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infotek 2020-12-09 09:18

Arizona眼睛模型

简介 Z'i@;^=A  
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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。 atZe`0  
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模型 #]dm/WzY  
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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。 ZQlk 5  
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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. _WNbuk0  
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光源 B :%Vq2`  
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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。 )Ra:s>  
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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。 frcX'M}%  
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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。 N7s0Ua'-v  
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图2. 字母F光源的设定方法光 mP*$wE9b,:  
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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 :WRD<D_4  
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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。 ,Mw93Kp Va  
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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。 -,/7u3  
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图5. 视网膜重点采样规格设定
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脚本 "81'{\(I_  
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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: *m]Y6  
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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。 Hx6O Dj[-  
余下的脚本计算与屈光度有关的所有参数。 I'IFBVhaYn  
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分析 <N<0?GQ  
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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。 Yp(0XP5o  
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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 7[=G;2<  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. 8\;, d  
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Dim entity As T_ENTITY  p[&J l  
Dim op As T_OPERATION ~ ?nn(Q-  
Dim mat As T_MODELMATERIAL A'CD,R+gR  
Dim A As Double `ZL^+h<b>M  
Dim pupilDiam As Double [>`.,k  
Dim eID As Long ~H#c-B  
Dim parID As Long }],l m  
Dim count As Integer )-X8RRw'  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double &L0Ii)Ns  
Dim tlens As Double, nlens As Double T7i>aM$+  
Dim curv As Double, conic As Double Z?S?O#FED  
Dim ok As Long bCP2_h3*  
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Sub Main d(}? \|  
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    '用户输入对话框 +h-% {  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 [[_>D M  
        TextBox 220,21,40,21,.TextBox1 'default: 0 #O_%!7M{4  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 jh z*Y}MX  
        OKButton 40,91,90,21 i5(qJ/u  
        CancelButton 190,91,90,21 =~D[M)UO|  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 3KqRw (BK  
        TextBox 220,49,40,21,.TextBox2 'default: 4 IJ+}  
    End Dialog t0cS.hi  
    Dim dlg As UserDialog 2Rys:$  
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    ok = Dialog (dlg) hwk] ;6[  
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    If ok=0 Then    'cancel button was pressed /Q9Cvj)"  
        Print "Execution cancelled." s8A"x`5(  
        End Vxrj(knck,  
    End If w8 S pt  
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    'Assign accommodation and pupil diameter & use defaults if field left empty X)(K|[  
    If dlg.TextBox1 = "" Then ?$)a[UnqX  
        A = 0           'Default accommodation 3R$R?^G  
    Else q9x@Pc29d  
        A = CDbl(dlg.TextBox1) S7j(4@  
    End If i+QVs_jW  
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    If dlg.TextBox2 = "" Then wGMoh.GTh  
        pupilDiam = 4   'Default pupil diameter 1r4NP  
    Else m%eCTpYo  
        pupilDiam = CDbl(dlg.TextBox2) !m=Js"  
    End If BbFLT@W4  
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    Print " " K_t >T)K  
    Print "Accommodation = " & A & " Diopters" T/u61}'U{  
    Print "Pupil Diameter = " & pupilDiam & " mm" nQ'NS  
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    ' Calculate new parameters with accommodation (' %Y3z;  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness xc'uC bH  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens _&G_SNa  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens 1Q^u#m3  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens bCTN^  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens LIJ#nb  
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    tlens = 3.767 + 0.04*A                  'Lens thickness (-1{W^(  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction Dg~m}La  
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    'Adjust parameters to account for accommodation hX,RuI  
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    '************************************************************************* RI<s mt.Ng  
    'Aqueous thickness (Position of Lens) _8SB+s*  
    '************************************************************************* 7C Sn79E  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) C_ ;nlG6  
    GetCustomElement eID, entity _ZJQE>]nWu  
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    parID = FindFullName( "Geometry.Arizona Eye" ) B<myt79F_[  
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    ' Delete any shift(s) in z #CJ ET  
    count = 0 9A{D<h}yk  
    While GetOperationCount(eID)>count "7fEL:|j  
