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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 <"HbX  
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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。 ;Svs|]d  
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    模型 4lsg%b6_%,  
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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。 -+,3aK<[  
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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. ]IeyJ  
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    光源 #Ks2a):8  
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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。 KL^hYjC  
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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。 W,-fnJk  
    ]zUvs6ksLG  
    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。 tZ*z.3\<  
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    图2. 字母F光源的设定方法光 *c{X\!YBh  
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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 /AhN$)(O  
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    在散射文件中,有一个名为“Retina surface”的72%的反射型朗伯散射,它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射,改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 5rPK7Jh`B  
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    图4. 视网膜朗伯散射设定
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    注意在视网膜的表面有散射重点采样规格定义,在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳,半角度10度。 0fP-[7P  
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    图5. 视网膜重点采样规格设定
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    脚本 alz2F.%Y  
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    内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框,如下图所示: MFqM 6_  
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    图6. 用户对话框的创建与编辑
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    图7. 用户对话框编辑器
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    如果“OK”按钮按下,将会核对对话框下面的代码行,如果点击取消则脚本终止。然后输入的参数赋予变量,如果此处是保留为空白,则使用默认值。因此,如果没有值输入并点击“OK”按钮,则脚本是以屈光度为0,光瞳直径为4mm来运行的。 pj/w9j G6  
    余下的脚本计算与屈光度有关的所有参数。 i?D KKjN$  
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    分析 j c-$l  
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    屈光度为4,光瞳直径为4mm,字母F点在视网膜上所成的像。 V+- ]txu|  
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    图7. 字母F在视网膜上颜色分析
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    脚本代码 #s]'2O  
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    Option Explicit     'Remove this to enable non-dimensioned variables to be used. wr{ [4$O  
    +#=l{_Z,ZJ  
    Dim entity As T_ENTITY dRu|*s  
    Dim op As T_OPERATION %FSY}65  
    Dim mat As T_MODELMATERIAL 9:1[4o)~  
    Dim A As Double vpL3XYs`  
    Dim pupilDiam As Double F!pgec%]'  
    Dim eID As Long zd-qQ.j0  
    Dim parID As Long 3,[#%}1(S  
    Dim count As Integer 9?L,DThQ  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double 2SHS!6:Rl  
    Dim tlens As Double, nlens As Double =&YhA}l\O  
    Dim curv As Double, conic As Double D g~L"  
    Dim ok As Long QxS=W2iN  
    71(C@/J  
    Sub Main =}^J6+TVL  
    w/UZ6fu  
        '用户输入对话框 w(-h!d51+  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 {j!+\neL  
            TextBox 220,21,40,21,.TextBox1 'default: 0 3sF^6<E  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 o b,%); m  
            OKButton 40,91,90,21 ?X5Y8n]y\h  
            CancelButton 190,91,90,21 M# a1ev  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 >Ndck2@  
            TextBox 220,49,40,21,.TextBox2 'default: 4 nlsif  
        End Dialog 6L4<c+v_  
        Dim dlg As UserDialog unZYFA}(  
    8{ooLdpX7  
        ok = Dialog (dlg) K|^'`FpPO  
    f tE2@}  
        If ok=0 Then    'cancel button was pressed =/zb$d cz  
            Print "Execution cancelled." N:nhS3N<L  
            End "2 "gTS  
        End If DJ.n8hne  
    `%oJa`  
        'Assign accommodation and pupil diameter & use defaults if field left empty #'lqE)T  
        If dlg.TextBox1 = "" Then h#o?O k  
            A = 0           'Default accommodation G>f2E49BXt  
        Else Q-7C'|  
            A = CDbl(dlg.TextBox1) 8AgKK=C =  
        End If D_2~ 6  
    Fh0cOp(  
        If dlg.TextBox2 = "" Then e$=UA%  
            pupilDiam = 4   'Default pupil diameter !wNj;ST*  
        Else 7 S 6@[-E  
            pupilDiam = CDbl(dlg.TextBox2) @})]4H  
        End If !eE;MaS>  
    ~8l(,N0  
        Print " " (]gd$BgD  
        Print "Accommodation = " & A & " Diopters" q"C(`S.@  
        Print "Pupil Diameter = " & pupilDiam & " mm" !${7)=|=1  
    PT/TQW  
        ' Calculate new parameters with accommodation 9hn+eU  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness pB0p?D)n  
    l+HF+v$  
        Rant = 12.0 - 0.4*A                     'Radius of anterior lens SSo7 U  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens p;0p!~F=49  
    mJN*DP{  
        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens rO3.%B}  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens ^T&@(|o  
    hw9qnSeRy  
        tlens = 3.767 + 0.04*A                  'Lens thickness }fT5(+ Wo  
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        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction INjr$'*  
    Ef~Ar@4fA  
        'Adjust parameters to account for accommodation -'%>Fon  
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        '************************************************************************* :XFr"aSt  
        'Aqueous thickness (Position of Lens) J<;@RK,c_  
        '************************************************************************* cM 5V%w  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) }"x#uG  
        GetCustomElement eID, entity 3[F9qDAy  
    PXrv2q[5?  
