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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 c"_H%x<[  
    #6#BSZ E  
    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。 =&<$I  
    s`7 _J9  
    模型 tue%L]hc  
    -t706(#k  
    模型的定义如表1种所示,由半径、圆锥常数、折射率、阿贝数、到下一面的距离等一系列表面组成。一些参数由屈光度(A)来决定。 `dq3=  
    4h0jX 9  
    Table 1. AZ眼睛模型的定义
    Xj&~N;Ysb  
    在FRED中使用0屈光度来创建的,光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. HhT8YH  
    hwb(W?*  
    光源 /R+]}Lt~%*  
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    多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 f%{ ag  
    `'{%szmD  
    5d>YE  
    图1. 光源和提示信息使用
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    除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处,并增加了pre-propagation distance= -8。尽管光线在光瞳处创建,规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射,而不是在光瞳处入射。 hghto \G5Y  
    w1/T>o  
    在往下看是内置的脚本用来修改屈光度,使其为4(250mm),光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 2ucsTh@  
    ]idD&5gd  
    图2. 字母F光源的设定方法光  z]R!l%`  
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    图3. 字母F在视网膜上位置点列图
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    视网膜的散射 .]d tRH<  
     26klW:2*  
    在散射文件中,有一个名为“Retina surface”的72%的反射型朗伯散射,它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射,改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 u\& [@v  
    F7PZV+\  
    3Tte8]0  
    图4. 视网膜朗伯散射设定
    M5bj |tQ4  
    注意在视网膜的表面有散射重点采样规格定义,在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳,半角度10度。 "/]tFY%Y  
    d?+oT0pCH  
    R5~vmT5W  
    图5. 视网膜重点采样规格设定
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    脚本 q.K$b  
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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: @nW(KF  
    d"$oV~>P|  
    图6. 用户对话框的创建与编辑
    "a_D]D(d5  
    图7. 用户对话框编辑器
    ~{tZ;YZ  
    如果“OK”按钮按下,将会核对对话框下面的代码行,如果点击取消则脚本终止。然后输入的参数赋予变量,如果此处是保留为空白,则使用默认值。因此,如果没有值输入并点击“OK”按钮,则脚本是以屈光度为0,光瞳直径为4mm来运行的。 ="nrq&2  
    余下的脚本计算与屈光度有关的所有参数。 :{='TMJ7  
    SbNUX  
    分析 )|1JcnNSa  
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    屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 o_^d>Klb8  
    ezy5Jqk5%  
    图7. 字母F在视网膜上颜色分析
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    脚本代码 *Zo o  
    2*;Y%NcP[  
    Option Explicit     'Remove this to enable non-dimensioned variables to be used. u$ / ]59  
    }u*@b10   
    Dim entity As T_ENTITY 9Q5P7}%p  
    Dim op As T_OPERATION ?01""Om   
    Dim mat As T_MODELMATERIAL a/`Yh>ou  
    Dim A As Double NqfDY  
    Dim pupilDiam As Double bB :X<  
    Dim eID As Long P!&CH4+  
    Dim parID As Long :[rKSA]@  
    Dim count As Integer uTloj .  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double 8q LgB  
    Dim tlens As Double, nlens As Double u! FSXX<  
    Dim curv As Double, conic As Double .7^-*HT}  
    Dim ok As Long  s !vROJ  
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    Sub Main L/+J|_J)  
    g#2X'%&+  
        '用户输入对话框 h*LL(ow5  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 5WN Z7cO  
            TextBox 220,21,40,21,.TextBox1 'default: 0 *U^hwL  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 a~TZ9yg+HL  
            OKButton 40,91,90,21 M HB]'  
            CancelButton 190,91,90,21 bHT@]`@@  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 xa*gQ%+F  
            TextBox 220,49,40,21,.TextBox2 'default: 4 ti2_kYq  
        End Dialog "8 mulE,  
        Dim dlg As UserDialog 491I  
    e%Xf*64  
        ok = Dialog (dlg) CXFAb1m  
     ;I@L  
        If ok=0 Then    'cancel button was pressed ll09j Ef  
            Print "Execution cancelled." F|K4zhK  
            End nEEGO~e  
        End If ABDUp:  
    )t=u(:u]  
        'Assign accommodation and pupil diameter & use defaults if field left empty L=FvLii.  
