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    [技术]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: 2021-10-22
    简介 *aWh]x9TlU  
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    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。 lt:&lIW,3  
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    模型 =A'JIssk  
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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。 |ZifrkD=  
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    Table 1. AZ眼睛模型的定义
    +$(y2F7|u-  
    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. M!!vr8}  
    dnwzf=+>e  
    光源 W?E,"z  
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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。 n7Eh!<  
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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。 K8BlEF`  
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    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。 rDoMz3[w  
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    图2. 字母F光源的设定方法光 <zvtQ^{]  
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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 ELMz~vp  
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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。 S[/udA   
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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。 cyHbAtl  
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    图5. 视网膜重点采样规格设定
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    脚本 pG)dF@  
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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: s%Ph  
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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。 ~.U \Y  
    余下的脚本计算与屈光度有关的所有参数。 qyKR]%yzi  
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    分析 MwSfuP  
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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。 Q7v1xBM  
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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 Lp|n)29+du  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. &1 yErGXC  
    ..'"kX:5  
    Dim entity As T_ENTITY T5T[$%]6  
    Dim op As T_OPERATION Da6l =M  
    Dim mat As T_MODELMATERIAL \k=%G_W  
    Dim A As Double 0 .T5% _ /  
    Dim pupilDiam As Double #{?RE?nD  
    Dim eID As Long 0Db=/sJ>  
    Dim parID As Long wEI? 9  
    Dim count As Integer ZXiJ5BZ  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double Q\xDAOEL  
    Dim tlens As Double, nlens As Double ;Q/1l=Bn  
    Dim curv As Double, conic As Double Rx&.,gzj[  
    Dim ok As Long N;!!*3a9=  
    W[Z[o+7pK  
    Sub Main *nHMQ/uf  
    ScVbo3{m*T  
        '用户输入对话框 e!w2_6?3  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 I|;zGmg#k  
            TextBox 220,21,40,21,.TextBox1 'default: 0 En&gI`3n  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 7o!t/WEEq  
            OKButton 40,91,90,21 .s41Tc5u  
            CancelButton 190,91,90,21 mO]dP;,  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 <)sL8G9Y  
            TextBox 220,49,40,21,.TextBox2 'default: 4 ^vxNS[C`;  
        End Dialog e(b$LUV  
        Dim dlg As UserDialog ]E DC s?,  
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        ok = Dialog (dlg) U-,s/VQ?  
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        If ok=0 Then    'cancel button was pressed 4:b'VHW.  
            Print "Execution cancelled." " L,9.b  
            End l)jP!k   
        End If ?pd /cj^  
    {:n1|_r4Z  
        'Assign accommodation and pupil diameter & use defaults if field left empty 4N7|LxNNl_  
        If dlg.TextBox1 = "" Then %i?v)EW  
            A = 0           'Default accommodation {KEmGHC4R  
        Else o :4#Ak S  
            A = CDbl(dlg.TextBox1) }rs>B,=*k  
        End If ]8Xip/uE  
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        If dlg.TextBox2 = "" Then >$ro\/  
            pupilDiam = 4   'Default pupil diameter A =&`TfXu  
        Else mWn0"1C  
            pupilDiam = CDbl(dlg.TextBox2) 1B~Z1w  
        End If q68m*1?y  
    * y wr_9  
        Print " " TK~KM  
        Print "Accommodation = " & A & " Diopters" d(b~s2\i  
        Print "Pupil Diameter = " & pupilDiam & " mm" ST g} Z  
    $2}%3{<j  
        ' Calculate new parameters with accommodation #!#s7^%K&  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness "*MF=VB1  
    Vu E$-)&)  
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens M&Ln'BC  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens <viC~=k;  
    ]-SJ";aU  
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens X2:23j<  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens _bgv +/  
    Ra H1aS(  
        tlens = 3.767 + 0.04*A                  'Lens thickness [U"/A1p  
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        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction [9MbNJt 8~  
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        'Adjust parameters to account for accommodation &"J;  
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        '************************************************************************* Mk+G(4p  
        'Aqueous thickness (Position of Lens) ?Drq!?3PDc  
        '************************************************************************* ~ ^   
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) .`v%9-5v  
        GetCustomElement eID, entity 9zIqSjos"  
    *BF[thB:a  
        parID = FindFullName( "Geometry.Arizona Eye" ) difX7)\  
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        ' Delete any shift(s) in z Un T\6u  
        count = 0 u3tT=5.D  
        While GetOperationCount(eID)>count Sw5-^2x0'  
            GetOperation eID, count, op kBoQjOV`  
            If op.Type="ShiftZ" Then ~gNFcJuy  
                DeleteOperation eID,count uaU2D-ft"  
                count=count-1 fz2}M:u  
            End If #5'& |<  
            count=count+1 3hUP>F8  
        Wend 1v,R<1)&  
    6f ?,v5  
        'Set new shift in $z 5kA9  
        op.Type = "ShiftZ" M:iH7K  
        op.val1 = taq X:g#&e_  
        op.parent = parID G|8>Q3D  
        AddOperation eID, op y=EVpd  
        Print "Set aqueous humor thickness = " & taq-0.55 F*>#Xr~/  
    Q {BA`Q@V  
        '************************************************************************* /4+(eI7  
        'Radius and conic constant of anterior lens !=a]Awr\  
        '************************************************************************* K' <[kh:cl  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) BNI)y@E^X  
        GetConic eID, entity, curv, conic jiLJiYMg  
    CXyb8z4/+  
        SetConic eID, entity, 1/Rant, CCant 1KBGML-K3  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant 7\R"RH-  
    w1aoEo"S  
        '************************************************************************* MxKTKBxQ  
        'Radius and conic constant of posterior lens 10OkrNQ  
        '************************************************************************* k6RVP: V  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) 2+~gZxHq  
        GetConic eID, entity, curv, conic G43r85LO  
    yBIX<P)vE'  
        SetConic eID, entity, 1/Rpost, CCpost 1<_/Qu>V  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost +{I" e,Nk  
    K :~tZ  
        '************************************************************************* =adHP|S  
        'Lens thickness (Position of posterior lens surface) ftl?x'P%  
        '************************************************************************* yO!M$aOn/  
    %d(= >  
        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) :2,NKdD  
    B.~] 7H5"(  
        ' Delete any z-shift(s) |g!d[ct]  
        count = 0 L G5_\sY!  