        GetOperation eID, count, op K)1Lg? j  
        If op.Type="ShiftZ" Then Q|VBH5}1O  
            DeleteOperation eID,count fGH)Fgo`  
            count=count-1 <tO@dI$~>  
        End If 2ER_?y  
        count=count+1 rT-.'aQ2t  
    Wend 9 M?UPE  
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    'Set new shift in x~m$(LT  
    op.Type = "ShiftZ" :%28*fl  
    op.val1 = taq 3z#> 1HD$  
    op.parent = parID ze LIOw  
    AddOperation eID, op VqD_FS;E  
    Print "Set aqueous humor thickness = " & taq-0.55 lHliMBSc  
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    '************************************************************************* M/xm6  
    'Radius and conic constant of anterior lens B4zuWCE@  
    '************************************************************************* UH7?JF-D  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) @yQ1F> t  
    GetConic eID, entity, curv, conic 7N5M=f.DS(  
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    SetConic eID, entity, 1/Rant, CCant ,T ^A?t  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant HsRoiqo  
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    '************************************************************************* [EVyCIcY,h  
    'Radius and conic constant of posterior lens {w ,^Z[<  
    '************************************************************************* Mx# P >.  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) GVf[H2%H  
    GetConic eID, entity, curv, conic :vS/Lzk  
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    SetConic eID, entity, 1/Rpost, CCpost ]$.w I~J%  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost |Ul4n@+2  
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    '************************************************************************* [%/B"w Tt  
    'Lens thickness (Position of posterior lens surface) vUL@i'0&o  
    '************************************************************************* hp7ni1V  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) P3a]*>.,  
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    ' Delete any z-shift(s) 2>J;P C[;  
    count = 0 :.{d,)G  
    While GetOperationCount(eID)>count \O~WMN  
        GetOperation eID, count, op U(~Nmo'  
        If op.Type="ShiftZ" Then OzH\YN  
            DeleteOperation eID,count 1b7?6CqV  
            count=count-1 3+ C;zDKa  
        End If ={p<|8`"  
        count=count+1 V.+a}J=Cw  
    Wend l4I',79l  
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    'Set new z-shift Ir- 1@_1Q  
    op.Type = "ShiftZ" ;d}n89DXj  
    op.val1 = tlens x6\^dVR}  
    op.parent = parID ^|!\IzDp  
    AddOperation eID, op ZXbq5p_  
    Print "Set lens thickness = " & tlens hO$29_^"  
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    '************************************************************************* ds2xl7jg  
    'Lens index of refraction tPw7zFy6r  
    '************************************************************************* h-m0Ro?6  
    eID = FindMaterial( "Lens" ) y#O/Xw  
    GetModelMaterial eID, mat Fv nf;']q  
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    mat.Nd = nlens e)L!4Y44K  
    SetModelMaterial eID, mat t?;=\%^<  
    Print "Set lens index of refraction = " & nlens J|z' <W  
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    '************************************************************************* Ghe@m6|D  
    'Pupil diameter ILHn~d IC  
    '************************************************************************* :19s=0  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) kWbY&]ZO  
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    'Adjust pupil diameter (trimming volume inner hole) 7i=ER*F~  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" Lk)TK/JM)  
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    ' Adjust pupil location to just in front of the lens X`]>J5  
    parID = FindFullName( "Geometry.Arizona Eye" ) S;{[];  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) k$,y1hH;f8  
    count = 0 Ml_!)b  
    While GetOperationCount(eID)>count S! .N3ezn  
        GetOperation eID, count, op YIl,8! z~  
        If op.Type="ShiftZ" Then fKs3H?|  
            DeleteOperation eID,count s21)*d  
            count=count-1 GlT/JZ9  
        End If U71A#OD^U  
        count=count+1 *m 6*sIR  
    Wend /\pUA!G)BD  
    op.Type = "ShiftZ" N VDvd6  
    op.val1 = taq-0.01 c[?&;# feV  
    op.parent = parID O-+!KXHd[  
    AddOperation eID, op ^$8WV&5q>  
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    Print "Set pupil diameter = " & pupilDiam S.owVMQ  
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    'Update AZ Eye subassembly Description ?&b"/sRS  
    eID = FindFullName( "Geometry.Arizona Eye" ) =?hbi]  
    GetEntity eID, entity p"n3JV.~k+  
    entity.Description = "Accommodation = " & A & "D" A+hT2Ew@t}  
    SetEntity eID, entity )U2%kmt  
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    Update :XO7#P  
    Print "DONE!" a S+i`A:a  
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End Sub 8WG_4e  
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如果屈光度是4,光瞳直径是4,则会输出如下数据: R9Y{kk0M  
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Accommodation = 4 Diopters 2AjP2  
Pupil Diameter = 4 mm &$pA,Gjin\  
Set aqueous humor thickness = 2.81 vLcOZ^iK  
Set anterior lens radius = 10.4 and conic constant = -2.375869 CWE^:kr6  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 `$r?^|T  
Set lens thickness = 3.927 \Xg`@JrTM  
Set lens index of refraction = 1.42672 ^aL> /'Y#|  
Set pupil diameter = 4 CSE!Abg  
DONE! !p 70g0+  
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