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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 ],?$&  
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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。 )XFaVkQ}  
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    模型 Ra!Br6  
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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。 lx)Bj6  
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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. IEP^u `}  
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    光源 xG7/[ jG  
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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。 d#W>"Cqxqa  
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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。 $xK*TJ(k  
    YqEB%Y~N+  
    在往下看是内置的脚本用来修改屈光度,使其为4(250mm),光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 0!5w0^1  
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    图2. 字母F光源的设定方法光 sI OT6L^7  
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    图3. 字母F在视网膜上位置点列图
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    视网膜的散射 kp=wz0#  
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    在散射文件中,有一个名为“Retina surface”的72%的反射型朗伯散射,它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射,改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 NGs@z^&V  
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    图4. 视网膜朗伯散射设定
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    注意在视网膜的表面有散射重点采样规格定义,在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳,半角度10度。 ej;\a:JL  
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    图5. 视网膜重点采样规格设定
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    脚本 |.~0Ulk,  
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    内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框,如下图所示: 2l.qINyz  
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    图6. 用户对话框的创建与编辑
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    图7. 用户对话框编辑器
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    如果“OK”按钮按下,将会核对对话框下面的代码行,如果点击取消则脚本终止。然后输入的参数赋予变量,如果此处是保留为空白,则使用默认值。因此,如果没有值输入并点击“OK”按钮,则脚本是以屈光度为0,光瞳直径为4mm来运行的。 >&?k^nI}J  
    余下的脚本计算与屈光度有关的所有参数。 H]<@\g*l@P  
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    分析 g?1! /+  
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    屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 ^)i1b:4  
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    图7. 字母F在视网膜上颜色分析
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    脚本代码 1c19$KHu  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. Ra-%,cS  
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    Dim entity As T_ENTITY L; (J6p]h  
    Dim op As T_OPERATION 5m\T~[`%  
    Dim mat As T_MODELMATERIAL h3BDHz,  
    Dim A As Double /s|4aro  
    Dim pupilDiam As Double %VsIg  
    Dim eID As Long <UE-9g5?G  
    Dim parID As Long oRZ--1oR_  
    Dim count As Integer r zO5 3\  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double y=q iGi[Nc  
    Dim tlens As Double, nlens As Double u~7 ,v  
    Dim curv As Double, conic As Double F\BD7W  
    Dim ok As Long K)_DaTmi)  
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    Sub Main /5&' U!:+  
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        '用户输入对话框 @@~Ql  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 <xO" E%t  
            TextBox 220,21,40,21,.TextBox1 'default: 0 >[&Zs3>  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 `44 }kkBT  
            OKButton 40,91,90,21 $9PscubM4  
            CancelButton 190,91,90,21 J<27w3bs~p  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 jFPD SR5  
            TextBox 220,49,40,21,.TextBox2 'default: 4 j" ~gEGfK  
        End Dialog M.h8Kr!.  
        Dim dlg As UserDialog '@3Kq\/  
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        ok = Dialog (dlg) *-lw2M9V  
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        If ok=0 Then    'cancel button was pressed y{O81 7 \  
            Print "Execution cancelled." )4CF*>*6V  
            End {6Qd,CX  
        End If :I/i"g7<  
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        'Assign accommodation and pupil diameter & use defaults if field left empty :o=a@Rqx  
        If dlg.TextBox1 = "" Then HCOE'24I  
            A = 0           'Default accommodation )D>= \ Me  
        Else &vHfuM`  
            A = CDbl(dlg.TextBox1) jTE~^  
        End If S :%SarhBD  
    C'oNGOEd  
        If dlg.TextBox2 = "" Then J0V\_ja-  
            pupilDiam = 4   'Default pupil diameter /KLs+^c5  
        Else 9f7T.}HM  
            pupilDiam = CDbl(dlg.TextBox2) _+NM<o#A  
        End If 2GW.'\D  
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        Print " " f.Feo  
        Print "Accommodation = " & A & " Diopters" j c-$l  
        Print "Pupil Diameter = " & pupilDiam & " mm" SZ3UR  
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        ' Calculate new parameters with accommodation ,[{Z_co  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness p"k[ac{  
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        Rant = 12.0 - 0.4*A                     'Radius of anterior lens *C"-$WU3o  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens zM+eb| >cr  
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        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens )"4v0dv  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens %FSY}65  
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        tlens = 3.767 + 0.04*A                  'Lens thickness "o6a{KY(  
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        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction #V#sg}IhM?  
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        'Adjust parameters to account for accommodation ne-; gTP;  
    Vb$4'K '  
        '************************************************************************* `%nj$-W:  
        'Aqueous thickness (Position of Lens) j$mCU?  
