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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 7N&3FER  
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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。 cj,&&3sbV  
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    模型 n:%'{}Jw  
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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。 C`=`Ce~|d  
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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. pZNlcB[Qn-  
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    光源 x`&P}4v0  
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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。 *}50q9)/  
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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。 ~8S4Kj)%  
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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。 _A# x&<c  
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    图2. 字母F光源的设定方法光 pw(*X,gj  
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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 NWq [22X |  
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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。 t2U]CI%  
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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。 iKCTYXN1(  
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    图5. 视网膜重点采样规格设定
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    脚本 xHR+((  
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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: i(TDJ@}  
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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。 m0q`A5!)  
    余下的脚本计算与屈光度有关的所有参数。  ;#Bh_f  
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    分析 p{pzOMi6  
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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。 ,1.([%z+r  
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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 F<'l'AsC-  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. K^1O =1gY  
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    Dim entity As T_ENTITY YnL?t-$Gg  
    Dim op As T_OPERATION Bo\dt@0;  
    Dim mat As T_MODELMATERIAL 5In8VE !P  
    Dim A As Double `EW_pwZPA  
    Dim pupilDiam As Double !B38! L  
    Dim eID As Long -X[8soz  
    Dim parID As Long s%?p%2&RA  
    Dim count As Integer frO/ nx|9  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double "rlSK >`  
    Dim tlens As Double, nlens As Double u:>3j,Cs  
    Dim curv As Double, conic As Double Ydd>A\v\;  
    Dim ok As Long 7&S|y]$~  
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    Sub Main !-}*jm p<  
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        '用户输入对话框 XIW: Nk!S  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 OU964vv  
            TextBox 220,21,40,21,.TextBox1 'default: 0 sV4tu(~  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 g(F*Y> hk  
            OKButton 40,91,90,21 f0'Wq^^  
            CancelButton 190,91,90,21 H\>I&gC'  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 B0SmE_u_N  
            TextBox 220,49,40,21,.TextBox2 'default: 4 8$xKg3-3M  
        End Dialog hx;kEJ  
        Dim dlg As UserDialog h[)aRo  
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        ok = Dialog (dlg) m.g@S30  
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        If ok=0 Then    'cancel button was pressed NqfDY  
            Print "Execution cancelled." 9%k.GE  
            End ;77o%J'l  
        End If T7_ SO,X  
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        'Assign accommodation and pupil diameter & use defaults if field left empty COJ!b  
        If dlg.TextBox1 = "" Then 10C91/  
            A = 0           'Default accommodation .*ovIU8  
        Else r4>I?lD  
            A = CDbl(dlg.TextBox1) wLp t2b8S  
        End If 9@a;1Wr/f  
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        If dlg.TextBox2 = "" Then %YAiSSsV  
            pupilDiam = 4   'Default pupil diameter -"tgEC\tD  
        Else NB#*`|qt  
            pupilDiam = CDbl(dlg.TextBox2) a~TZ9yg+HL  
        End If =}KbE4D+8  
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        Print " " r/<JY5  
        Print "Accommodation = " & A & " Diopters" 6OW-Dif^AG  
        Print "Pupil Diameter = " & pupilDiam & " mm" T@WMT,J6j  
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        ' Calculate new parameters with accommodation #C7j|9Ew1]  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness 0e](N`  
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        Rant = 12.0 - 0.4*A                     'Radius of anterior lens d iLl>z  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens k0uwG'(z9  
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        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens meD (ja  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens ! HC<aWb  
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        tlens = 3.767 + 0.04*A                  'Lens thickness 9o'6es..@Z  
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        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction E\N=p&g$  
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        'Adjust parameters to account for accommodation [ LDzR7vnf  
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        '************************************************************************* ghj~r  
        'Aqueous thickness (Position of Lens) .u?$h0u5  
        '************************************************************************* GP'Y!cl  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) 5z>\'a1U  
        GetCustomElement eID, entity I@M^Wu]wW  
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        parID = FindFullName( "Geometry.Arizona Eye" ) cN>i3}fq  
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        ' Delete any shift(s) in z k4rB S  
