGT&HAVA  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. Q#I"_G&{  
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Dim entity As T_ENTITY 3rW|kkn  
Dim op As T_OPERATION \W5O&G-C  
Dim mat As T_MODELMATERIAL ?Ea;J0V  
Dim A As Double }_/Hdmmx  
Dim pupilDiam As Double 3981
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Dim eID As Long
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Dim parID As Long $ i)bq6  
Dim count As Integer ]B"'}%>ez  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double F_iXd/  
Dim tlens As Double, nlens As Double (/d5UIM{&  
Dim curv As Double, conic As Double qU2~fNY  
Dim ok As Long Xazo9J  
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Sub Main i$G;f^Z!Y  
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    '用户输入对话框 G'2#9<c*  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 >WJf=F`_H  
        TextBox 220,21,40,21,.TextBox1 'default: 0 <~ad:[  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 k(>h^  
        OKButton 40,91,90,21 _R'Fco  
        CancelButton 190,91,90,21 <9E0iz+j  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 Y?CCD4"qn  
        TextBox 220,49,40,21,.TextBox2 'default: 4  Amr[wx  
    End Dialog [Aj Q#;#Q  
    Dim dlg As UserDialog WG*t::NN  
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    ok = Dialog (dlg) E#J';tUQ  
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    If ok=0 Then    'cancel button was pressed YBYZ=,"d  
        Print "Execution cancelled." KoE8Mp  
        End n55Pv3}C  
    End If Tus}\0/i>  
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    'Assign accommodation and pupil diameter & use defaults if field left empty M;cO0UIwO  
    If dlg.TextBox1 = "" Then iHwLZ[O{  
        A = 0           'Default accommodation V@>r*7\F  
    Else 5>3}_  
        A = CDbl(dlg.TextBox1) $vHU$lZ/W  
    End If ?88[|;b3  
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    If dlg.TextBox2 = "" Then R>DaOH2K*  
        pupilDiam = 4   'Default pupil diameter WLF0US'  
    Else Nx{$}  
        pupilDiam = CDbl(dlg.TextBox2) 4h5g'!9-g  
    End If Z3>N<u8)  
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    Print " " xe7O/',pa=  
    Print "Accommodation = " & A & " Diopters" FX9F"42@  
    Print "Pupil Diameter = " & pupilDiam & " mm" CkJCi  
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    ' Calculate new parameters with accommodation :4~g;2oag  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness lb'GXd%  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens 3qY K_M^[  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens %6AW7q t  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens qB)"qFa  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens d,8mY/S>w  
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    tlens = 3.767 + 0.04*A                  'Lens thickness n
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction ;'81jbh  
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    'Adjust parameters to account for accommodation Ib
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    '************************************************************************* YF+n b.0.  
    'Aqueous thickness (Position of Lens) aM7uBx\8 5  
    '************************************************************************* Vy_2
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    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) P&Pj>!T5  
    GetCustomElement eID, entity rr#K"SP  
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    parID = FindFullName( "Geometry.Arizona Eye" ) *3T|
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    ' Delete any shift(s) in z o)OUWGjb/K  
    count = 0 hJzxbr <  
    While GetOperationCount(eID)>count LH:i| I  
        GetOperation eID, count, op >~K qg~  
        If op.Type="ShiftZ" Then oI^4pwnh  
            DeleteOperation eID,count Oy 2+b1{  
            count=count-1 tzy'G"P|  
        End If `/HUV&i"S  
        count=count+1 aZEn6*0B  
    Wend TYI7<-Mp:[  
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    'Set new shift in 0rGSH*(  
    op.Type = "ShiftZ" *D'$"@w3  
    op.val1 = taq C/(M"j M  
    op.parent = parID c)@>zto#  
    AddOperation eID, op S1/`th  
    Print "Set aqueous humor thickness = " & taq-0.55 _ Ro!"YVX  
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    '************************************************************************* VXR]"W=  
    'Radius and conic constant of anterior lens bFA!=uvA  
    '************************************************************************* ' oFxR003  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" )  BUwONF  
    GetConic eID, entity, curv, conic J)mhu}  
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    SetConic eID, entity, 1/Rant, CCant p-+K4  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant 6\
