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    [技术]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: 2021-10-22
    简介 y :457R2F  
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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。 [1s B  
    * @oAM,@  
    模型 LOp<c<+aW  
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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。 l{;vD=D  
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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. FzNs >*  
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    光源 d/"e3S1  
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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。 VPf=LSxJe  
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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。 GUMO;rZs  
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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。 f 1]1ZOb  
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    图2. 字母F光源的设定方法光 0kmZO"K#e  
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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 oKzLt  
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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。 V,lz}&3L  
    @'dtlY5;  
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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。 *_@8v?  
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    图5. 视网膜重点采样规格设定
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    脚本 &_G^=Nc,H  
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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: tK0?9M.)  
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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。 .t$~>e .  
    余下的脚本计算与屈光度有关的所有参数。 )nQA) uz  
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    分析 S}mqK|!  
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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。 (@[c;+x  
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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 0escp~\Z  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. }HRM6fR1S  
    <S <@V?h  
    Dim entity As T_ENTITY ]+Ik/+Nz  
    Dim op As T_OPERATION [HLXWu3  
    Dim mat As T_MODELMATERIAL @WEDXB  
    Dim A As Double 5Ay\s:hb[u  
    Dim pupilDiam As Double ET.c8K1f  
    Dim eID As Long 7G z f>n  
    Dim parID As Long <XDYnWz  
    Dim count As Integer :/A3l=}iV  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double TldqF BX  
    Dim tlens As Double, nlens As Double unY+/p $  
    Dim curv As Double, conic As Double oF7o"NHaWa  
    Dim ok As Long Db3# ;  
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    Sub Main Yi:@>A<#  
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        '用户输入对话框 68 vu  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 m:_'r"o  
            TextBox 220,21,40,21,.TextBox1 'default: 0 ]rY:C "#  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 +`'=K ;{U  
            OKButton 40,91,90,21 {$5?[KD  
            CancelButton 190,91,90,21 OTwIR<_B+  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 B~xT:r  
            TextBox 220,49,40,21,.TextBox2 'default: 4 dTcrJ|/Y  
        End Dialog =Kqb V{!  
        Dim dlg As UserDialog .ww~'5b0  
    #2{H!jr  
        ok = Dialog (dlg)  <m7m  
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        If ok=0 Then    'cancel button was pressed Jga;nrU  
            Print "Execution cancelled." 8=\}#F  
            End j%%& G$Tfu  
        End If OpWTw&B"+  
    )jc`_{PQg  
        'Assign accommodation and pupil diameter & use defaults if field left empty &BxDS .  
        If dlg.TextBox1 = "" Then <MdIQ;I8  
            A = 0           'Default accommodation {^(h*zxn  
        Else 0[E}[{t`  
            A = CDbl(dlg.TextBox1) apy9B6%PJ+  
        End If !79eF)  
    + xYU$e6Z  
        If dlg.TextBox2 = "" Then d%?$UnQ  
            pupilDiam = 4   'Default pupil diameter N5K\h}'%  
        Else - ,YoVB!T  
            pupilDiam = CDbl(dlg.TextBox2) ] 40@yrc  
        End If !:BmDX[<n  
    fD:BKJQ  
        Print " " g  Z!q  
        Print "Accommodation = " & A & " Diopters" yVZLZLm  
        Print "Pupil Diameter = " & pupilDiam & " mm" -}:; EGUtd  
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        ' Calculate new parameters with accommodation sQ"; t=yC  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness \%BII>VS  
    b;xn0sDn#  
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens o|`%>&jP  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens v=8sj{g3,3  
    ~$PY6s  
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens Rq`d I~5!b  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens Nl$b;~ u  
    W *.j=?)\[  
        tlens = 3.767 + 0.04*A                  'Lens thickness 6>Dm cG:.  
    @y1:=["b  
        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction ^K3Bn  
    i0q<,VSl$_  
        'Adjust parameters to account for accommodation <Dk6o`7^N  
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        '************************************************************************* K&'Vd@  
        'Aqueous thickness (Position of Lens) `En>o~L;  
        '************************************************************************* nF1}?  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) H3#rFO"C*  
        GetCustomElement eID, entity {J~VB~('  
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        parID = FindFullName( "Geometry.Arizona Eye" ) Ht4A   
    ;)Fc@OXN>  
        ' Delete any shift(s) in z 3sD/4 ?  
        count = 0 eHE?#r16Z  
        While GetOperationCount(eID)>count &RB{0Qhx  
            GetOperation eID, count, op `=%mU/v  
            If op.Type="ShiftZ" Then g>*P}r~;^b  
                DeleteOperation eID,count +?9. &<?  
