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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 &DQ4=/Z  
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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。 K[>@'P}y  
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    模型 P[GX}~_k  
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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。 %*6oUb  
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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. Xtu`5p_Qv  
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    光源 ~d7Wjn$@  
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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。 'W?v.W &  
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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。 DR yESi  
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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。 O? Gl4_y  
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    图2. 字母F光源的设定方法光 _{c|o{2sj  
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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 B=gsd0^]  
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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。 gF,[u  
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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。 b%[ nB  
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    图5. 视网膜重点采样规格设定
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    脚本 5@UC 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: ;naq-%'Sg  
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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。 Ev+HWx~Y  
    余下的脚本计算与屈光度有关的所有参数。 'wz\tT^  
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    分析 +dCDM1{_a  
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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。 &SjHrOG?  
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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 so!w!O@@  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. {K45~ha9!m  
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    Dim entity As T_ENTITY ?E+:]j_  
    Dim op As T_OPERATION .# 6n  
    Dim mat As T_MODELMATERIAL MegE--h  
    Dim A As Double 3!.H^v?  
    Dim pupilDiam As Double fO^e+M z  
    Dim eID As Long '?"t<$b  
    Dim parID As Long j\`EUC  
    Dim count As Integer 1p7cv~#95  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double =My}{n[  
    Dim tlens As Double, nlens As Double :DdBn.  
    Dim curv As Double, conic As Double AV:Xg4UJv  
    Dim ok As Long n#+%!HTh  
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    Sub Main .3lGX`d{  
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        '用户输入对话框 bBUbw*DF)  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 AT B\^;n.  
            TextBox 220,21,40,21,.TextBox1 'default: 0 Q_&}^  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 bQ-Gp;]  
            OKButton 40,91,90,21 CM%|pB/z  
            CancelButton 190,91,90,21 jWH{;V&ZV  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 A1T<  
            TextBox 220,49,40,21,.TextBox2 'default: 4 Sl3KpZ  
        End Dialog =\~E n5  
        Dim dlg As UserDialog P%zH>K  
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        ok = Dialog (dlg) de> ?*%<  
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        If ok=0 Then    'cancel button was pressed =?/N5O(  
            Print "Execution cancelled." -VS9`7k  
            End j5L)N  
        End If N\9}\Rk@  
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        'Assign accommodation and pupil diameter & use defaults if field left empty <eB<^ &nd  
        If dlg.TextBox1 = "" Then 3@^MvoC  
            A = 0           'Default accommodation slU  
        Else qqnclqkw&  
            A = CDbl(dlg.TextBox1) eeuZUf+~]  
        End If bTZ>@~$  
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        If dlg.TextBox2 = "" Then )^4ko  
            pupilDiam = 4   'Default pupil diameter J+Q+&-a  
        Else M]}l^ m>L  
            pupilDiam = CDbl(dlg.TextBox2) 6!P`XTTE  
        End If H@V 7!d  
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        Print " " (+|X<Bl:`  
        Print "Accommodation = " & A & " Diopters" nD7|8,'  
        Print "Pupil Diameter = " & pupilDiam & " mm" v`y6y8:>  
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        ' Calculate new parameters with accommodation &!ED# gs  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness HbcOTd)=5  
    !7}IqSs  
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens o4$Ott%Wm  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens \[:PykS  
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        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens w{pUUo:<  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens XC=%H'p  
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        tlens = 3.767 + 0.04*A                  'Lens thickness >DHp*$y  
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        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction K*~]fy  
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        'Adjust parameters to account for accommodation [`d$X^<y;  
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        '************************************************************************* !<&m]K  
        'Aqueous thickness (Position of Lens) nSS>\$  
        '************************************************************************* WvujcmOf  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) }^9]jSq5  
        GetCustomElement eID, entity #?dUv#  
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        parID = FindFullName( "Geometry.Arizona Eye" ) !=3Rg-'d1  
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        ' Delete any shift(s) in z 7|YN:7iA  
        count = 0 oK2pM18  
        While GetOperationCount(eID)>count -T7%dLHY  
            GetOperation eID, count, op ;6ky5}z  
            If op.Type="ShiftZ" Then J{`eLmTu  
                DeleteOperation eID,count 98fu>>*G{  
                count=count-1 ` @8`qXg  
            End If 'n0 .#E_  
            count=count+1 1"}cdq.  