        '************************************************************************* ]UFbG40Zo  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) dub %fs  
        GetCustomElement eID, entity Ka|, qkb  
    _zF*S]9 X  
        parID = FindFullName( "Geometry.Arizona Eye" ) -lDAxp6p  
    3wf&,4`EX  
        ' Delete any shift(s) in z fOtzb YVC  
        count = 0 |z%:{  
        While GetOperationCount(eID)>count ?D8 +wj  
            GetOperation eID, count, op  QnN cGH  
            If op.Type="ShiftZ" Then _oBJ'8R\  
                DeleteOperation eID,count IyJHKDFk  
                count=count-1 ##_Jz5P  
            End If ^oYudb^%  
            count=count+1 p81Vt   
        Wend V_p[mSKJv  
    UD}#c:I  
        'Set new shift in gSn9L)k(O  
        op.Type = "ShiftZ" SoPiEq  
        op.val1 = taq { M&Vh]  
        op.parent = parID L^><APlX  
        AddOperation eID, op dw"{inMf  
        Print "Set aqueous humor thickness = " & taq-0.55 lU&[){  
    e|2@z-Sp-  
        '************************************************************************* H4{CiZ  
        'Radius and conic constant of anterior lens ?Q#yf8  
        '************************************************************************* [ :*Jn}  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) eemw I  
        GetConic eID, entity, curv, conic K#_x.: <J  
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        SetConic eID, entity, 1/Rant, CCant |ryV7VJ8  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant @})]4H  
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        '************************************************************************* ~8l(,N0  
        'Radius and conic constant of posterior lens (]gd$BgD  
        '************************************************************************* q"C(`S.@  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) {>rGe#Vu  
        GetConic eID, entity, curv, conic Al-;-t#Dc  
    pS6p}S=1]  
        SetConic eID, entity, 1/Rpost, CCpost yDe6f(D  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost %3;vDB*L$  
    5%)<e-  
        '************************************************************************* sjIUW$  
        'Lens thickness (Position of posterior lens surface) bpp{Z1/4  
        '************************************************************************* tkj QSz  
    (u:^4,Z  
        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) jqv"8S5  
    AAW])c`.  
        ' Delete any z-shift(s) 2/F";tc\'  
        count = 0 ;%W]b  
        While GetOperationCount(eID)>count ~dz,eB  
            GetOperation eID, count, op Q!*}^W  
            If op.Type="ShiftZ" Then rU!QXg]uD  
                DeleteOperation eID,count mi]bS  
                count=count-1 F :p9y_W  
            End If R!Lh ~~@{(  
            count=count+1 |9'`;4W  
        Wend 1XXuFa&  
    [Rxbb+,U  
        'Set new z-shift k3yA*Ec  
        op.Type = "ShiftZ" 1O,:fTG<  
        op.val1 = tlens cN 3 !wE  
        op.parent = parID ;vuqI5k  
        AddOperation eID, op *l{GD1ZDk  
        Print "Set lens thickness = " & tlens w _ONy9  
    HzQ Y\Y6  
        '************************************************************************* 0ub0 [A  
        'Lens index of refraction {'@`: p&3r  
        '*************************************************************************  Qo$j'|lD  
        eID = FindMaterial( "Lens" ) Mv?$zV"`#  
        GetModelMaterial eID, mat D`NPU  
    +{h.nqdAE  
        mat.Nd = nlens MP_LdJM1E  
        SetModelMaterial eID, mat +S6(Fvp  
        Print "Set lens index of refraction = " & nlens -~] q?k?  
    cKED RX3  
        '************************************************************************* *YO^+]nmY  
        'Pupil diameter RIdh],-  
        '************************************************************************* XT%\Ce!  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) f1w_Cl  
    Q5xQ5Le  
        'Adjust pupil diameter (trimming volume inner hole) sOqT*gwr:  
    G0~6A@>  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" G nPrwDB  
    5_7y1  
        ' Adjust pupil location to just in front of the lens qd<-{  
        parID = FindFullName( "Geometry.Arizona Eye" ) yQ!I`T>a  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) B? Z_~Bf&  
        count = 0 W7#dc89}  
        While GetOperationCount(eID)>count '4ip~>3?w  
            GetOperation eID, count, op ?Gqq]ozm  
            If op.Type="ShiftZ" Then :Xi&H.k)p  
                DeleteOperation eID,count NH'Dz6K5  
                count=count-1 wQ9?Z.-$  
            End If 6^e}^~|  
            count=count+1 WCD)yTg:ES  
        Wend _J"fgxW  
        op.Type = "ShiftZ" eXQLE]L]  
        op.val1 = taq-0.01 iY*fp=c9  
        op.parent = parID +3F%soum95  
        AddOperation eID, op $W]}m"l  
    Jo''yrJpB  
        Print "Set pupil diameter = " & pupilDiam /b7]NC%  
    |/;;uK,y  
        'Update AZ Eye subassembly Description 43?uTnX/  
        eID = FindFullName( "Geometry.Arizona Eye" ) ,GF]+nI89  
        GetEntity eID, entity VVJIJ9L&C  
        entity.Description = "Accommodation = " & A & "D" WZM  
        SetEntity eID, entity tj4/x7!  
    *7o@HBbF  
        Update p""\uG'  
        Print "DONE!" T5Iz{Ha  
         H/U.Bg 4  
    End Sub bae;2| w  
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    如果屈光度是4,光瞳直径是4,则会输出如下数据: />n!2'!  
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    Accommodation = 4 Diopters H<") )EJI  
    Pupil Diameter = 4 mm Z4oD6k5oc  
    Set aqueous humor thickness = 2.81 -}u1ZEND  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 rf+Z0C0WYi  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 o3$dl`'  
    Set lens thickness = 3.927 8]mRX~  
    Set lens index of refraction = 1.42672 hof>:Rk  
    Set pupil diameter = 4 5PsjGvm.%  
    DONE! $0R5 ]]db)  
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    QQ:2987619807 :T{VCw:*  
     
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