切换到宽版
  • 广告投放
  • 稿件投递
  • 繁體中文
    • 1376阅读
    • 0回复

    [技术]Arizona眼睛模型 [复制链接]

    上一主题 下一主题
    离线infotek
     
    发帖
    5734
    光币
    22822
    光券
    0
    只看楼主 倒序阅读 楼主  发表于: 2021-10-22
    简介 HA9Nr.NqC@  
    Z&]+A,  
    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。 =,d* {m~A  
    N+s?ZE*  
    模型 B221}t  
    XiRT|%j  
    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 cTL#OTP  
    fATA%eA8;  
    Table 1. AZ眼睛模型的定义
    >C:"$x2"#(  
    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. nGv23R(?G  
    \)otu\3/  
    光源 c{,y{2c]LT  
    5]H))}9>d  
    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。 OY^n0Zof,  
    Oj"pj:fB  
    UbY~xs7_  
    图1. 光源和提示信息使用
    +f X}O9  
    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。 K$<`4#i  
    Ld\LKwo  
    在往下看是内置的脚本用来修改屈光度,使其为4(250mm),光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 qIDWl{b<  
    s!@=rq  
    图2. 字母F光源的设定方法光 8<yV  
    xTJ Sr2f  
    图3. 字母F在视网膜上位置点列图
    P /c Q1  
    视网膜的散射 *K+jsVDY  
    '&-5CpDUs  
    在散射文件中,有一个名为“Retina surface”的72%的反射型朗伯散射,它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射,改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 Mhv1K|4s  
    b(#"w[|  
    j<ABO")v  
    图4. 视网膜朗伯散射设定
    .'^6QST  
    注意在视网膜的表面有散射重点采样规格定义,在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳,半角度10度。 ~aJW"\{  
    ;|>q zx  
    nDHHYp  
    图5. 视网膜重点采样规格设定
    7P/?wv9+n*  
    脚本 'v\1:zi  
    ,7^d9v3t  
    内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框,如下图所示: s[G |q5n  
    ),cQUB  
    图6. 用户对话框的创建与编辑
    dGbU{#"3s  
    图7. 用户对话框编辑器
    AI1@-  
    如果“OK”按钮按下,将会核对对话框下面的代码行,如果点击取消则脚本终止。然后输入的参数赋予变量,如果此处是保留为空白,则使用默认值。因此,如果没有值输入并点击“OK”按钮,则脚本是以屈光度为0,光瞳直径为4mm来运行的。 +{,N X  
    余下的脚本计算与屈光度有关的所有参数。 g08*}0-k  
    pqyWv;  
    分析 z5XYpi_;[  
    Ku<b0<`  
    屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 :y+B;qw  
    IL~]m?'V(  
    图7. 字母F在视网膜上颜色分析
    (3 IZ  
    脚本代码 `z9)YH  
    7?6xPKQ)H  
    Option Explicit     'Remove this to enable non-dimensioned variables to be used. 81GQijq  
    #4P8Rzl$/  
    Dim entity As T_ENTITY *QbM*oH  
    Dim op As T_OPERATION H$z>OS_6U  
    Dim mat As T_MODELMATERIAL { 1+Cw?1d  
    Dim A As Double q';&SR#"`K  
    Dim pupilDiam As Double $|4cJ#;^L  
    Dim eID As Long <8u>_o6  
    Dim parID As Long UWQtvQ f  
    Dim count As Integer K :1g"  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double 8[8|*8xqs  
    Dim tlens As Double, nlens As Double .)LZ`Ge3F  
    Dim curv As Double, conic As Double YV5Yx-+3w$  
    Dim ok As Long v6wRME;JA  
    fNmE,~  
    Sub Main 0CPxIF&  
    \Dn&"YG7  
        '用户输入对话框 CQ@LmTW[  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 2>F\&  
            TextBox 220,21,40,21,.TextBox1 'default: 0 }5Yj  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 u@<Pu@?xm  
            OKButton 40,91,90,21 PeO]lq  
            CancelButton 190,91,90,21 JZ`>|<W  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 cNe0x2Z$?  
