[技术]Arizona眼睛模型 [复制链接]

简介 -{A64gfFxT  
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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。 |jH Yf42Q  
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模型 t#f-3zd9  
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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。 wmbG$T%k  
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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. 6L~5qbQ  
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光源 LCIe1P2  
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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。 asvM/9  
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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。 66WJ=?JV  
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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。 tG"EbWi  
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视网膜的散射 [BKTZQ@G@  
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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。 Ly`.~t(~l  
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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。 Ql}#mC.>/  
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脚本 W-1Ub
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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： p7Yb8#XfU  
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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。 u]3VK  
余下的脚本计算与屈光度有关的所有参数。 )Y1+F,C  
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分析 w*Ze5j4@ \  
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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。 S U P  
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脚本代码 LwI4 2  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. Pf<BQ*n  
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Dim entity As T_ENTITY ;ejtP #$  
Dim op As T_OPERATION c<)O#i@3/  
Dim mat As T_MODELMATERIAL 2+\@0j[q  
Dim A As Double \xk8+=/A  
Dim pupilDiam As Double =\jPnov!  
Dim eID As Long g3'yqIjQL  
Dim parID As Long w4uY/!~k  
Dim count As Integer _cc9+o  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double g.Kyfs4`  
Dim tlens As Double, nlens As Double #|cr
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Dim curv As Double, conic As Double N?%FVF  
Dim ok As Long 4':U rJ+  
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Sub Main Y]}>he1/5  
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    '用户输入对话框 W^9=z~-h  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 Z#_VxA>]v  
        TextBox 220,21,40,21,.TextBox1 'default: 0 R8u9tTW  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 .|J-(J<>[.  
        OKButton 40,91,90,21 -hO[^^i9  
        CancelButton 190,91,90,21 <:0d%YB)  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 B}ASZYpW>  
        TextBox 220,49,40,21,.TextBox2 'default: 4 NK(; -~{P  
    End Dialog u*!/J R  
    Dim dlg As UserDialog * p,2>[e  
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    ok = Dialog (dlg) 9Or  
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    If ok=0 Then    'cancel button was pressed [JX=
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        Print "Execution cancelled." l`<u\],  
        End fK9wr@1  
    End If 
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    'Assign accommodation and pupil diameter & use defaults if field left empty R)5zHCwOw  
    If dlg.TextBox1 = "" Then ~_yz\;#
 
        A = 0           'Default accommodation .:+&2#b  
    Else I
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        A = CDbl(dlg.TextBox1) GH6ozWA  
    End If C'//(gjQ-G  
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    If dlg.TextBox2 = "" Then bp(X\:zAy  
        pupilDiam = 4   'Default pupil diameter 5Og=`T
 
