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infotek 2022-02-25 09:52

Arizona眼睛模型

简介 >s*ZT%TF  
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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。 ph5rS<  
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模型 DAvF ND$=  
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模型的定义如表1种所示,由半径、圆锥常数、折射率、阿贝数、到下一面的距离等一系列表面组成。一些参数由屈光度(A)来决定。 Dej_(Dz_S  
Table 1. AZ眼睛模型的定义
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在FRED中使用0屈光度来创建的,光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. 6$.I>8n  
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光源 VyF|d? b  
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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。 p]lZ4#3  
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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。 8? U!PW  
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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。 |L}1@0i  
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图2. 字母F光源的设定方法光 wr`+xYuuC=  
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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 ,JU3 w  
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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。 AP:(/@K|  
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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。 VnU/_# n  
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图5. 视网膜重点采样规格设定
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脚本 3_ P<0%  
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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: [t}@>@W|  
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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。 Ug P  
余下的脚本计算与屈光度有关的所有参数。 6o cTQ}=  
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分析 #`5>XfbmQ(  
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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。 iTu~Y<'m  
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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 YLU.]UC  
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  1. Option Explicit     'Remove this to enable non-dimensioned variables to be used. ]IM/R@  
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    Dim entity As T_ENTITY =3H*%  
    Dim op As T_OPERATION G)8H9EV  
    Dim mat As T_MODELMATERIAL 0Z&ua  
    Dim A As Double 8bf~uHAr  
    Dim pupilDiam As Double 7 ~9Lj  
    Dim eID As Long b+tm[@|,v  
    Dim parID As Long o+% ($p  
    Dim count As Integer 8iwH^+h~  
    Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double xWuvT,^  
    Dim tlens As Double, nlens As Double F5s`AjU  
    Dim curv As Double, conic As Double d&owS+B{48  
    Dim ok As Long }9*NEU) o  
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    Sub Main !M(3[(Ni  
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        '用户输入对话框 JF6=0  
        Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 m.b}A'GT  
            TextBox 220,21,40,21,.TextBox1 'default: 0 ? \p,s-CR:  
            Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 {;^GKb+  
            OKButton 40,91,90,21 hx$b Y  
            CancelButton 190,91,90,21 k8S`44vj  
            Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 m+=L}[  
            TextBox 220,49,40,21,.TextBox2 'default: 4 ^$x1~}D  
        End Dialog |Ca %dg9$@  
        Dim dlg As UserDialog 2SRmh!hr  
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        ok = Dialog (dlg) K4vOy_wT  
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        If ok=0 Then    'cancel button was pressed l<8+>W`_  
            Print "Execution cancelled." |FP@NUX\  
            End d]I3zS IC  
        End If &S9O:>=*  
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        'Assign accommodation and pupil diameter & use defaults if field left empty &j!q9F  
        If dlg.TextBox1 = "" Then i0g/'ZP  
            A = 0           'Default accommodation O3En+m~3n)  
        Else o! Y61S(  
            A = CDbl(dlg.TextBox1) i@o'Fc  
        End If )>r sX)  
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        If dlg.TextBox2 = "" Then ,UATT]>  
            pupilDiam = 4   'Default pupil diameter X 3(CY`HH[  
        Else Rxl/)H[Lc"  
            pupilDiam = CDbl(dlg.TextBox2) qE@H~&  
        End If :P?zy|aBi  
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        Print " " )F3>  
        Print "Accommodation = " & A & " Diopters" W;^6=(&xn  
        Print "Pupil Diameter = " & pupilDiam & " mm" |gwGCa+  
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        ' Calculate new parameters with accommodation 8!|LJI  
        taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness z:W|GDD1  
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        Rant = 12.0 - 0.4*A                     'Radius of anterior lens ' )~G2Ys  
        CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens yGE)EBH  
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        Rpost = -5.224557 + 0.2*A               'Radius of posterior lens 0RGqpJxk  
        CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens L',7@W  
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        tlens = 3.767 + 0.04*A                  'Lens thickness ~zc B@; :  
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        nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction KF}_|~~T  
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        'Adjust parameters to account for accommodation K'zBDrkW-x  
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        '************************************************************************* _[{oK G^u  
        'Aqueous thickness (Position of Lens) GN=-dLN  
        '************************************************************************* \(`,z}Ht _  
        eID = FindFullName( "Geometry.Arizona Eye.Lens" ) 5O]eD84B  
        GetCustomElement eID, entity sHm :G_  
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        parID = FindFullName( "Geometry.Arizona Eye" ) tvR|!N }  
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        ' Delete any shift(s) in z f,:2\b?.  
