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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 @7%.7LK  
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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。 jQ|:I7y  
    =DC 3a3&%  
    模型 s%O Y<B@V2  
    |kc@L`7s  
    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。 V 9Hl1\j^  
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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. ?2ItTrlB  
    W+\?~L.  
    光源 T)~!mifX  
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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。 0<Q*7aY  
    !b63ik15O~  
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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。 !D;c,{Oz  
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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。 \7 Gz\=\LR  
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    图2. 字母F光源的设定方法光 ]Jn2Ra"j  
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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 = ^s$ <  
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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。 MMd.0JuaO  
    V&iS~V0.  
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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。 ~b6GrY"vB  
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    图5. 视网膜重点采样规格设定
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    脚本 'Wp @b678  
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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: RG1\=J$:E  
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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。 !i Jipe5  
    余下的脚本计算与屈光度有关的所有参数。 P)hi||[  
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    分析 "V}qf3 qU  
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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。 kceyuD$3G  
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    图7. 字母F在视网膜上颜色分析
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    脚本代码 ShGp^xVj  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. cmDT +$s  
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    Dim entity As T_ENTITY T5e^J"   
    Dim op As T_OPERATION 1tGgDbJU  
    Dim mat As T_MODELMATERIAL ix*muVBj.  
    Dim A As Double a g;dc  
    Dim pupilDiam As Double 8,*3zVk-  
    Dim eID As Long 6bL~6-h%)  
    Dim parID As Long (a#pvEY  
    Dim count As Integer NwpS)6<-  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double ti2  
    Dim tlens As Double, nlens As Double =/}X$,@2  
    Dim curv As Double, conic As Double HeozJ^u\?  
    Dim ok As Long mb{q(WEPP  
    H~Uq?!=b  
    Sub Main <5IQc[3]aP  
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        '用户输入对话框 ri=+(NKo-  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 {y-`QS  
            TextBox 220,21,40,21,.TextBox1 'default: 0 h<NRE0-  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 ,YB1 y)x  
            OKButton 40,91,90,21  zy>}L #  
            CancelButton 190,91,90,21 "% Y u wMY  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 u)~s4tP4  
            TextBox 220,49,40,21,.TextBox2 'default: 4 vYnftJK&  
        End Dialog WeVi] n  
        Dim dlg As UserDialog .NnGVxc5*  
    rQj~[Y.c  
        ok = Dialog (dlg) BIfi:7I;Q  
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        If ok=0 Then    'cancel button was pressed hSMV&Cs  
            Print "Execution cancelled." W[|[;{  
            End DsQ/aG9c%  
        End If BX3lP v  
    RL&lKHA  
        'Assign accommodation and pupil diameter & use defaults if field left empty OKPJuV`y6  
        If dlg.TextBox1 = "" Then % rcFT_  
            A = 0           'Default accommodation i!,HB|wQ  
        Else m =k%,J_  
            A = CDbl(dlg.TextBox1) r/PKrw sC  
        End If .@k*p>K  
    "&-C$J5 Id  
        If dlg.TextBox2 = "" Then 7>,rvW:]  
            pupilDiam = 4   'Default pupil diameter TB#N k5  
        Else PAoX$q  
            pupilDiam = CDbl(dlg.TextBox2) Ef,Cd[]b  
        End If K\^&+7&zVg  
    [@2s&Ct;  
        Print " " w+_Wc~f  
        Print "Accommodation = " & A & " Diopters" aU(tu2  
        Print "Pupil Diameter = " & pupilDiam & " mm" t?3BCm$Mi  
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        ' Calculate new parameters with accommodation f:vD`Fz1  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness  yekRwo|  
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        Rant = 12.0 - 0.4*A                     'Radius of anterior lens #T"64%dX  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens 3cThu43c  
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        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens I?M@5u  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens ML= z<u+  
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        tlens = 3.767 + 0.04*A                  'Lens thickness 5;Ia$lm=y  
    sykFSPy`'  
        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction {^m5#f 0"  
    61:9(*4~!F  
        'Adjust parameters to account for accommodation x'i0KF   
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        '************************************************************************* P) 1 EA;  
        'Aqueous thickness (Position of Lens) VDiOO  
        '************************************************************************* 2AK}D%jfc  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) (\& 62B1  
        GetCustomElement eID, entity !Uy>eji}  
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        parID = FindFullName( "Geometry.Arizona Eye" ) Z4@y?f v7s  
    7K:FeW'N  
        ' Delete any shift(s) in z \ V?I+Gc  
        count = 0 qZbHMTnT6  
        While GetOperationCount(eID)>count [YE?OQ7#  
            GetOperation eID, count, op 5hz_P+Q  
            If op.Type="ShiftZ" Then u+z~  
                DeleteOperation eID,count jw4TLc7p  
                count=count-1 KPggDKS  
            End If Cuv|6t75'  
            count=count+1 tJm{I)G  
        Wend ^c'f<<z|7r  
    26PD[af64O  
        'Set new shift in 3:AU:  
        op.Type = "ShiftZ" f4 O]`U  
        op.val1 = taq ccMd/  
        op.parent = parID h2;l1 G,  
        AddOperation eID, op 6t$N78U  
        Print "Set aqueous humor thickness = " & taq-0.55 (&c,twa~  
    3#mE( `|P  
        '************************************************************************* U8[Qw}T P  
        'Radius and conic constant of anterior lens tqhh<u;  
        '************************************************************************* `^%@b SE(  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) R@$+t:}  
        GetConic eID, entity, curv, conic nx$bM(.  
