[分享]Arizona眼睛模型 [复制链接]

简介 PG
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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。 w`UB_h#Bl  
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模型 qWfG@hn  
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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。 BI3Q~ADV  
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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. +q|2j>k@  
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光源 Q!(C$&f  
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多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 oL
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除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处，并增加了pre-propagation distance= -8。尽管光线在光瞳处创建，规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射，而不是在光瞳处入射。  I?.$  
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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。 weEmUw Z  
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视网膜的散射 Q *![u5#  
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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。 Ig-9Y;hdmn  
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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。 Eb7qM.Q] &  
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脚本 > nDx)!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： bJj<xjBM  
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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。 oe}nrkmb  
余下的脚本计算与屈光度有关的所有参数。 4&~ft  
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分析 rhO ]4A  
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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。 vz</|s  
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脚本代码 T]l_B2.  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. Q* ifmnB'  
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Dim entity As T_ENTITY
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Dim op As T_OPERATION ;Oh4W<hH}  
Dim mat As T_MODELMATERIAL aT$q1!U`j2  
Dim A As Double 9JV(}v5[  
Dim pupilDiam As Double x48Y#"'  
Dim eID As Long D *RF._  
Dim parID As Long ;Y5"[C9|  
Dim count As Integer L']EYK5  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double 7^P!@o$v!  
Dim tlens As Double, nlens As Double zA=gDuy3@  
Dim curv As Double, conic As Double T>2)YOx  
Dim ok As Long L!x7]g,^  
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Sub Main M)C.bo{p  
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    '用户输入对话框 S^? @vj  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 -K hXb  
        TextBox 220,21,40,21,.TextBox1 'default: 0 i% 19|an  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 -H5n>j0!{  
        OKButton 40,91,90,21 2qLRcA=R  
        CancelButton 190,91,90,21 fEf",{I  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 h4N!zj[  
        TextBox 220,49,40,21,.TextBox2 'default: 4
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    End Dialog rT9
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    Dim dlg As UserDialog )
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    ok = Dialog (dlg) ,rVm81-2  
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    If ok=0 Then    'cancel button was pressed vU0j!XqE  
        Print "Execution cancelled." O3WhO@`6)  
        End Ve#VGlI  
    End If ~n9BN'@x  
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    'Assign accommodation and pupil diameter & use defaults if field left empty 6*9hAnH  
    If dlg.TextBox1 = "" Then t"k6wv;Tq  
        A = 0           'Default accommodation p!BZTwP  
    Else :M)B#@ c=  
        A = CDbl(dlg.TextBox1) S7&w r@  
    End If ~9c?g(0  
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    If dlg.TextBox2 = "" Then L/dG0a@1X  
        pupilDiam = 4   'Default pupil diameter L"6qS3[=  
    Else xvOGE]n  
        pupilDiam = CDbl(dlg.TextBox2) `p1szZD&  
    End If U\'.rT[#  
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    Print " " u~FXO[b  
    Print "Accommodation = " & A & " Diopters" 0PO'9#  
    Print "Pupil Diameter = " & pupilDiam & " mm" 8##-fv]  
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    ' Calculate new parameters with accommodation m|
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    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness &.D3f"  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens m"*j J.MX  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens Hf!o6 o  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens fQ c%a1'  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens m?bd6'&FR  
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    tlens = 3.767 + 0.04*A                  'Lens thickness WtOpxAq  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction yx?Z&9z <  
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    'Adjust parameters to account for accommodation 0; GnR0  
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    '************************************************************************* \x?q!(;G2  
    'Aqueous thickness (Position of Lens) VL=.JwK  
    '************************************************************************* _1jd{?kt  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) B@g 0QgA  
    GetCustomElement eID, entity Y^DS~CrM  
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    parID = FindFullName( "Geometry.Arizona Eye" ) (8DJ
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    ' Delete any shift(s) in z 8JxJ>I-9p  
    count = 0 <?UbzT7X  
    While GetOperationCount(eID)>count "`]G>,r_  
        GetOperation eID, count, op P(pw$ q$S  
        If op.Type="ShiftZ" Then H0<(j(JK  
            DeleteOperation eID,count _Kdqa%L !  
            count=count-1 NFq&a i  
        End If MTJ ."e<B  
        count=count+1 iIWz\FM  
    Wend [iVCorU  
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    'Set new shift in
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    op.Type = "ShiftZ" 6[fpe  
    op.val1 = taq
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    op.parent = parID e0iE6:i  
    AddOperation eID, op /Y$UJt  
    Print "Set aqueous humor thickness = " & taq-0.55 W" >[sn|  
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    '************************************************************************* GPBp.$q+B  
    'Radius and conic constant of anterior lens +-tvNX%IJ  
    '************************************************************************* )yvI {  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) cojtQD
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    GetConic eID, entity, curv, conic
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    SetConic eID, entity, 1/Rant, CCant k"_i7  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant On x[}x  
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    '************************************************************************* IvuKpX>*  
    'Radius and conic constant of posterior lens egQB!%D  
    '************************************************************************* ~uy{6U{&I  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) CqW:m*c  
    GetConic eID, entity, curv, conic NIZN}DnP  
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    SetConic eID, entity, 1/Rpost, CCpost Py2AnpYa  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost 533n z8&9@  
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    '************************************************************************* &+V6mH9m@  
    'Lens thickness (Position of posterior lens surface) mS?.xu  
    '************************************************************************* g'2'K  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) K_/-mwA v  
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    ' Delete any z-shift(s) A+3,y<j\  
    count = 0 ZlaU+Y(_[  
    While GetOperationCount(eID)>count *12,MO>go  
        GetOperation eID, count, op 4n6EkTa  
        If op.Type="ShiftZ" Then #p'Xq }]  
            DeleteOperation eID,count zTA+s 2  
            count=count-1 Uc oVp}vl  
        End If ee7#PE]}  
        count=count+1 hcWYz  
    Wend R9=K/  

