[技术]Arizona眼睛模型 [复制链接]

简介 IkGfnXJ  
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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。 e=+?K5q{P(  
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模型 #3+!ee27#  
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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。 s;6CExH  
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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. id1s3b;  
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光源 <c2'0I >  
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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。 #~<0t(3Q  
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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。 <|SRe6m  
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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。 j4cwI90=  
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视网膜的散射 }<9cL'  
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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。 YJJB.hR+  
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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。 'qOREN  
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脚本 v5QqS8u_C  
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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： !BOY@$Y  
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如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 -T[lx\}  
余下的脚本计算与屈光度有关的所有参数。 ^$'z!+QRM  
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分析  y"H*%]  
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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。 /XzH?n/{R  
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脚本代码 LQngK7>  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. !U'QqnT  
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Dim entity As T_ENTITY aD=A^ktx  
Dim op As T_OPERATION DUC#NZgw  
Dim mat As T_MODELMATERIAL C'o64+W^  
Dim A As Double vM*($qpAy  
Dim pupilDiam As Double Os
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Dim eID As Long / ;,Md,p  
Dim parID As Long \ytJ=0r  
Dim count As Integer @jsDq Ln  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double VBcy9|lD  
Dim tlens As Double, nlens As Double :$m}UA-9  
Dim curv As Double, conic As Double =1Oj*x@*4  
Dim ok As Long C i
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Sub Main R}4So1  
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    '用户输入对话框 Pl"Nus   
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 JAQb{KefdO  
        TextBox 220,21,40,21,.TextBox1 'default: 0 S/ODqL|  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 %Ntcvp)  
        OKButton 40,91,90,21 uoX:^'q   
        CancelButton 190,91,90,21 \8?Tdx=  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 C0}IE,]  
        TextBox 220,49,40,21,.TextBox2 'default: 4 :q
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    End Dialog RWgNo#<  
    Dim dlg As UserDialog EioB%f3  
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    ok = Dialog (dlg) n3D;"
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    If ok=0 Then    'cancel button was pressed 2gq9k}38  
        Print "Execution cancelled." |,!
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        End lJis~JLd`  
    End If ] 0B2# d  
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    'Assign accommodation and pupil diameter & use defaults if field left empty 
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    If dlg.TextBox1 = "" Then !VI]oRgP  
        A = 0           'Default accommodation |(q9"  
    Else Y<Fz)dQo  
        A = CDbl(dlg.TextBox1) A#95&kJpy  
    End If 8_tK4Pw
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    If dlg.TextBox2 = "" Then ( 8c9 /7h  
        pupilDiam = 4   'Default pupil diameter .[JYj(p  
    Else =y
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        pupilDiam = CDbl(dlg.TextBox2) N,;5{y1;J  
    End If 8@2OJ=`[  
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    Print " "  oze&  
    Print "Accommodation = " & A & " Diopters" T3pmVl  
    Print "Pupil Diameter = " & pupilDiam & " mm" m/y2WlcRx  
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    ' Calculate new parameters with accommodation |>JS!NM I  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness a8 mVFm  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens \8 h;K>=h  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens KjE+QUa  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens )_i qAqkS  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens W>p-u6u%E|  
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    tlens = 3.767 + 0.04*A                  'Lens thickness (C@~3!AVa  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction Lg*B
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    'Adjust parameters to account for accommodation naw0$kXTA  
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    '************************************************************************* S4h:|jLUF  
    'Aqueous thickness (Position of Lens) \u>"s   
    '************************************************************************* f1_<G  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) 3T}izG]  
    GetCustomElement eID, entity :
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    parID = FindFullName( "Geometry.Arizona Eye" ) nCj2N,mT  
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    ' Delete any shift(s) in z PUBWZ^63  
    count = 0 'toa@5  
    While GetOperationCount(eID)>count +{W>i;U  
        GetOperation eID, count, op (Xq)py9  
        If op.Type="ShiftZ" Then vL\&6n~M>  
            DeleteOperation eID,count Z<SLc,]^  
            count=count-1 L.1_(3NG  
        End If ( 2n>A D_  
        count=count+1 ^*S)t. "  
    Wend \e'R@  
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    'Set new shift in "Za>ZRR  
    op.Type = "ShiftZ" MF'$~gxo  
    op.val1 = taq R@6zGZ1  
    op.parent = parID SOi*SwQ8  
    AddOperation eID, op Y<Xz wro0  
    Print "Set aqueous humor thickness = " & taq-0.55 ,XIz?R>;c  
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    '************************************************************************* l#H#+*F  
    'Radius and conic constant of anterior lens 8&3V#sn'  
    '************************************************************************* 3`B6w$z>(  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) *IY*yR6  
    GetConic eID, entity, curv, conic IuOgxm~Y  
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    SetConic eID, entity, 1/Rant, CCant bX*Hi#J~A  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant { Q`QX`#  
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    '************************************************************************* %T)oCjM[\  
    'Radius and conic constant of posterior lens L
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    '************************************************************************* dz*7gL;7G  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) Nv/v$Z{k  
    GetConic eID, entity, curv, conic j^;I3_P  
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    SetConic eID, entity, 1/Rpost, CCpost y6IXdW  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost -#2)?NkeE  
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    '************************************************************************* 'C:>UlzLy  
    'Lens thickness (Position of posterior lens surface) P '>SmQ  
    '*************************************************************************
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) kIGbG;"_  
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    ' Delete any z-shift(s) (q4),y<:[  
    count = 0 `S2[5i  
    While GetOperationCount(eID)>count .GsO.#p{  
        GetOperation eID, count, op n%k!vJ)]  
        If op.Type="ShiftZ" Then &g.+V/<[  
            DeleteOperation eID,count 5o6>T!