        While GetOperationCount(eID)>count <'SS IMr  
            GetOperation eID, count, op *h3iAcM8  
            If op.Type="ShiftZ" Then ,-8 -Y>[  
                DeleteOperation eID,count }*xjO/Ey  
                count=count-1 ?# _{h  
            End If k,k>w#&  
            count=count+1 U,;796h  
        Wend \]5I atli  
    $j<KXR  
        'Set new z-shift 7}6CUo  
        op.Type = "ShiftZ" [Z#Sj=z  
        op.val1 = tlens #9!7-!4pW  
        op.parent = parID g<.Is V  
        AddOperation eID, op pq&[cA_w  
        Print "Set lens thickness = " & tlens c"Vp5lo0  
    xz.Jmv  
        '************************************************************************* -C3[:g  
        'Lens index of refraction u;c WIRG  
        '************************************************************************* yGAFQ|+  
        eID = FindMaterial( "Lens" ) Y68A+ B.  
        GetModelMaterial eID, mat Xo/H+[;X  
    Rb& 9!z  
        mat.Nd = nlens m|{^T/kIbQ  
        SetModelMaterial eID, mat ,qv\Y]  
        Print "Set lens index of refraction = " & nlens  -D'XxOI  
    `?3f76}h  
        '************************************************************************* kmc"`Ogotw  
        'Pupil diameter Y7r;}^+WY  
        '************************************************************************* NjOUe?BQ  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) jHn7H)F8  
    $/ IFSB9  
        'Adjust pupil diameter (trimming volume inner hole) tkr&Fs"t+  
    [X!w@d= i  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" gK({InOP  
    w]{c*4o  
        ' Adjust pupil location to just in front of the lens PgT8 1u  
        parID = FindFullName( "Geometry.Arizona Eye" ) 111A e *U  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) H)7v$A,5%  
        count = 0 /]!2 k9u\  
        While GetOperationCount(eID)>count igk<]AwxS  
            GetOperation eID, count, op T>rmm7F  
            If op.Type="ShiftZ" Then Q+9:]Bt  
                DeleteOperation eID,count ~i>DF`w$  
                count=count-1 prz COw  
            End If -8Mb~Hfl0  
            count=count+1 U{M3QOF  
        Wend ?{B5gaU9F  
        op.Type = "ShiftZ" nM2<u[{gF  
        op.val1 = taq-0.01 NGl 8*Af   
        op.parent = parID k)S1Zs~G  
        AddOperation eID, op ~a`[p\  
    0r1GGEW`s  
        Print "Set pupil diameter = " & pupilDiam __.MS6"N  
    C:5- h(#  
        'Update AZ Eye subassembly Description qfE0J;e   
        eID = FindFullName( "Geometry.Arizona Eye" ) u*)/e9C  
        GetEntity eID, entity }" vxYB!h3  
        entity.Description = "Accommodation = " & A & "D" *0!p_Hco  
        SetEntity eID, entity J~]@#=,v  
    =N\; ?eF(  
        Update L4m Vk  
        Print "DONE!" xS/W}-dPv  
         /#M1J:SV  
    End Sub D~ Y6%9  
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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: S1U0sP@o  
    Nb&j?./  
    Accommodation = 4 Diopters ya8p 4N{_  
    Pupil Diameter = 4 mm aM;SE9/U  
    Set aqueous humor thickness = 2.81 iv *$!\Cd  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 @NRN#~S,_]  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 <7\j\`  
    Set lens thickness = 3.927 Nbd4>M<  
    Set lens index of refraction = 1.42672 ) bI.K[0^  
    Set pupil diameter = 4 1~L;S  
    DONE! P|$n   
     
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