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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 S%- kN;  
    /ZyMD(_J  
    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。 -=5~h  
    sJLOz>  
    模型 @)d_zWE  
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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。 )#i@DHt=  
    1 ^|#QMT  
    Table 1. AZ眼睛模型的定义
    # Wi?I =,  
    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. :\[l~S  
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    光源 '> ib K|  
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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。 x=cucZ  
    QF/ULW0G!  
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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。 <&m50pq  
    a <C?- g|  
    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。 v,iZnANZ&P  
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    图2. 字母F光源的设定方法光 _^W;J/He  
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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  ,]EhDW6  
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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。 SV o?o|<  
    =.z;:0]'n  
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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。 fHd[8{;P:  
    <<!fA ><W  
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    图5. 视网膜重点采样规格设定
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    脚本 !~|-CF0z=  
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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: qHZDo[  
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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。 (6$ P/k8  
    余下的脚本计算与屈光度有关的所有参数。 #_.J kY  
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    分析 e' M&Eh  
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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。 ir<e^a  
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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 ymv/  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. ,jRAVt +{N  
    5hmfdj6  
    Dim entity As T_ENTITY XHU$&t`7>g  
    Dim op As T_OPERATION sex\dg<  
    Dim mat As T_MODELMATERIAL {V/>5pz4e  
    Dim A As Double [uU!\xe  
    Dim pupilDiam As Double qS\#MMsTd  
    Dim eID As Long e4` L8  
    Dim parID As Long 3'.@aMA@  
    Dim count As Integer J- S.m(  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double }T4|Kyu?  
    Dim tlens As Double, nlens As Double N#l2wT  
    Dim curv As Double, conic As Double 67iI wY*8'  
    Dim ok As Long .yy-jf/  
    ~Fuq{e9`  
    Sub Main ZMQ=D!kT  
    l$/pp  
        '用户输入对话框 2yK">xYY@  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 Y]SF0:v!n  
            TextBox 220,21,40,21,.TextBox1 'default: 0 'O(=Pz  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 yIL=jzm`7  
            OKButton 40,91,90,21 tq59w  
            CancelButton 190,91,90,21 dLp1l2h!0  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 m}'_Poc  
            TextBox 220,49,40,21,.TextBox2 'default: 4 bq E'9GI  
        End Dialog ^;_~ mq.  
        Dim dlg As UserDialog ."+lij=56  
    i"G'#n~e  
        ok = Dialog (dlg) B)Y[~4o  
    %C_tBNE <  
        If ok=0 Then    'cancel button was pressed R `tJ7MB  
            Print "Execution cancelled." 2'@m'4-N  
            End ~Y x_ 3  
        End If fF)Q;~_VA  
    N_T5sZ\  
        'Assign accommodation and pupil diameter & use defaults if field left empty S-Y{Vi"2  
        If dlg.TextBox1 = "" Then T2Yf7Szp  
            A = 0           'Default accommodation Z i6s0Uck  
        Else x{:U$[_  
            A = CDbl(dlg.TextBox1) n>}Y@{<]/  
        End If *Y(59J2  
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        If dlg.TextBox2 = "" Then FC1rwXL(  
            pupilDiam = 4   'Default pupil diameter ]u5TvI,C  
        Else Em(_W5 ND{  
            pupilDiam = CDbl(dlg.TextBox2) yq-~5ui  
        End If 2?~nA2+vm  
    8@rYT5e3c  
        Print " " R0=f`;  
        Print "Accommodation = " & A & " Diopters" i%9vZ  
        Print "Pupil Diameter = " & pupilDiam & " mm" WRD z*Zf  
    t,9+G<)>H  
        ' Calculate new parameters with accommodation =c@hE'{  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness  Lw\u{E@  
    YcA. Bn|as  
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens ^i8,9T'=  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens G0 EXgq8  
    "\@J0 |ppb  
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens s^zlBvr|.  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens B!Wp=9)G  
    tKt}]KHV  
        tlens = 3.767 + 0.04*A                  'Lens thickness ytY\&m  
    ^^v3iCT  
        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction L"'=[O~  
    BHY-fb@R]H  
        'Adjust parameters to account for accommodation :=hL}(~]  
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        '************************************************************************* h-PJC/>  
        'Aqueous thickness (Position of Lens) b;VIR,2  
        '************************************************************************* J920A^)j!  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) nDvfb* \  
        GetCustomElement eID, entity <Z-Pc?F&(k  
    9^!.!%6O$  
        parID = FindFullName( "Geometry.Arizona Eye" ) %$ya>0?mq  
    _5Lcr)  
        ' Delete any shift(s) in z qR.FjQOvn  
        count = 0 sGY}(9ED;  