        count = 0 ,e_#   
        While GetOperationCount(eID)>count wO%:WL$5  
            GetOperation eID, count, op p00AcUTq  
            If op.Type="ShiftZ" Then `{_PSzM  
                DeleteOperation eID,count +N@F,3yNa  
                count=count-1 VrxH6Y  
            End If 0Wm-` ZA  
            count=count+1 ybO,~TQ  
        Wend d vxEXy  
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        'Set new shift in (*BW/.Fq  
        op.Type = "ShiftZ" -=IM8Dny  
        op.val1 = taq n82Q.M-H  
        op.parent = parID *)I1gR~  
        AddOperation eID, op LL [>Uu?Y  
        Print "Set aqueous humor thickness = " & taq-0.55 _AbEQ\P{  
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        '************************************************************************* LS;anNk@.}  
        'Radius and conic constant of anterior lens ii9/ UtIQ  
        '************************************************************************* FM[To  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) s+- aHn  
        GetConic eID, entity, curv, conic RkwY3 s"  
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        SetConic eID, entity, 1/Rant, CCant 7k|(5P;  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant $twF93u$  
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        '************************************************************************* /)TEx}wk  
        'Radius and conic constant of posterior lens 7`!( 8  
        '************************************************************************* k;7.qhe:  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) ~\,6 C1M  
        GetConic eID, entity, curv, conic 1}*;  
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        SetConic eID, entity, 1/Rpost, CCpost Am4(WXVQ  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost 1bkUT_  
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        '************************************************************************* nDy=ZsK  
        'Lens thickness (Position of posterior lens surface) 7!;/w;C  
        '************************************************************************* A o$z )<d'  
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        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) /vu!5?S  
    qV,j)b3M  
        ' Delete any z-shift(s) He3zV\X[Z  
        count = 0 pSFWNWQ'B  
        While GetOperationCount(eID)>count f*Js= hvO  
            GetOperation eID, count, op v19`7qgR(  
            If op.Type="ShiftZ" Then F9w&!yW:  
                DeleteOperation eID,count t@M] ec  
                count=count-1 uD5yw #`  
            End If 1A-EP@# J  
            count=count+1 _xt(II   
        Wend x$DJ  
    &S]v+wF  
        'Set new z-shift *`T &Dlt'8  
        op.Type = "ShiftZ" 8 GN{*Hg  
        op.val1 = tlens Ya 4$7|(  
        op.parent = parID sb.SpF>   
        AddOperation eID, op )W|jt/  
        Print "Set lens thickness = " & tlens [)n}!5fE  
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        '************************************************************************* _B FX5ifK  
        'Lens index of refraction Dj(7'jT  
        '************************************************************************* . *xq =  
        eID = FindMaterial( "Lens" ) 3HR]TQ%r  
        GetModelMaterial eID, mat *!@x<Hf<  
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        mat.Nd = nlens Ct+%  
        SetModelMaterial eID, mat [S+-ovl  
        Print "Set lens index of refraction = " & nlens uiA:(2AQ  
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        '************************************************************************* ^I?y\:.  
        'Pupil diameter X{9o8 *V  
        '************************************************************************* !5!$h` g  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) 1:UC\WW  
    F:GKnbY  
        'Adjust pupil diameter (trimming volume inner hole) \zL7 j 4  
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        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" v=-3 ,C  
    9Ib(x0_  
        ' Adjust pupil location to just in front of the lens w{EU9C  
        parID = FindFullName( "Geometry.Arizona Eye" ) N~_jiVD>  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) 1[9j`~[([  
        count = 0 /,$\H  
        While GetOperationCount(eID)>count uA`PZ|  
            GetOperation eID, count, op 6 <S&~q  
            If op.Type="ShiftZ" Then %v:h]TA  
                DeleteOperation eID,count ^ZWFj?`\UV  
                count=count-1 )0MshgM  
            End If chzR4"WZFt  
            count=count+1 {bqKb=nyZ  
        Wend Go7hDmu  
        op.Type = "ShiftZ" <dPxy`_  
        op.val1 = taq-0.01 ) '`AX\  
        op.parent = parID C?|3\@7  
        AddOperation eID, op Ltd?#HP  
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        Print "Set pupil diameter = " & pupilDiam utJVuJw:t  
    NVWeJ+w  
        'Update AZ Eye subassembly Description #ic 2ofI  
        eID = FindFullName( "Geometry.Arizona Eye" ) (ul-J4E\O  
        GetEntity eID, entity \OT)KVwO  
        entity.Description = "Accommodation = " & A & "D" [Fj+p4*N  
        SetEntity eID, entity G5y  
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        Update B00wcYM<1r  
        Print "DONE!" `G0rF\[  
         &dDI*v+  
    End Sub 7P^{*!  
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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: ^WW|AS  
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    Accommodation = 4 Diopters b\j&!_   
    Pupil Diameter = 4 mm %g@3S!lK  
    Set aqueous humor thickness = 2.81 s_Oh >y?Aq  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 3]OP9!\6  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 tDHHQ  
    Set lens thickness = 3.927 4S0++Hp4  
    Set lens index of refraction = 1.42672 L[Yp\[#-q  
    Set pupil diameter = 4 p6y0W`U  
    DONE! mQ60@_"Y=,  
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    QQ:2987619807 }-q`&1!t  
     
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