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    'Set new z-shift <}e2\x  
    op.Type = "ShiftZ" )qXl8HI  
    op.val1 = tlens ;. jnRPo";  
    op.parent = parID \HR<^xY  
    AddOperation eID, op PL+r*M%ll  
    Print "Set lens thickness = " & tlens >K]s)VuWR  
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    '************************************************************************* WhPwD6l>  
    'Lens index of refraction 7G,{BBB  
    '************************************************************************* ey'x3s_  
    eID = FindMaterial( "Lens" ) o1jDQ+  
    GetModelMaterial eID, mat Fh2$,$ 2  
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    mat.Nd = nlens S b0p?  
    SetModelMaterial eID, mat "J51\8G@@  
    Print "Set lens index of refraction = " & nlens }M3f ?Jv  
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    '************************************************************************* q. zBm@:  
    'Pupil diameter ]IX6>p,  
    '************************************************************************* rHS;wT  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) B 4s^X`?z  

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    'Adjust pupil diameter (trimming volume inner hole) ^]nnvvp  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" &yu3nA:7D  
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    ' Adjust pupil location to just in front of the lens 7Jm&z/  
    parID = FindFullName( "Geometry.Arizona Eye" ) $bf&ct*$h  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) U[l7n3Y=  
    count = 0 \*>r[6]*&5  
    While GetOperationCount(eID)>count R$[nYw  
        GetOperation eID, count, op +TA'P$j  
        If op.Type="ShiftZ" Then ;rBd_  
            DeleteOperation eID,count ].E89_|O  
            count=count-1
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        End If G8]DK3#  
        count=count+1 fY)Dx c&ue  
    Wend X<pg^Y0  
    op.Type = "ShiftZ" OR{<)L  
    op.val1 = taq-0.01 Y}db<Cz X  
    op.parent = parID $-HP5Kj(k-  
    AddOperation eID, op oJ r&9.S  
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    Print "Set pupil diameter = " & pupilDiam r>!$eqX_  
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    'Update AZ Eye subassembly Description G~$.Af!9W  
    eID = FindFullName( "Geometry.Arizona Eye" ) ,r
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    GetEntity eID, entity hxwo<wEg  
    entity.Description = "Accommodation = " & A & "D" s& INcjC  
    SetEntity eID, entity s^atBqw,  
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    Update U;o$=,_p  
    Print "DONE!" 8$!&D&v  
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End Sub ]4{ )VXod  
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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： kTC'`xv  
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Accommodation = 4 Diopters wiwAdYEQ\  
Pupil Diameter = 4 mm @W4tnM,#  
Set aqueous humor thickness = 2.81 5=;LHS*   
Set anterior lens radius = 10.4 and conic constant = -2.375869 we4k VAn  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 gD13(G98  
Set lens thickness = 3.927 >GbCRN~  
Set lens index of refraction = 1.42672 i~};5j(  
Set pupil diameter = 4 iy<|<*s2D  
DONE! y4@zi"G  
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