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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 KO/Z|I  
    1+6)0 OH{  
    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。   )z#  
    !C>}j* 4  
    模型 =jZ}@L/+  
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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。 &t1?=F,]  
    _ S%3?Q  
    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. |f+|OZY  
    *|S.[i_7  
    光源 h6c0BmS{1  
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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。 (bnyT?p%  
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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 2E  
    /y/O&`X(  
    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。 63R?=u@  
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    图2. 字母F光源的设定方法光 =8BMCedH|  
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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 04{*iS95J  
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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。 +RLHe]9&  
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    % \OG#36  
    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。 #P[d?pY  
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    图5. 视网膜重点采样规格设定
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    脚本 a(>oQG8F  
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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: V 2-fJ!  
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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。 8%-+@ \=  
    余下的脚本计算与屈光度有关的所有参数。 \va'>?#o1  
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    分析 C4vmgl&  
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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。 |#hj O3  
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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 )*j>g38?  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. t+C9QXY  
    |l5ol @2*  
    Dim entity As T_ENTITY <Z^P8nu  
    Dim op As T_OPERATION Q4;eN w  
    Dim mat As T_MODELMATERIAL 70s.  
    Dim A As Double %6-5hBzZN  
    Dim pupilDiam As Double 3{wr*L1%-~  
    Dim eID As Long "VEA71  
    Dim parID As Long 5}J|YKyP  
    Dim count As Integer L< 3U)Gp  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double ""LCyKu   
    Dim tlens As Double, nlens As Double U;%I" p`Z/  
    Dim curv As Double, conic As Double D|zlC,J,  
    Dim ok As Long @KtQ~D  
    6|# +  
    Sub Main WO=X*O ne  
    ~M@'=Q*~  
        '用户输入对话框 $F> #1:=v<  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 <A%}  
            TextBox 220,21,40,21,.TextBox1 'default: 0 ldEZ_g^  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 hEG-,   
            OKButton 40,91,90,21 |g o jb  
            CancelButton 190,91,90,21  U~%V;*|4  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 >GRL5Iow  
            TextBox 220,49,40,21,.TextBox2 'default: 4 (?luV#{5  
        End Dialog p72:oX\Q I  
        Dim dlg As UserDialog /{|<3CEe  
    *Ru@F:  
        ok = Dialog (dlg) 2?=R_&0 Q  
    ] T `6Hz!  
        If ok=0 Then    'cancel button was pressed Iud]*5W  
            Print "Execution cancelled." vn5X]U"  
            End M6$9-  
        End If R~9\mi5^UH  
    *RM?SE6;  
        'Assign accommodation and pupil diameter & use defaults if field left empty l# -4}95  
        If dlg.TextBox1 = "" Then )HLe8:PG~  
            A = 0           'Default accommodation y,I?3 p|S  
        Else g[Tl#X7F  
            A = CDbl(dlg.TextBox1) m@Ziif-A  
        End If 3$c Im+  
    -K+" :kiS  
        If dlg.TextBox2 = "" Then Q i&!Ub]  
            pupilDiam = 4   'Default pupil diameter \W"N{N  
        Else K6vF}A|  
            pupilDiam = CDbl(dlg.TextBox2) x2@Q5|a  
        End If K|Q|v39{b  
    gY)NPi}!`  
        Print " " wI\ n%#  
        Print "Accommodation = " & A & " Diopters" p([g/Q  
        Print "Pupil Diameter = " & pupilDiam & " mm" BU\P5uB!V  
    - v\n0Jt  
        ' Calculate new parameters with accommodation %}t<,ex(yO  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness {Q/XV=  
    <IiX_*  
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens d E0 `tX  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens ]QB<N|ps  
    tS$^k)ZXip  
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens yJ(BPSt  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens ze%kP#c6!  
    /FzO9'kj  
        tlens = 3.767 + 0.04*A                  'Lens thickness qu}`;\9@ld  
    AOh\%|}  
        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction {J`]6ba  
    2(_+PQ6C=  
        'Adjust parameters to account for accommodation p&Os5zw;|  
    'Q R @G  
        '************************************************************************* BvXA9YQ3  
        'Aqueous thickness (Position of Lens) Equj[yw%@  
        '************************************************************************* };rxpw>ms  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) O26'|w@$  
        GetCustomElement eID, entity u`%Kh_  
    (}$pf6s  
        parID = FindFullName( "Geometry.Arizona Eye" ) Ek0zFnb[Gx  
    ]u;Ma G=;  
        ' Delete any shift(s) in z vr/O%mDp  
        count = 0 D..dGh.MY  
        While GetOperationCount(eID)>count _$wXHONt  
            GetOperation eID, count, op ?Cg",k'  
            If op.Type="ShiftZ" Then jm|x=s3}h  
                DeleteOperation eID,count =qQH,{]c6  
                count=count-1 {km~,]N  
            End If QkEIV<T&)l  
            count=count+1 'N-nFc^  
        Wend 5>E]C=maD  
    -vRZCIj!  
        'Set new shift in d0@&2hO  
        op.Type = "ShiftZ" J%_m`?  
        op.val1 = taq '<Nhq_u{  
        op.parent = parID >8I?YT.  
