[技术]Arizona眼睛模型 [复制链接]

简介 LE7o[<>  
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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。 '8dqJ`Gj  
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模型 R)#"Ab Z'  
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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。 *6uiOtH  
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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. )&*&ZL0  
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光源 [\I\).  
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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。 Q 5Ln'La$  
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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。 9;:
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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。 ,\Cy'TSz  
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视网膜的散射 OYe @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。 /H}83 C  
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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。 ;X\,-pjv  
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脚本 ny{|{a  
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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： D(yRI  
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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。 {]`O$S  
余下的脚本计算与屈光度有关的所有参数。 $ -;,O8yR  
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分析 Qb/qUUQO;0  
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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。 gaVWfG  
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脚本代码 mI@]{K}Q%  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. ;ZB[g78%R%  
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Dim entity As T_ENTITY v 6Tz7  
Dim op As T_OPERATION }>>BKn   
Dim mat As T_MODELMATERIAL Yaht<Hy  
Dim A As Double 9tWu>keu  
Dim pupilDiam As Double "\Z.YZUa\  
Dim eID As Long R Mrh@9g  
Dim parID As Long eNpGa0 eG  
Dim count As Integer |I6\_K.=L  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double N =)9O  
Dim tlens As Double, nlens As Double P;{f+I|`  
Dim curv As Double, conic As Double NO8)XJ3s  
Dim ok As Long l>Z"y\l=  
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Sub Main i_Ab0vye  
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    '用户输入对话框 .e~17}Ka}  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 *6?h,Dt L  
        TextBox 220,21,40,21,.TextBox1 'default: 0 EE=!Y NP]  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 4DaLmQ2O  
        OKButton 40,91,90,21 f9?\Q'v8  
        CancelButton 190,91,90,21 { owK~  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 O'*KNJX  
        TextBox 220,49,40,21,.TextBox2 'default: 4 9s7sn*aB#5  
    End Dialog [}}?a  
    Dim dlg As UserDialog F$F,I,$ "  
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    ok = Dialog (dlg) >$j?2,Za(V  
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    If ok=0 Then    'cancel button was pressed q ^Un,h64t  
        Print "Execution cancelled." >hQeu1 ~W  
        End |VQ17*4ff1  
    End If HN]roSt~  
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    'Assign accommodation and pupil diameter & use defaults if field left empty \]1qAF
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    If dlg.TextBox1 = "" Then =W$ f+  
        A = 0           'Default accommodation ;shhgz$  
    Else DD{-xCCR  
        A = CDbl(dlg.TextBox1) P>j^w#$n  
    End If 2+m%f"  
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    If dlg.TextBox2 = "" Then \R\?`8Orz  
        pupilDiam = 4   'Default pupil diameter m-Z<zEQ  
    Else jgNdcP  
        pupilDiam = CDbl(dlg.TextBox2) 3|x*lmit  
    End If wc`UcGO  
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    Print " " ^YiGvZJ  
    Print "Accommodation = " & A & " Diopters" 6}4?,r  
    Print "Pupil Diameter = " & pupilDiam & " mm" 3}~.#`QeY  
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    ' Calculate new parameters with accommodation wyJ
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    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness pY]T32  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens nI]8w6eCV  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens A:!_ &  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens 7vZtEwC)n  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens $FX
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    tlens = 3.767 + 0.04*A                  'Lens thickness a4aM.o  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction GWd71ZtFO  
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    'Adjust parameters to account for accommodation 5XtIVHA@{  
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    '************************************************************************* ,Y9bXC8+dU  
    'Aqueous thickness (Position of Lens) ISa}Km>Q  
    '************************************************************************* -4wr)zjfW  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) u|(;SY  
    GetCustomElement eID, entity X6 E^5m  
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    parID = FindFullName( "Geometry.Arizona Eye" ) F^4mO|  
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    ' Delete any shift(s) in z 'aV])(Wm>  
    count = 0 f[1 s4Dp3-  
    While GetOperationCount(eID)>count ^Mvgm3hg  
        GetOperation eID, count, op @~7y\G  
        If op.Type="ShiftZ" Then lC.Q61J@  
            DeleteOperation eID,count ,L_u X  
            count=count-1 {:;6 *W  
        End If Rp^fY_  
        count=count+1 hufpky[&8  
    Wend l(A)Gd5>  
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    'Set new shift in 'Nkd *  
    op.Type = "ShiftZ" wF=?EK(;P{  
    op.val1 = taq Hnft1   
    op.parent = parID iHa:6  
    AddOperation eID, op ]C'^&:&<  
    Print "Set aqueous humor thickness = " & taq-0.55 LO;7NK  
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    '************************************************************************* N=T 0Td  
    'Radius and conic constant of anterior lens qt{l
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    '************************************************************************* s,CN<`/>x  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" )  ^t}1$H  
    GetConic eID, entity, curv, conic 3s\}|LqX#  
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    SetConic eID, entity, 1/Rant, CCant -kk0zg &|i  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant 3-/F]}0y6  
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    '************************************************************************* G!)Q"+  
    'Radius and conic constant of posterior lens 0?o<cC1Z  
    '************************************************************************* Y6 <.]H  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) gWD46+A){  
    GetConic eID, entity, curv, conic T{So2@_&  
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    SetConic eID, entity, 1/Rpost, CCpost v?Zo5uVoq  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost &K*Kr=9
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    '************************************************************************* 8|L;y[v  
    'Lens thickness (Position of posterior lens surface) 9ls*L!Jw  
    '************************************************************************* W"Tj.oCUG  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) ^ 0
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    ' Delete any z-shift(s) 6bDizS}  
    count = 0 @+{F\SD\  
    While GetOperationCount(eID)>count -K (>uV!?  
