切换到宽版
  • 广告投放
  • 稿件投递
  • 繁體中文
    • 2114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
    6535
    光币
    26824
    光券
    0
    只看楼主 倒序阅读 楼主  发表于: 2021-10-22
    简介 YV%y KD  
    z)tULnR8  
    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。 qwhDv+o  
    5Z;iK(>IX  
    模型 HxUJ 0Q  
    \ -n&z;`  
    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。 p : {,~ 1  
    Ml,~@} p  
    Table 1. AZ眼睛模型的定义
    ]S0=&x@,  
    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. uNKf!\Y  
    @LSfP  
    光源 t,NE`LC  
    _tlr8vL  
    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。 , wXixf2  
    O0l1AX"  
    \jmT#Gt`9  
    图1. 光源和提示信息使用
    >o:y.2yCe  
    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。 [n]C  
    h\T}$jgfWm  
    在往下看是内置的脚本用来修改屈光度,使其为4(250mm),光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 QLxe1[qI  
    kxQ al  
    图2. 字母F光源的设定方法光 M{z&h>  
    s4uZ>  
    图3. 字母F在视网膜上位置点列图
    w`GjQIA  
    视网膜的散射 :(Ak:  
    LbkQuq/d  
    在散射文件中,有一个名为“Retina surface”的72%的反射型朗伯散射,它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射,改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 }!uwWBw`  
    n\GN}?4  
    ^*G UcQ$  
    图4. 视网膜朗伯散射设定
    ?`= <*{_o  
    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。 {K N7Y"AI  
    Skl:~'W.&|  
    uK%0,!q  
    图5. 视网膜重点采样规格设定
    bg\9Lbjr  
    脚本 dvE~EZcS  
    &( ZEs c  
    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: Aflf]G1  
    M1z ?E@kz  
    图6. 用户对话框的创建与编辑
    :jy}V'bn$  
    图7. 用户对话框编辑器
    yi8AzUW cW  
    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。 B.A;1VE5  
    余下的脚本计算与屈光度有关的所有参数。 x.9[c m-!  
    |Ed?s  
    分析 FM=XoMP q  
    wG&Z7C b  
    屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 |J"\~%8  
    e/uLBZ  
    图7. 字母F在视网膜上颜色分析
    !a4`SjOgu  
    脚本代码 _WGWU7h  
    !q~f;&rg  
    Option Explicit     'Remove this to enable non-dimensioned variables to be used. c8N pk<  
    2Akh/pb  
    Dim entity As T_ENTITY ]n! oa  
    Dim op As T_OPERATION \#v(f2jPF  
    Dim mat As T_MODELMATERIAL +4n}H}9l  
    Dim A As Double $0cE iq?Hf  
    Dim pupilDiam As Double x*!*2{  
    Dim eID As Long 8Ow#W5_3|  
    Dim parID As Long \'r;1W  
    Dim count As Integer 8%`h:fE  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double SmS6B5j\R  
    Dim tlens As Double, nlens As Double ?AVnv(_  
    Dim curv As Double, conic As Double "yK)9F[9Mo  
    Dim ok As Long \qDY0hIv t  
    [x%8l,O #l  
    Sub Main th{ie2$  
    nf-6[dg  
        '用户输入对话框 )8taMC:H^  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 9e7):ZupO  
            TextBox 220,21,40,21,.TextBox1 'default: 0 _&N:%;9uD  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 _} j6Pw'  
            OKButton 40,91,90,21 %EYh*g{G  
            CancelButton 190,91,90,21 sC ?e%B  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 k~2FlRoC^  
            TextBox 220,49,40,21,.TextBox2 'default: 4 xouBBb=  
        End Dialog /eBcPu"[Vb  
        Dim dlg As UserDialog 5Z(q|nn7P  
    -M+o;  
        ok = Dialog (dlg) |RBL5,t^  
    gk}.L E  
        If ok=0 Then    'cancel button was pressed ]D^zTl3=q  
            Print "Execution cancelled." =I9hGj6  
            End a *bc#!e  
        End If /GO((v+J  
    H? %I((+  
        'Assign accommodation and pupil diameter & use defaults if field left empty + jN)$Y3Ya  
        If dlg.TextBox1 = "" Then +O1=Ao  
            A = 0           'Default accommodation J! "m{ 8-  
        Else x}f)P  
            A = CDbl(dlg.TextBox1) vos-[$  
