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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 v&(=^A\eN  
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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。 !q,7@W3i  
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    模型 J_7@d]0R  
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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。 XkkzY5rxOc  
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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. ^n<YO=|u  
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    光源 Cse`MP  
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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。 u=qaz7E  
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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。 NOwd'iU  
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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。 q2J |koT  
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    图2. 字母F光源的设定方法光 ?< ^8,H  
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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 ~E((n  
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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。 XEbVsw  
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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。 vV$t`PEY  
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    图5. 视网膜重点采样规格设定
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    脚本 YkMFU'?[  
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    内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框,如下图所示: P (7Q8i'  
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    图6. 用户对话框的创建与编辑
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    图7. 用户对话框编辑器
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    如果“OK”按钮按下,将会核对对话框下面的代码行,如果点击取消则脚本终止。然后输入的参数赋予变量,如果此处是保留为空白,则使用默认值。因此,如果没有值输入并点击“OK”按钮,则脚本是以屈光度为0,光瞳直径为4mm来运行的。 ?B;7J7T  
    余下的脚本计算与屈光度有关的所有参数。 ,g}$u'A+d  
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    分析 %X.g+uu  
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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 P&u  
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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 w{dRf!b69  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. K-\wx5#l/  
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    Dim entity As T_ENTITY VVAcbAGJ  
    Dim op As T_OPERATION aXqig&:  
    Dim mat As T_MODELMATERIAL d9U)O6=  
    Dim A As Double &PL=nI\)  
    Dim pupilDiam As Double Mb[4_Dc  
    Dim eID As Long *_YR*e0^nN  
    Dim parID As Long F.aG7  
    Dim count As Integer 1aIGC9xQ`  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double t7u*j-YE  
    Dim tlens As Double, nlens As Double &}Wi@;G]2  
    Dim curv As Double, conic As Double r9N?z2X  
    Dim ok As Long b(R.&X  
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    Sub Main CP; <B1  
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        '用户输入对话框 `5h^!="  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 0{ B<A^Bf  
            TextBox 220,21,40,21,.TextBox1 'default: 0 :vEfJSA 1<  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 M[z1B!rT  
            OKButton 40,91,90,21 !e<2o2~.  
            CancelButton 190,91,90,21 2*O# m  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 ;>6~}lMgJ  
            TextBox 220,49,40,21,.TextBox2 'default: 4 {*hvzS{1d  
        End Dialog N2}Y8aR~  
        Dim dlg As UserDialog Rzs u 7w  
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        ok = Dialog (dlg) 8'zl\:@N  
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        If ok=0 Then    'cancel button was pressed tCO?<QBE  
            Print "Execution cancelled." p6BDhT(RS  
            End 0U*f"5F  
        End If 8N"WKBj|_d  
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        'Assign accommodation and pupil diameter & use defaults if field left empty 1,OkuyXy!>  
        If dlg.TextBox1 = "" Then %>9L}OAm  
            A = 0           'Default accommodation :NWIUN  
        Else Wp:vz']V  
            A = CDbl(dlg.TextBox1) d`flYNg4  
        End If ;8&/JSN M  
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        If dlg.TextBox2 = "" Then d oEuKT  
            pupilDiam = 4   'Default pupil diameter T+B-R\@t  
        Else G}l9 [lE  
            pupilDiam = CDbl(dlg.TextBox2) 6QT&{|q=  
        End If Cc{{9Ud  
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        Print " " -R]~kGa6m<  
        Print "Accommodation = " & A & " Diopters" H? z~V-8  
        Print "Pupil Diameter = " & pupilDiam & " mm" FCwE/ 2,  
    k= 9+"4:  
        ' Calculate new parameters with accommodation WFk%nO/  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness ]ke9ipj]:  
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        Rant = 12.0 - 0.4*A                     'Radius of anterior lens ]v>[r?X#V  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens pi#a!Quf\  
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        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens d6[' [dG  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens tl~ZuS/  
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        tlens = 3.767 + 0.04*A                  'Lens thickness z(%tu  
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        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction 6[R6P:v&'G  
    8`)* ?Q9~  
        'Adjust parameters to account for accommodation }xBO;  
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        '************************************************************************* ',]Aj!q  
        'Aqueous thickness (Position of Lens) ey9hrRMR  
        '************************************************************************* VR1]CN"G  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) CC3 i@  
        GetCustomElement eID, entity f2o6GC_  
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        parID = FindFullName( "Geometry.Arizona Eye" ) "bRjY?D  
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        ' Delete any shift(s) in z F[jqJzCz  
        count = 0 0iR?r+|  
        While GetOperationCount(eID)>count <{;'0> ToM  
            GetOperation eID, count, op ,38M6yD  
            If op.Type="ShiftZ" Then ?Q"<AL>Z  
                DeleteOperation eID,count 7\yh(+kN  
                count=count-1 - uO(qUa#  
            End If 4B[pQlg  
            count=count+1 9-_Lc<  
        Wend gq*W 0S  
    r 20!   
