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    [分享]Arizona眼睛模型 [复制链接]

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    只看楼主 倒序阅读 楼主  发表于: 2020-12-09
    简介 DZ5QC aA  
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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。 ~fR-cXj"  
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    模型 DfV'1s4y  
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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。 *e}1KcJ  
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    Table 1. AZ眼睛模型的定义
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    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. kb2M3%6 V  
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    光源 [[gfR'79{  
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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。 j^qI~|#  
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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。 =?s0.(;  
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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。 Q3|I.I e  
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    图2. 字母F光源的设定方法光 Z|IFT1K  
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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 F`U YgN  
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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。 Z&j?@k,k  
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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。 ztHEXM.  
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    图5. 视网膜重点采样规格设定
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    脚本 'Bb@K[=s  
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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: l5fF.A7TT  
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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。 JwM Fu5@  
    余下的脚本计算与屈光度有关的所有参数。 U7@)RJ  
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    分析 h(H b+7g  
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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。 SF?s^  
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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 **L3T3$)  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. yNk E>  
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    Dim entity As T_ENTITY Mh;rhQ  
    Dim op As T_OPERATION 1?5UVv_F  
    Dim mat As T_MODELMATERIAL `p{,C`g,R  
    Dim A As Double H]JVv8  
    Dim pupilDiam As Double 08JVX'X-mr  
    Dim eID As Long AiE\PMF~{P  
    Dim parID As Long H G)c\b  
    Dim count As Integer Pu7cL  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double Yiy|^j  
    Dim tlens As Double, nlens As Double qtLXdSc  
    Dim curv As Double, conic As Double 'I *&P5|  
    Dim ok As Long 'YUx&F cM  
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    Sub Main $bv l.c  
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        '用户输入对话框 u{"@ 4  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 #w:6<$  
            TextBox 220,21,40,21,.TextBox1 'default: 0 l5bd);L tq  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 YMEI J}  
            OKButton 40,91,90,21 #m<<]L(o8W  
            CancelButton 190,91,90,21 6a\YD{D] _  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 ZFsJeF'"  
            TextBox 220,49,40,21,.TextBox2 'default: 4 "-;l{tL  
        End Dialog %B{NH~  
        Dim dlg As UserDialog !NfN16  
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        ok = Dialog (dlg) baVSQtda  
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        If ok=0 Then    'cancel button was pressed A"8"e*  
            Print "Execution cancelled." OK"B`*  
            End rJ UXA<:2  
        End If @JL+xfz  
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        'Assign accommodation and pupil diameter & use defaults if field left empty _hb@O2f  
        If dlg.TextBox1 = "" Then \dIQhF%%2  
            A = 0           'Default accommodation 1~# 2AdG  
        Else zz+p6`   
            A = CDbl(dlg.TextBox1) z nc'  
        End If w 9mi2=  
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        If dlg.TextBox2 = "" Then [# '38  
            pupilDiam = 4   'Default pupil diameter `/z6 Q"  
        Else Ydr/ T/1  
            pupilDiam = CDbl(dlg.TextBox2) p#V h[UTl^  
        End If *Tt*\ O  
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        Print " " &4ScwK:  
        Print "Accommodation = " & A & " Diopters" W l+[{#  
        Print "Pupil Diameter = " & pupilDiam & " mm" 2"~QI xY=  
    {LLy4m  
        ' Calculate new parameters with accommodation G} &{]w@  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness e:~r_,K  
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        Rant = 12.0 - 0.4*A                     'Radius of anterior lens $rh{f<  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens R""P01IZH  
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        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens 6DFF:wrm&  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens M=hH:[6 &  
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        tlens = 3.767 + 0.04*A                  'Lens thickness lo*)% fy  
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        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction D{{ ME8  
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        'Adjust parameters to account for accommodation }!i#1uHUH:  
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        '************************************************************************* SJtQK-%wK>  
        'Aqueous thickness (Position of Lens) UtF8T6PKdW  
        '************************************************************************* aF9p%HPDw  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) hwaU;>F  
        GetCustomElement eID, entity 5;5DEMe  
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        parID = FindFullName( "Geometry.Arizona Eye" ) `!.)"BI/s  
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        ' Delete any shift(s) in z d_j% ,1-#  
        count = 0 #S/]=D  
        While GetOperationCount(eID)>count ) /kf  
            GetOperation eID, count, op W -Yv0n3  
            If op.Type="ShiftZ" Then (hB&OP5Fne  
                DeleteOperation eID,count mZ^z%+Ca|  
                count=count-1 H+`s#'(i_P  
            End If QQso<.d&  
            count=count+1 P,x'1 `k~  
        Wend )x/Spb  
    <6]TazW?S  
        'Set new shift in  fWx %?J  
        op.Type = "ShiftZ" 5U&b")3IT!  
