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    [技术]Arizona眼睛模型 [复制链接]

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    只看楼主 倒序阅读 楼主  发表于: 2021-10-22
    简介 IBT 1If3  
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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。 rpB0?h!$  
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    模型 w \U?64  
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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。 *eF'<._[U  
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    Table 1. AZ眼睛模型的定义
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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. e+TSjm  
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    光源 {V7W!0;!  
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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。 6zZT5 Kn  
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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。 # n_gry!5  
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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。 (zmL MG(R  
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    图2. 字母F光源的设定方法光 A)5;ae  
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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 )` ^/Dj;  
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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。 zMg(\8  
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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。 M669G;w(K  
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    图5. 视网膜重点采样规格设定
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    脚本 INRP@Cp1  
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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: _, r6t  
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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
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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%1  
    余下的脚本计算与屈光度有关的所有参数。 sLOkLz"x  
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    分析 <*@!>6mS  
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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。 X EL~y  
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    图7. 字母F在视网膜上颜色分析
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    脚本代码 ( d1ho=  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. L$3{L"/   
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    Dim entity As T_ENTITY }08Sv=XM  
    Dim op As T_OPERATION ai]KH7  
    Dim mat As T_MODELMATERIAL ,R7RXpP7t  
    Dim A As Double eAK=ylF;  
    Dim pupilDiam As Double !E~czC\p6  
    Dim eID As Long 87-z=>IU  
    Dim parID As Long l H{~?x  
    Dim count As Integer El^V[s'3  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double 5,#aN}v#?  
    Dim tlens As Double, nlens As Double b ~C^cM  
    Dim curv As Double, conic As Double N+zR7`AG8  
    Dim ok As Long c9ea%7o{0a  
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    Sub Main !a7YM4D  
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        '用户输入对话框 e8U6D+jY  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 swfjKBfw+g  
            TextBox 220,21,40,21,.TextBox1 'default: 0 H03R?S9AQ  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 &9 khIJI n  
            OKButton 40,91,90,21  'EO"0,  
            CancelButton 190,91,90,21 o<L=l Q  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 h/NI5   
            TextBox 220,49,40,21,.TextBox2 'default: 4 ZJ%iiY  
        End Dialog >/9Qgyc 0  
        Dim dlg As UserDialog Id?2(Tg  
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        ok = Dialog (dlg) i{}Q5iy  
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        If ok=0 Then    'cancel button was pressed F @uOXNz)  
            Print "Execution cancelled." |HQFqa <  
            End bI:cYn1  
        End If UJ^-T+fut  
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        'Assign accommodation and pupil diameter & use defaults if field left empty K}!YXy h  
        If dlg.TextBox1 = "" Then PX5U)  
            A = 0           'Default accommodation "vo o!&<  
        Else n7,LfO#  
            A = CDbl(dlg.TextBox1) ADT8A."R[  
        End If K{`3,U2Wx  
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        If dlg.TextBox2 = "" Then }3 S6TJ+  
            pupilDiam = 4   'Default pupil diameter iz:O]kI  
        Else :Y[?@/m4  
            pupilDiam = CDbl(dlg.TextBox2) <*+Y]=  
        End If VcORRUp  
    %!V=noo  
        Print " " ?dQ#%06mn  
        Print "Accommodation = " & A & " Diopters" PHg(O:3WG  
        Print "Pupil Diameter = " & pupilDiam & " mm" g acE?bW'  
    7DB!s@"  
        ' Calculate new parameters with accommodation X~rHNRIU  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness PaBqv]  
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        Rant = 12.0 - 0.4*A                     'Radius of anterior lens  m8z414o  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens [OwrIL  
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        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens `YK%I8  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens $m0-IyXcv  
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        tlens = 3.767 + 0.04*A                  'Lens thickness D|"^ :Gi  
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        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction Wf9K+my  
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        'Adjust parameters to account for accommodation z{G@t0q  
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        '************************************************************************* 7w5 L?,a  
        'Aqueous thickness (Position of Lens) H JjW  
        '************************************************************************* ~MZ.988:<  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) ^A;(#5A]7  
        GetCustomElement eID, entity  4d )Q  
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        parID = FindFullName( "Geometry.Arizona Eye" ) W=?s-*F[~  
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        ' Delete any shift(s) in z 1/ vcj~|)t  
        count = 0 Z=y^9]  
        While GetOperationCount(eID)>count ?ubIh.d  
            GetOperation eID, count, op  #)28ESj  
            If op.Type="ShiftZ" Then %|gj46  
                DeleteOperation eID,count Iw;J7[hJ&$  
                count=count-1 Xd@x(T~'X  
            End If `I)ftj%  
            count=count+1 qh~S)^zFJ  
        Wend tC'@yX  
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        'Set new shift in etLA F  
        op.Type = "ShiftZ" '/K-i.8F  
        op.val1 = taq r Q$Jk[Y  
        op.parent = parID \:d|'r8OCM  
        AddOperation eID, op 7s'r3}B`  
        Print "Set aqueous humor thickness = " & taq-0.55 P1}Fn:Xe%7  
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        '************************************************************************* qC$h~Epp4  
        'Radius and conic constant of anterior lens "T'?Ah6  
        '************************************************************************* 1F58 2 l  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) eXsFPM  
        GetConic eID, entity, curv, conic *<T,Fyc|  
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        SetConic eID, entity, 1/Rant, CCant <aEY=IF4  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant S!wY6z  
    d&[.=M\E8  
        '************************************************************************* Q.]RYv}\  
        'Radius and conic constant of posterior lens >XiTl;UU  
        '*************************************************************************  C#x9RW  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) ]U,f}T"e  
        GetConic eID, entity, curv, conic vW:XM0  
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        SetConic eID, entity, 1/Rpost, CCpost ZsikI@?  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost +x"cWOg  
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        '************************************************************************* f;PvXq<7"  
        'Lens thickness (Position of posterior lens surface) 6K zdWT  
        '************************************************************************* rezH5d6z62  
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        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) sVJwe\!  