        count = 0 2|D<0d#W  
        While GetOperationCount(eID)>count sZ%wQqy~k  
            GetOperation eID, count, op 2^ kK2D$o  
            If op.Type="ShiftZ" Then G&@vTcF  
                DeleteOperation eID,count M6:$ 0(r  
                count=count-1 }ZkGH}K_}  
            End If @i>o+>V  
            count=count+1 m:5x"o7)ln  
        Wend m?]= =9  
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        'Set new shift in R/ 3#(5  
        op.Type = "ShiftZ" mExJ--}  
        op.val1 = taq pL`)^BJ  
        op.parent = parID gM_MK8py  
        AddOperation eID, op 0*50uK=5  
        Print "Set aqueous humor thickness = " & taq-0.55 yPT\9"/  
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        '************************************************************************* WS2@; 8.N  
        'Radius and conic constant of anterior lens YnW,6U['{g  
        '************************************************************************* (&xIB F_6  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) s,]z6L0  
        GetConic eID, entity, curv, conic eGi|S'L'  
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        SetConic eID, entity, 1/Rant, CCant g7O , <  
        Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant FcmL 4^s.`  
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        '************************************************************************* 2/RW(U  
        'Radius and conic constant of posterior lens AN4(]_ ]  
        '************************************************************************* b*dEX%H8sf  
        eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) 3TF'[(K=  
        GetConic eID, entity, curv, conic 3y]rhB  
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        SetConic eID, entity, 1/Rpost, CCpost P/ 7aj:h~P  
        Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost 2br~Vn0N  
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        '************************************************************************* d1hXzJs  
        'Lens thickness (Position of posterior lens surface) 'jjJ[16"d  
        '************************************************************************* Vo(V<2lw}  
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        parID = FindFullName( "Geometry.Arizona Eye.Lens" ) @+(a{%~7y  
    4 k y/a1y-  
        ' Delete any z-shift(s) ~[`*)(4E  
        count = 0 _{48s8V  
        While GetOperationCount(eID)>count !?J?R-C  
            GetOperation eID, count, op %\?Gzc_  
            If op.Type="ShiftZ" Then (m& ''yaH  
                DeleteOperation eID,count -r@/8"  
                count=count-1 ^ Mw=!n[  
            End If .tt=\R  
            count=count+1 &T[BS;  
        Wend )ioIn`g^-  
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        'Set new z-shift avEsX_.  
        op.Type = "ShiftZ" m_,j)A%  
        op.val1 = tlens of>}fJ_p  
        op.parent = parID /<it2=  
        AddOperation eID, op VIg=| Oe),  
        Print "Set lens thickness = " & tlens k=JT%  
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        '************************************************************************* ,7*-%05[\  
        'Lens index of refraction b@yFqgJ_  
        '************************************************************************* z+F:_  
        eID = FindMaterial( "Lens" ) VO+3@d:  
        GetModelMaterial eID, mat kq=tL@W`0}  
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        mat.Nd = nlens 4Vrx9 sA1  
        SetModelMaterial eID, mat _~_6qTv-d  
        Print "Set lens index of refraction = " & nlens 2Wq/_:  
    b%M|R%)]  
        '************************************************************************* I<L<xwh1(E  
        'Pupil diameter 6Rc%P)6  
        '************************************************************************* u(P;) E"1  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) ?*A"#0  
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        'Adjust pupil diameter (trimming volume inner hole) R; Gf3K  
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        SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder"  =[G)  
    :h)A/k_  
        ' Adjust pupil location to just in front of the lens 8@'Q=".J  
        parID = FindFullName( "Geometry.Arizona Eye" ) }doJ= lc  
        eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) )uIH onXU  
        count = 0 Mv^G%zg2  
        While GetOperationCount(eID)>count 32ae? d  
            GetOperation eID, count, op 8GFA}_(^R  
            If op.Type="ShiftZ" Then 1[r;  
                DeleteOperation eID,count L}5IX)#gH  
                count=count-1 Lmw{ `R  
            End If C*fSPdg?  
            count=count+1 HnmByn\j  
        Wend *) ?Fo  
        op.Type = "ShiftZ" _I}rQfPJ  
        op.val1 = taq-0.01 ^7&0P m  
        op.parent = parID HOY9{>E}z  
        AddOperation eID, op t(F] -[  
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        Print "Set pupil diameter = " & pupilDiam C/je5  
    t?R=a-ZI  
        'Update AZ Eye subassembly Description \qh -fW; #  
        eID = FindFullName( "Geometry.Arizona Eye" ) !%_H1jk  
        GetEntity eID, entity hr] :bR  
        entity.Description = "Accommodation = " & A & "D" ViG4tb  
        SetEntity eID, entity Uv"GG: K_  
    Sk 10"DB/  
        Update !rMl" Y[  
        Print "DONE!" pr(16P  
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    End Sub #Zy-X_r  
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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: 63?fn~0\  
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    Accommodation = 4 Diopters 'hM?J*m  
    Pupil Diameter = 4 mm >@o}l:*  
    Set aqueous humor thickness = 2.81 I=3e@aTZ,  
    Set anterior lens radius = 10.4 and conic constant = -2.375869 ii :h E=  
    Set posterior lens radius = -4.424557 and conic constant = -3.081019 #815h,nP+  
    Set lens thickness = 3.927 (SlrV8;  
    Set lens index of refraction = 1.42672 ceu}Lp^%/  
    Set pupil diameter = 4 (mJqI)m8  
    DONE!
silence唯爱 2022-02-25 13:53
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