        Wend 'B_\TU0 O  
    7 {f_fkbs  
        'Set new shift in  B$^7h!  
        op.Type = "ShiftZ" 6k"P&AD  
        op.val1 = taq ' _dzcN,z  
        op.parent = parID w1r$='*I  
        AddOperation eID, op Rs*v m  
        Print "Set aqueous humor thickness = " & taq-0.55 Po(]rQbE  
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        '************************************************************************* [$\z'}  
        'Radius and conic constant of anterior lens z% 1{  
        '************************************************************************* +Ng0WS_0  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) C)Jn[/BD  
        GetConic eID, entity, curv, conic +R6a}d/K  
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        SetConic eID, entity, 1/Rant, CCant ,LZX@'5  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant F[saP0 *  
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        '************************************************************************* HSN8O@dy  
        'Radius and conic constant of posterior lens Sw8kIC  
        '************************************************************************* y,=du  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) >xu [q\:"  
        GetConic eID, entity, curv, conic k6"KB  
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        SetConic eID, entity, 1/Rpost, CCpost #eK=  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost [mUBHYD7OI  
    #?[.JD51l  
        '************************************************************************* FB:<zmwR  
        'Lens thickness (Position of posterior lens surface) aRJcSV  
        '************************************************************************* LZ U$  
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        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) YE}s  
    9 [jTs3l:  
        ' Delete any z-shift(s) PXzT6)  
        count = 0 T[?6[,.  
        While GetOperationCount(eID)>count _q?<at}y  
            GetOperation eID, count, op 0)!Ll*L!p  
            If op.Type="ShiftZ" Then 1mH%H*#  
                DeleteOperation eID,count tNIlzR-  
                count=count-1 i)ASsYG!  
            End If [zkikZy  
            count=count+1 ~D[?$`x:  
        Wend ]3Dl)[R  
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        'Set new z-shift xSK~s  
        op.Type = "ShiftZ" 28andfl  
        op.val1 = tlens *[+)7  
        op.parent = parID QHt4",Ij  
        AddOperation eID, op O 5 Nb  
        Print "Set lens thickness = " & tlens ?BA^YF  
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        '************************************************************************* 2F`cv1M  
        'Lens index of refraction m~#%Q?_ %  
        '************************************************************************* C\ZkGX  
        eID = FindMaterial( "Lens" ) w}R~C   
        GetModelMaterial eID, mat 5 BtX63  
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        mat.Nd = nlens xI*#(!x"G  
        SetModelMaterial eID, mat wJ<Oo@snm  
        Print "Set lens index of refraction = " & nlens vhuw &.\  
    zTbVp8\pI  
        '************************************************************************* ,Gk}"w  
        'Pupil diameter U`|0 jJ  
        '************************************************************************* cbYLU\!  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) &w 8)* T  
    RW$:9~  
        'Adjust pupil diameter (trimming volume inner hole) A'&n5)tb  
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        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" mqff]m  
    @4$\ 5 %j  
        ' Adjust pupil location to just in front of the lens +>~?m*$  
        parID = FindFullName( "Geometry.Arizona Eye" ) JwnQ0 e  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) ;6ecrQMw&  
        count = 0 CSPKP#,B0[  
        While GetOperationCount(eID)>count 6 15s5ZA  
            GetOperation eID, count, op G rmzkNlN  
            If op.Type="ShiftZ" Then xVL5'y1g B  
                DeleteOperation eID,count '})0!g<Y  
                count=count-1 Nc Pgq?3p  
            End If [+m?G4[  
            count=count+1 G` fC/Le  
        Wend l1U=f]  
        op.Type = "ShiftZ" 5}$b0<em~  
        op.val1 = taq-0.01 u]+~VT1C,3  
        op.parent = parID ml|W~-6l  
        AddOperation eID, op [YrHA~=U  
    Rm1A>1a :  
        Print "Set pupil diameter = " & pupilDiam ps .]N   
    #rO8Kf  
        'Update AZ Eye subassembly Description &!aAO(g  
        eID = FindFullName( "Geometry.Arizona Eye" ) [[d(jV=*  
        GetEntity eID, entity l!}:|N Yh!  
        entity.Description = "Accommodation = " & A & "D" p Dx-2:}  
        SetEntity eID, entity 1i:|3PA~  
    +YLejjQ  
        Update ae"]\a\&1o  
        Print "DONE!" hQ6a~?f  
         N,2s?Y_!  
    End Sub 0;4t&v7  
    #_Z$2L"U  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: r:&` $8$  
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    Accommodation = 4 Diopters b^D$jY  
    Pupil Diameter = 4 mm -[U1]R  
    Set aqueous humor thickness = 2.81 kr$ b^"Ku  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 /!^&;$A'  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 o9xlu.QL{c  
    Set lens thickness = 3.927 #ET/ =  
    Set lens index of refraction = 1.42672 )ZrS{vY  
    Set pupil diameter = 4 O=SkAsim  
    DONE! &B! o,qp  
     
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