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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 !~04^(  
    lDe9(5|)Q  
    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。 Wd_bDZQ  
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    模型 z!)_'A  
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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。 Z*.fSmT8)  
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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. { > {|3  
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    光源 l^:m!SA_  
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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。 -_ .f&l8  
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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。 x6* {@J&5*  
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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。 @j`_)Y\  
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    图2. 字母F光源的设定方法光 (Z=ziopDE  
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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 49bzHEqZ  
    8*6vX!Z|  
    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。 sVZb[|zSri  
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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。 Ra'0 ^4t  
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    图5. 视网膜重点采样规格设定
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    脚本 HD IB GG~  
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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: sT[)r]`T  
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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。 XrYMv WT  
    余下的脚本计算与屈光度有关的所有参数。  02Ur'|  
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    分析 >T%Jlj3ZG  
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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。 i5?)E7-  
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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 5z~Ji77!  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. VQZ3&]o  
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    Dim entity As T_ENTITY =   
    Dim op As T_OPERATION ;DL|%-%;$r  
    Dim mat As T_MODELMATERIAL ?1xBhKq  
    Dim A As Double n&i WYECz  
    Dim pupilDiam As Double 6dV@.(][a  
    Dim eID As Long o{4ya jt  
    Dim parID As Long l,1}1{k&  
    Dim count As Integer *qAF#  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double )F0 _V 4  
    Dim tlens As Double, nlens As Double >MUwT$szs  
    Dim curv As Double, conic As Double `. /[/ z-g  
    Dim ok As Long [@ "H2#CQ  
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    Sub Main r62x*?/  
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        '用户输入对话框 79~,KFct  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 >a%NC'~rc  
            TextBox 220,21,40,21,.TextBox1 'default: 0 UG s <<  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 ~=Z&l  
            OKButton 40,91,90,21 0Tp?ED_  
            CancelButton 190,91,90,21 O4@Ki4f3A%  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 G-G!c2o  
            TextBox 220,49,40,21,.TextBox2 'default: 4 "z69jxXo  
        End Dialog xp7,0'(;  
        Dim dlg As UserDialog iVd*62$@$  
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        ok = Dialog (dlg) T$06DS  
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        If ok=0 Then    'cancel button was pressed MfJk`-%~  
            Print "Execution cancelled." +>.plvZhu  
            End X;w1@4!  
        End If % rdW:  
    L4zSro:Si  
        'Assign accommodation and pupil diameter & use defaults if field left empty ?#qA>:2,  
        If dlg.TextBox1 = "" Then @ ~ N:F~  
            A = 0           'Default accommodation UY5ia4_D  
        Else ~B:Lai4"  
            A = CDbl(dlg.TextBox1) F] +t/  
        End If 9HLn_|yU  
    YdV5\!  
        If dlg.TextBox2 = "" Then 5u:+hB  
            pupilDiam = 4   'Default pupil diameter ,M>W)TSH  
        Else $9y]>R  
            pupilDiam = CDbl(dlg.TextBox2) s2@N&7"u)  
        End If o2 W pi  
    bFVz ;  
        Print " " s C e7ni  
        Print "Accommodation = " & A & " Diopters" =gGK243  
        Print "Pupil Diameter = " & pupilDiam & " mm" x1/Usupi  
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        ' Calculate new parameters with accommodation l'W?X '  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness x~$P.X7(~  
    $sU?VA'h  
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens ";`ddN3  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens )3.udx  
    9*[!uu  
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens !#rZ eDmw  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens 7V4 iPx  
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        tlens = 3.767 + 0.04*A                  'Lens thickness X-3L4@T:?  
    T)3#U8sT  
        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction , ZD!Qb  
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        'Adjust parameters to account for accommodation 0+/L?J3  
    #Jy+:|jJ  
        '************************************************************************* D?}LKs[  
        'Aqueous thickness (Position of Lens) <!y_L5S|   
        '************************************************************************* /Or76kE  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) J%aW^+O  
        GetCustomElement eID, entity 3 cT  
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        parID = FindFullName( "Geometry.Arizona Eye" ) UldKlQ8  
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        ' Delete any shift(s) in z *7ap[YXZ\w  
        count = 0 a gBKp!  
