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    [分享]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: 2020-12-09
    简介 7Q<uk[d0  
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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|HP#iwu  
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    模型 UarU.~Uqi  
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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。 XpzdvR1  
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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. $+IE`(Ckf  
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    光源 8Ek<J+& |I  
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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。 yQ4]LyS  
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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。 A>6 b 6  
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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。 0s = h*"[  
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    图2. 字母F光源的设定方法光 0lNVQxG  
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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 2}u hPW+  
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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。 a z 7Vy-  
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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。 V *=To  
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    图5. 视网膜重点采样规格设定
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    脚本 eL9 RrSXz  
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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: GzK{. xf  
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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。 'v4#mf  
    余下的脚本计算与屈光度有关的所有参数。 }cyHR1K  
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    分析 wJJ4F$"b  
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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。 w[z^B&  
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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 nM  D^x  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. k,M%/AXd  
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    Dim entity As T_ENTITY >#B%gxff  
    Dim op As T_OPERATION D%umL/[]  
    Dim mat As T_MODELMATERIAL s z/7cLo  
    Dim A As Double %y33evX/B  
    Dim pupilDiam As Double &R/)#NAp  
    Dim eID As Long  (7x5  
    Dim parID As Long L,.Ae i9  
    Dim count As Integer 7]Y Le+Ds  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double m8H|cQ@Uu  
    Dim tlens As Double, nlens As Double p~I+ZYWF'  
    Dim curv As Double, conic As Double m/n_e g  
    Dim ok As Long XF(I$Mxl6  
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    Sub Main ,St#/tu  
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        '用户输入对话框 QJp _>K  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 fi+u!Y*3Z  
            TextBox 220,21,40,21,.TextBox1 'default: 0 6 k+FTDL  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 zJ7vAL  
            OKButton 40,91,90,21 st ( l85  
            CancelButton 190,91,90,21 E\#hcvP  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 j$^3  
            TextBox 220,49,40,21,.TextBox2 'default: 4 M(x5D;db/  
        End Dialog :kqJ~  
        Dim dlg As UserDialog (E59)z -  
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        ok = Dialog (dlg) ex7zg!  
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        If ok=0 Then    'cancel button was pressed "T@9]>6.f  
            Print "Execution cancelled." E#r6e+e1Q%  
            End *}Zd QJL  
        End If v0|A N  
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        'Assign accommodation and pupil diameter & use defaults if field left empty ]K0<DO9  
        If dlg.TextBox1 = "" Then |r1\  
            A = 0           'Default accommodation U 9TEC)  
        Else Y8`4K*58%  
            A = CDbl(dlg.TextBox1) LYNd^}  
        End If )6iY9[@tN  
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        If dlg.TextBox2 = "" Then \-N 4G1  
            pupilDiam = 4   'Default pupil diameter {&8-OoH ~  
        Else _ 0%sYkUc  
            pupilDiam = CDbl(dlg.TextBox2) Jf@M>BT^A  
        End If 6+BR5Nr  
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        Print " " [jve |-v=  
        Print "Accommodation = " & A & " Diopters" *:bNK5I.t  
        Print "Pupil Diameter = " & pupilDiam & " mm" -}1S6dzr  
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        ' Calculate new parameters with accommodation sXOGIv  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness id@!kSR  
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        Rant = 12.0 - 0.4*A                     'Radius of anterior lens aM5zYj`pW  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens |_8 ::kir:  
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        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens #sdW3m_%  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens E{sTxO I$  
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        tlens = 3.767 + 0.04*A                  'Lens thickness |Y|{9Osus  
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        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction G*uy@s:  
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        'Adjust parameters to account for accommodation .,(bDXl?  
