切换到宽版
  • 广告投放
  • 稿件投递
  • 繁體中文
    • 1962阅读
    • 0回复

    [技术]Arizona眼睛模型 [复制链接]

    上一主题 下一主题
    在线infotek
     
    发帖
    6429
    光币
    26290
    光券
    0
    只看楼主 倒序阅读 楼主  发表于: 2021-10-22
    简介  f>s?4  
    M[z)6 .  
    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。 2P]L9'N{Y  
    @"Z7nJX  
    模型 _{Sm k [  
    / }Rz=&  
    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。 Cn>ADWpT&  
     Ug:\  
    Table 1. AZ眼睛模型的定义
    dgDy5{_  
    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. $ ''9K  
    !r`,=jK"  
    光源 ifo7%XPcg  
    50 A^bbid  
    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。 l^d[EL+  
    ]r3Kg12Mi  
    O:{U^K:*  
    图1. 光源和提示信息使用
    X*Z8CM_  
    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。 4O:W#bx  
    ~V/?H!r'{}  
    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。 t6BHGX{o  
    <" @zn  
    图2. 字母F光源的设定方法光 oG7q_4+&  
    kNT}dv]<  
    图3. 字母F在视网膜上位置点列图
    }<z_Q_b+e  
    视网膜的散射 `]LSbS  
    l<Q>N|1#k%  
    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。 '+ xu#R  
    DI`%zLDcY  
    0 a~HiIh  
    图4. 视网膜朗伯散射设定
    7~ztwL  
    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。 ( Y+N@d  
    |v[Rp=?]  
    bu&t'?z x!  
    图5. 视网膜重点采样规格设定
    p#SY /KIw  
    脚本 0aoHKeP  
    5/gDK+%4D(  
    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: *WE1;msr  
    JbO ~n )%x  
    图6. 用户对话框的创建与编辑
    _SACqamo5s  
    图7. 用户对话框编辑器
    (_r EAEo  
    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。 '!P"xBVAu  
    余下的脚本计算与屈光度有关的所有参数。 &TG5rUUg  
    pG^}Xf2a  
    分析 cECi')  
    n,~;x@=5  
    屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 .D4bqL  
    w[_x(Ojq;  
    图7. 字母F在视网膜上颜色分析
    PY3ps2^K.  
    脚本代码 NZN-^ >  
    0t#g }  
    Option Explicit     'Remove this to enable non-dimensioned variables to be used. ES<{4<Kpx  
    5efxEt>U  
    Dim entity As T_ENTITY \V2,pi8'v  
    Dim op As T_OPERATION &x-TW,#Ks  
    Dim mat As T_MODELMATERIAL vG^#Sfgtw  
    Dim A As Double pPVRsXy  
    Dim pupilDiam As Double o{*ay$vA]  
    Dim eID As Long )' xETA  
    Dim parID As Long =2y8 CgLj  
    Dim count As Integer pium$4l2#  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double x'Pi5NRE  
    Dim tlens As Double, nlens As Double kCUT ^  
    Dim curv As Double, conic As Double 19(Dj&x  
    Dim ok As Long u@p?  