        While GetOperationCount(eID)>count %O9Wm_%  
            GetOperation eID, count, op Qp<*o r@  
            If op.Type="ShiftZ" Then eI ( S)q  
                DeleteOperation eID,count `e ZDG  
                count=count-1 !U?C _  
            End If H}r]j\  
            count=count+1 c $1u  
        Wend Q qF<HCO  
    vT#R>0@mi  
        'Set new shift in d9JAt-6z2  
        op.Type = "ShiftZ" |y7TYjg6  
        op.val1 = taq dlo`](5m  
        op.parent = parID "=Z=SJ1D  
        AddOperation eID, op l0G{{R 0Y  
        Print "Set aqueous humor thickness = " & taq-0.55 yr+QV:oVA  
    )s>|;K{  
        '************************************************************************* 6|p8_[e`  
        'Radius and conic constant of anterior lens YQD `4ND  
        '************************************************************************* <p<6!tdO  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) 0i}.l\  
        GetConic eID, entity, curv, conic n}Z%-w$K#  
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        SetConic eID, entity, 1/Rant, CCant ^JxVs 7  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant fP<== DK  
    RK@K>)"f  
        '************************************************************************* P>q~ocq<  
        'Radius and conic constant of posterior lens 9%kO%j,3  
        '************************************************************************* tfHr'Qy BC  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) qf K gNZ  
        GetConic eID, entity, curv, conic NCg("n,jx  
    8o:h/F  
        SetConic eID, entity, 1/Rpost, CCpost F lVG,Z  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost ;LgMi5dN  
    ~<u\YIJ  
        '************************************************************************* d0T 8Cwc b  
        'Lens thickness (Position of posterior lens surface) ?6*\  M  
        '************************************************************************* 1g=T"O&=  
    b6;MTz*k>  
        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) Ew]&~:$Ki  
    G-D}J2r=F  
        ' Delete any z-shift(s) X7*ossv  
        count = 0 WMKxGZg"  
        While GetOperationCount(eID)>count A]iT uu5p  
            GetOperation eID, count, op Gmu[UI}w8  
            If op.Type="ShiftZ" Then :{eYm|2-  
                DeleteOperation eID,count -ik$<>{X  
                count=count-1 x%)oL:ue  
            End If wy|b Hkr_  
            count=count+1 X%I@4 B7Ts  
        Wend !*DY dqQ/  
    @=g{4(zR ^  
        'Set new z-shift yz3=#  
        op.Type = "ShiftZ" 7&etnQJ{  
        op.val1 = tlens V,zFHXO  
        op.parent = parID }x6)}sz7  
        AddOperation eID, op mb_6f:Qh3  
        Print "Set lens thickness = " & tlens %*q^i}5)E  
    ~W"@[*6w  
        '************************************************************************* Z!q$d/1  
        'Lens index of refraction j<WsFVS  
        '************************************************************************* u=PLjrB~}  
        eID = FindMaterial( "Lens" ) ENA"T-p  
        GetModelMaterial eID, mat t0<RtIh9e  
    18~jUYMV  
        mat.Nd = nlens Wf?[GO  
        SetModelMaterial eID, mat HXh:8 3  
        Print "Set lens index of refraction = " & nlens <QgpePyoN  
    o=![+g  
        '************************************************************************* asQ^33g z  
        'Pupil diameter "\lO Op^-  
        '************************************************************************* w$]wd`N}  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) }]1C=~lC  
    {qSMJja!t  
        'Adjust pupil diameter (trimming volume inner hole) 8YPX8d8u  
    6%9 kc+ 9  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" _`*G71PS  
    K{Nj-Rqd  
        ' Adjust pupil location to just in front of the lens D0_CDdW%7  
        parID = FindFullName( "Geometry.Arizona Eye" ) Dm?:j9o]g  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) m1K4_a)^[  
        count = 0 Z>/ *q2  
        While GetOperationCount(eID)>count _iA oNT!  
            GetOperation eID, count, op a&kt!%p:  
            If op.Type="ShiftZ" Then O<AGAD  
                DeleteOperation eID,count Z"l].\= F  
                count=count-1 xqDz*V/mD  
            End If ^\S~rW.3_  
            count=count+1 Vv`94aQTD  
        Wend 6c>:h)?  
        op.Type = "ShiftZ" bO('y@)X  
        op.val1 = taq-0.01 =~,2E;#X  
        op.parent = parID Gf!c  
        AddOperation eID, op zDm3 $P=  
    @I&k|\  
        Print "Set pupil diameter = " & pupilDiam >`yRL[c;  
    '19?  
        'Update AZ Eye subassembly Description 8B "^}y\0  
        eID = FindFullName( "Geometry.Arizona Eye" ) +~==qLsU  
        GetEntity eID, entity  Ew;AYZX  
        entity.Description = "Accommodation = " & A & "D" D2Q0p(#%  
        SetEntity eID, entity -`X`Ff  
    Ai:, cY5%  
        Update ]R^xO;g'  
        Print "DONE!" Rb^G~82d?  
         VV[Fb9W ;  
    End Sub AnE] kq u  
    roi,?B_8  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: 6#:V3 ;  
    BNO+-ob-  
    Accommodation = 4 Diopters =RM]/O9  
    Pupil Diameter = 4 mm YoK )fh$  
    Set aqueous humor thickness = 2.81 "ChJR[4@  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 {EVy.F  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 cUw$F{|W  
    Set lens thickness = 3.927 yr.sfPnJK  
    Set lens index of refraction = 1.42672 R%9,.g <  
    Set pupil diameter = 4 _Wp.s]D [  
    DONE! Lv)1 )'v0  
     
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