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        '************************************************************************* Dg%zNi2GS  
        'Aqueous thickness (Position of Lens) mza1Q~<  
        '************************************************************************* {^>m3  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) :M9'wg  
        GetCustomElement eID, entity -MOPm]iA  
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        parID = FindFullName( "Geometry.Arizona Eye" ) HT)b3Ws~M8  
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        ' Delete any shift(s) in z RN238]K  
        count = 0 iJIPH>UMX  
        While GetOperationCount(eID)>count xcwyn\93)  
            GetOperation eID, count, op EMzJJe{Cv  
            If op.Type="ShiftZ" Then Ke,UwYG2~G  
                DeleteOperation eID,count Y>geP+ -  
                count=count-1 _ $PZID  
            End If JVf8KHDj  
            count=count+1 qY`)W[  
        Wend Mz# &"WjF  
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        'Set new shift in j0^~="p%C  
        op.Type = "ShiftZ" Fx 2 KRxk  
        op.val1 = taq 'A .c*<_  
        op.parent = parID Q ,30  
        AddOperation eID, op 7kx)/Rw\B  
        Print "Set aqueous humor thickness = " & taq-0.55 Enm#\(j  
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        '************************************************************************* ]]`hnzJX  
        'Radius and conic constant of anterior lens KhAj`vOzK  
        '************************************************************************* xK9"t;!C&  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) KRQKL`}}  
        GetConic eID, entity, curv, conic DvHcT] l>5  
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        SetConic eID, entity, 1/Rant, CCant =i  }  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant =($RT  
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        '************************************************************************* PN[ `p1F  
        'Radius and conic constant of posterior lens v+f:VA  
        '************************************************************************* :TJv<NZi'  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) 0?  (  
        GetConic eID, entity, curv, conic uQazUFw  
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        SetConic eID, entity, 1/Rpost, CCpost vBx*bZ  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost akHcN]sa2  
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        '************************************************************************* 8M*[RlUJB  
        'Lens thickness (Position of posterior lens surface) EQ'iyXhEe  
        '*************************************************************************  }tv%  
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        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) -hj@^Auf  
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        ' Delete any z-shift(s) /2pf*\u  
        count = 0 |F[E h ~  
        While GetOperationCount(eID)>count MO&QR-OY  
            GetOperation eID, count, op r,X5@/  
            If op.Type="ShiftZ" Then *`OgwMr)M  
                DeleteOperation eID,count #\KSv Z  
                count=count-1 W.TZU'%  
            End If BlUl5mP}>  
            count=count+1 ps=jGh[  
        Wend j9Ptd$Uj  
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        'Set new z-shift 7;RhA5M  
        op.Type = "ShiftZ" Xd/gvg{??0  
        op.val1 = tlens 9~98v;Z1  
        op.parent = parID RQ}(}|1+\  
        AddOperation eID, op #Ki(9oWd  
        Print "Set lens thickness = " & tlens w|:UTJ>@  
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        '************************************************************************* w^Qb9vTa8  
        'Lens index of refraction 2*Hw6@Jj  
        '************************************************************************* |&B.YLx  
        eID = FindMaterial( "Lens" ) L&M6s f$N  
        GetModelMaterial eID, mat sG`||Kb;n  
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        mat.Nd = nlens .}>d[},F  
        SetModelMaterial eID, mat l G12Su/  
        Print "Set lens index of refraction = " & nlens O 4@sN=o  
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        '************************************************************************* p>4$&-  
        'Pupil diameter qYv/" 1  
        '************************************************************************* l0AgW_T  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) zJJ KLr;  
    |P7c {  
        'Adjust pupil diameter (trimming volume inner hole) ^(y=DJ7  
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        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" HPl!r0 h  
    =S/$h}Vi  
        ' Adjust pupil location to just in front of the lens `l,=iy$  
        parID = FindFullName( "Geometry.Arizona Eye" ) 0Ci\(  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) g.OBh_j-v  
        count = 0 #R$d6N[H  
        While GetOperationCount(eID)>count 08AC 9  
            GetOperation eID, count, op "]J4BZD  
            If op.Type="ShiftZ" Then le*mr0a  
                DeleteOperation eID,count W$LaXytmak  
                count=count-1 Cc*"cQe  
            End If CqX2R:#  
            count=count+1 -BUxQ8/,  
        Wend *n mr4Q'v{  
        op.Type = "ShiftZ" $G/h-6+8  
        op.val1 = taq-0.01 N1$lG? )+  
        op.parent = parID jqxeON  
        AddOperation eID, op WmU4~.  
    }&#R-eQT  
        Print "Set pupil diameter = " & pupilDiam V\^rs41$;  
    w"d~R   
        'Update AZ Eye subassembly Description bK;I:JK3  
        eID = FindFullName( "Geometry.Arizona Eye" ) !GI*R2<W  
        GetEntity eID, entity wy6>^_z  
        entity.Description = "Accommodation = " & A & "D" x&9}] E^<  
        SetEntity eID, entity 2%4dA$H#4w  
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        Update f`'?2  
        Print "DONE!" Eyi^N0  
         xLX<. z!r  
    End Sub cPA-EH  
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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: '9^+J7iO(+  
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    Accommodation = 4 Diopters j<H`<S  
    Pupil Diameter = 4 mm ]oB-qfbH  
    Set aqueous humor thickness = 2.81 [tYly`F  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 MMg"G6?  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 ZN>oz@j Y  
    Set lens thickness = 3.927 JU+Uzp   
    Set lens index of refraction = 1.42672 yf`Nh  
    Set pupil diameter = 4 BwtjTwd  
    DONE! y1R53u`;L  
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    QQ:2987619807 n'R9SnW  
     
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