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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 2B`#c}PP  
    O;m@fS2%3  
    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。 d&ap u{  
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    模型 6-!U\R2Z>  
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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。 w/UZ6fu  
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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. *Z:'jV<  
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    光源  QnN cGH  
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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。 IyJHKDFk  
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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。 .lE7v -e  
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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。 ^p}|""\j  
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    图2. 字母F光源的设定方法光 lw j,8  
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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|2@z-Sp-  
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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。 ZA{T0:  
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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。 `j)S7KN  
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    图5. 视网膜重点采样规格设定
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    脚本 Al-;-t#Dc  
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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: yDe6f(D  
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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。 E 8LA+dKN:  
    余下的脚本计算与屈光度有关的所有参数。 vj,OX~|  
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    分析 aTLu7C\-e  
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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。 Q!*}^W  
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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 ~4^~w#R  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. ?_V&~?r   
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    Dim entity As T_ENTITY T0TgV  
    Dim op As T_OPERATION orON)S ks  
    Dim mat As T_MODELMATERIAL PXrv2q[5?  
    Dim A As Double #ExNiFZ  
    Dim pupilDiam As Double :f_fp(T  
    Dim eID As Long hb ="J349  
    Dim parID As Long #X t|"Z  
    Dim count As Integer w]O [{3"  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double "&Rt&S  
    Dim tlens As Double, nlens As Double sFbN)Cx  
    Dim curv As Double, conic As Double scQnL'\  
    Dim ok As Long ?%A9}"q]  
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    Sub Main SPN5H;{[]K  
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        '用户输入对话框 n4sO#p)'  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 uEui{_2$  
            TextBox 220,21,40,21,.TextBox1 'default: 0 H~:EPFi.(  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 a${<~M hm  
            OKButton 40,91,90,21 slTE.  
            CancelButton 190,91,90,21 e%_J O7  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 'B\7P*L"p  
            TextBox 220,49,40,21,.TextBox2 'default: 4 Q&]f9j_  
        End Dialog |5TzRz  
        Dim dlg As UserDialog G$mAyK:  
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        ok = Dialog (dlg) L.?QZN%cN  
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        If ok=0 Then    'cancel button was pressed cXod43  
            Print "Execution cancelled." F87/p  
            End ItD&L ))  
        End If C C B'  
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        'Assign accommodation and pupil diameter & use defaults if field left empty (Cb;=:3G  
        If dlg.TextBox1 = "" Then MSaOFv_Q  
            A = 0           'Default accommodation nq5qUErew  
        Else JnIE6@g<y  
            A = CDbl(dlg.TextBox1) ^_gH}~l+U  
        End If XY^]nm-{I  
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        If dlg.TextBox2 = "" Then Qg]+&8!*  
            pupilDiam = 4   'Default pupil diameter p|+TgOYOc  
        Else 0,whTnH|  
            pupilDiam = CDbl(dlg.TextBox2) \,S4-~(:!  
        End If 6,cJ3~!48  
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        Print " " g{^~g  
        Print "Accommodation = " & A & " Diopters" )uu(I5St  
        Print "Pupil Diameter = " & pupilDiam & " mm" =}g-N)^  
    74r$)\q  
        ' Calculate new parameters with accommodation ryNe=9p  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness HtV8=.^  
    |*$0~mA  
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens FBxg^g%PB@  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens B~B,L*kC2  
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        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens 3Fw7q"  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens MY}/h@  
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        tlens = 3.767 + 0.04*A                  'Lens thickness Cto>~pV  
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        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction rf+Z0C0WYi  
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        'Adjust parameters to account for accommodation 8]mRX~  
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        '************************************************************************* !dq$qUl/  
        'Aqueous thickness (Position of Lens) a<J< Oc!  
        '************************************************************************* ^8KxU  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) <JIqkGeAi  
        GetCustomElement eID, entity I?RUVs  
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        parID = FindFullName( "Geometry.Arizona Eye" ) ,BFw-A  
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        ' Delete any shift(s) in z RzU9]e  
        count = 0 _(-i46x}  
        While GetOperationCount(eID)>count ,xg-H6Xfa{  
            GetOperation eID, count, op xR8y"CpE  
            If op.Type="ShiftZ" Then {n&GZG"f  
                DeleteOperation eID,count x_t$*  
                count=count-1 ZUD{V  
            End If  ~)F_FS  
            count=count+1 rJh$>V+ '  
        Wend 6"?#E[ #[  
    g/(BV7V  
        'Set new shift in 5=\^DeM@ H  
        op.Type = "ShiftZ" WcQkeh3n  
        op.val1 = taq 8"TlWHF`  
        op.parent = parID 4V c``Um  
        AddOperation eID, op P%ThW9^vnj  
        Print "Set aqueous humor thickness = " & taq-0.55 Jd~Mq9(  
    &dPUd ~&EL  
        '************************************************************************* I@5$<SN  
        'Radius and conic constant of anterior lens 1]9l SE!E7  
        '************************************************************************* bI^F (  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) cc3/XBo  
        GetConic eID, entity, curv, conic BNe>Lko  
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        SetConic eID, entity, 1/Rant, CCant 5 `@yX[G  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant /;vHAtt;f  
    b6xz\zCL  
        '************************************************************************* cY Qm8TR<  
        'Radius and conic constant of posterior lens v_WF.sb~  
        '************************************************************************* EEMRy  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) @-Y,9mM   
        GetConic eID, entity, curv, conic re,}}'  
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        SetConic eID, entity, 1/Rpost, CCpost R#i`H(N  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost bN6i*) }  
    tt CC] Q  
        '************************************************************************* O\gVB!x  
        'Lens thickness (Position of posterior lens surface) ;VEKrVD  
        '************************************************************************* scTt53v^  
    *CbV/j"P?  
