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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 1jQz%^~  
    ]xV7)/b5G  
    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。 bCc^)o/w  
    e,8C} 2  
    模型 5a-8/.}cP  
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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。 Qp%kX@Z'  
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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. 0Ac]&N d`  
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    光源 BxlpI[yWq  
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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。 Zj!S('hSY  
    7 ?/ Fr(\  
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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。 =suj3.   
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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。 RIb< 7  
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    图2. 字母F光源的设定方法光 x@(91f  
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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 j {S\X'?  
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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。 $UO7AHk  
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    图4. 视网膜朗伯散射设定
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    注意在视网膜的表面有散射重点采样规格定义,在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳,半角度10度。 x)nBy)<  
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    图5. 视网膜重点采样规格设定
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    脚本 Dy0cA| E  
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    内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框,如下图所示: 7@|(z:uw  
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    图6. 用户对话框的创建与编辑
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    图7. 用户对话框编辑器
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    如果“OK”按钮按下,将会核对对话框下面的代码行,如果点击取消则脚本终止。然后输入的参数赋予变量,如果此处是保留为空白,则使用默认值。因此,如果没有值输入并点击“OK”按钮,则脚本是以屈光度为0,光瞳直径为4mm来运行的。 `N ;!=7y7Y  
    余下的脚本计算与屈光度有关的所有参数。 >"N\ZC^  
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    分析 _sJp"4?  
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    屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 C5 ^_R  
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    图7. 字母F在视网膜上颜色分析
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    脚本代码 bG;vl; C  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. *cq#>rN  
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    Dim entity As T_ENTITY <`~] P$  
    Dim op As T_OPERATION )"=BbMfhu  
    Dim mat As T_MODELMATERIAL Nr6YQH*[  
    Dim A As Double y @h^  
    Dim pupilDiam As Double boJQ3Xc  
    Dim eID As Long `:?padZG  
    Dim parID As Long ^L<1S/~)  
    Dim count As Integer ^ 4c2}>f  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double "f3, w   
    Dim tlens As Double, nlens As Double N{L]H _=  
    Dim curv As Double, conic As Double %[&cy'  
    Dim ok As Long nS]/=xP{  
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    Sub Main >LwAG:Ud  
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        '用户输入对话框 /$]dVvhX%  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 ir3iW*5k  
            TextBox 220,21,40,21,.TextBox1 'default: 0 a}El!7RO0  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 ^k t#[N  
            OKButton 40,91,90,21 VS1gg4tCv  
            CancelButton 190,91,90,21 C} Ewi-  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 wF$8#=  
            TextBox 220,49,40,21,.TextBox2 'default: 4 NJLU +b yU  
        End Dialog qA Jgz7=c  
        Dim dlg As UserDialog E':y3T@."  
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        ok = Dialog (dlg) ukzXQe;l1  
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        If ok=0 Then    'cancel button was pressed _dIv{L!  
            Print "Execution cancelled." S'B7C>i`#N  
            End *.n9D  
        End If 80c\O-{  
    e8--qV#<  
        'Assign accommodation and pupil diameter & use defaults if field left empty VL7zU->  
        If dlg.TextBox1 = "" Then oRmN|d ~4  
            A = 0           'Default accommodation *`=V"nXw$|  
        Else P=(\3ok  
            A = CDbl(dlg.TextBox1) }7wQFKME  
        End If !@p@u;djJ  
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        If dlg.TextBox2 = "" Then /'!F \ kz  
            pupilDiam = 4   'Default pupil diameter &*T57tE  
        Else xa5I{<<U  
            pupilDiam = CDbl(dlg.TextBox2)  UTHGjE  
        End If ^mkplp a  
    d=Q0 /sI&  
        Print " " '~<D[](/F  
        Print "Accommodation = " & A & " Diopters" w3fi2B&q  
        Print "Pupil Diameter = " & pupilDiam & " mm" i *nNu-g  
    'FO^VJ;ha  
        ' Calculate new parameters with accommodation V: 2|l!l*  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness 6*tI~  
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        Rant = 12.0 - 0.4*A                     'Radius of anterior lens pc:~_6S  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens $NT{ssh  
    +wS?Z5%mU  
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens Y[ a$~n^:n  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens k%VV(P]sT  
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        tlens = 3.767 + 0.04*A                  'Lens thickness Wd3/Y/MD  
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        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction L&.9.Ll  
    7o'kdY Jzo  
        'Adjust parameters to account for accommodation 87r#;ND  
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        '************************************************************************* $ [0  
        'Aqueous thickness (Position of Lens) v>;6pcp[F  
        '************************************************************************* xpRQ"6  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) 6psK2d0  
        GetCustomElement eID, entity Jd7+~isu~  
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        parID = FindFullName( "Geometry.Arizona Eye" ) P)7SK&]r;=  
    j@&F[r  
        ' Delete any shift(s) in z cQA;Y!Q #  
        count = 0 Ro$l/lXl8t  
        While GetOperationCount(eID)>count cK1r9ED|  
            GetOperation eID, count, op ikw_t?  
