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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 | ^G38  
    #qW#>0U  
    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。 LqNyi   
    "BZ@m:I6hy  
    模型 Wg20H23XW  
    PkLNIp1  
    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。 "Q{ l])N  
    3gnO)"$  
    Table 1. AZ眼睛模型的定义
    1jO%\uR/  
    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. pw`'q(ad  
    6b9J3~d\E  
    光源 ,RW`9+gx  
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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。 Ubgn^+AI  
    z:Z-2WV2o  
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    图1. 光源和提示信息使用
    M93*"jA  
    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。 pRd'\+  
    =3`|D0E  
    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。 K$w;|UJc  
    AyPtbrO  
    图2. 字母F光源的设定方法光 qDU4W7|T`  
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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 K/j u=>  
    @_7rd  
    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。 _,IjB/PR(  
    "eqzn KT%u  
    o\]U;#YD  
    图4. 视网膜朗伯散射设定
    `'&mO9,<-  
    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。 :HwdXhA6  
    Ln t 1  
    HUAYtUBH  
    图5. 视网膜重点采样规格设定
    H5 V>d  
    脚本 `( w"{8laB  
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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: iJZNSRQJ}r  
    5-y*]:g(  
    图6. 用户对话框的创建与编辑
    h(<>s#=E  
    图7. 用户对话框编辑器
    >^GV #z  
    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。 V1pBKr)v  
    余下的脚本计算与屈光度有关的所有参数。 Dh}(B$~Oz+  
    79D~Mau#  
    分析 :`Ut.E~.  
    ~KYzEqy  
    屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 W]bgWKd  
    fGqX dlP  
    图7. 字母F在视网膜上颜色分析
    &pjj  
    脚本代码 ^g5E&0a`g  
    EwkSUA>Tm  
    Option Explicit     'Remove this to enable non-dimensioned variables to be used. $;'M8L  
    .a7RGT3]m  
    Dim entity As T_ENTITY miu?X!  
    Dim op As T_OPERATION =QGmJ3  
    Dim mat As T_MODELMATERIAL ^L)TfI_n  
    Dim A As Double GBT|1c'i  
    Dim pupilDiam As Double `GdH ,:S>  
    Dim eID As Long FO%pdLs,  
    Dim parID As Long 'Grii,  
    Dim count As Integer |R _rfJh  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double &(A#F[ =0  
    Dim tlens As Double, nlens As Double GK!@|Kk8q7  
    Dim curv As Double, conic As Double xr7}@rq"U<  
    Dim ok As Long M<d!j I9)  
    tx~,7TMS/  
    Sub Main _#NibW  
    IZ7o6Etti  
        '用户输入对话框 lwrh4<~\,*  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 aHmg!s}&  
            TextBox 220,21,40,21,.TextBox1 'default: 0 iw3\`,5   
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 ",D!8>=s  
            OKButton 40,91,90,21 )Uy%iE*  
            CancelButton 190,91,90,21 U|V,&RlbR  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 Tx!t3;Yz[  
            TextBox 220,49,40,21,.TextBox2 'default: 4 Mms|jF oQ  
        End Dialog _uLpU4# ?  
        Dim dlg As UserDialog jwa6`u  
    #dL,d6a  
        ok = Dialog (dlg) wbrOL(q.m  
    ]oVP_ &E  
        If ok=0 Then    'cancel button was pressed 6QCV i  
            Print "Execution cancelled." Z4Dx:m-  
            End 7@%qm|i>w  
        End If ndzADVP  
    `;+x\0@<  
        'Assign accommodation and pupil diameter & use defaults if field left empty ]vvA]e  
        If dlg.TextBox1 = "" Then I9qFXvqL  
            A = 0           'Default accommodation /MY's&D(  
        Else L"vrX  
            A = CDbl(dlg.TextBox1) v_EgY2l(  
        End If zGR, }v%%  
    19qH WU^0V  
        If dlg.TextBox2 = "" Then M,@M5o2u  
            pupilDiam = 4   'Default pupil diameter gv>DOez/  
        Else ;mQ|+|F6X  
            pupilDiam = CDbl(dlg.TextBox2) k>mXh{ (  
        End If V 97ORI  
    pxgf%P<7  
        Print " " r9WR1&T)  
        Print "Accommodation = " & A & " Diopters" 5=I({=/>  
        Print "Pupil Diameter = " & pupilDiam & " mm" #p>&|I  
    kC%H E  
        ' Calculate new parameters with accommodation [|oG}'Xz  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness d{JI] !  
    oSD=3DQ;  
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens M$%ON>K q  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens 6E-eD\?I&  
    v#&;z_I+  
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens ~6n|GxR.[  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens A{ T9-f@X  
    @I?,!3`jS  
        tlens = 3.767 + 0.04*A                  'Lens thickness zPp22  
    s_/@`kd{  
        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction =o~+R\1ux+  
    ^3$U[u%q/{  
        'Adjust parameters to account for accommodation `WOoC   
    X-(( [A  
        '************************************************************************* >^Wpc  
        'Aqueous thickness (Position of Lens) _Sfu8k>):  
        '************************************************************************* Zt! $"N.,  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) T$"~V u  
        GetCustomElement eID, entity #1E4 R}B  
    'RKpMdoz  
        parID = FindFullName( "Geometry.Arizona Eye" ) 3-hcKE  
    >;,23X  
        ' Delete any shift(s) in z / ^d9At614  
        count = 0 A?#i{R  
        While GetOperationCount(eID)>count 4AJT)I.  