        GetOperation eID, count, op f"z;'  
        If op.Type="ShiftZ" Then &g"`J`  
            DeleteOperation eID,count }  fa  
            count=count-1 (u4'*[o\t  
        End If W m&*  
        count=count+1 z3c7  
    Wend []jbzVwS2  
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    'Set new z-shift ~8&P*oFC  
    op.Type = "ShiftZ" ?bAv{1dvT=  
    op.val1 = tlens _lDNYpv  
    op.parent = parID J#gG*(  
    AddOperation eID, op UHgW-N"  
    Print "Set lens thickness = " & tlens x1h&`QUP  
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    '************************************************************************* sd9b9?qiu  
    'Lens index of refraction _+j#
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    '************************************************************************* p9 G{Q  
    eID = FindMaterial( "Lens" ) Jot7 L%,TB  
    GetModelMaterial eID, mat 4T]A! y{  
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    mat.Nd = nlens '#C5m#v  
    SetModelMaterial eID, mat .}5qi;CA  
    Print "Set lens index of refraction = " & nlens D*>#]0X  
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    '************************************************************************* Z,tHyyF?j  
    'Pupil diameter 1Va=.#<  
    '************************************************************************* ;|`<B7xf  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) D\Y,2!I  
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    'Adjust pupil diameter (trimming volume inner hole) .D;6 r4S  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" :p%#U$S4  
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    ' Adjust pupil location to just in front of the lens W] WH4.y  
    parID = FindFullName( "Geometry.Arizona Eye" ) yDJy'Z_F{  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) D|amKW7  
    count = 0 CpB,L  
    While GetOperationCount(eID)>count +|x{?%
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        GetOperation eID, count, op q
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        If op.Type="ShiftZ" Then (xE |T f  
            DeleteOperation eID,count `v-O 4Pk  
            count=count-1 ]9PG"<^k  
        End If &Yo|Pj  
        count=count+1 NG`Y{QT6N  
    Wend P,xIDj4d  
    op.Type = "ShiftZ" *$5p,m6G  
    op.val1 = taq-0.01 N~0ihTG5  
    op.parent = parID }'?qUy3x  
    AddOperation eID, op eY-h<K)y  
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    Print "Set pupil diameter = " & pupilDiam @q`T#vd  
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    'Update AZ Eye subassembly Description 6#AEVRJKU@  
    eID = FindFullName( "Geometry.Arizona Eye" ) VR .t  
    GetEntity eID, entity 4AKr.a0q  
    entity.Description = "Accommodation = " & A & "D" 5F!Qn\{u{  
    SetEntity eID, entity w3 kkam"  
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    Update [Y~~C J  
    Print "DONE!" 4"H*hKp  
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End Sub ZyDNtX%  
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如果屈光度是4，光瞳直径是4，则会输出如下数据： g?xD*3<  
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Accommodation = 4 Diopters OR*JWW[]  
Pupil Diameter = 4 mm g$jTP#%b  
Set aqueous humor thickness = 2.81 Te[v+jgLY,  
Set anterior lens radius = 10.4 and conic constant = -2.375869 :8]8
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Set posterior lens radius = -4.424557 and conic constant = -3.081019 IuT)?S7O*k  
Set lens thickness = 3.927 @?3^Ks_  
Set lens index of refraction = 1.42672 6VC|] |*  
Set pupil diameter = 4 kG{};Vm  
DONE! M^Y[Y@U
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