[技术]Arizona眼睛模型 [复制链接]

简介 cj$6  
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人眼光学模型可用来设计眼科用设备，光学系统注定了要与人眼一起使用。本文演示了这样一个模型：Arizona眼睛模型，在Jim Schwiegerling教授的书中有详细描述：《Field Guide to Visual and Ophthalmic Optics》。AZ眼睛模型达到了基于平均临床数据所决定的轴上和轴外像差等级。FRED文件包含了此眼睛模型及几个用来分析它的光源，并包括一个基于想要的屈光度来调整模型的内嵌脚本。 &#
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模型 [2c{
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模型的定义如表1种所示，由半径、圆锥常数、折射率、阿贝数、到下一面的距离等一系列表面组成。一些参数由屈光度（A）来决定。 []pN$]+c  
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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. ;0%OB*lcgE  
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光源 K\?]$dK5  
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多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 lCT{v@pp  
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除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处，并增加了pre-propagation distance= -8。尽管光线在光瞳处创建，规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射，而不是在光瞳处入射。 gE7L L=x  
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在往下看是内置的脚本用来修改屈光度，使其为4（250mm），光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 ;{Ux_JEg  
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视网膜的散射 X[$++p .
  
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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。 bZwnaM4"F  
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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。 Tny>D0Z#  
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脚本 4_?7&G0(  
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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： 6QQfQ,  
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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。 &"Ux6mF-"  
余下的脚本计算与屈光度有关的所有参数。 ,\)a_@@k  
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分析 cQNsL  
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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。 WN]<q`.  
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脚本代码 YPDf Y<?v  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. r),PtI0X  
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Dim entity As T_ENTITY mB'3N;~  
Dim op As T_OPERATION %:v`EjRD0  
Dim mat As T_MODELMATERIAL *~XA'Vw!  
Dim A As Double uzOYVN$t  
Dim pupilDiam As Double LaFZ?7@|}  
Dim eID As Long g2cVZ!GIj  
Dim parID As Long W~n.Xeu{C  
Dim count As Integer R[tC^]ai  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double -NGK@Yk22  
Dim tlens As Double, nlens As Double k`KGB  
Dim curv As Double, conic As Double OR6ML-|  
Dim ok As Long fT\:V5-  
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Sub Main OTWkUB{  
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    '用户输入对话框 t0&
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    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 Qq& W3  
        TextBox 220,21,40,21,.TextBox1 'default: 0 ]$-cMX  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 ed 59B)?l  
        OKButton 40,91,90,21 Rg&-0b  
        CancelButton 190,91,90,21 yc;3Id5?>  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 )EM7,xMz  
        TextBox 220,49,40,21,.TextBox2 'default: 4 !v|ISyK  
    End Dialog 5v.DX`"  
    Dim dlg As UserDialog bp<^R  
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    ok = Dialog (dlg) @r
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    If ok=0 Then    'cancel button was pressed rt-\g1x  
        Print "Execution cancelled." b]Kk2S/  
        End F'PQqb{  
    End If jjs&`Fy,  
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    'Assign accommodation and pupil diameter & use defaults if field left empty QWnndI_4p  
    If dlg.TextBox1 = "" Then  cc=gCE  
        A = 0           'Default accommodation "bQ[CD  
    Else fG L
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        A = CDbl(dlg.TextBox1) =v~1qWX  
    End If 8ip7^  
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    If dlg.TextBox2 = "" Then 8kL4~(hY  
        pupilDiam = 4   'Default pupil diameter *V^ #ga#A  
    Else i%Z2wP.o  
        pupilDiam = CDbl(dlg.TextBox2) VL+C&k v]  
    End If j`*N,*ha  
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    Print " " _,AzJ^  
    Print "Accommodation = " & A & " Diopters" 'm=*u SJK  
    Print "Pupil Diameter = " & pupilDiam & " mm" W_M'.1 t  
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    ' Calculate new parameters with accommodation yq[Cq=rBk  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness *4Fr&^M\  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens 7^TV~E#  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens 5`[n8mU  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens :&XH?/Wi  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens ~ AQp|  
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    tlens = 3.767 + 0.04*A                  'Lens thickness ;$j7H&UNQj  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction w)]H ^6  
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    'Adjust parameters to account for accommodation xG&SX#[2  
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    '************************************************************************* U!5)5c}G  
    'Aqueous thickness (Position of Lens) Kr`]_m  
    '************************************************************************* mY!iu(R1  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) )U<Y0bZA!
 
    GetCustomElement eID, entity ~|Y>:M+0Z  
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    parID = FindFullName( "Geometry.Arizona Eye" ) ~3h-jK?
 
