[技术]Arizona眼睛模型 [复制链接]

简介 P#w}3^  
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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。 )?F$-~7  
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模型 wCV>F-  
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模型的定义如表1种所示，由半径、圆锥常数、折射率、阿贝数、到下一面的距离等一系列表面组成。一些参数由屈光度（A）来决定。 17WNJ  
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在FRED中使用0屈光度来创建的，光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. Oyi;bb<#  
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光源 =$^Wkau  
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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。 f@wsSm  
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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。 \Pw8wayr%  
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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。 I(z>)S'7r  
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视网膜的散射 B`g<Ge~  
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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。 <{$ev&bQ  
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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。 fl} rz  
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脚本 [ea6dv4p  
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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： XX]5T`D  
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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。 {toyQ)C7  
余下的脚本计算与屈光度有关的所有参数。 el <<D  
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分析 [<#<:h
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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。 E[)7tr  
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脚本代码 J{nyo1A  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. h]J&A  
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Dim entity As T_ENTITY p?dGZ2` [I  
Dim op As T_OPERATION 8\qCj.>S  
Dim mat As T_MODELMATERIAL ka?IX9t\  
Dim A As Double <Dt/Rad  
Dim pupilDiam As Double % j[O&[s}  
Dim eID As Long -4*'WzWr  
Dim parID As Long 2x<Qt2"  
Dim count As Integer iF#}t(CrH  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double %\(y8QV  
Dim tlens As Double, nlens As Double T+AlcOP  
Dim curv As Double, conic As Double 9#Aipu\  
Dim ok As Long ,<uiitOo  
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Sub Main '(3Nopl  
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    '用户输入对话框 YLA557~  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 %=NM_5a}]  
        TextBox 220,21,40,21,.TextBox1 'default: 0 |xsV(jK8  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 8!o{W=m^4  
        OKButton 40,91,90,21 >D`fp  
        CancelButton 190,91,90,21 U}RS*7`  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 ~uhyROO,G"  
        TextBox 220,49,40,21,.TextBox2 'default: 4 M5cOz|j/*R  
    End Dialog zCBtD_@  
    Dim dlg As UserDialog #.\,y>`  
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    ok = Dialog (dlg) }%o+1 <=  
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    If ok=0 Then    'cancel button was pressed c:h.J4mv  
        Print "Execution cancelled." 6mI_Q2  
        End Y2=Brtc[@  
    End If m'Ekp  
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    'Assign accommodation and pupil diameter & use defaults if field left empty DuO%B  
    If dlg.TextBox1 = "" Then A]tf>H#1  
        A = 0           'Default accommodation ~`G;=ITo  
    Else h0QYoDvbC  
        A = CDbl(dlg.TextBox1) G)tq/`zNw  
    End If L5zG0mC8  
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    If dlg.TextBox2 = "" Then UALg!M#  
        pupilDiam = 4   'Default pupil diameter c5B_WqjJ  
    Else T}w*K[z $  
        pupilDiam = CDbl(dlg.TextBox2) CD8JYiJ  
    End If JL.ydH79  
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    Print " " -KIVnV=&m  
    Print "Accommodation = " & A & " Diopters"
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    Print "Pupil Diameter = " & pupilDiam & " mm" a!0?L0_W&  
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    ' Calculate new parameters with accommodation skR,M=F~  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness ZHiICh|et%  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens 80s~ae;  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens B(en5|  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens _Y ><ih  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens SVg@xu+  
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    tlens = 3.767 + 0.04*A                  'Lens thickness g<hv7?"[  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction ](9{}DHV  
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    'Adjust parameters to account for accommodation XY+au
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    '************************************************************************* xPfnyAo?%z  
    'Aqueous thickness (Position of Lens) l9ifUhe  
    '************************************************************************* St3(1mApl  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) *(\;}JF-  
    GetCustomElement eID, entity .~A"Wyu\  
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    parID = FindFullName( "Geometry.Arizona Eye" ) 2LxVt@_R!%  
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    ' Delete any shift(s) in z %8}ksl07  
    count = 0 LG&Q>pt.  