        End If a ~k*Gd(  
    >J,IxRGi  
        If dlg.TextBox2 = "" Then 3!Mb<W.3  
            pupilDiam = 4   'Default pupil diameter :4>LtfA  
        Else Pk8(2fAYk  
            pupilDiam = CDbl(dlg.TextBox2) 6|Crc$4l  
        End If rc}=`D`  
    ()fYhk|W  
        Print " " )LL.fPic  
        Print "Accommodation = " & A & " Diopters" :U faMe5  
        Print "Pupil Diameter = " & pupilDiam & " mm" >p3S,2SM  
    D7v.Xq|  
        ' Calculate new parameters with accommodation :io~{a#.2\  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness j[=P3Z0q  
    ^C8f(  
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens '<wZe.Q!  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens s{fL~}Yz  
    i;J*9B_U  
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens rD>q/,X=\  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens ` kZ"5}li  
    Z"G?+gM@  
        tlens = 3.767 + 0.04*A                  'Lens thickness ]2z Gb5s"  
    UFE~6"t(  
        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction Tt{ft?H71  
    5?TjuGc  
        'Adjust parameters to account for accommodation ?o(Y\YJf  
    ,27=i>>  
        '************************************************************************* 6w0r)  
        'Aqueous thickness (Position of Lens) "; ?^gA  
        '************************************************************************* Bn Nu/02.=  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) mTa^At"  
        GetCustomElement eID, entity Csm23QLsg)  
    wHErF #xo  
        parID = FindFullName( "Geometry.Arizona Eye" ) ZQ~EaI9R  
    h-@_.&P0e  
        ' Delete any shift(s) in z d`KW]HJw  
        count = 0 "oCXG`.k&  
        While GetOperationCount(eID)>count +B OuU#  
            GetOperation eID, count, op {Yt i  
            If op.Type="ShiftZ" Then zh4m`}p  
                DeleteOperation eID,count M5B?`mTl  
                count=count-1 T) cbpkH4  
            End If 84-7!< 6i  
            count=count+1 YifTC-Q;  
        Wend m6 a @Y<  
    -\~x^5K  
        'Set new shift in T(bFn?  
        op.Type = "ShiftZ" 7/Mhz{o;W  
        op.val1 = taq EJO6k1  
        op.parent = parID [M:BJ%*  
        AddOperation eID, op OSCeTkR  
        Print "Set aqueous humor thickness = " & taq-0.55 :sek MNM  
    5,?Au  
        '************************************************************************* YRP$tz+ _  
        'Radius and conic constant of anterior lens @33-UP9o  
        '************************************************************************* PciiDh~/  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) +tFl  
        GetConic eID, entity, curv, conic qgsKbsl  
    2<+9lk  
        SetConic eID, entity, 1/Rant, CCant 2d-C}&}L\  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant T8J[B( )L  
    W_G'wU3R  
        '************************************************************************* Gw Z(3  
        'Radius and conic constant of posterior lens mdIa`OZr  
        '************************************************************************* 6V c&g  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) jiAN8t*P  
        GetConic eID, entity, curv, conic <7sGA{  
    )Waz bT@  
        SetConic eID, entity, 1/Rpost, CCpost v"smmQZik  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost =ZN~*HLl}  
    xn 4-^2  
        '************************************************************************* T=->~@5  
        'Lens thickness (Position of posterior lens surface) S%m$LM]NCg  