            GetOperation eID, count, op 1a(\F 7  
            If op.Type="ShiftZ" Then #;a+)~3*O  
                DeleteOperation eID,count )jgz(\KZ  
                count=count-1 ME]4tu  
            End If f|B\Y/*X  
            count=count+1 qfl!>  
        Wend ,Ohhl`q(  
    ]rj~3du\  
        'Set new shift in 0vfMJzk  
        op.Type = "ShiftZ" ^UKY1Q .  
        op.val1 = taq g]L8Jli  
        op.parent = parID \-]Jm[]^  
        AddOperation eID, op Al*=%nY  
        Print "Set aqueous humor thickness = " & taq-0.55 J' P:SC1  
    "r@#3T$  
        '************************************************************************* fDns r" T  
        'Radius and conic constant of anterior lens ~3j +hN8<  
        '************************************************************************* 5A`>3w{3n  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) elGBX h  
        GetConic eID, entity, curv, conic 6O{QmB0KK  
    e_epuki  
        SetConic eID, entity, 1/Rant, CCant 9)vU/fJ|  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant )J@[8 x`  
    >l)x~Bkf$j  
        '************************************************************************* n$SL"iezW?  
        'Radius and conic constant of posterior lens _@XueNU1hS  
        '************************************************************************* ,0h{RZKw  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) T DR|*Cs  
        GetConic eID, entity, curv, conic w,j!%N  
    P{K\}+9F   
        SetConic eID, entity, 1/Rpost, CCpost 1YMi4.  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost OXM=@B<"  
    Pzzzv^+  
        '************************************************************************* b*h:e.q  
        'Lens thickness (Position of posterior lens surface) {= &&J@:  
        '************************************************************************* >Vq07R  
    |khFQ(  
        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) :* |WE29U  
    OCdX'HN5Y  
        ' Delete any z-shift(s) "6%{#TZ  
        count = 0 x'}z NEXI  
        While GetOperationCount(eID)>count H?r~% bh  
            GetOperation eID, count, op Pl'lmUR  
            If op.Type="ShiftZ" Then <ndY6n3  
                DeleteOperation eID,count \ky oA Z  
                count=count-1 apJXRH`  
            End If -2}ons(  
            count=count+1 Z:h'kgG&  
        Wend *^[6uaa  
    Adiw@q1&  
        'Set new z-shift k}g4?  
        op.Type = "ShiftZ" NKFeND  
        op.val1 = tlens 3'L =S  
        op.parent = parID $ZyOBxI  
        AddOperation eID, op 6rE8P#  
        Print "Set lens thickness = " & tlens :yJ#yad  
    fGe ie m  
        '************************************************************************* {Q$8p2W  
        'Lens index of refraction eVMnI yr  
        '************************************************************************* ;>ml@@Z  
        eID = FindMaterial( "Lens" ) :##$-K*W"  
        GetModelMaterial eID, mat t;3).F  
    `Zmdlp@  
        mat.Nd = nlens = YO<.(Lu  
        SetModelMaterial eID, mat N\]-/$z  
        Print "Set lens index of refraction = " & nlens T-4dD  
    E Y !o#m  
        '************************************************************************* f\$_^dV  
        'Pupil diameter !} x-o`a5  
        '************************************************************************* FU*q9s`  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) 45-x$o  
    &QQ6F>'T  
        'Adjust pupil diameter (trimming volume inner hole) @`B_Q v@  
    >f&L7@  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" TT;ls<(Lg  
    dhP")@3K;p  
        ' Adjust pupil location to just in front of the lens g*_n|7pB  
        parID = FindFullName( "Geometry.Arizona Eye" ) N8x&<H  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) PpLh j  
        count = 0 ^pY8'LF6  
        While GetOperationCount(eID)>count #d<"Ub  
            GetOperation eID, count, op w?*79 u  
            If op.Type="ShiftZ" Then ep5`&g]3  
                DeleteOperation eID,count S Cn)j:gH;  
                count=count-1 _@)-#7  
            End If S~m8j |3K  
            count=count+1 p/LV^TQ  
        Wend ^XYK }J  
        op.Type = "ShiftZ" Ke#Rkt  
        op.val1 = taq-0.01 =_N $0  
        op.parent = parID pIpdVKen  
        AddOperation eID, op EcytNYn  
    X<W${L$G  
        Print "Set pupil diameter = " & pupilDiam 3TV4|&W;  
    XCxxm3t  
        'Update AZ Eye subassembly Description eq"Xwq*  
        eID = FindFullName( "Geometry.Arizona Eye" ) l*CCnqE  
        GetEntity eID, entity =%I;Y& K  
        entity.Description = "Accommodation = " & A & "D" icVB?M,m  
        SetEntity eID, entity "Il) _Ui  
    O\=Zo9(NHF  
        Update f*xv#G  
        Print "DONE!" G<rAM+B*g  
         e^;:iJS  
    End Sub 'F/uD 1;  
    l  LBzY`j  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: Zv mkb%8  
    'vq0Tw5  
    Accommodation = 4 Diopters 23ho uS   
    Pupil Diameter = 4 mm QAl4w)F  
    Set aqueous humor thickness = 2.81 muK.x7zyl  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 !lZ}kz0  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 noB8*n0  
    Set lens thickness = 3.927 B=r+ m;(  
    Set lens index of refraction = 1.42672 h^,L) E  
    Set pupil diameter = 4 o7PS1qcya<  
    DONE! \j.l1O  
    >lJTS t5{  
    K0I.3| 6C  
    QQ:2987619807 f\RTO63|O  
     
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