        parID = FindFullName( "Geometry.Arizona Eye" ) Z`]r)z%f  
    3Z%~WE;I  
        ' Delete any shift(s) in z )Bw}T  
        count = 0 <reALC  
        While GetOperationCount(eID)>count DV{0|E  
            GetOperation eID, count, op s{9 G//  
            If op.Type="ShiftZ" Then pB5#Ho>S  
                DeleteOperation eID,count <N'v-9=2jl  
                count=count-1 '^!#*O  
            End If :tf'Gw6v  
            count=count+1 l' mdj!{&  
        Wend L'L[Vpx  
    |w].*c}Z  
        'Set new shift in `~k`m{4.a  
        op.Type = "ShiftZ" ,[UK32KWI  
        op.val1 = taq N(Sc!rX  
        op.parent = parID gzd<D}2F~  
        AddOperation eID, op +=MN_  
        Print "Set aqueous humor thickness = " & taq-0.55 6"YcM:5~  
    YG_|L[/#  
        '*************************************************************************  PrqyJ  
        'Radius and conic constant of anterior lens (|9t+KP  
        '************************************************************************* 4..M *U  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) m"/ o4  
        GetConic eID, entity, curv, conic Aw$+Ew[8 2  
    Lvd es.0|  
        SetConic eID, entity, 1/Rant, CCant q5xF~SQGw2  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant w<&R|= 93  
    Lm3~< vP1e  
        '************************************************************************* ^V7'S<  
        'Radius and conic constant of posterior lens z3Zo64V~7  
        '************************************************************************* g^: & Dh  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) zvbO q  
        GetConic eID, entity, curv, conic G_]zymXQ  
    Ji)Ys ebV  
        SetConic eID, entity, 1/Rpost, CCpost b[KZJLZ)  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost %zz,qs)Eu  
    ZA+w7S3  
        '************************************************************************* "IN[(  
        'Lens thickness (Position of posterior lens surface) BIh^b?:zU  
        '************************************************************************* vzFo"  
    \2))c@@%  
        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) ey@ccc*sZ9  
    {n\Ai3F-  
        ' Delete any z-shift(s) 4$+1&+@ ]  
        count = 0 +Ly@5y"  
        While GetOperationCount(eID)>count +L|x^ B3  
            GetOperation eID, count, op mg]t)+PQ  
            If op.Type="ShiftZ" Then FrC)2wX  
                DeleteOperation eID,count V+5av Z}  
                count=count-1 q ;"/i*+3  
            End If ykYef  
            count=count+1 fE"-W{M  
        Wend Z 4QL&?U  
    qV0GpVJZU?  
        'Set new z-shift *#9?9SYSk  
        op.Type = "ShiftZ" jwpahy;\WL  
        op.val1 = tlens Du #>y!  
        op.parent = parID "`NAg  
        AddOperation eID, op ua E,F^p  
        Print "Set lens thickness = " & tlens (q@%eor&}  
    )FN\jo!!.  
        '************************************************************************* 6WX?Xc]$3  
        'Lens index of refraction 6UI6E)g  
        '************************************************************************* q|V|Jl  
        eID = FindMaterial( "Lens" ) KM"BHaSkF  
        GetModelMaterial eID, mat ,_ TE@ ]!$  
    C8W_f( i~  
        mat.Nd = nlens 1~Z   
        SetModelMaterial eID, mat vnWt8?)]^  
        Print "Set lens index of refraction = " & nlens (mplo|>  
    2H1 [ oD[  
        '************************************************************************* EM(%|#  
        'Pupil diameter ++n_$Qug  
        '************************************************************************* K~4bT=   
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) $*`E;}S0  
    IrUoAQ2xpG  
        'Adjust pupil diameter (trimming volume inner hole) 9k \M<jA  
    fA"c9(>m%]  
        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" $xCJ5M4  
    }@"v7X $  
        ' Adjust pupil location to just in front of the lens _Wq;bKG  
        parID = FindFullName( "Geometry.Arizona Eye" ) +/ {lz8^,  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) WcQkeh3n  
        count = 0 8"TlWHF`  
        While GetOperationCount(eID)>count 4V c``Um  
            GetOperation eID, count, op T"t.t%(8  
            If op.Type="ShiftZ" Then E@EP9X >  
                DeleteOperation eID,count jGoQXiX  
                count=count-1 Yxy!&hPLv:  
            End If YC$>D? FW  
            count=count+1 #0?3RP  
        Wend Apj[z2nr  
        op.Type = "ShiftZ" 3-oKY*jO  
        op.val1 = taq-0.01 p( )LQT!  
        op.parent = parID <*+[E!oi  
        AddOperation eID, op <,Pl31g^  
    hYh~%^0dt  
        Print "Set pupil diameter = " & pupilDiam f:t j   
    cY Qm8TR<  
        'Update AZ Eye subassembly Description v_WF.sb~  
        eID = FindFullName( "Geometry.Arizona Eye" ) f|ERZN`uB  
        GetEntity eID, entity nBLb1T  
        entity.Description = "Accommodation = " & A & "D" =dwy 4  
        SetEntity eID, entity OsW*@v(  
    }u1h6rd `  
        Update gW^4@q  
        Print "DONE!" )?I*zc  
         8)M WC:  
    End Sub 6Eus_aP  
    mN> (n+ly  
    如果屈光度是4,光瞳直径是4,则会输出如下数据: NB5lxaL  
    F@HJ3O9  
    Accommodation = 4 Diopters GvvKM=1  
    Pupil Diameter = 4 mm a_]l?t  
    Set aqueous humor thickness = 2.81 \%9QE  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 )TyP{X>  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 OG_v[  C5  
    Set lens thickness = 3.927 _k;HhLj`  
    Set lens index of refraction = 1.42672 )| |CU]"b?  
    Set pupil diameter = 4 J qmL|S)  
    DONE! ;JMmr-@  
     
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