    ^U{P3 %uZ  
        SetConic eID, entity, 1/Rant, CCant t= *Jg/$  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant O{BW;Deo  
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        '************************************************************************* +f]u5p[  
        'Radius and conic constant of posterior lens TrQm]9@  
        '************************************************************************* y#e ?iE@  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) }VZM,.w  
        GetConic eID, entity, curv, conic 1tyNRoET  
    Q@Dkl F  
        SetConic eID, entity, 1/Rpost, CCpost X+*<B(E  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost b"3uD`  
    eA&t %  
        '************************************************************************* i'iO H|s  
        'Lens thickness (Position of posterior lens surface) wt\m+!u`  
        '************************************************************************* z L8J`W  
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        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) xD^wTtT  
    P eHW[\)  
        ' Delete any z-shift(s) MYu`c[$jZ  
        count = 0 {83C,C-  
        While GetOperationCount(eID)>count :mn(0 R~  
            GetOperation eID, count, op 1VGpq-4*j  
            If op.Type="ShiftZ" Then Bs@:rhDi  
                DeleteOperation eID,count +K&?)?/=  
                count=count-1 yZ|+VXO  
            End If wA1Ey:q  
            count=count+1 sX!3_ '-  
        Wend X&.:H~xS+  
    <OIUyZS  
        'Set new z-shift iel-<(~   
        op.Type = "ShiftZ" _hWuAJ9Qy  
        op.val1 = tlens 3l$E8?[Zwi  
        op.parent = parID ",QYDFFeF  
        AddOperation eID, op  d~sJ=)  
        Print "Set lens thickness = " & tlens X'xUwT|_+  
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        '************************************************************************* dB@FI  
        'Lens index of refraction {x9j_/R  
        '************************************************************************* r(]98a]o~  
        eID = FindMaterial( "Lens" ) m|lM.]2_  
        GetModelMaterial eID, mat {wHvE4F2  
    C_-%*]*,j  
        mat.Nd = nlens ,!r@9T  
        SetModelMaterial eID, mat {hM"TO7\  
        Print "Set lens index of refraction = " & nlens Y}S.37|+^  
    'V1!&Q6  
        '************************************************************************* X8i[fk1.R  
        'Pupil diameter hRa\1Jt>a  
        '************************************************************************* =pyVn_dg  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) k?< i*;7  
    ?P%|P   
        'Adjust pupil diameter (trimming volume inner hole) ]W+)ee|D  
    El{r$-}  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" > n1h^AW  
    Shs')Zs bv  
        ' Adjust pupil location to just in front of the lens C0gfJ~M )  
        parID = FindFullName( "Geometry.Arizona Eye" ) \|blRm;  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) )dqR<)  
        count = 0 ?vMK'"  
        While GetOperationCount(eID)>count "oHp.$+K  
            GetOperation eID, count, op /9P^{ OZ;y  
            If op.Type="ShiftZ" Then )sRN!~  
                DeleteOperation eID,count 'y< t/qo  
                count=count-1 7,f:Qi@g  
            End If U7jhV,gO4  
            count=count+1  ccRlql(  
        Wend $y8mK|3.3u  
        op.Type = "ShiftZ" JR] )xPI`  
        op.val1 = taq-0.01 s%5Uj }  
        op.parent = parID ZTr:xX{R6  
        AddOperation eID, op hK Fk$A  
    E2h(w_l  
        Print "Set pupil diameter = " & pupilDiam HJc<Gwm  
    +I*k0"gj6  
        'Update AZ Eye subassembly Description tsck|;v  
        eID = FindFullName( "Geometry.Arizona Eye" ) I; ^xAd3G  
        GetEntity eID, entity =sxkrih  
        entity.Description = "Accommodation = " & A & "D" UP}feN  
        SetEntity eID, entity B^H4Q 4-  
    :sU!PF[<  
        Update fDL3:%D  
        Print "DONE!" 9*BoYFw92*  
         jMTRcj];(  
    End Sub  o1 jk=  
    b*cW<vX}~  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: )gr}<}X)B  
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    Accommodation = 4 Diopters |Uc <;> l  
    Pupil Diameter = 4 mm \)FeuLGL9  
    Set aqueous humor thickness = 2.81 >s;oOo+5  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 4 U3C~J  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 rH[5~U  
    Set lens thickness = 3.927 (irk$d %  
    Set lens index of refraction = 1.42672 @m5O{[euj<  
    Set pupil diameter = 4 S4;wa6  
    DONE! i:C.8hmAE  
     
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