        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) ;.<HpDfG_  
    rxs:)# ?A  
        ' Delete any z-shift(s) R\Ckk;<$  
        count = 0 u{w,y.l1h  
        While GetOperationCount(eID)>count #2lvRJB  
            GetOperation eID, count, op E^A!k=>  
            If op.Type="ShiftZ" Then ]826kpq_  
                DeleteOperation eID,count G*,7pc  
                count=count-1 ef!f4u\  
            End If aK]AhOG   
            count=count+1  4CtWEq  
        Wend |lk:(~DM  
    Jw>na _FJ  
        'Set new z-shift m>3\1`ZF~<  
        op.Type = "ShiftZ" :6Tv4ZUvcG  
        op.val1 = tlens So75h*e  
        op.parent = parID u#`51Hr$  
        AddOperation eID, op KV-h~C  
        Print "Set lens thickness = " & tlens 6'x3g2C/  
    ^N7 C/" p  
        '************************************************************************* O4:_c-V2  
        'Lens index of refraction :Rnwyj])  
        '************************************************************************* ic4hO>p&  
        eID = FindMaterial( "Lens" ) zD<8.AIGC  
        GetModelMaterial eID, mat ];5Auh 0o  
    r:Q=6j,  
        mat.Nd = nlens B9Wd '  
        SetModelMaterial eID, mat G'';VoW=   
        Print "Set lens index of refraction = " & nlens I~Qi):&x  
    w~jm0jK]  
        '************************************************************************* LU8:]zOY  
        'Pupil diameter Ct zW do.  
        '************************************************************************* +\u\BJ!LAJ  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) FQE(qltf,  
    pSEaE9AX%  
        'Adjust pupil diameter (trimming volume inner hole)  DO9K  
    o}f$?{)|   
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" }W(t> >  
    O(9*VoD  
        ' Adjust pupil location to just in front of the lens NB86+2stu  
        parID = FindFullName( "Geometry.Arizona Eye" ) lDF7~N9J_  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) rhX?\_7o  
        count = 0 :7JP(j2  
        While GetOperationCount(eID)>count PfB9 .f{  
            GetOperation eID, count, op 94]i|2qj*  
            If op.Type="ShiftZ" Then U.b|3E/^  
                DeleteOperation eID,count *UXa.kT@  
                count=count-1 Fey^hx w =  
            End If jGo\_O<of  
            count=count+1 /[ft{:#&t  
        Wend ;O 5Iu  
        op.Type = "ShiftZ" &3x da1H  
        op.val1 = taq-0.01 jxt]Z3a~0  
        op.parent = parID <b\8<mTr  
        AddOperation eID, op .2_xTt   
    f^F"e'1  
        Print "Set pupil diameter = " & pupilDiam (H:A|Lw  
    84i0h$ZZo  
        'Update AZ Eye subassembly Description 4L4u<  
        eID = FindFullName( "Geometry.Arizona Eye" ) =W2I0nr.  
        GetEntity eID, entity hd[t&?{=  
        entity.Description = "Accommodation = " & A & "D" wlslG^^(!  
        SetEntity eID, entity I3izLi  
    Fpwhyls  
        Update Nez '1  
        Print "DONE!" _JA)""l%  
         ^gNbcWc7CU  
    End Sub 0]$-}AYM  
    -/*VR$c  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: g:U -kK!i  
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    Accommodation = 4 Diopters sJl>evw  
    Pupil Diameter = 4 mm )7Qp9Fxo  
    Set aqueous humor thickness = 2.81 C@-cLk  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 b^()[4M;  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 yJlRW!@&:  
    Set lens thickness = 3.927 )KkV<$  
    Set lens index of refraction = 1.42672 "A5z!6T{  
    Set pupil diameter = 4 jqTK7b  
    DONE! ,9ew75Jl  
     
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