        If dlg.TextBox1 = "" Then cb,sb^-  
            A = 0           'Default accommodation j}*+-.YF  
        Else # Kr.!uD  
            A = CDbl(dlg.TextBox1) OIT;fKl9  
        End If sYI':UQe  
    W+S; Do  
        If dlg.TextBox2 = "" Then -{%''(G  
            pupilDiam = 4   'Default pupil diameter .4(f0RG  
        Else )eMh,r  
            pupilDiam = CDbl(dlg.TextBox2) W A}@n  
        End If k|C8sSH  
     nGd  
        Print " " :J-5Q]#  
        Print "Accommodation = " & A & " Diopters" {\zr_v`g  
        Print "Pupil Diameter = " & pupilDiam & " mm" gI3rF=  
    ~l6Y<-!  
        ' Calculate new parameters with accommodation _?c.3+;s  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness ,e_#   
    wO%:WL$5  
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens /CE d 14.  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens =lD]sk  
    O3: dOL/C  
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens LS$82UB&  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens loe>"_`Cq  
    %/on\*Vh3  
        tlens = 3.767 + 0.04*A                  'Lens thickness .Y.# d7TA  
    nHrCSfK  
        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction mh]$g<*m  
    LTct0Gh  
        'Adjust parameters to account for accommodation W10fjMC}^  
    1z:N$O _v  
        '************************************************************************* N|S xAg  
        'Aqueous thickness (Position of Lens) wm71,R1  
        '************************************************************************* kc[["w&  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) MT0{hsuK9  
        GetCustomElement eID, entity gAP}KR#T  
    `p|vutk)U  
        parID = FindFullName( "Geometry.Arizona Eye" ) s+- aHn  
    xrnH= >.;m  
        ' Delete any shift(s) in z FJ"9Hs2  
        count = 0 V+z)B+  
        While GetOperationCount(eID)>count w'XgW0j{  
            GetOperation eID, count, op i@L2W>{P  
            If op.Type="ShiftZ" Then 3fTI&2:  
                DeleteOperation eID,count s\!vko'M  
                count=count-1 Bdepvc}[#  
            End If #+k[[; 0  
            count=count+1 ![^h<Om  
        Wend {Z.@-Tl_  
    Am4(WXVQ  
        'Set new shift in +r_[Tj|Er  
        op.Type = "ShiftZ" 7d)' y  
        op.val1 = taq {[ *_HAy7  
        op.parent = parID zK?[dO  
        AddOperation eID, op ]E^f8s0#V  
        Print "Set aqueous humor thickness = " & taq-0.55 DA~ELje^j  
    I_7EfAqg(  
        '************************************************************************* wP"|$HN  
        'Radius and conic constant of anterior lens >oDP(]YGg  
        '************************************************************************* k^jCB>b  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) 'bPo 5V|  
        GetConic eID, entity, curv, conic k)Wz b  
    ^j}sS!p  
        SetConic eID, entity, 1/Rant, CCant d 4R+gIA  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant G|_aU8b|t  
    3~rc=e  
        '************************************************************************* 1A-EP@# J  
        'Radius and conic constant of posterior lens yTiqG5r  
        '************************************************************************* yfQE8v+  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) k1zt|  
        GetConic eID, entity, curv, conic 2"mj=}y6  
    rK|&u v*b  
        SetConic eID, entity, 1/Rpost, CCpost 8ZfIh   
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost ZQA C &:  
    <t{AY^:r  
        '************************************************************************* 5AU3s  
        'Lens thickness (Position of posterior lens surface) n4y6Ua9m{  
        '************************************************************************* wkA!Jv%  
    B)8Hj).@B  
        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) }* JMc+!9@  
    ?GU!ke p  
        ' Delete any z-shift(s) uF"`y&go  
        count = 0 hATy 3*4  
        While GetOperationCount(eID)>count >nEnX  
            GetOperation eID, count, op %tQ{Hf~  
            If op.Type="ShiftZ" Then pUGfm  
                DeleteOperation eID,count w[YbL2p  
                count=count-1 $uynW3h  
            End If ^I?y\:.  