        '************************************************************************* a(`@u&]WZ  
    qQ UCK  
        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) s:#\U!>0`  
    v/WvT!6V`  
        ' Delete any z-shift(s) ].<B:]:,  
        count = 0 G2}e@L0  
        While GetOperationCount(eID)>count AIFI@#3  
            GetOperation eID, count, op K ZSvT{  
            If op.Type="ShiftZ" Then sYb(g'W*'  
                DeleteOperation eID,count YV>]c9!q  
                count=count-1 B>M@'  
            End If -V)DKf"f  
            count=count+1 Q'S"$^~{  
        Wend {z/Y~rf  
     ,L}  
        'Set new z-shift K0O&-v0"1  
        op.Type = "ShiftZ" Ljjuf=]  
        op.val1 = tlens !z]2+  
        op.parent = parID d% :   
        AddOperation eID, op * "Z5bKL  
        Print "Set lens thickness = " & tlens <)\  
    ^5 sO;vf  
        '************************************************************************* B#K{Y$!v  
        'Lens index of refraction WD7IF+v  
        '************************************************************************* td#B$$[  
        eID = FindMaterial( "Lens" ) &z(E-w/S  
        GetModelMaterial eID, mat /&#Gh?z  
    Qs5^kddz=  
        mat.Nd = nlens :v!e8kM\x  
        SetModelMaterial eID, mat GF-\WD  
        Print "Set lens index of refraction = " & nlens d}t7bgk'j  
    e$3{URg  
        '************************************************************************* 3,<$z1Jm  
        'Pupil diameter sox0:9Oqnf  
        '************************************************************************* 54%@q[-  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) ;NHZD  
    r2]KP(T8|  
        'Adjust pupil diameter (trimming volume inner hole) E9IU,P6a  
    Nf<mgOAT1  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" %cl=n!T  
    M_wj>NXZ  
        ' Adjust pupil location to just in front of the lens jr<`@  
        parID = FindFullName( "Geometry.Arizona Eye" ) 1]i{b/ 4  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) As;@T$G  
        count = 0 *|T]('xwC  
        While GetOperationCount(eID)>count Pu=,L#+FN  
            GetOperation eID, count, op L:ox$RU  
            If op.Type="ShiftZ" Then $-}a<UFE;  
                DeleteOperation eID,count <n)J~B^  
                count=count-1 [%alnY  
            End If ,X05&'@Z  
            count=count+1 U$fh ~w<[  
        Wend ([r4N#lx  
        op.Type = "ShiftZ" ]c.1&OB7o  
        op.val1 = taq-0.01 1'[RrJ$Q  
        op.parent = parID ke sg]K  
        AddOperation eID, op -r6cK,WVU  
    ")t ^!x(v  
        Print "Set pupil diameter = " & pupilDiam GEdWpYKS-`  
    PE~umY]  
        'Update AZ Eye subassembly Description H <|ilL'fX  
        eID = FindFullName( "Geometry.Arizona Eye" ) 3$u 3ssOL  
        GetEntity eID, entity 78}QaE  
        entity.Description = "Accommodation = " & A & "D" qW1d;pt  
        SetEntity eID, entity wE.CZ% f  
    Vy:I[@6@+  
        Update ' DZYN {}  
        Print "DONE!" \{HbL,s  
         zq=X;}qYj  
    End Sub sw={bUr6G`  
    *v}8n95*2  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: o"te7nBI  
    "B~c/%#PH  
    Accommodation = 4 Diopters ADTx _tE  
    Pupil Diameter = 4 mm Nq`@ >Ml  
    Set aqueous humor thickness = 2.81 PgeC\#;9  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 "0Wi-52=V  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 M7O5uW`  
    Set lens thickness = 3.927 CWP),]#n  
    Set lens index of refraction = 1.42672 EqN<""2  
    Set pupil diameter = 4 JumZ>\'p(  
    DONE! Z`UwXp_s  
     
    分享到