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    [技术]Arizona眼睛模型 [复制链接]

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    离线infotek
     
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    只看楼主 倒序阅读 楼主  发表于: 2021-10-22
    简介 2TB>d+  
    vZ[wr@)  
    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。  }t}y  
    (27bNKr  
    模型 >5Y%4++(  
    Y=+pz^/"  
    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。 $'# hCs  
    Nv!If$d  
    Table 1. AZ眼睛模型的定义
    !5lb+%7  
    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. 8."B  
    "NR`{1f:O  
    光源 d>[=]  
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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。 qKu/~0a/  
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    图1. 光源和提示信息使用
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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。 57 (bd0@8  
    %mKM9>lf#  
    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。 ASA ]7qyO  
    m,YBk<Bx  
    图2. 字母F光源的设定方法光 2wR?ON=Q  
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    图3. 字母F在视网膜上位置点列图
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    视网膜的散射 BN??3F8C  
    1.29%O8V_  
    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。 ;7,>2VTm  
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    图4. 视网膜朗伯散射设定
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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。 RLl*@SEi"  
    (lPiv+'n  
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    图5. 视网膜重点采样规格设定
    +d/V^ <#  
    脚本 {v CB$@/o  
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    内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框,如下图所示: KV&4Ep#  
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    图6. 用户对话框的创建与编辑
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    图7. 用户对话框编辑器
    JK.<(=y\  
    如果“OK”按钮按下,将会核对对话框下面的代码行,如果点击取消则脚本终止。然后输入的参数赋予变量,如果此处是保留为空白,则使用默认值。因此,如果没有值输入并点击“OK”按钮,则脚本是以屈光度为0,光瞳直径为4mm来运行的。 :Y4 m3|  
    余下的脚本计算与屈光度有关的所有参数。 |.]sL0; 4Z  
    #Y|t,x;  
    分析 oUSv)G.zb  
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    屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 ":igYh  
    s>pM+PoGYd  
    图7. 字母F在视网膜上颜色分析
    +"P!es\q  
    脚本代码 7 LotN6H  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. V.\12P  
    4$W}6 v  
    Dim entity As T_ENTITY +g.lLb*#  
    Dim op As T_OPERATION 3.0t5F<B  
    Dim mat As T_MODELMATERIAL  (zIWJJw  
    Dim A As Double 4eD>DW  
    Dim pupilDiam As Double kH4xP3. i  
    Dim eID As Long $0[t<4K`yn  
    Dim parID As Long rl/]Ym4j  
    Dim count As Integer "+dByaY  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double bf4QW JZD  
    Dim tlens As Double, nlens As Double G!<-9HA5  
    Dim curv As Double, conic As Double 1@}s:  
    Dim ok As Long 4CH/~b1 (  
    AQ)DiH  
    Sub Main zEBUR%9  
    DH IC:6EY  
        '用户输入对话框 2=]Xe#5J=  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 wf`e3S  
            TextBox 220,21,40,21,.TextBox1 'default: 0 %+8" -u  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 P >>VBh?  
            OKButton 40,91,90,21 ;N(9nX}%)  
            CancelButton 190,91,90,21 ]=Tle&yM+T  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 V'M#."Of/  
            TextBox 220,49,40,21,.TextBox2 'default: 4 bI?uV;m>  
        End Dialog $:}sm0;  
        Dim dlg As UserDialog pu OAt  
    (qyT,K8  
        ok = Dialog (dlg) ^.g BHZ  
    07 E9[U[  
        If ok=0 Then    'cancel button was pressed >{1 i8 b@  
            Print "Execution cancelled." E7`Q =4@e  
            End 4N K{RN3  
        End If k1_" }B5  
    4 Q<c I2|  
        'Assign accommodation and pupil diameter & use defaults if field left empty jCK 0+,;  
        If dlg.TextBox1 = "" Then LW#$%}  
            A = 0           'Default accommodation !kQJ6U  
        Else uXuA4o$t-  
            A = CDbl(dlg.TextBox1) Rm&4Pku  
        End If w l#jSj%pd  
    bAwFC2jO[  
        If dlg.TextBox2 = "" Then H"b}lf  
            pupilDiam = 4   'Default pupil diameter 7=`_UqCV  
        Else 0J z|BE3Y  
            pupilDiam = CDbl(dlg.TextBox2) ,t|qhJF  
        End If &6O0h0Vy  
    ^3O`8o  
        Print " " N@x5h8  
        Print "Accommodation = " & A & " Diopters" P.Gmj;  
        Print "Pupil Diameter = " & pupilDiam & " mm" N= G!r  
    WB|N)3-1  
        ' Calculate new parameters with accommodation 6|10OTVu`  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness [,TK"  
    'z$!9ufY,  
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens LUKt!I0l  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens ?Zh,W(7W  
    @g%^H)T  
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens ;=lQMKx0  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens z/P^Bx]r  
    "?Yf3G:\0  
        tlens = 3.767 + 0.04*A                  'Lens thickness /I~(*X  
    XtftG7r9S  
        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction L a8D%N  
    g$T% C?  
        'Adjust parameters to account for accommodation h { M=V  
    &:[hUn8jU  
        '************************************************************************* %(ms74R+  
        'Aqueous thickness (Position of Lens) t2hI^J0y  
        '************************************************************************* tdOox87YK  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) 9?I?;l{  
        GetCustomElement eID, entity Xmv^O  
    ['_W <  
        parID = FindFullName( "Geometry.Arizona Eye" ) f5P@PG]{  