            If op.Type="ShiftZ" Then ?2aglj*"v,  
                DeleteOperation eID,count _ ?xORzO  
                count=count-1 [?.k8;k  
            End If 65)/|j+  
            count=count+1 !J3g,p*  
        Wend 3tA6r  
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        'Set new shift in E}b" qOV  
        op.Type = "ShiftZ" p*8=($j4  
        op.val1 = taq F  MHp a  
        op.parent = parID /MosE,7l  
        AddOperation eID, op 6L}$R`s5H  
        Print "Set aqueous humor thickness = " & taq-0.55 a>ZV'~zTf  
    |Q@4F&k  
        '************************************************************************* ]wc'h>w  
        'Radius and conic constant of anterior lens ~Yb5F YE  
        '************************************************************************* J)"2^?!&B  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) s%1O}X$c  
        GetConic eID, entity, curv, conic OT+=H)/  
    9!NL<}]{  
        SetConic eID, entity, 1/Rant, CCant H"=%|/1M0  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant AD_")_B|i  
    nxS|]  
        '************************************************************************* N>/!e787OU  
        'Radius and conic constant of posterior lens ;%0$3a  
        '************************************************************************* sC(IeGbX  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) K7 -AVMY  
        GetConic eID, entity, curv, conic |Rd?s0u  
    ; $i{>mDT  
        SetConic eID, entity, 1/Rpost, CCpost qRZv[T%*Q  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost wDVKp['  
    {P&{+`sov  
        '************************************************************************* V|13%aE_v  
        'Lens thickness (Position of posterior lens surface) "jb`KBH%"  
        '************************************************************************* TWZ* *S-  
    "v@Y[QI  
        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) Ub2t7MU  
    m(i84~  
        ' Delete any z-shift(s) 1hp`.!3]H  
        count = 0 2!Yq9,`  
        While GetOperationCount(eID)>count ]w`)"{j5m  
            GetOperation eID, count, op WYSqnmi  
            If op.Type="ShiftZ" Then ywTt<;  
                DeleteOperation eID,count Z-z^0QO  
                count=count-1 -K eoq  
            End If dWqKt0uh!  
            count=count+1 mvgsf(a*'  
        Wend d,8L-pT$FM  
    I$7|?8  
        'Set new z-shift #s>AiD  
        op.Type = "ShiftZ" e=Ko4Ao2y  
        op.val1 = tlens JZI)jIh  
        op.parent = parID kw{dvE\K  
        AddOperation eID, op ~" |MwR!0  
        Print "Set lens thickness = " & tlens 6 <XQ'tM]N  
    `@TWZ%f6  
        '************************************************************************* )O\w'|$G  
        'Lens index of refraction "jV :L  
        '************************************************************************* 7^)8DwAl  
        eID = FindMaterial( "Lens" ) S52'!WTq  
        GetModelMaterial eID, mat .8e]-^Z  
    QOiPDu=8z  
        mat.Nd = nlens {*mf Is  
        SetModelMaterial eID, mat KCP$i@Pjv  
        Print "Set lens index of refraction = " & nlens G5*"P!@6  
    ]8@s+ N  
        '************************************************************************* jV{?.0/h|  
        'Pupil diameter D+#OB|&Dn  
        '************************************************************************* C2}n &{T  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) xB-\yWDZe  
    :j^IXZW  
        'Adjust pupil diameter (trimming volume inner hole) M^IEu }  
    K|L&mL&8  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" ;>hRj!  
    8u8-:c%{  
        ' Adjust pupil location to just in front of the lens m.F}9HI%hN  
        parID = FindFullName( "Geometry.Arizona Eye" ) xmVW6 ,<?  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) P* X^)R  
        count = 0 u00w'=pe)  
        While GetOperationCount(eID)>count 0JT"Pv_  
            GetOperation eID, count, op ^_\S)P2c  
            If op.Type="ShiftZ" Then TOT#l6yqdd  
                DeleteOperation eID,count u ,R R|/@  
                count=count-1 90wGS_P04  
            End If 21k,{FB'?  
            count=count+1 W&~\@j]!D  
        Wend ycq+C8J+Ep  
        op.Type = "ShiftZ" 4Jn+Ot.,d  
        op.val1 = taq-0.01 >Nam@,hm  
        op.parent = parID r 4 $<,~  
        AddOperation eID, op o|G'vMph  
    1.0:  
        Print "Set pupil diameter = " & pupilDiam bG)EZ  
    ?e{hidg  
        'Update AZ Eye subassembly Description *@I/TX'\rY  
        eID = FindFullName( "Geometry.Arizona Eye" ) ~3& *>H^U  
        GetEntity eID, entity vh"wXu  
        entity.Description = "Accommodation = " & A & "D" aT4I sPA?_  
        SetEntity eID, entity >sjvE4s  
    n'To:  
        Update #<K'RJn  
        Print "DONE!" >P+o NY  
         ' !2NSv  
    End Sub buldA5*!o  
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    如果屈光度是4,光瞳直径是4,则会输出如下数据: =;"eZ  
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    Accommodation = 4 Diopters H Y~[/H+:  
    Pupil Diameter = 4 mm /HH_Zi0?N|  
    Set aqueous humor thickness = 2.81 9Y:Iha`$w  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 ?[]jJ  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 i>7]9gBm1q  
    Set lens thickness = 3.927 %Rt 5$+dNT  
    Set lens index of refraction = 1.42672 wRdN(`;v  
    Set pupil diameter = 4 I5*<J n  
    DONE! ( Sjlm^bca  
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