        'Set new shift in +0*\q  
        op.Type = "ShiftZ" =a=:+q g  
        op.val1 = taq <<gW`KF   
        op.parent = parID K+M\E[1W  
        AddOperation eID, op II _CT=  
        Print "Set aqueous humor thickness = " & taq-0.55  gsi2  
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        '************************************************************************* ]:2Ro:4Yv  
        'Radius and conic constant of anterior lens baTd;`Pn  
        '************************************************************************* "x;FE<I  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) bk=;=K  
        GetConic eID, entity, curv, conic SQU@JKi; g  
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        SetConic eID, entity, 1/Rant, CCant Ho(}_Q&  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant m;xa}b{(i  
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        '************************************************************************* (gvnIoDl0  
        'Radius and conic constant of posterior lens o2$A2L9P  
        '************************************************************************* ZR|s]'  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) Wql=PqF  
        GetConic eID, entity, curv, conic 1TfFWlf[B  
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        SetConic eID, entity, 1/Rpost, CCpost |=VWE>g  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost 2{ l|<'  
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        '************************************************************************* ,+OVRc  
        'Lens thickness (Position of posterior lens surface) /5epDDP-t5  
        '************************************************************************* sD?Ynpt  
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        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) [K4 k7$  
    -%>Tjo@B n  
        ' Delete any z-shift(s) dikX_ Q>D  
        count = 0 K+L9cv4 |*  
        While GetOperationCount(eID)>count ,SdxIhL  
            GetOperation eID, count, op qJl DQc-  
            If op.Type="ShiftZ" Then n,-*$~{  
                DeleteOperation eID,count A4d3hF~l`  
                count=count-1 #^|2PFh5  
            End If +5R8mbD!  
            count=count+1 @J^ Oy 3z  
        Wend qyy .&+  
    mxJe\[I  
        'Set new z-shift \YF;/KwX$  
        op.Type = "ShiftZ" wNFx1u^/)  
        op.val1 = tlens 5__B M5|  
        op.parent = parID j3+ hsA/(k  
        AddOperation eID, op Q=[ IO,f  
        Print "Set lens thickness = " & tlens &"Cy&[  
    )`W|J%w+  
        '************************************************************************* =)iAU/*N  
        'Lens index of refraction E"/k"1@  
        '************************************************************************* 4v5qK  
        eID = FindMaterial( "Lens" ) vs$. i  
        GetModelMaterial eID, mat /Gb)BJk!  
    p R`nQM-D  
        mat.Nd = nlens )N3/;U;  
        SetModelMaterial eID, mat j2:9ahW  
        Print "Set lens index of refraction = " & nlens O\]{6+$fm!  
    QJx<1#  
        '************************************************************************* ehe#"exCB  
        'Pupil diameter D6yE/QeK4  
        '************************************************************************* $kR%G{j 4  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) T|(w-)mv  
    D=5%lL  
        'Adjust pupil diameter (trimming volume inner hole) Y|/,*,u+  
    j#p3<V S4  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" ]D2 d=\  
    pA@R,O>zr  
        ' Adjust pupil location to just in front of the lens .ubZ  
        parID = FindFullName( "Geometry.Arizona Eye" ) dIQ3snG  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) awQB0ow'$P  
        count = 0 *'{9(Oj  
        While GetOperationCount(eID)>count l[WX77bp=  
            GetOperation eID, count, op L1@<7?@X  
            If op.Type="ShiftZ" Then G/(tgQ  
                DeleteOperation eID,count iM8l,Os]<f  
                count=count-1 @qA11C.hq  
            End If jEP'jib%  
            count=count+1 i{HzY[  
        Wend gKWUHlQY  
        op.Type = "ShiftZ" Q;m8 drU  
        op.val1 = taq-0.01 ):L0{W{  
        op.parent = parID 3|URlz  
        AddOperation eID, op zE}ry!{  
    {e[~1]j3  
        Print "Set pupil diameter = " & pupilDiam !0KN A1w,  
    Ogh,  
        'Update AZ Eye subassembly Description ^p%3@)&  
        eID = FindFullName( "Geometry.Arizona Eye" ) l?^}n(_.  
        GetEntity eID, entity `'bu8JK  
        entity.Description = "Accommodation = " & A & "D" <hgfgk7<  
        SetEntity eID, entity N{Pa&/V  
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        Update mGw*6kOIS  
        Print "DONE!" kp)1s>c  
         a72L%oJ   
    End Sub ;_=dB[M  
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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: h?->A#  
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    Accommodation = 4 Diopters `yRt?UQRS  
    Pupil Diameter = 4 mm mJVru0  
    Set aqueous humor thickness = 2.81 pWoeF=+y]W  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 s|:j~>53  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 X#MC|Fzy@  
    Set lens thickness = 3.927 %=vU Z4  
    Set lens index of refraction = 1.42672 Y5mk*Q#q  
    Set pupil diameter = 4  y]ya.YG  
    DONE! ?,eq86-M  
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    QQ:2987619807 R:44Gv7  
     
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