    ?F^O7\rw  
        ' Delete any shift(s) in z 'q7&MM'oS^  
        count = 0 tk66Ggi[K  
        While GetOperationCount(eID)>count Q=?YY-*$  
            GetOperation eID, count, op Gq =i-I  
            If op.Type="ShiftZ" Then ftRzgW);  
                DeleteOperation eID,count |wkUnn4UB8  
                count=count-1 Q7pjF`wu  
            End If HSlAm&Y\  
            count=count+1 ,r,$x4*  
        Wend 3Bbd2[<W  
    bF c %  
        'Set new shift in -`ss7j&b3  
        op.Type = "ShiftZ" 2|JtRE+  
        op.val1 = taq @,;VMO  
        op.parent = parID I`uOsZBO/  
        AddOperation eID, op fDrjR6xV  
        Print "Set aqueous humor thickness = " & taq-0.55 v@Bk)Z  
    k{E!X  
        '************************************************************************* Rd ,5 &X$  
        'Radius and conic constant of anterior lens R=<uf:ca  
        '************************************************************************* qs3V2lvYw{  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) ^-g-]?q  
        GetConic eID, entity, curv, conic d_)VeuE2  
    >slGicZ0  
        SetConic eID, entity, 1/Rant, CCant m98w0D@Ee  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant !BEl6h  
    C7_nA:Rc  
        '************************************************************************* @!,W]?{  
        'Radius and conic constant of posterior lens T3In0LQ  
        '************************************************************************* Y~P* !g  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) XG8UdR|  
        GetConic eID, entity, curv, conic XpT+xv1`;  
    *ulkqpO  
        SetConic eID, entity, 1/Rpost, CCpost JB9s# `  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost x]pZcx9  
    6GsB*hW  
        '************************************************************************* H57wzG{xG  
        'Lens thickness (Position of posterior lens surface) Xr]<v%,C  
        '************************************************************************* j7 \y1$w  
     ?h3t"9  
        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) qV:TuR-|w  
    2'7)D}p  
        ' Delete any z-shift(s) 4rH:`494  
        count = 0 ]<:qMLg  
        While GetOperationCount(eID)>count !f)^z9QX8  
            GetOperation eID, count, op *5q_fO  
            If op.Type="ShiftZ" Then p.x!dt\1kC  
                DeleteOperation eID,count 1aS66TS3  
                count=count-1 WNo<0|X  
            End If L /V;;  
            count=count+1 #s0Wx47~  
        Wend Ry"N_Fb  
    xM D]b  
        'Set new z-shift Ht&%`\9s  
        op.Type = "ShiftZ" :za:gs0  
        op.val1 = tlens ;]Ko7M(4  
        op.parent = parID 9 $ Ud\   
        AddOperation eID, op (laVmU?I7  
        Print "Set lens thickness = " & tlens \>)#cEX5  
    ` l}+BI`4  
        '************************************************************************* {7d\du&G  
        'Lens index of refraction (x/xqDpmBS  
        '************************************************************************* /tu\q  
        eID = FindMaterial( "Lens" ) cnR18NK  
        GetModelMaterial eID, mat lJdwbuB6  
    ^8{:RiN6e~  
        mat.Nd = nlens ;Ff5ooL{  
        SetModelMaterial eID, mat qTrb)95  
        Print "Set lens index of refraction = " & nlens -"/l)1ox,  
    qExmf%q:q  
        '************************************************************************* `Uy4>?  
        'Pupil diameter DH'0#  
        '************************************************************************* '<%;Nv  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) Usf7 AS=  
    $-"V 2  
        'Adjust pupil diameter (trimming volume inner hole) S%2qX"8  
    _>(qQ-Px  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" 2PG= T/  
    M}qrF~   
        ' Adjust pupil location to just in front of the lens cB|Rj}40v  
        parID = FindFullName( "Geometry.Arizona Eye" ) xL} ~R7  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) F9 2et<y.  
        count = 0 qZ rv2dT  
        While GetOperationCount(eID)>count 8mv}-;  
            GetOperation eID, count, op Bb@m-+f  
            If op.Type="ShiftZ" Then +w9X$<?_  
                DeleteOperation eID,count taqmtXU=(  
                count=count-1 kqt.?iJw  
            End If 6/l{e)rX2o  
            count=count+1 3B3l)eX  
        Wend l@<yC-Xd  
        op.Type = "ShiftZ" 2t 1u{  
        op.val1 = taq-0.01 v>E3|w%  
        op.parent = parID _l$X![@6=  
        AddOperation eID, op   7)  
    W B7gY\Y&M  
        Print "Set pupil diameter = " & pupilDiam MT(G=r8  
    f1 TYQ?e  
        'Update AZ Eye subassembly Description Nk@ag)  
        eID = FindFullName( "Geometry.Arizona Eye" ) {p)=#Jd`.P  
        GetEntity eID, entity 8bW,.to(?x  
        entity.Description = "Accommodation = " & A & "D" y5$AAas  
        SetEntity eID, entity sq1v._^s  
    VY_<c98v  
        Update ~-K<gT/  
        Print "DONE!" ^K`Vqo  
         IM*T+iRKqF  
    End Sub c^%&-],  
    :?J0e4.]  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: Lk:Sju  
    y-k]Tr  
    Accommodation = 4 Diopters 5#hsy;q;[  
    Pupil Diameter = 4 mm Lzy Ix!S  
    Set aqueous humor thickness = 2.81 3{R7y  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 j  hr pS  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 *$EcP`K$  
    Set lens thickness = 3.927 GK8x<Aq%z  
    Set lens index of refraction = 1.42672 sB'Z9  
    Set pupil diameter = 4 Nx^r&pr  
    DONE! IPEJ7 n49  
     
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