 
            count=count-1 GF>'\@Th  
        End If m^H21P"z  
        count=count+1 L dm?JrU  
    Wend 0MkSf*  
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    'Set new z-shift z%e8K(  
    op.Type = "ShiftZ" ~5 *5  
    op.val1 = tlens XP1~d>j  
    op.parent = parID  -Y H<  
    AddOperation eID, op Pp|*J^U 4  
    Print "Set lens thickness = " & tlens .9"Y_/0   
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    '************************************************************************* qWx][D"  
    'Lens index of refraction xw3YK!$sIF  
    '************************************************************************* ']>Mp#j  
    eID = FindMaterial( "Lens" ) d ,Y#H0`  
    GetModelMaterial eID, mat o.'g]Q<}UB  
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    mat.Nd = nlens HS.^y x  
    SetModelMaterial eID, mat .{=$!8|&I9  
    Print "Set lens index of refraction = " & nlens x#Q>J"g  
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    '************************************************************************* gF0q@My~  
    'Pupil diameter V`RNM%Y  
    '************************************************************************* S3@|Q\*r  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) v$7EvFS  
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    'Adjust pupil diameter (trimming volume inner hole) ]ZoD'-,  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" DF g,Xa#  
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    ' Adjust pupil location to just in front of the lens XO9M_*Va  
    parID = FindFullName( "Geometry.Arizona Eye" ) 9&2Vm;F_  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) 1I*7SkgKv  
    count = 0 ! /NG.Wf  
    While GetOperationCount(eID)>count \T\b NbPn  
        GetOperation eID, count, op d5>H3D{49  
        If op.Type="ShiftZ" Then v\,N5  
            DeleteOperation eID,count 6sE{{,
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            count=count-1 aj"M>zd*}  
        End If RiTa \  
        count=count+1 =Me5ftw  
    Wend yY&3p1AxW]  
    op.Type = "ShiftZ" qBQ`~4s  
    op.val1 = taq-0.01 tBm_YP[  
    op.parent = parID ]/!<PF  
    AddOperation eID, op Z{ u a=0  
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    Print "Set pupil diameter = " & pupilDiam a3VM'  
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    'Update AZ Eye subassembly Description !bD@aVf?5  
    eID = FindFullName( "Geometry.Arizona Eye" ) d @*GUmJ  
    GetEntity eID, entity g1UGd  
    entity.Description = "Accommodation = " & A & "D" \(PohwWWo  
    SetEntity eID, entity 1O!/g  
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    Update {\z({Wlb]  
    Print "DONE!" V=X:=  
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End Sub 8:o<ry  
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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： /Ux*u#  
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Accommodation = 4 Diopters ZKz,|+X0G  
Pupil Diameter = 4 mm r,]#b[:.s|  
Set aqueous humor thickness = 2.81 K9kUS  
Set anterior lens radius = 10.4 and conic constant = -2.375869 ~fa(=.h  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 Dgql?+2$  
Set lens thickness = 3.927 QnI.zq V  
Set lens index of refraction = 1.42672 5I,gBT|B  
Set pupil diameter = 4 c.|l-zAeX  
DONE! WA$>pG5
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