    hNXBVIL<&  
    Sub Main NZu)j["  
    %~j2 ('Y  
        '用户输入对话框 <DH*~tLp2  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 7%OKH<i\2<  
            TextBox 220,21,40,21,.TextBox1 'default: 0 *QM~O'WhD  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 [oc~iDx%W  
            OKButton 40,91,90,21 4R>zPEo  
            CancelButton 190,91,90,21 Je4Z(kj 0  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 kW6%32  
            TextBox 220,49,40,21,.TextBox2 'default: 4 rZ_>`}O2  
        End Dialog oK+ WF  
        Dim dlg As UserDialog IfDx@?OB  
    8_d -81Dd  
        ok = Dialog (dlg) nzX@:7g  
    Uz%Z&K  
        If ok=0 Then    'cancel button was pressed ? 8 1X  
            Print "Execution cancelled." Q\{x)|{$  
            End [O-sVYB  
        End If d~ng6pA  
    vMSW$Bx ;  
        'Assign accommodation and pupil diameter & use defaults if field left empty >+cVs:  
        If dlg.TextBox1 = "" Then %'L;FPxB  
            A = 0           'Default accommodation 'ul\Q `N3  
        Else l{P\No  
            A = CDbl(dlg.TextBox1) DE{h5-g  
        End If 0MIUI<;j  
    AB.(CS=i  
        If dlg.TextBox2 = "" Then v7trr W}  
            pupilDiam = 4   'Default pupil diameter <c,~aq#W'  
        Else d]0a%Xh[  
            pupilDiam = CDbl(dlg.TextBox2) F.q|x|9j  
        End If Jd 3@cLCe-  
    :ipoD%@  
        Print " " Q^eJ4{Ya:  
        Print "Accommodation = " & A & " Diopters" 3$M3Q]z  
        Print "Pupil Diameter = " & pupilDiam & " mm" 9w;?-  
    T bE:||r?^  
        ' Calculate new parameters with accommodation (7$$;  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness /jD-\,:L}  
    fW0$s`  
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens ^E>CGGS4  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens d-!<C7O}  
    ]]iO- }  
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens {^q)^<#JT  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens Ar, 9U9  
    0x)dnq\  
        tlens = 3.767 + 0.04*A                  'Lens thickness 2BB<mv K4  
    !FG%2L4?,5  
        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction t Y1Et0  
    Mpx/S<Z  
        'Adjust parameters to account for accommodation 'Am-vhpm  
    x%BF {Sw  
        '************************************************************************* : iY$82wQ  
        'Aqueous thickness (Position of Lens) 6`nR5fh  
        '************************************************************************* >w'$1tc?+F  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) X, fu!  
        GetCustomElement eID, entity @YL}km&Fw  
    KS>$`ax,  
        parID = FindFullName( "Geometry.Arizona Eye" ) ahIE;Y\j'  
    QocQowz  
        ' Delete any shift(s) in z setL dEi  
        count = 0 ~a+NJ6e1  
        While GetOperationCount(eID)>count y8s=\`~PR  
            GetOperation eID, count, op LPE)  
            If op.Type="ShiftZ" Then FRyPeZR  
                DeleteOperation eID,count oNRG25  
                count=count-1 *v #/Y9}  
            End If ]W9B6G_  
            count=count+1 ]A:( L9  
        Wend Pern*x9$  
    o'UHStk  
        'Set new shift in `bP?o  
        op.Type = "ShiftZ" C|e+0aW  
        op.val1 = taq |XcH]7Ai"  
        op.parent = parID SPwPCI1?  
        AddOperation eID, op W,NL*($^  
        Print "Set aqueous humor thickness = " & taq-0.55 Gt^d;7x]  
    QUP|FIpZ  
        '************************************************************************* %!W%#U0  
        'Radius and conic constant of anterior lens \|+/0 USn  
        '************************************************************************* M<oA<#IW  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) h[U7!aM  
        GetConic eID, entity, curv, conic #( uj$[o  
    ' iQ9hQjD  
        SetConic eID, entity, 1/Rant, CCant nm):SEkC  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant 9O >z4o  
    sJ6a7A8)  
        '************************************************************************* k,_i#9 X  
        'Radius and conic constant of posterior lens GXeAe}T  
        '************************************************************************* 8R/ *6S=&  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) +i)AS0?d  
        GetConic eID, entity, curv, conic {8m1dEC^@Q  
    8eX8IR!K9  
        SetConic eID, entity, 1/Rpost, CCpost e[4V%h  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost %cj58zO |y  
    QMb^&?;s  
        '************************************************************************* nEVbfNo0  
        'Lens thickness (Position of posterior lens surface) 5; f\0<-  
        '************************************************************************* )F E8D  
    [$:@X V(  
        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) H-a^BZ&iU  
    Xiju"Cup"  
        ' Delete any z-shift(s) SsRVd^=;x  
        count = 0 ay[ZsQC  
        While GetOperationCount(eID)>count PW^ 8;[\QP  
            GetOperation eID, count, op 5B|,S1b  
            If op.Type="ShiftZ" Then EIK*49b2  
                DeleteOperation eID,count xMsGs  
                count=count-1 G+C} <S}  
            End If Q?]w{f(  
            count=count+1 $3:X+X  
        Wend Bm<^rhJ9  
    |8'B/ p=  
        'Set new z-shift ~,Mr0  
        op.Type = "ShiftZ" 8r^j P.V  
        op.val1 = tlens f !!P  
        op.parent = parID |D(&w+(  
        AddOperation eID, op "OJr*B  
        Print "Set lens thickness = " & tlens `vX4! @Tw  
    cuMc*i$w!  
