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    [分享]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: 2020-12-09
    简介 #{BHH;J+  
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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。 5m]N%{<jAB  
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    模型 6S GV}dAx  
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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。 ?8GggJC  
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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. Y%1 94fY$  
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    光源 _P{f+HxU  
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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。 4Nun-(q  
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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。 fR$_=WWN>h  
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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。 R ~ZcTY[8  
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    图2. 字母F光源的设定方法光 @/,:". SM  
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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 $Vp*,oRL  
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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。 }NJKkj?  
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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。 TT@ U_^o  
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    图5. 视网膜重点采样规格设定
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    脚本 48IrC_0j  
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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: re~T,PPM  
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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。 AU1U?En  
    余下的脚本计算与屈光度有关的所有参数。 )_YB8jUR-X  
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    分析 )dd1B>ej]  
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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。 RH.qbPjx  
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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 byFO^pce  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. &|<f|B MX  
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    Dim entity As T_ENTITY z2>LjM) #  
    Dim op As T_OPERATION <5? pa3  
    Dim mat As T_MODELMATERIAL NS65F7<&  
    Dim A As Double * bd3^mP  
    Dim pupilDiam As Double R RE8|%p;B  
    Dim eID As Long jsQHg2Vd  
    Dim parID As Long au04F]-|j8  
    Dim count As Integer QtwQVOK  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double b[GhI+_  
    Dim tlens As Double, nlens As Double ?G5,}%  
    Dim curv As Double, conic As Double M.K^W`  
    Dim ok As Long c"v75lW-J  
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    Sub Main )S 7+y6f&*  
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        '用户输入对话框 3 3|t5Ia  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 (-g*U#   
            TextBox 220,21,40,21,.TextBox1 'default: 0 MoE&)~0u&  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 &iInru3  
            OKButton 40,91,90,21 SIV !8mz  
            CancelButton 190,91,90,21 :{2~s  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 -?-XO<I  
            TextBox 220,49,40,21,.TextBox2 'default: 4 ujRXAN@mC  
        End Dialog !( rAI  
        Dim dlg As UserDialog p_h/hTi  
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        ok = Dialog (dlg) ejlns ~  
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        If ok=0 Then    'cancel button was pressed !JDr58  
            Print "Execution cancelled." ~x^y5[5{  
            End *^uK=CH1?(  
        End If )Cl>%9  
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        'Assign accommodation and pupil diameter & use defaults if field left empty Xj 1Oxm 42  
        If dlg.TextBox1 = "" Then dMH_:jb  
            A = 0           'Default accommodation ' @RF  
        Else Jv8:GgSg  
            A = CDbl(dlg.TextBox1) [zx|3wWAX-  
        End If &t^*0/~  
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        If dlg.TextBox2 = "" Then $<v4c5r]O  
            pupilDiam = 4   'Default pupil diameter [(heE  
        Else XI\Slq  
            pupilDiam = CDbl(dlg.TextBox2) >$JE!.p%o  
        End If hOwb   
    ]SCHni_  
        Print " " ENZym  
        Print "Accommodation = " & A & " Diopters" S=_u3OH0  
        Print "Pupil Diameter = " & pupilDiam & " mm" V: D;?$Jl  
    '#7k9\  
        ' Calculate new parameters with accommodation Uj7YTB  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness ij$NTY=u  
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        Rant = 12.0 - 0.4*A                     'Radius of anterior lens TcaW'&(K  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens X5iD <Lh  
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        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens /x??J4r0  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens 93]63NY  
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        tlens = 3.767 + 0.04*A                  'Lens thickness rRRh-%.RU  
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        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction C ~h#pAh  
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        'Adjust parameters to account for accommodation OkciL]  
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        '************************************************************************* @&m [w'tn  
        'Aqueous thickness (Position of Lens) ".>#Qp%  
        '************************************************************************* !0l|[c4 e>  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) 2H`r:x<Z-  
        GetCustomElement eID, entity :zU4K=kR  
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        parID = FindFullName( "Geometry.Arizona Eye" ) >GIQT ?O6  
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        ' Delete any shift(s) in z D9g*+KM&  
        count = 0 96\FJHt Z  
        While GetOperationCount(eID)>count j0L%jz  
            GetOperation eID, count, op < dE7+w  
            If op.Type="ShiftZ" Then vE[d& b[  
                DeleteOperation eID,count Z2W&_(^.h  
                count=count-1 W>' DQB  
            End If :7(fBf5  
            count=count+1 F[c oa5  
        Wend bmHj)^v 5]  
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        'Set new shift in 2_Lu 0Yrg  
        op.Type = "ShiftZ" w8+ phN(-M  
        op.val1 = taq IYe[IHny1  
        op.parent = parID *fY*Wy9  
        AddOperation eID, op pp|$y\ZzB  
        Print "Set aqueous humor thickness = " & taq-0.55 @[D5{v)S  
    iw.F8[})  
        '************************************************************************* Z&@P<  
        'Radius and conic constant of anterior lens &x (D%+  
        '************************************************************************* <DMm [V{  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) #}1yBxB<=  
        GetConic eID, entity, curv, conic 9|jMN j]vo  
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        SetConic eID, entity, 1/Rant, CCant Z2;~{$&M+  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant rxx VLW  
    9a:(ab'  
        '************************************************************************* -Nr*na^H9#  
        'Radius and conic constant of posterior lens -4Q\FLC'k  
        '************************************************************************* DW,Z})9  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) >d;U>P5.  