        AddOperation eID, op ~EYsUC#B_  
        Print "Set aqueous humor thickness = " & taq-0.55 !B&OK&*  
    7Wd}H Z  
        '************************************************************************* QD<GXPu?N  
        'Radius and conic constant of anterior lens *]L(,_:"  
        '************************************************************************* V^n?0^o  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) J}$St|1y  
        GetConic eID, entity, curv, conic wt8?@lJ"/  
    0E6>P E;  
        SetConic eID, entity, 1/Rant, CCant v)^8e0vx  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant byT@O:fL  
    R2]2#3`  
        '************************************************************************* Y|*a,H"_  
        'Radius and conic constant of posterior lens aan)yP  
        '************************************************************************* aP#nK  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) q_5hKipd\b  
        GetConic eID, entity, curv, conic 7W)*IJ  
    Ia> 07av  
        SetConic eID, entity, 1/Rpost, CCpost V30Om3C  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost D*!UB5<>/t  
    *%[L @WF  
        '************************************************************************* s)gUvS\  
        'Lens thickness (Position of posterior lens surface) G*oqhep  
        '************************************************************************* %K9 9_Cl3  
    1 P0)La#  
        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) 91|0{1  
    #@ quuiYq  
        ' Delete any z-shift(s) yvQRr75  
        count = 0 vz\^Aa #fv  
        While GetOperationCount(eID)>count hd~3I4D  
            GetOperation eID, count, op 5,i0QT"  
            If op.Type="ShiftZ" Then kYwV0xQ  
                DeleteOperation eID,count vpnOc2 -  
                count=count-1 1FkS$ j8:  
            End If ~d9R:t1  
            count=count+1 M, uQ8SZA[  
        Wend !=-{$& {  
    ;ui=7[ Us  
        'Set new z-shift /t4#-vz  
        op.Type = "ShiftZ" ZxDh94w/  
        op.val1 = tlens X(YR).a~  
        op.parent = parID 1N3qMm^  
        AddOperation eID, op w=|"{-ijo  
        Print "Set lens thickness = " & tlens j'2:z#  
    pGwBhZnb>  
        '************************************************************************* vXq2="+  
        'Lens index of refraction j9voeV|7  
        '************************************************************************* %^zGM^PD  
        eID = FindMaterial( "Lens" ) B&bQvdp  
        GetModelMaterial eID, mat 4s <|8   
    %o4d(C B  
        mat.Nd = nlens ZQ MK1  
        SetModelMaterial eID, mat L/39<&W  
        Print "Set lens index of refraction = " & nlens l-~ o&n  
    a7Xa3 vlpO  
        '************************************************************************* h#e((j3-2Z  
        'Pupil diameter x/)o'#d$|l  
        '************************************************************************* <kc9KE  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) kuQ+MQHs  
    8c1ma  
        'Adjust pupil diameter (trimming volume inner hole) 4ayZ.`aK  
    /'g/yBY  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" 3|Vh[iAa\  
    v 7g?  
        ' Adjust pupil location to just in front of the lens P { 8d.  
        parID = FindFullName( "Geometry.Arizona Eye" ) *# 7 1aZ  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) %F.^cd"  
        count = 0 axpn*(yE  
        While GetOperationCount(eID)>count %]KOxaf_z  
            GetOperation eID, count, op It@1!_tO2  
            If op.Type="ShiftZ" Then x&['g*[L0  
                DeleteOperation eID,count  4u.v7r  
                count=count-1 ?h1r6?Sug{  
            End If !#b8QER  
            count=count+1 W["c3c  
        Wend 0|L%)'F  
        op.Type = "ShiftZ" Iu=n$H  
        op.val1 = taq-0.01 ~4}'R_  
        op.parent = parID Wh7}G   
        AddOperation eID, op 8s@k0T<O  
    m7n8{J1O2  
        Print "Set pupil diameter = " & pupilDiam |s}7<A  
    !^h{7NmP[  
        'Update AZ Eye subassembly Description k04CSzE"%  
        eID = FindFullName( "Geometry.Arizona Eye" ) @/yQ4Gr  
        GetEntity eID, entity o;^k"bo6   
        entity.Description = "Accommodation = " & A & "D"  FTk`Mq  
        SetEntity eID, entity 920 o]Dh=t  
    'xn3g;5  
        Update \0'0)@uziQ  
        Print "DONE!" ky^u.+cZ  
         -h|YS/$f  
    End Sub /z(;1$Ld6{  
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    如果屈光度是4,光瞳直径是4,则会输出如下数据: C3#mmiL-  
    1#OM~v6B  
    Accommodation = 4 Diopters !#' y#  
    Pupil Diameter = 4 mm rO;Vr},3\%  
    Set aqueous humor thickness = 2.81 :}[RDF?  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 'U %L\v,  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 +o*&JoC  
    Set lens thickness = 3.927 V+yyy- /  
    Set lens index of refraction = 1.42672 o$[alh;c+W  
    Set pupil diameter = 4 Ga9^+.j  
    DONE! rf[w&~R  
     
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