        '************************************************************************* 4tnjXP8  
        'Lens index of refraction :p$EiR  
        '************************************************************************* WVkG 2  
        eID = FindMaterial( "Lens" ) &%:*\_2s  
        GetModelMaterial eID, mat -fQX4'3R  
    3.~h6r5-  
        mat.Nd = nlens x Ty7lfSe  
        SetModelMaterial eID, mat N1s.3`  
        Print "Set lens index of refraction = " & nlens #'iPDRYy  
    c.-cpFk^L&  
        '************************************************************************* `$f2eB&   
        'Pupil diameter iP,v=pS6  
        '************************************************************************* 4JSZ0:O  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) &/DOO ^  
    o oDdV >  
        'Adjust pupil diameter (trimming volume inner hole) 8.-S$^hj~6  
    &58 {  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" rFO_fIJno  
    ;,v.(Z ic  
        ' Adjust pupil location to just in front of the lens QSv^l-<  
        parID = FindFullName( "Geometry.Arizona Eye" ) H}a)^90_  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) *@~`d*d  
        count = 0 p4y6R4kyT  
        While GetOperationCount(eID)>count >F~ITk5`Oo  
            GetOperation eID, count, op sU0Stg8&b  
            If op.Type="ShiftZ" Then Vp\80D&  
                DeleteOperation eID,count 3Cd<p[%3#,  
                count=count-1 q>P[nz%  
            End If ^+URv  
            count=count+1 unJ iE!  
        Wend =!YP$hfY  
        op.Type = "ShiftZ" bu_/R~&3{  
        op.val1 = taq-0.01 nrF!;:x  
        op.parent = parID )FV6,  
        AddOperation eID, op Dl&PL  
    [~!.a\[RW  
        Print "Set pupil diameter = " & pupilDiam 7^&lbzVbm(  
    S;>4i!Mb ^  
        'Update AZ Eye subassembly Description @OY1`Eu O  
        eID = FindFullName( "Geometry.Arizona Eye" ) [' ?^>jfr  
        GetEntity eID, entity (;C$gnr.C  
        entity.Description = "Accommodation = " & A & "D" gu^_iU  
        SetEntity eID, entity |$Qp0vOA}  
    f!mE1,eBEe  
        Update U{HyxZ|q<  
        Print "DONE!" :&qC<UD  
         5"$e=y/  
    End Sub $]nVr(OZ_  
    QN3 qF|))  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: bG "6pU  
    Tw}@+-  
    Accommodation = 4 Diopters :a=ro2NH  
    Pupil Diameter = 4 mm ?<Z)*CF)  
    Set aqueous humor thickness = 2.81 vwm|I7/w  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 5Ws5X_?d  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 8I<_w4fC  
    Set lens thickness = 3.927 =jsx (3V   
    Set lens index of refraction = 1.42672 Av@& hD\  
    Set pupil diameter = 4 tN[St  
    DONE! yB 1I53E  
     
    分享到