    WQT;k0;T]  
        ' Delete any z-shift(s) FD*w4U5  
        count = 0 "vnWq=E 2  
        While GetOperationCount(eID)>count ^@0-E@ {c  
            GetOperation eID, count, op 0/Wo":R:  
            If op.Type="ShiftZ" Then /\&Wk;u3  
                DeleteOperation eID,count " O,TL *$  
                count=count-1 _N-JRM m<  
            End If 09 >lx$  
            count=count+1 -8r9DS -/W  
        Wend q[w.[]  
    Q~p[jQ,4wZ  
        'Set new z-shift y $K#M  
        op.Type = "ShiftZ" \.7O0Q{  
        op.val1 = tlens < BNCo5*  
        op.parent = parID |p1 pa4%}  
        AddOperation eID, op KoPhPH  
        Print "Set lens thickness = " & tlens M)oJ06`K  
    !@<>S>uGG  
        '*************************************************************************  EL[N%M3  
        'Lens index of refraction VD*xhuy$k  
        '************************************************************************* ^?3e?Q?  
        eID = FindMaterial( "Lens" )  #FfUkV  
        GetModelMaterial eID, mat P_f>a?OL:  
    @94_'i7\  
        mat.Nd = nlens 0Tm"Zh?B|  
        SetModelMaterial eID, mat u*NU MT2  
        Print "Set lens index of refraction = " & nlens 5Se S^kJC  
    !Y3 *\  
        '************************************************************************* oqOXRUy  
        'Pupil diameter 3g#fX{e_5!  
        '************************************************************************* zkt+"P{az[  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) *?#t (Y[  
    ]k (n_+!  
        'Adjust pupil diameter (trimming volume inner hole) MFyMo  
    jBvZ>H+w~  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" _\P9~w `  
    p2UZqq2  
        ' Adjust pupil location to just in front of the lens |H)WJ/`  
        parID = FindFullName( "Geometry.Arizona Eye" ) !PfIe94{`  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) !%x=o&  
        count = 0 cO#e AQf7  
        While GetOperationCount(eID)>count ]eJjffx  
            GetOperation eID, count, op jR^>xp;  
            If op.Type="ShiftZ" Then (!nhU  
                DeleteOperation eID,count Q7]VB p4  
                count=count-1 p?X`f#  
            End If kS$HIOt823  
            count=count+1 (]yOd/ru/C  
        Wend 3??*G8Yp  
        op.Type = "ShiftZ" dD2N!umW  
        op.val1 = taq-0.01 z5CWgN  
        op.parent = parID $z9z'^HqO  
        AddOperation eID, op &&w7-  
    z.9 #AN=&[  
        Print "Set pupil diameter = " & pupilDiam "KY9MBzPD  
    GA{Q6]B  
        'Update AZ Eye subassembly Description A|BvRZd  
        eID = FindFullName( "Geometry.Arizona Eye" ) J!QzF)$4J  
        GetEntity eID, entity  (BgO<  
        entity.Description = "Accommodation = " & A & "D" wNuS'P_(:T  
        SetEntity eID, entity !Z7 ~R sdm  
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        Update ms8PFu(f  
        Print "DONE!" NC 0H5  
         SR#%gR_SC  
    End Sub >Hr0ScmN@"  
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    如果屈光度是4,光瞳直径是4,则会输出如下数据: ")U`Wgx  
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    Accommodation = 4 Diopters \jdpL1  
    Pupil Diameter = 4 mm wR;_x x  
    Set aqueous humor thickness = 2.81 Kt%`]Wp  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 IkSzjXE{  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 ;X u&['  
    Set lens thickness = 3.927 "R$ee^  
    Set lens index of refraction = 1.42672 rs@,<DV)u  
    Set pupil diameter = 4 :8;8-c  
    DONE! Pl=X<Bp  
     
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