            TextBox 220,49,40,21,.TextBox2 'default: 4 P+[QI U  
        End Dialog  b<[jaI0  
        Dim dlg As UserDialog 3^{8_^I  
    hT?6sWa  
        ok = Dialog (dlg) +T9Q_e*  
    Vwjk[ DOL  
        If ok=0 Then    'cancel button was pressed \ jE CSV|  
            Print "Execution cancelled." $j57LY|r  
            End }$l8d/_$[  
        End If GxxDY]!  
    +wipfL~&S  
        'Assign accommodation and pupil diameter & use defaults if field left empty m;dm|4L^  
        If dlg.TextBox1 = "" Then G3G/ xC"  
            A = 0           'Default accommodation 59.$ULQVMY  
        Else &,J*_F<s2<  
            A = CDbl(dlg.TextBox1) Odm#wL~E  
        End If vB^uxdt|m  
    _}D%iJg#  
        If dlg.TextBox2 = "" Then bG "H D?A_  
            pupilDiam = 4   'Default pupil diameter >QXzMN}o  
        Else l09Fn>wa  
            pupilDiam = CDbl(dlg.TextBox2) )B6# A0  
        End If <0#^7Z  
    2gt+l?O<PS  
        Print " " 7AFE-'S  
        Print "Accommodation = " & A & " Diopters" 2Zy_5>~  
        Print "Pupil Diameter = " & pupilDiam & " mm" kB o;h.[l  
    2UiR~P]%  
        ' Calculate new parameters with accommodation K}x_nW  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness o+NMA (  
    '_V #;DI  
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens ;J]25j]]  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens _pW_G1U  
    vYdR ht\(  
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens N>0LQ MI  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens 8!&nKy<Y  
    >L gVj$Z  
        tlens = 3.767 + 0.04*A                  'Lens thickness Ry&q1j  
    %#u.J  
        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction 3V?817&6z  
    K/^ +eoW(  
        'Adjust parameters to account for accommodation <?YA,"~  
    e'34Pw!m  
        '************************************************************************* =Q-k'=6\  
        'Aqueous thickness (Position of Lens) ~O{W;Cyh  
        '************************************************************************* %t*  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) P>(P2~$Y"  
        GetCustomElement eID, entity b HE7yv [  
    xST4}Mb^f  
        parID = FindFullName( "Geometry.Arizona Eye" ) -p`L% xj\  
    NgVR,G|1  
        ' Delete any shift(s) in z ,X68xk.'  
        count = 0 OUI6 ax\[  
        While GetOperationCount(eID)>count iCP~O  
            GetOperation eID, count, op Ow@v"L;jF!  
            If op.Type="ShiftZ" Then F)S PaC4  
                DeleteOperation eID,count ^]>aHz9  
                count=count-1 je%ldY]/@  
            End If m2xBS!fm  
            count=count+1 +6l]]*H  
        Wend 'N\&<dT>  
    gzf-)J  
        'Set new shift in X`:'i?(yj  
        op.Type = "ShiftZ" G>w+#{(  
        op.val1 = taq T_LLJ}6M  
        op.parent = parID + BL{@,zr  
        AddOperation eID, op eh(<m8I  
        Print "Set aqueous humor thickness = " & taq-0.55 dz-y}J11  
    )*|(i]  
        '************************************************************************* E7nFb:zlV  
        'Radius and conic constant of anterior lens 8]bz(P#  
        '************************************************************************* 6ZOy&fd,Ty  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) xq[Yg15d%  
        GetConic eID, entity, curv, conic D."=k{r.  
