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    [分享]Arizona眼睛模型 [复制链接]

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    离线infotek
     
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    只看楼主 倒序阅读 楼主  发表于: 2020-12-09
    简介 T%KZV/  
    tk<dp7y7  
    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。 e\k=T}  
    G|Ic6Sd  
    模型 _C&2-tnp  
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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。 u1ggLH!U  
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    Table 1. AZ眼睛模型的定义
    ?BQZ\SXU  
    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. q>%KIBh(  
    $/5Jc[Ow  
    光源 HW"|Hm$Y(  
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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。 - P1OD)B  
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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。 ^T)HRT-k  
    d%81}4f:  
    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。 O!lZ%j@%  
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    图2. 字母F光源的设定方法光 iT%aAVs  
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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 V z8o  
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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。  ^vYH"2  
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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。 {^Vkxf]  
    rF2`4j&!  
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    图5. 视网膜重点采样规格设定
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    脚本 (8qMF{  
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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: JaXT B"e  
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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。 BdG~y1%:  
    余下的脚本计算与屈光度有关的所有参数。 Z%y>q|:  
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    分析 a57Y9.H`o  
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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。 iN"kv   
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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 >E|@3g +2  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. ^G[xQcM73  
    Sav]Kxq{  
    Dim entity As T_ENTITY lTv I;zy  
    Dim op As T_OPERATION zIi|z}WJ  
    Dim mat As T_MODELMATERIAL =dHM)OXD"  
    Dim A As Double WM.JoQ  
    Dim pupilDiam As Double S 3Tp__  
    Dim eID As Long (8TB*BhQ_  
    Dim parID As Long {(w/_C9  
    Dim count As Integer K~H)XJFF  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double PBbJfm  
    Dim tlens As Double, nlens As Double <|c n Qj*  
    Dim curv As Double, conic As Double }=z_3JfO  
    Dim ok As Long 'C8VD+p  
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    Sub Main ]>E*s3h  
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        '用户输入对话框 "^F#oo%L  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 SUINV_>7  
            TextBox 220,21,40,21,.TextBox1 'default: 0 '$YB -  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 U&yXs'3a&  
            OKButton 40,91,90,21 15+>W4v  
            CancelButton 190,91,90,21 E0!}~Z)  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 `uM:>  
            TextBox 220,49,40,21,.TextBox2 'default: 4 z8_m<uewz  
        End Dialog seC]=UJh#>  
        Dim dlg As UserDialog 4 sasf94  
    &)JQ6J_|\  
        ok = Dialog (dlg) I|9(*tq)  
    7yD=~l\Bbs  
        If ok=0 Then    'cancel button was pressed Q1jU{  
            Print "Execution cancelled." @X4Ur+d  
            End PElC0 qCn[  
        End If ."&,_F  
    GL[#XB>n  
        'Assign accommodation and pupil diameter & use defaults if field left empty <nlZ?~%}  
        If dlg.TextBox1 = "" Then rl4B(NZi}  
            A = 0           'Default accommodation ig<Eyr  
        Else Tm(XM<  
            A = CDbl(dlg.TextBox1) :i_818h!?[  
        End If _x&;Fa%  
    qYR $5  
        If dlg.TextBox2 = "" Then wwrP7T+d  
            pupilDiam = 4   'Default pupil diameter dU1w)Y  
        Else W^npzgDCo  
            pupilDiam = CDbl(dlg.TextBox2) :,g nOfV=  
        End If c[\ :^w^I6  
    |x@)%QeC  
        Print " " mbB,j~;^6H  
        Print "Accommodation = " & A & " Diopters" x;)bp7  
        Print "Pupil Diameter = " & pupilDiam & " mm" ;Pf |\q  
    ' N^\9X0  
        ' Calculate new parameters with accommodation ! Ob  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness =M'M/vKD  
    rqW[B/a{  
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens HM57b>6  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens A'r 3%mC  
    psyxNM=dN#  
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens kP~'C'5Ys  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens 59mNb:<  
    oJa6)+b(3  
        tlens = 3.767 + 0.04*A                  'Lens thickness bwo-9B  
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        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction @)PA9P |  
    xxkU u6x#  
        'Adjust parameters to account for accommodation !+T\}1f7d  
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        '************************************************************************* 6hDK;J J&  
        'Aqueous thickness (Position of Lens) @)s;u}H  
        '************************************************************************* fHhm)T8KB  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) uw!  
        GetCustomElement eID, entity h07Z.q ;  
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        parID = FindFullName( "Geometry.Arizona Eye" ) sqTBlP  