        GetConic eID, entity, curv, conic auB+g'l  
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        SetConic eID, entity, 1/Rpost, CCpost U4"&T,'lTL  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost L{ej<0yr  
    -{oZK{a1  
        '************************************************************************* $5#DU__F/  
        'Lens thickness (Position of posterior lens surface) 8VpmcGvc3  
        '************************************************************************* (\'lV8}U  
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        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) 'K23oQwDB  
    fHuWBC_YO  
        ' Delete any z-shift(s) U[pR `u  
        count = 0 DLq'V.M:  
        While GetOperationCount(eID)>count v/7^v}[<  
            GetOperation eID, count, op dF&@q,  
            If op.Type="ShiftZ" Then jlyuu  
                DeleteOperation eID,count ;iN [du  
                count=count-1 i:&$I=  
            End If =FAIbM>u  
            count=count+1 {H=<5   
        Wend H-% B<7  
    ;e2D}  
        'Set new z-shift 'O 7>w%#  
        op.Type = "ShiftZ" s?9`dv} P  
        op.val1 = tlens z wn#E  
        op.parent = parID qnU`Q{  
        AddOperation eID, op wF-H{C'  
        Print "Set lens thickness = " & tlens IR8qFWDZ  
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        '************************************************************************* 5^{2 g^jH6  
        'Lens index of refraction z>*\nomOn=  
        '************************************************************************* ( _MY;S  
        eID = FindMaterial( "Lens" ) 7Xh ;dJAF3  
        GetModelMaterial eID, mat Gl4f:`  
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        mat.Nd = nlens z|<?=c2P  
        SetModelMaterial eID, mat !#4b#l(e6  
        Print "Set lens index of refraction = " & nlens \XbCJJP  
    m&- -$sr  
        '************************************************************************* G,b*Qn5#  
        'Pupil diameter DH])Q5  
        '************************************************************************* 4SIS #m  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) <,t6A?YoMP  
    5[`f(;  
        'Adjust pupil diameter (trimming volume inner hole) 6^,;^   
    nYTPcT4x|  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" EuKkIr/(  
    1 l-Y)   
        ' Adjust pupil location to just in front of the lens 'Z6x\p  
        parID = FindFullName( "Geometry.Arizona Eye" ) 5?>ES*  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) =AX"'q  
        count = 0 nx5I  
        While GetOperationCount(eID)>count tf>"fU\P  
            GetOperation eID, count, op N@I=X-7nh|  
            If op.Type="ShiftZ" Then Eu[/* t+l  
                DeleteOperation eID,count OyIIJ!(  
                count=count-1 O-n JuZJgX  
            End If G54`{V4&s  
            count=count+1 V=H:`n3k  
        Wend }`+9ie7]/  
        op.Type = "ShiftZ" 3qy4nPg  
        op.val1 = taq-0.01 ]3L/8]:  
        op.parent = parID ULzrJbP'7  
        AddOperation eID, op a[E}o<{  
    >LW}N!IBy  
        Print "Set pupil diameter = " & pupilDiam f%rZ2h)  
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        'Update AZ Eye subassembly Description ]$I}r= Em  
        eID = FindFullName( "Geometry.Arizona Eye" ) YRU95K [  
        GetEntity eID, entity m{r#o?  
        entity.Description = "Accommodation = " & A & "D" cVDcda|PE  
        SetEntity eID, entity <,y> W!  
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        Update =X7_!vSv  
        Print "DONE!" xL"O~jTS  
         k`J|]99Wb  
    End Sub kq@~QI?9  
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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: zpZfsn!  
    @4n>I+6*&  
    Accommodation = 4 Diopters #\\|:`YV  
    Pupil Diameter = 4 mm z7TyS.z  
    Set aqueous humor thickness = 2.81 *q+X ?3  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 A# Y:VavQ?  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 [pInF Qh6  
    Set lens thickness = 3.927 %< `D' V@  
    Set lens index of refraction = 1.42672 uaZHM@D  
    Set pupil diameter = 4 U>DCra;  
    DONE! gFsqCx<q  
    }_5R9w]"  
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    QQ:2987619807 'xEK0~awD  
     
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