        While GetOperationCount(eID)>count A!Ng@r  
            GetOperation eID, count, op xE9^4-Px*  
            If op.Type="ShiftZ" Then *B#OLx  
                DeleteOperation eID,count &VR<'^>  
                count=count-1 5irewh'R  
            End If 5;`([oX|_  
            count=count+1 klT6?'S  
        Wend \Y>^L{  
    Lg9]kpOpa  
        'Set new shift in bkmX@+Pe  
        op.Type = "ShiftZ" q1r\ 60M  
        op.val1 = taq `gfK#0x#  
        op.parent = parID 4yQ4lU,r  
        AddOperation eID, op j[iJo 5  
        Print "Set aqueous humor thickness = " & taq-0.55 7; T S  
    ,{J2i#g<  
        '************************************************************************* ;f?OT7>kN  
        'Radius and conic constant of anterior lens O5_E"um  
        '************************************************************************* m(B6FPjr  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) ~>>o'H6  
        GetConic eID, entity, curv, conic Z'S>i*Ts  
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        SetConic eID, entity, 1/Rant, CCant WVy"MD  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant fN0D\Mu!)b  
    F:hJ^:BP  
        '************************************************************************* ?B@hCd)  
        'Radius and conic constant of posterior lens J#Bz )WmR  
        '************************************************************************* #kLM=a/_NO  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) i;6\tK"!  
        GetConic eID, entity, curv, conic oWs&W  
    d@C ;rzR  
        SetConic eID, entity, 1/Rpost, CCpost /I[cj3}{+f  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost @m6pAo4P  
    :".!6~:2  
        '************************************************************************* O- |RPW}  
        'Lens thickness (Position of posterior lens surface) YV! !bI  
        '************************************************************************* %{zM> le9  
    _'2r=a#`  
        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) :JW~$4  
    kwWO1=ikz@  
        ' Delete any z-shift(s) &+&^Hc  
        count = 0 s15f <sp  
        While GetOperationCount(eID)>count /V7u0y  
            GetOperation eID, count, op w\$b(HC  
            If op.Type="ShiftZ" Then ^,U&v;   
                DeleteOperation eID,count b <=K@I.=  
                count=count-1 dN\pe@#lKP  
            End If  9FWn  
            count=count+1 | @di<d@  
        Wend [POy" O  
    1/HPcCsHb  
        'Set new z-shift IgN,]y  
        op.Type = "ShiftZ" p,kJ#I  
        op.val1 = tlens M{~eI  
        op.parent = parID V#3VRh  
        AddOperation eID, op zYls>fbp,  
        Print "Set lens thickness = " & tlens Bm~>w`1wK  
    ?KS9Dh  
        '************************************************************************* fC~WuG 3  
        'Lens index of refraction w`!Yr:dU  
        '************************************************************************* f3v/Y5)  
        eID = FindMaterial( "Lens" ) D+ jk0*bJ  
        GetModelMaterial eID, mat 0;k3  
    0&5}[9?V'  
        mat.Nd = nlens 'JkK0a2D  
        SetModelMaterial eID, mat d%]7:  
        Print "Set lens index of refraction = " & nlens R^PQ`$W 'R  
    ~_S`zzcZy4  
        '************************************************************************* V!ajD!00  
        'Pupil diameter 78 UT]<Q;K  
        '************************************************************************* &TK%igL  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) j$8 ~M  
    5R o5Cg~  
        'Adjust pupil diameter (trimming volume inner hole) 9oGsrC lH  
    0 _&oMPY  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" m m`:ci  
    Crww\#E;  
        ' Adjust pupil location to just in front of the lens JVXBm]  
        parID = FindFullName( "Geometry.Arizona Eye" ) }>tUkXlhJ<  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) { ET+V  
        count = 0 `8'|g8,wb0  
        While GetOperationCount(eID)>count & JF^a  
            GetOperation eID, count, op B<0lif|  
            If op.Type="ShiftZ" Then D ORFK  
                DeleteOperation eID,count Z ,T TI>P  
                count=count-1 %/sf#8^m  
            End If nY~CAo/:  
            count=count+1 cFH,fj  
        Wend [9>1e  
        op.Type = "ShiftZ" xNm<` Y?  
        op.val1 = taq-0.01 yq&]>ox  
        op.parent = parID H:~LL0Md%  
        AddOperation eID, op +,PBhB  
    ){wE)NN  
        Print "Set pupil diameter = " & pupilDiam 1miTE4;?  
    ;OVJM qg  
        'Update AZ Eye subassembly Description nR ,j1IUF  
        eID = FindFullName( "Geometry.Arizona Eye" ) Ad`; O+/;  
        GetEntity eID, entity w>m/c1  
        entity.Description = "Accommodation = " & A & "D" g(<@r2p  
        SetEntity eID, entity Xw![}L >  
    *_^AK=i  
        Update 0}w>8L7i{  
        Print "DONE!" .|o7YTcR:  
         dc:|)bK M  
    End Sub o3uv"# C  
    P/ug'  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: ?MN?.O9-  
    "lUw{3  
    Accommodation = 4 Diopters &d6'$h:kHb  
    Pupil Diameter = 4 mm ,AM6E63  
    Set aqueous humor thickness = 2.81 .Mm8\].  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 N4$0ptz#}G  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 &z,w0FOre  
    Set lens thickness = 3.927 [81k4kU  
    Set lens index of refraction = 1.42672 1Z*-@%RX  
    Set pupil diameter = 4 > Y[{m $-  
    DONE! RAxA H  
     
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