    ?&;d#z*4  
        ' Delete any shift(s) in z J$6h% Eyo  
        count = 0 w}+#w8hu  
        While GetOperationCount(eID)>count GslUN% UJr  
            GetOperation eID, count, op j_N><_Jc  
            If op.Type="ShiftZ" Then [ []'U'  
                DeleteOperation eID,count xw_VK1  
                count=count-1 ?xEQ'(UBQ  
            End If {Hncm  
            count=count+1 S Y\ UuZ  
        Wend (ii6w d< *  
    [-o`^;  
        'Set new shift in HR)Dz~Obw  
        op.Type = "ShiftZ" pRI<L'  
        op.val1 = taq mr:;Wwd  
        op.parent = parID RtVy^~=G  
        AddOperation eID, op ~3byAL  
        Print "Set aqueous humor thickness = " & taq-0.55 O@JgVdgf  
    ,XT#V\qne  
        '************************************************************************* )E;+C2G  
        'Radius and conic constant of anterior lens ~RcI+jR)  
        '************************************************************************* 1d/-SxhZ  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) ] jbQou@  
        GetConic eID, entity, curv, conic Q'-V\G)11  
    [A$5~/Q{U1  
        SetConic eID, entity, 1/Rant, CCant h(}$-'g  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant Eu/~4:XN  
    V3;4,^=6Dd  
        '************************************************************************* `$og]Dn;  
        'Radius and conic constant of posterior lens $=dp)  
        '************************************************************************* a*LT<N  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) u] C/RDTH  
        GetConic eID, entity, curv, conic u@|izRk  
    D'V0b"  
        SetConic eID, entity, 1/Rpost, CCpost 9pPb]v,6  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost _XT],"  
    xml@]N*D#E  
        '************************************************************************* RjS;Ck@;  
        'Lens thickness (Position of posterior lens surface) o(xRq;i  
        '************************************************************************* =Y`P}vI]w%  
    '\%c"?  
        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) `5 py6,  
    Zgp]s+%E  
        ' Delete any z-shift(s) mv@cGdxu  
        count = 0 ?pgdj|"a  
        While GetOperationCount(eID)>count <hi@$.u_Q^  
            GetOperation eID, count, op ( Lj{V}^  
            If op.Type="ShiftZ" Then +|.}oL^}G  
                DeleteOperation eID,count 5 e:Urv77  
                count=count-1 ;t47cUm6j  
            End If \m-fLX  
            count=count+1 Gd0-}4S?  
        Wend &tY3nr  
    ;9r Z{'i+|  
        'Set new z-shift {Z[yY6Nu  
        op.Type = "ShiftZ" rQiX7  
        op.val1 = tlens Z=%+U _,  
        op.parent = parID \8\)5#?  
        AddOperation eID, op -_=0PW5{  
        Print "Set lens thickness = " & tlens v+-f pl&  
    eeIh }t>[  
        '************************************************************************* o?\)!_Z|  
        'Lens index of refraction <%eY>E  
        '************************************************************************* kg[u@LgvoN  
        eID = FindMaterial( "Lens" ) 'Z2:u!E  
        GetModelMaterial eID, mat EM/NT/  
    y7SOz'd  
        mat.Nd = nlens jB }O6u[%  
        SetModelMaterial eID, mat 7t-j2 n`<  
        Print "Set lens index of refraction = " & nlens 9@AGx<S1  
    3nuf3)  
        '************************************************************************* M,V+bt  
        'Pupil diameter 70_T;K6  
        '************************************************************************* J5LP#o(V  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) Vzy]N6QT{  
    xO'I*)  
        'Adjust pupil diameter (trimming volume inner hole) (^GVy=  
    lJ]r %YlF  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" '|^LNAx  
    N_<sCRd]9  
        ' Adjust pupil location to just in front of the lens /^96|  
        parID = FindFullName( "Geometry.Arizona Eye" ) -Hzn7L  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) FzmCS@yA  
        count = 0 >(z{1'f{  
        While GetOperationCount(eID)>count qG"|,bA  
            GetOperation eID, count, op  iU^ 4a  
            If op.Type="ShiftZ" Then 2'g< H-[  
                DeleteOperation eID,count Hxr2Q]c?u  
                count=count-1 q! W ~>c!  
            End If nPq\J~M  
            count=count+1 j)\&#g0u6  
        Wend ~WuElns  
        op.Type = "ShiftZ" Qu]0BVIe  
        op.val1 = taq-0.01 475yX-A  
        op.parent = parID mm$D1=h{|  
        AddOperation eID, op RBx`<iBe  
    I^Ichn  
        Print "Set pupil diameter = " & pupilDiam !s,<h U#  
    &Pxt6M\d  
        'Update AZ Eye subassembly Description k Fv\V   
        eID = FindFullName( "Geometry.Arizona Eye" ) 1=#r$H  
        GetEntity eID, entity V5rnI\:7  
        entity.Description = "Accommodation = " & A & "D" T Uhp  
        SetEntity eID, entity <mHptgd,  
    $N;!. 5lX3  
        Update t )Z2"_5  
        Print "DONE!" 3DK^S2\zBm  
         V2es.I  
    End Sub %9M; MK  
    qt]QO1pAd  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: +C;ZO6%w  
    Y=X"YH|  
    Accommodation = 4 Diopters OdQ >h$ gZ  
    Pupil Diameter = 4 mm 7^sU/3z  
    Set aqueous humor thickness = 2.81 0vG}c5;F  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 OfTcF_%  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 *wt yyP@  
    Set lens thickness = 3.927 g|<)J-`Q  
    Set lens index of refraction = 1.42672 2BH>TmS  
    Set pupil diameter = 4 sxL;o >{  
    DONE! P@9>4}r$  
    &_4A6  
    5K'EuI)  
    QQ:2987619807 QXJD' c  
     
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