    Else dI9u:-  
        pupilDiam = CDbl(dlg.TextBox2) ;1woTAuD  
    End If P<gr=&  
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    Print " " YumHECej  
    Print "Accommodation = " & A & " Diopters" g:>Mooxzi  
    Print "Pupil Diameter = " & pupilDiam & " mm" N[dv  
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    ' Calculate new parameters with accommodation }c0EGoU}?  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness >c 5V VA8  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens x3?:"D2  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens  D^JuL6U  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens FrBJv<  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens mg7Q~SLL{  
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    tlens = 3.767 + 0.04*A                  'Lens thickness SPK% '
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction nd1%txIsr  
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    'Adjust parameters to account for accommodation Yv[j5\:x  
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    '************************************************************************* %o9;jX  
    'Aqueous thickness (Position of Lens) Yhkn(k2  
    '************************************************************************* ,k5b,}tN  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) ir*T,O 2J  
    GetCustomElement eID, entity atO/Tp  
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    parID = FindFullName( "Geometry.Arizona Eye" ) .TTXg,8#D  
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    ' Delete any shift(s) in z g` QbJ61a  
    count = 0 =W~K_jE5lo  
    While GetOperationCount(eID)>count w$5#jJX\  
        GetOperation eID, count, op SecZ5(+=  
        If op.Type="ShiftZ" Then ?u]%T]W  
            DeleteOperation eID,count ?YO$NYwE  
            count=count-1 D.\s mk  
        End If X3j<HQcK  
        count=count+1 g[~"c}  
    Wend 3Vj,O?(Z  
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    'Set new shift in ,
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    op.Type = "ShiftZ" AK*F,H9  
    op.val1 = taq O1_dA%m  
    op.parent = parID i; 3^vhbQ  
    AddOperation eID, op aN5w  
    Print "Set aqueous humor thickness = " & taq-0.55 5-ju5z?=  
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    '************************************************************************* C
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    'Radius and conic constant of anterior lens &_EjP hZ  
    '************************************************************************* okO^/"  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) iYJzSVO  
    GetConic eID, entity, curv, conic .l->O-=  
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    SetConic eID, entity, 1/Rant, CCant IW.~I,!x  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant aBO%qmtt  
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    '************************************************************************* q{W@J0U  
    'Radius and conic constant of posterior lens +h$)l/>:  
    '************************************************************************* zl W5$cC[  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) iS{8cN3R  
    GetConic eID, entity, curv, conic ]~SOGAFW  
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    SetConic eID, entity, 1/Rpost, CCpost 9*+%Qt,{B  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost :Q\{LBc  
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    '************************************************************************* CmNd0S4v  
    'Lens thickness (Position of posterior lens surface) 8yH*  
    '************************************************************************* vElVw. P  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) 6Y|jK<n?H  
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    ' Delete any z-shift(s) fBptjt_  
    count = 0 <xm>_~,w  
    While GetOperationCount(eID)>count j zaC  
        GetOperation eID, count, op szY=N7\S*  
        If op.Type="ShiftZ" Then $~|#Rz%v  
            DeleteOperation eID,count "YUyM5X  
            count=count-1 /=zzym~<>  
        End If 4wZ{Z 2w  
        count=count+1 0{/P1  
    Wend e>Vr#a4  
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    'Set new z-shift 2\xv Yf-  
    op.Type = "ShiftZ" G &'eP  
    op.val1 = tlens 5Mfs)a4j.  
    op.parent = parID ,haCZH{  
    AddOperation eID, op ?G[<~J3-E  
    Print "Set lens thickness = " & tlens rRN7HL+b  
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    '************************************************************************* Mt@
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    'Lens index of refraction u;xl}  
    '************************************************************************* Kp+Lk  
    eID = FindMaterial( "Lens" ) ?qeBgkL(B^  
    GetModelMaterial eID, mat kMGK8y  
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    mat.Nd = nlens ?NZKu6  
    SetModelMaterial eID, mat /qW5M4.w  
    Print "Set lens index of refraction = " & nlens tdTD!'  
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    '************************************************************************* %rpJZ t  
    'Pupil diameter fX,L;Se"  
    '************************************************************************* @_tQ:U,v  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) #Y3:~dmJ-  
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    'Adjust pupil diameter (trimming volume inner hole) ,O@xv
 
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" q
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    ' Adjust pupil location to just in front of the lens +?[,y  
    parID = FindFullName( "Geometry.Arizona Eye" ) uaMf3HeYV  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) -_bHLoI  
    count = 0 (vCMff/ Y1  
    While GetOperationCount(eID)>count c?qg i"kS  
        GetOperation eID, count, op v$R+5_@[l  
        If op.Type="ShiftZ" Then D"WqJcDt  
            DeleteOperation eID,count [E_eaez
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            count=count-1 C3n_'O  
        End If $2uZdl8Rvj  
        count=count+1 }QszOi\fV1  
    Wend K-&&%Id6R  
    op.Type = "ShiftZ" HH>"J/;c,  
    op.val1 = taq-0.01 L lmdydC%  
    op.parent = parID sh []OSM
 
    AddOperation eID, op vc.:du  
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    Print "Set pupil diameter = " & pupilDiam ;P9P2&c8c  
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    'Update AZ Eye subassembly Description SF.4["$  
    eID = FindFullName( "Geometry.Arizona Eye" ) &Q>)3]|p  
    GetEntity eID, entity X<\y%2B|l  
    entity.Description = "Accommodation = " & A & "D" bi:m;R  
    SetEntity eID, entity E5d?toZ,8"  
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    Update R;9
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    Print "DONE!" ?@U7tNI  
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End Sub 8r^~`rL  
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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： =VMV^[&>  
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Accommodation = 4 Diopters 3V]B|^S  
Pupil Diameter = 4 mm 49%qBO$R  
Set aqueous humor thickness = 2.81 >hcA:\UPk  
Set anterior lens radius = 10.4 and conic constant = -2.375869 GzJLG
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Set posterior lens radius = -4.424557 and conic constant = -3.081019 zGrUl|j  
Set lens thickness = 3.927 ze!S4&B  
Set lens index of refraction = 1.42672 t.sbfLu  
Set pupil diameter = 4 2c>eMfa  
DONE! E DuLgg@