        op.val1 = taq 2g elmQnc  
        op.parent = parID 9+G.86Iky  
        AddOperation eID, op ieN}Ajl2  
        Print "Set aqueous humor thickness = " & taq-0.55 G[}$s7@k  
    3[g%T2&[  
        '************************************************************************* {8)Pke  
        'Radius and conic constant of anterior lens X|}yp|  
        '************************************************************************* "lcNjyU\O  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) Jhclg0q  
        GetConic eID, entity, curv, conic Fb&Xy{kt1  
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        SetConic eID, entity, 1/Rant, CCant @5!Mr5;  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant ]Q Y:t:-  
    Q k e8BRBn  
        '************************************************************************* *;Q IAd  
        'Radius and conic constant of posterior lens $TON`+lB  
        '************************************************************************* $4^cbk  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) '?Mt*%J@=$  
        GetConic eID, entity, curv, conic }Ut*Y*  
    CdCo+U5z{  
        SetConic eID, entity, 1/Rpost, CCpost Yj/aa0Ka4  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost p5|.E  
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        '*************************************************************************  |,*N>e  
        'Lens thickness (Position of posterior lens surface) ]Ek6EuaK  
        '************************************************************************* {9kH<,PJ;!  
    ;GW[Yw>Rz  
        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) 3*< O-Jr  
    J*Dt\[X  
        ' Delete any z-shift(s) D00I!D16  
        count = 0 RRW/.y  
        While GetOperationCount(eID)>count 4~mYj@lvd  
            GetOperation eID, count, op kvWP[! j?)  
            If op.Type="ShiftZ" Then {MP8B'r-6  
                DeleteOperation eID,count : +Na8\d  
                count=count-1 .<0|V  
            End If kD&% 7Vz  
            count=count+1 a$0,T_wD  
        Wend F't4Q  
    K4 \{G  
        'Set new z-shift o~Jce$ X  
        op.Type = "ShiftZ" mlq+Z#9  
        op.val1 = tlens +#%#QL  
        op.parent = parID ObK-<kGcB  
        AddOperation eID, op }V20~ hi  
        Print "Set lens thickness = " & tlens }HO3D.HE^  
    V}?*kx~T2C  
        '************************************************************************* asDk@G cu  
        'Lens index of refraction J7Z`wjX1  
        '************************************************************************* Q"o* \I  
        eID = FindMaterial( "Lens" ) p:*)rE  
        GetModelMaterial eID, mat Z~&$s  
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        mat.Nd = nlens mGss9eZa  
        SetModelMaterial eID, mat 1k=w 9  
        Print "Set lens index of refraction = " & nlens 5<Ly^Na:  
    9|kc$+(+6  
        '************************************************************************* :%_*C09  
        'Pupil diameter vJybhdvP  
        '************************************************************************* vpt*?eR  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) OvL@@SX |  
    $KSdNFtM)A  
        'Adjust pupil diameter (trimming volume inner hole) R,+Pcn$ws  
    uu5AW=j  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" 5Q)hl.<{o7  
    (R'GrN>  
        ' Adjust pupil location to just in front of the lens %y7&~me  
        parID = FindFullName( "Geometry.Arizona Eye" ) }XOTK^YA  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) #6fQ$x(F#j  
        count = 0 Lek!5Ug  
        While GetOperationCount(eID)>count |hx"yy'ux  
            GetOperation eID, count, op #$-zg^  
            If op.Type="ShiftZ" Then w'[^RZW:j  
                DeleteOperation eID,count cSbyVC[r  
                count=count-1 = aO1uC|6C  
            End If \`ya08DP(  
            count=count+1 }MUQO<=*  
        Wend !hMD>B2Z  
        op.Type = "ShiftZ" 5 )A(q\  
        op.val1 = taq-0.01 Eo\pNz#)  
        op.parent = parID V-1H(wRu  
        AddOperation eID, op Z<P?P`  
    x9DG87P~+  
        Print "Set pupil diameter = " & pupilDiam bD2):U*Fzo  
    *5e"suS2  
        'Update AZ Eye subassembly Description o\TXW qt  
        eID = FindFullName( "Geometry.Arizona Eye" ) p`+=) n  
        GetEntity eID, entity aXv[~  
        entity.Description = "Accommodation = " & A & "D" ";kwh8wB  
        SetEntity eID, entity teQ <v[W.  
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        Update 0A,u!"4[  
        Print "DONE!" 6dH> 0l  
         g!QX#_~Il  
    End Sub [Re.sX}$Y  
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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: "dkDT7  
    %qycxEVP  
    Accommodation = 4 Diopters *#n#J[  
    Pupil Diameter = 4 mm E Pd9'9S  
    Set aqueous humor thickness = 2.81 O:% ,.??<%  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 =<BPoGs5  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 E;o "^[we  
    Set lens thickness = 3.927 zfsGf 'U  
    Set lens index of refraction = 1.42672 w\K(kNd(  
    Set pupil diameter = 4 Qhc>,v)  
    DONE! G5oBe6\C  
    Kggc9^ 7  
    ! %~P[;.  
    QQ:2987619807 Ye=c;0V(w  
     
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