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    '************************************************************************* EC|
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    'Radius and conic constant of posterior lens +:3*  
    '************************************************************************* "bDs2E+W  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) 6%Be36<  
    GetConic eID, entity, curv, conic O$IjNx  
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    SetConic eID, entity, 1/Rpost, CCpost Cuc$3l(%  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost /O]t R  
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    '************************************************************************* h
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    'Lens thickness (Position of posterior lens surface) KRjV}\}  
    '************************************************************************* >AJSqgHQ,  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) )]#aauC+  
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    ' Delete any z-shift(s) W d0NT@  
    count = 0 c*UvYzDZL  
    While GetOperationCount(eID)>count m!U9m  
        GetOperation eID, count, op 0-{tFN  
        If op.Type="ShiftZ" Then -gQCn>"  
            DeleteOperation eID,count 4[r/}/iGo  
            count=count-1 85;b9k&\M  
        End If ]jpu,jz:  
        count=count+1 wp7!>%s{  
    Wend N?X~w <  
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    'Set new z-shift Ged
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    op.Type = "ShiftZ" JF/,K"J  
    op.val1 = tlens k<+0o))  
    op.parent = parID ^fz+41lE\  
    AddOperation eID, op hR5_+cuIp  
    Print "Set lens thickness = " & tlens mw5?[@G-  
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    '************************************************************************* Ngg?@pG0y  
    'Lens index of refraction zXsc1erli  
    '************************************************************************* 1n\ t+F  
    eID = FindMaterial( "Lens" ) ){r2T1+-%  
    GetModelMaterial eID, mat id?h>g  
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    mat.Nd = nlens )!tK[K?5  
    SetModelMaterial eID, mat !a$ D4(`v  
    Print "Set lens index of refraction = " & nlens )#F]G$51r  
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    '************************************************************************* >c-fI$]  
    'Pupil diameter l]<L [Y,E-  
    '************************************************************************* l
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    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) rWh6RYd<T  
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    'Adjust pupil diameter (trimming volume inner hole) ={?vAb:  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" =+w*gDr  
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    ' Adjust pupil location to just in front of the lens exdx\@72  
    parID = FindFullName( "Geometry.Arizona Eye" ) -YD+(c`l  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) L#)(H^[  
    count = 0 _
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    While GetOperationCount(eID)>count 7hy&-<  
        GetOperation eID, count, op M/Pme&%  
        If op.Type="ShiftZ" Then 2BCtJ`S`  
            DeleteOperation eID,count ET];%~ ^  
            count=count-1 OGiV{9U  
        End If jPnM>=  
        count=count+1  fI\
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    Wend `"@X.}\  
    op.Type = "ShiftZ" _lW+>xQ  
    op.val1 = taq-0.01 a(]`F(L  
    op.parent = parID @Mvd'.r<;  
    AddOperation eID, op fJZp?e"  
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    Print "Set pupil diameter = " & pupilDiam e4FM} z[  
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    'Update AZ Eye subassembly Description Il.Ed-&62  
    eID = FindFullName( "Geometry.Arizona Eye" ) rw
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    GetEntity eID, entity y$81Zq  
    entity.Description = "Accommodation = " & A & "D" .}')f;jH5<  
    SetEntity eID, entity `MP|Ovns:H  
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    Update n]+W 3[i  
    Print "DONE!" 4lKVY<  
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End Sub S]sk7  
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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： w#i[_  
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Accommodation = 4 Diopters midsnG+jnf  
Pupil Diameter = 4 mm
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Set aqueous humor thickness = 2.81 hC_Vts[v/  
Set anterior lens radius = 10.4 and conic constant = -2.375869 fQ+VT|jzx  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 Cc?TSZ8[  
Set lens thickness = 3.927 *]JdHO  
Set lens index of refraction = 1.42672 UueD
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Set pupil diameter = 4 l!E7AKk8  
DONE! #[MJ|^\i