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    ' Delete any shift(s) in z qa >Ay|92e  
    count = 0 =ziwxIo6  
    While GetOperationCount(eID)>count =4!nFi  
        GetOperation eID, count, op 1YxgR}7  
        If op.Type="ShiftZ" Then I,6/21kO  
            DeleteOperation eID,count cp Ear  
            count=count-1 oT
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        End If \[2lvft!  
        count=count+1 wmr-}Y!9u%  
    Wend *~$~yM/~3U  
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    'Set new shift in 4pz|1Hw7  
    op.Type = "ShiftZ" =TvzS%U  
    op.val1 = taq 4B+9z^oQ  
    op.parent = parID vdoZ&Tu  
    AddOperation eID, op Y]`.InG@  
    Print "Set aqueous humor thickness = " & taq-0.55 !{^\1QK  
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    '************************************************************************* y? (2U6c  
    'Radius and conic constant of anterior lens eBN)g^  
    '************************************************************************* )o _j]K+xI  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) o6kNx>tc)  
    GetConic eID, entity, curv, conic YMpf+kN  
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    SetConic eID, entity, 1/Rant, CCant H%f:K2  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant IputF<p  
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    '************************************************************************* 5wtTP ;P  
    'Radius and conic constant of posterior lens Q'B6^%:<~  
    '************************************************************************* qd@&59zSh  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) sPAg)6&M  
    GetConic eID, entity, curv, conic 5__+_hO ;3  
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    SetConic eID, entity, 1/Rpost, CCpost c2SC|s]  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost U4?(A@z9^  
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    '************************************************************************* (AY9oei>  
    'Lens thickness (Position of posterior lens surface) {0\,0*^p  
    '************************************************************************* Z-=YM P ]Q  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) V)o,1  
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    ' Delete any z-shift(s) )(Iy<Y?#  
    count = 0 tYW>t9  
    While GetOperationCount(eID)>count w&&2H8  
        GetOperation eID, count, op ?^H
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        If op.Type="ShiftZ" Then nCg66-3A  
            DeleteOperation eID,count XdgUqQb}  
            count=count-1 :q3+AtF  
        End If u8
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        count=count+1 9W*+SlH@!  
    Wend <T?oKOD ]  
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    'Set new z-shift n ?[/ufl  
    op.Type = "ShiftZ" D.!~dyI.,$  
    op.val1 = tlens }SyxPXs  
    op.parent = parID !SOrCMHx  
    AddOperation eID, op PrF}a<:n:  
    Print "Set lens thickness = " & tlens S|AM9*k9  
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    '************************************************************************* kW3E =pr  
    'Lens index of refraction _hf4A8ak  
    '************************************************************************* QA!_} N4n  
    eID = FindMaterial( "Lens" ) iSRpfU  
    GetModelMaterial eID, mat Eq%@"-mo  
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    mat.Nd = nlens n7aU<`U  
    SetModelMaterial eID, mat E&$_`m;  
    Print "Set lens index of refraction = " & nlens 4] > ]-b  
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    '************************************************************************* =%)+%[wv  
    'Pupil diameter Uh}seB#mJj  
    '************************************************************************* $V>98M>j  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) 59uwB('|lH  

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    'Adjust pupil diameter (trimming volume inner hole) $>M<j  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" XK(`mEi  
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    ' Adjust pupil location to just in front of the lens "ceed)(:  
    parID = FindFullName( "Geometry.Arizona Eye" ) MWk:sBCqr  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) 2],_^XBvB  
    count = 0 ~`;rNnOT3  
    While GetOperationCount(eID)>count X8eJ4%  
        GetOperation eID, count, op Z[!d*O%R_  
        If op.Type="ShiftZ" Then _#e&t"@GS  
            DeleteOperation eID,count ajl 2I/D  
            count=count-1 %WG9 dYdS  
        End If jdeV|H} u  
        count=count+1 ({0)@+V8  
    Wend W)j|rz.  
    op.Type = "ShiftZ" TZir>5  
    op.val1 = taq-0.01 $5`!Z%>/  
    op.parent = parID V+-$jOh  
    AddOperation eID, op j Ib  
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    Print "Set pupil diameter = " & pupilDiam v}G]X Z8  
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    'Update AZ Eye subassembly Description jg 2qGC  
    eID = FindFullName( "Geometry.Arizona Eye" ) 7DW]JK l  
    GetEntity eID, entity pqM~l&  
    entity.Description = "Accommodation = " & A & "D" s}&bJ"!Z  
    SetEntity eID, entity m^%|ZTrwN7  
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    Update NW|f7 ItX  
    Print "DONE!" p5=|Y^g !  
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End Sub rRES8/  
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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： z9 u$~  
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Accommodation = 4 Diopters !U_K&f  
Pupil Diameter = 4 mm %ugHhS!  
Set aqueous humor thickness = 2.81 5 v^yQ<70  
Set anterior lens radius = 10.4 and conic constant = -2.375869 7x]4`#u  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 o{v&.z  
Set lens thickness = 3.927 Ph&urxH@  
Set lens index of refraction = 1.42672 rn@`yTw^  
Set pupil diameter = 4 _s,ao'/  
DONE! vP%tk s+.