                count=count-1 O= 84ZP%  
            End If i+@t_pxc  
            count=count+1 A<p6]#t#X)  
        Wend }}b &IA#  
    Um%$TGw5  
        'Set new shift in Eg+ z(m$M  
        op.Type = "ShiftZ" HRg< f= oz  
        op.val1 = taq AGGNJ4m  
        op.parent = parID CNM pyr  
        AddOperation eID, op n?mV(?N  
        Print "Set aqueous humor thickness = " & taq-0.55 |V-)3 #c  
    >(He,o@M  
        '************************************************************************* zvOSQxGQ  
        'Radius and conic constant of anterior lens }rA _4%  
        '************************************************************************* |C`.m |  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) kO}Q OL4  
        GetConic eID, entity, curv, conic k#"}oI{< 6  
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        SetConic eID, entity, 1/Rant, CCant / NB;eV?  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant $s<bKju  
    7El:$H  
        '************************************************************************* $:IEpV{  
        'Radius and conic constant of posterior lens ?#gYu %7DN  
        '************************************************************************* tB#-}Gf  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) >Pwu>  
        GetConic eID, entity, curv, conic ?4sF:Y+\  
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        SetConic eID, entity, 1/Rpost, CCpost =bh.V@*  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost }J+ \o~  
    4l?"zv1  
        '************************************************************************* QHPC?a6CD  
        'Lens thickness (Position of posterior lens surface) f9a_:]F  
        '************************************************************************* BvqypLI  
    s#>``E!  
        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) F.$NYr/|y  
    glUf. :]  
        ' Delete any z-shift(s) u(C?\HaH  
        count = 0 JW9U&Bj{  
        While GetOperationCount(eID)>count ;@s'JSPt  
            GetOperation eID, count, op ICm/9Onh&  
            If op.Type="ShiftZ" Then EZ)$lw/!J  
                DeleteOperation eID,count ;oivG)hJl  
                count=count-1 HwxME%w  
            End If (aX6jdvo  
            count=count+1 8dCa@r&tz  
        Wend dPb@[k  
    JG*Lc@Q  
        'Set new z-shift Dl=qss~g+  
        op.Type = "ShiftZ" v~KgCLo  
        op.val1 = tlens ~T:L0||.%9  
        op.parent = parID i1ss}JJp*  
        AddOperation eID, op ] :n! \G  
        Print "Set lens thickness = " & tlens "!z9UiA  
    <~iA{sY)O  
        '************************************************************************* g3kF&+2i  
        'Lens index of refraction XHYVcwmDz-  
        '************************************************************************* &- 2i+KjEX  
        eID = FindMaterial( "Lens" ) U( (F<  
        GetModelMaterial eID, mat g/BlTi  
    8j jq)d4#  
        mat.Nd = nlens :FWo,fq?:{  
        SetModelMaterial eID, mat zOT(>1'  
        Print "Set lens index of refraction = " & nlens ~]C m  
    }1? 2  
        '************************************************************************* `%Jq^uW  
        'Pupil diameter _su$]s  
        '************************************************************************* <j&LC /]o  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) Y4,LXuQ  
    :uQ~?amM  
        'Adjust pupil diameter (trimming volume inner hole) MClvmv^  
    [O\[,E"K  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" ![hVTZ,hyZ  
    PNG!q}(c  
        ' Adjust pupil location to just in front of the lens NTy0NH  
        parID = FindFullName( "Geometry.Arizona Eye" ) i5CBLv  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) /p7-D;  
        count = 0 5~E'21hJ  
        While GetOperationCount(eID)>count Mhiz{Td  
            GetOperation eID, count, op d'*:2;)g^  
            If op.Type="ShiftZ" Then MNV OloA  
                DeleteOperation eID,count |z]--h  
                count=count-1 <L>$Y#wU  
            End If 9vw0box  
            count=count+1 qJq2Z.>hy  
        Wend ht5eb"c+ 8  
        op.Type = "ShiftZ" * v W#XDx  
        op.val1 = taq-0.01 %eQw\o,a  
        op.parent = parID e sDd>W  
        AddOperation eID, op #b5V/)K  
    4.qW ~ W{  
        Print "Set pupil diameter = " & pupilDiam 5,u'p8}.  
    >uVr;,=y  
        'Update AZ Eye subassembly Description 7^*[ XH  
        eID = FindFullName( "Geometry.Arizona Eye" ) XfYhLE  
        GetEntity eID, entity w//L2.  
        entity.Description = "Accommodation = " & A & "D" #t?tt,nc}  
        SetEntity eID, entity eZk4 $y  
    %VmHw~xyF:  
        Update s6.#uT7h  
        Print "DONE!" cr"AK"TQ  
         {v~.zRW%]r  
    End Sub C3z#A3&J  
    kSq1Q#Bxq  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: 7qT>wCVT  
    e9@7GaL`"S  
    Accommodation = 4 Diopters 9>1Gj-S2:  
    Pupil Diameter = 4 mm 4Y:[YlfD.  
    Set aqueous humor thickness = 2.81 ,+hH|$  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 m[%*O#_  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 M73d^z  
    Set lens thickness = 3.927 > nOU 8  
    Set lens index of refraction = 1.42672 w|0w<K  
    Set pupil diameter = 4 & U6bOH%P  
    DONE! ">hOD'PG  
     
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