            count=count+1 Q}]kw}b  
        Wend i]%"s_l  
    t'x:fO?cp  
        'Set new z-shift 6qpV53H  
        op.Type = "ShiftZ" tuV?:g?  
        op.val1 = tlens (`? snMc  
        op.parent = parID 5zna?(#}  
        AddOperation eID, op "e<. n  
        Print "Set lens thickness = " & tlens SJ^?D8  
    7#qL9+G  
        '************************************************************************* b)^ZiRW``  
        'Lens index of refraction { BL1j  
        '************************************************************************* n3j h\  
        eID = FindMaterial( "Lens" ) } /3pC a  
        GetModelMaterial eID, mat 6'! {0 5=m  
    OUO^/] J1S  
        mat.Nd = nlens ){6)?[G  
        SetModelMaterial eID, mat WVK-dBU  
        Print "Set lens index of refraction = " & nlens 8;&S9'ci  
    G<6grd5PP  
        '************************************************************************* pF+wH MhUe  
        'Pupil diameter [iy;}5XK  
        '************************************************************************* Ab<Ok\e5  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) Jd"s~n<>K  
    q'@Ei4  
        'Adjust pupil diameter (trimming volume inner hole) wD^do  
    X`QW(rq  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" ! H=k7s  
    >1I2R/'  
        ' Adjust pupil location to just in front of the lens HKN"$(Q  
        parID = FindFullName( "Geometry.Arizona Eye" ) e`M]ZG rr  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) UZXcKl>u  
        count = 0 kS#DKo  
        While GetOperationCount(eID)>count RTBBb:eX  
            GetOperation eID, count, op B00wcYM<1r  
            If op.Type="ShiftZ" Then _D,f 4.R  
                DeleteOperation eID,count Cf=q_\0|W  
                count=count-1 "`*a)'.'^c  
            End If m&0BbyE.z  
            count=count+1 l~!fQ$~  
        Wend q}v04Yy,o  
        op.Type = "ShiftZ" HmB[oH "x  
        op.val1 = taq-0.01 +xBK^5/x  
        op.parent = parID  >fA@tUQB  
        AddOperation eID, op vcJb\LW  
    BRXb<M^;_  
        Print "Set pupil diameter = " & pupilDiam 'L|GClc6)  
    giPo;z\c  
        'Update AZ Eye subassembly Description [^}>AC*im  
        eID = FindFullName( "Geometry.Arizona Eye" ) s?x>Yl %  
        GetEntity eID, entity ka)LK@p6  
        entity.Description = "Accommodation = " & A & "D" X >Xp&o  
        SetEntity eID, entity ]{2{:`s  
    Ld3Bi2d|  
        Update 3 [)s;e  
        Print "DONE!" rjAkpAT  
         ) UDJ[pL@  
    End Sub ngY+Ym  
    $:BK{,\  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: }8F$& AFt  
    %3c|  
    Accommodation = 4 Diopters DkF2R @  
    Pupil Diameter = 4 mm KWh M  
    Set aqueous humor thickness = 2.81 ^c0$pqZ}r  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 FO(0D?PCR  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 <r+!hJ[s'  
    Set lens thickness = 3.927 '0_j{ig  
    Set lens index of refraction = 1.42672 $,e?X}4  
    Set pupil diameter = 4 [b i3%yWh  
    DONE! hi3sOK*r;<  
    sE%<"h\_0  
    f5yux}A{  
    QQ:2987619807 yg+IkQDf4U  
     
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