    ~Y7dH Dn  
        SetConic eID, entity, 1/Rant, CCant })Yv9],6  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant @0NJ{  
    fDh] tua  
        '************************************************************************* X(*!2uS  
        'Radius and conic constant of posterior lens Y3Oz'%B  
        '************************************************************************* %w ) +V  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) V5p0h~PK  
        GetConic eID, entity, curv, conic tU@zhGb  
    3^,QIG  
        SetConic eID, entity, 1/Rpost, CCpost tg\|?  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost e,gyQjJR  
    3@<zg1.9-  
        '************************************************************************* )OP){/   
        'Lens thickness (Position of posterior lens surface) :Ht; 0|[H  
        '************************************************************************* r.yK,  
    @Jn!0Y1_3  
        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) F #`=oM $5  
    <RXwM6G2  
        ' Delete any z-shift(s) &7>zURv  
        count = 0 HrM$NRhu  
        While GetOperationCount(eID)>count FX}Gt=  
            GetOperation eID, count, op 2C=Q8ayvX  
            If op.Type="ShiftZ" Then 8sOQ9  
                DeleteOperation eID,count *O~e T  
                count=count-1 G~,:2 o3  
            End If vXE0%QE'Q  
            count=count+1 iE].&>w  
        Wend b:W-l?  
    j;0vAf  
        'Set new z-shift sG7u}r  
        op.Type = "ShiftZ" Cu;5RSr2Z  
        op.val1 = tlens 78 f$6J q  
        op.parent = parID !l@zT}i??  
        AddOperation eID, op jgv`>o%<W  
        Print "Set lens thickness = " & tlens 9=`Wp6Gmn  
    i)a%!1Ar  
        '************************************************************************* L%"LlS g  
        'Lens index of refraction YJV%a  
        '************************************************************************* dT|vYK}\  
        eID = FindMaterial( "Lens" ) |{>ER,<-  
        GetModelMaterial eID, mat yx38g ca  
    zUJZ`seF  
        mat.Nd = nlens h^UKT`9vt  
        SetModelMaterial eID, mat IxZb$h[  
        Print "Set lens index of refraction = " & nlens C1kYl0 zR[  
    GL$De,V  
        '************************************************************************* baV>N[F&  
        'Pupil diameter Fh$slow4!  
        '************************************************************************* }_9,w;M$  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) =FP0\cQ.  
    co8"sz0(U  
        'Adjust pupil diameter (trimming volume inner hole)  as yZe  
    4<dcB@v  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" >Gml4vGK  
    i%m"@7.kk  
        ' Adjust pupil location to just in front of the lens k <iTjI*N  
        parID = FindFullName( "Geometry.Arizona Eye" ) m0n)dje  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) T;TA7{B  
        count = 0 Z<[<n0o1  
        While GetOperationCount(eID)>count bNs4 5hDP  
            GetOperation eID, count, op <7SpEVQ  
            If op.Type="ShiftZ" Then x!LQxoNF  
                DeleteOperation eID,count a8k;(/  
                count=count-1 `{k"8#4:qA  
            End If Hb} X-6N  
            count=count+1 W!Hm~9fz  
        Wend {9Y+.46S  
        op.Type = "ShiftZ" Dl(3wgA  
        op.val1 = taq-0.01 @hQlrq5c  
        op.parent = parID ~c^>54  
        AddOperation eID, op XR2~Q)@  
    MTg:dR_  
        Print "Set pupil diameter = " & pupilDiam 9vUO *D  
    'm1N/)F  
        'Update AZ Eye subassembly Description ^z1&8k"[^  
        eID = FindFullName( "Geometry.Arizona Eye" ) X+L) -d  
        GetEntity eID, entity DI+]D~N  
        entity.Description = "Accommodation = " & A & "D" 3$.deYa$R  
        SetEntity eID, entity ^k5ll=}  
    |F,R&<2  
        Update {"oxJ`z4  
        Print "DONE!" An;MVA  
         MFTk qbc  
    End Sub U*Ge<(v$  
    drzL.@h|  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: \$0F-=w`8  
    D]w!2k%V  
    Accommodation = 4 Diopters mMsTyM-f  
    Pupil Diameter = 4 mm Bj k]ZU0T  
    Set aqueous humor thickness = 2.81 Tc8 un.  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 kB?al#`  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 w0w G-R ?  
    Set lens thickness = 3.927 m'P1BLk  
    Set lens index of refraction = 1.42672 3vcO!6Z5  
    Set pupil diameter = 4 O+g3X5f+  
    DONE! rSXh;\MfB4  
     
    分享到