    While GetOperationCount(eID)>count , R.+-X  
        GetOperation eID, count, op XJxs4a1[t  
        If op.Type="ShiftZ" Then /_k hFw  
            DeleteOperation eID,count /[0 /8f6  
            count=count-1 !(ux.T0  
        End If ]!tYrSM!  
        count=count+1 E!}-qbH^  
    Wend }%>$}4 ,  
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    'Set new shift in #Lxj )  
    op.Type = "ShiftZ" |Z7bd^  
    op.val1 = taq L$TKO,T  
    op.parent = parID mk`cyN>m  
    AddOperation eID, op P{i8  
    Print "Set aqueous humor thickness = " & taq-0.55 L$u&~"z-  
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    '*************************************************************************
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    'Radius and conic constant of anterior lens *Xtc`XH  
    '************************************************************************* 6B;_uIq5  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) j=jrzG+`  
    GetConic eID, entity, curv, conic B> "r-O  
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    SetConic eID, entity, 1/Rant, CCant 0Li'a{n2  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant :AE;x&  
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    '************************************************************************* 3~3(G[w  
    'Radius and conic constant of posterior lens &v9PT!R~  
    '************************************************************************* m/F(h-?  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" )  0[!gk]p  
    GetConic eID, entity, curv, conic .vOpU4  
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    SetConic eID, entity, 1/Rpost, CCpost iB`WXU  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost w6In{uO-Z  
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    '************************************************************************* #<i><EG  
    'Lens thickness (Position of posterior lens surface)
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    '************************************************************************* O->(9k<  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) :qSi>KCGh  
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    ' Delete any z-shift(s) %J ( }D7-,  
    count = 0 f({-j%m  
    While GetOperationCount(eID)>count gl7vM  
        GetOperation eID, count, op +uiH0iGS  
        If op.Type="ShiftZ" Then 9@z|2z2\G  
            DeleteOperation eID,count g@6X|W5,J  
            count=count-1 rPGE-d3  
        End If y:[VRLo  
        count=count+1 +i_f.Ipp  
    Wend .6Lhy3x  
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    'Set new z-shift `:BQ&T%UQR  
    op.Type = "ShiftZ" J
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    op.val1 = tlens 'SD|ObBY  
    op.parent = parID A&lgiR*ObT  
    AddOperation eID, op -"dy z(  
    Print "Set lens thickness = " & tlens 4k2c mM$  
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    '************************************************************************* iN/!k.ybW}  
    'Lens index of refraction 6p]R)K>wS  
    '************************************************************************* }}bi#G:R+  
    eID = FindMaterial( "Lens" ) u-M$45vct  
    GetModelMaterial eID, mat qH$rvD!]  
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    mat.Nd = nlens FjLv*K[#d  
    SetModelMaterial eID, mat dVtLYx  
    Print "Set lens index of refraction = " & nlens Cv(N5mA2  
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    '************************************************************************* C\>Mt  
    'Pupil diameter ?gMrcc/{  
    '************************************************************************* 3)Awj++  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) +:Q/<^Z  
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    'Adjust pupil diameter (trimming volume inner hole) )7%]<2V%  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" (5DGs_>  
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    ' Adjust pupil location to just in front of the lens e}yu<~v_  
    parID = FindFullName( "Geometry.Arizona Eye" ) X%1.mTU~K  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) 7{6.  
    count = 0 /z?7ic0  
    While GetOperationCount(eID)>count PEn^.v@  
        GetOperation eID, count, op /(pD^D  
        If op.Type="ShiftZ" Then qg:I+"u  
            DeleteOperation eID,count M9jo<+  
            count=count-1 Rpd/9x.)&  
        End If gw"l&r  
        count=count+1 `ur9KP4Dq  
    Wend C2|2XL'l(C  
    op.Type = "ShiftZ" z2q5f:d8  
    op.val1 = taq-0.01 4m(>"dHP  
    op.parent = parID Au*?)X- $  
    AddOperation eID, op H;Qn?^  
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    Print "Set pupil diameter = " & pupilDiam YYr&r.6  
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    'Update AZ Eye subassembly Description (BQ3M-  
    eID = FindFullName( "Geometry.Arizona Eye" ) $$f$$  
    GetEntity eID, entity 7b%
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    entity.Description = "Accommodation = " & A & "D" 4S EC4yO  
    SetEntity eID, entity A.x}%v,E  
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    Update :;Rt#!  
    Print "DONE!" +5|nCp6||j  
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End Sub 2
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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： 4 Wd5Goe:  
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Accommodation = 4 Diopters T`{M
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Pupil Diameter = 4 mm VgTI2  
Set aqueous humor thickness = 2.81 'J0s%m|j  
Set anterior lens radius = 10.4 and conic constant = -2.375869 _W@Fk)E6N  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 _rVX_   
Set lens thickness = 3.927 _`
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Set lens index of refraction = 1.42672 q&6=oss!  
Set pupil diameter = 4 t%B!\]  
DONE! ZDJWd
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