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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 WO4=Mte?  
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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。 4D%9Rc0 G  
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    模型 {CG_P,FO  
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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。 5AS[\CB4  
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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. a {}|Bf<  
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    光源 M2x["  
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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。 X{n- N5*  
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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。 \l"&A  
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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。 $WYbm}j  
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    图2. 字母F光源的设定方法光 K3uG2g(>2  
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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 n?\ nn3  
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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。 qmTb-~  
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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。 uPYmHA} _/  
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    图5. 视网膜重点采样规格设定
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    脚本 MS(JR  
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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: [S.ZJUns  
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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。 -U<Upn)2  
    余下的脚本计算与屈光度有关的所有参数。 Z3k(P  
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    分析 a9n^WOJ6  
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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。 ;fw1  
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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 "fg](Cp[z  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. EF pIp4_Y  
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    Dim entity As T_ENTITY hlu:=<B  
    Dim op As T_OPERATION  hjO*~  
    Dim mat As T_MODELMATERIAL ^qCkt1C-M  
    Dim A As Double ]M)O YY  
    Dim pupilDiam As Double \BWyk A>  
    Dim eID As Long f<+ 4rHT  
    Dim parID As Long hYQ_45Z*?  
    Dim count As Integer ,#.9^J  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double  z:d+RMA  
    Dim tlens As Double, nlens As Double `;Xwv)  
    Dim curv As Double, conic As Double Mb+CtI_'  
    Dim ok As Long \eCQL(_  
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    Sub Main )QB9zl:  
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        '用户输入对话框 $yZ(ws  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 Fv3:J~Yf  
            TextBox 220,21,40,21,.TextBox1 'default: 0 ?mh0^G  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 kOV6O?h  
            OKButton 40,91,90,21 =UV=F/Af^  
            CancelButton 190,91,90,21 71G00@&w9D  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 :Oc&{z?q  
            TextBox 220,49,40,21,.TextBox2 'default: 4 jO5We mqf  
        End Dialog *h~(LH"tN  
        Dim dlg As UserDialog v]m#+E   
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        ok = Dialog (dlg) JT*Pm"}  
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        If ok=0 Then    'cancel button was pressed s/OXZ<C|  
            Print "Execution cancelled." 8_uh2`+Bvb  
            End ixJwv\6Y  
        End If 7J$Yd976  
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        'Assign accommodation and pupil diameter & use defaults if field left empty }>m3V2>[  
        If dlg.TextBox1 = "" Then }\d3   
            A = 0           'Default accommodation du^r EMb%  
        Else _R;+}1G/  
            A = CDbl(dlg.TextBox1) -P$E)5?^  
        End If G2hBJTW  
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        If dlg.TextBox2 = "" Then 5h>t4 [~  
            pupilDiam = 4   'Default pupil diameter .iH#8Z  
        Else l&m'?. g f  
            pupilDiam = CDbl(dlg.TextBox2) ?r}!d2:dX  
        End If zNQ|G1o  
    )4bZ;'B5  
        Print " " d5tp w$A  
        Print "Accommodation = " & A & " Diopters" dWhF[q"  
        Print "Pupil Diameter = " & pupilDiam & " mm" x^JjoI2vf  
    'W|@d8}h  
        ' Calculate new parameters with accommodation D(gpF85t  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness 0%5x&vx'S  
    :@q9ll`6u  
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens *!x/ia9  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens b}jLI_R{  
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        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens o)IcAqN$H  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens 0Z>oiBr4  
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        tlens = 3.767 + 0.04*A                  'Lens thickness m#(ve1E  
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        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction ^Sz?c_<2P  
    &)|3OJ'o  
        'Adjust parameters to account for accommodation b{Kw.?85  
    7<c&)No;  
        '************************************************************************* @DYkWivLu  
        'Aqueous thickness (Position of Lens) /WI HG0D  
        '************************************************************************* Gq r(.  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) 9=Rj9%  
        GetCustomElement eID, entity UT7".1H  
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        parID = FindFullName( "Geometry.Arizona Eye" ) `)R@\@jt  
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        ' Delete any shift(s) in z "Z6:d"S`  
        count = 0 6">jf #pE  
        While GetOperationCount(eID)>count c~UYs\  
            GetOperation eID, count, op RU'DUf  
            If op.Type="ShiftZ" Then 4c=oAL  
                DeleteOperation eID,count 1f1J'du  
                count=count-1 u!DSyHR '  
            End If #/9(^6f:  
            count=count+1 _"`U.!3*  
        Wend kM\O2 ay  
    `-N&cc  
        'Set new shift in {G%!M+n<  
        op.Type = "ShiftZ" fE/8;v!=  
        op.val1 = taq jsvD[\P  
        op.parent = parID &p$SFH?s  
        AddOperation eID, op #YSUPO%F  
        Print "Set aqueous humor thickness = " & taq-0.55 < &'r_m  
    -ijQT B  
        '************************************************************************* 1H_#5hd  
        'Radius and conic constant of anterior lens <`q|6XWL  
        '************************************************************************* 0Fh*8a}?b  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) bMD'teJ  
        GetConic eID, entity, curv, conic 5i$~1ZC  
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        SetConic eID, entity, 1/Rant, CCant 5yQv(<~*G  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant WLWE%bDP  
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        '************************************************************************* hoihdVjv  
        'Radius and conic constant of posterior lens  ~Rcd  
        '************************************************************************* m!:7ur:Y  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) ^F~e?^s  
        GetConic eID, entity, curv, conic #?i#q%q  
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        SetConic eID, entity, 1/Rpost, CCpost WU1o4&OF  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost oA~m*|  
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        '************************************************************************* q9oF8&O,  
        'Lens thickness (Position of posterior lens surface) = sIR[V'(  
        '************************************************************************* j78xMGKO  
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        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) 9kP!O_  
    C<fNIc~.  
        ' Delete any z-shift(s) K. R2)o`  
        count = 0 +c\s%Gzrh  
        While GetOperationCount(eID)>count 64 \ZOG\,  
            GetOperation eID, count, op tb0XXE E  
            If op.Type="ShiftZ" Then 3_T'TzQ u  
                DeleteOperation eID,count 4ij`   
                count=count-1 ;?2vW8{p<  
            End If VSZ6;&2^  
            count=count+1 VJCh5t*  
        Wend ^;s`[f|w  
    H8K<.RY  
        'Set new z-shift %TG$5' )0  
        op.Type = "ShiftZ" X{#@ :z$  
        op.val1 = tlens Ai->,<Ig]  
        op.parent = parID Mn~A;=%qF  
        AddOperation eID, op 9$Mi/eLG2N  
        Print "Set lens thickness = " & tlens 45j+n.9=  
    2c%}p0<;|?  
        '************************************************************************* .3|9 ~]  
        'Lens index of refraction  R/^JyL  
        '************************************************************************* sp**Sg)  
        eID = FindMaterial( "Lens" )  A ]U]  
        GetModelMaterial eID, mat MmWJYF=  
    h0.Fstf]  
        mat.Nd = nlens `6mHt6"h  
        SetModelMaterial eID, mat : 6>H\  
        Print "Set lens index of refraction = " & nlens [k'Ph33c  
    y-n\;d>[(  
        '************************************************************************* -'PpY302  
        'Pupil diameter `FJnR~d  
        '************************************************************************* Xq>e]#gR  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) ;7`<.y  
    ri JyH;)  
        'Adjust pupil diameter (trimming volume inner hole) B E"nyTQ  
    w ^<Y5K  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" ){YPP!8cI  
    GmL|76  
        ' Adjust pupil location to just in front of the lens ~2H7_+.#  
        parID = FindFullName( "Geometry.Arizona Eye" ) ($S{td;  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) BRD'5 1]|  
        count = 0 [V)sCAW  
        While GetOperationCount(eID)>count )E7A,ZW,  
            GetOperation eID, count, op u\e#_*>  
            If op.Type="ShiftZ" Then -/gS s<"  
                DeleteOperation eID,count Gr6ma*)y~t  
                count=count-1 !7xp<=  
            End If (J$A  
            count=count+1 "}OFwes  
        Wend Y$ChMf  
        op.Type = "ShiftZ" Oq[E\8Wn  
        op.val1 = taq-0.01 jujx3rnK?  
        op.parent = parID =` i 7?  
        AddOperation eID, op S-rqrbr|AT  
    `C*!de]Y%  
        Print "Set pupil diameter = " & pupilDiam bg HaheU  
    %C3cdy_c  
        'Update AZ Eye subassembly Description *}_/:\v  
        eID = FindFullName( "Geometry.Arizona Eye" ) y2+a2  
        GetEntity eID, entity  Nr[Rp  
        entity.Description = "Accommodation = " & A & "D" k( g$_ ]X  
        SetEntity eID, entity _"sRL} -Z  
    M)J*Df0@  
        Update nUd\4;J#  
        Print "DONE!" sd[QtK^  
         wFJK!9KA8  
    End Sub Agi1r]W  
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    如果屈光度是4,光瞳直径是4,则会输出如下数据: zJnVO$A'  
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    Accommodation = 4 Diopters {;4PP463  
    Pupil Diameter = 4 mm _#gsR"FZ$  
    Set aqueous humor thickness = 2.81 aqM_t  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 t~M<j| ]k  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 vv0zUvmT  
    Set lens thickness = 3.927 W vJ?e  
    Set lens index of refraction = 1.42672 +E [bLz^  
    Set pupil diameter = 4 yQA[X}  
    DONE! (Z$6J Nkz  
     
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