[技术]Arizona眼睛模型 [复制链接]

简介 MtAD&+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。 CVsc#=w0  
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模型 n/_cJD\  
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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。 yQ> *F  

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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. ?@ ei_<A{  
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光源 4C&L%A  
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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。 `jR;RczC  
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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。 ]*+ozAG4  
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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。 Pm]6E[zC  
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视网膜的散射 c?L_n=B  
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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。 n$ye:p>`-  
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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。 .}.5|z} A  
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脚本 %p?u ^rq  
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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： @9|sNS  
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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。 v/f&rK*>  
余下的脚本计算与屈光度有关的所有参数。 K"1xtpy  
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分析 8"+Re [  
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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。 `zAo IQ  
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脚本代码 v`B7[B4K3  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. + oyW_!(  
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Dim entity As T_ENTITY w5|az6wZB!  
Dim op As T_OPERATION & v=2u,]T  
Dim mat As T_MODELMATERIAL 5I5~GH  
Dim A As Double r'fNQJ >  
Dim pupilDiam As Double r?d601(fa  
Dim eID As Long pU)wxv[~  
Dim parID As Long $@q)IK%FDL  
Dim count As Integer 39?iX'*p
 
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double }Tn]cL{]C  
Dim tlens As Double, nlens As Double 72} MspzUt  
Dim curv As Double, conic As Double X""<5s'0  
Dim ok As Long ^lB'7#7  
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Sub Main S|
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    '用户输入对话框 ~q#UH'=%  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 J\XYUs  
        TextBox 220,21,40,21,.TextBox1 'default: 0 mY2Ubn*  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1  Mi.xay%  
        OKButton 40,91,90,21 5SFe
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        CancelButton 190,91,90,21 d}%GHvOi  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 ~h?zK1  
        TextBox 220,49,40,21,.TextBox2 'default: 4 EP7L5GZ-a  
    End Dialog ZVEq{x1Zc  
    Dim dlg As UserDialog E N%cjvE  
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    ok = Dialog (dlg) MsCY5g  
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    If ok=0 Then    'cancel button was pressed LJYFz=p"  
        Print "Execution cancelled." |"DQ^)3Pi  
        End U$6N-q  
    End If ZeF PwW  
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    'Assign accommodation and pupil diameter & use defaults if field left empty em<(wJ-Y  
    If dlg.TextBox1 = "" Then jR\&2;T  
        A = 0           'Default accommodation )(b]- )  
    Else !HM{imT  
        A = CDbl(dlg.TextBox1) Q/
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    End If D#508{)  
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    If dlg.TextBox2 = "" Then 4&~1|B{Z  
        pupilDiam = 4   'Default pupil diameter zS18Kl  
    Else XJDp%B  
        pupilDiam = CDbl(dlg.TextBox2) =9FY;9  
    End If $`x4|a8-  
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    Print " " G%-[vk#]  
    Print "Accommodation = " & A & " Diopters" >y"V%  
    Print "Pupil Diameter = " & pupilDiam & " mm"
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    ' Calculate new parameters with accommodation $fV47;U'*  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness >%x7-->IB  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens C^XJE1D.
 
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens w
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens :84fd\It4  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens DG}t!  
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    tlens = 3.767 + 0.04*A                  'Lens thickness q>X#Aaib  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction A#RA;Dt:  
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    'Adjust parameters to account for accommodation
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    '************************************************************************* *KN'0Z@W  
    'Aqueous thickness (Position of Lens) |E&a3TQW  
    '************************************************************************* .&=nP?ZPC6  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) oOUL<ihe?  
    GetCustomElement eID, entity Y` Oz\W  
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    parID = FindFullName( "Geometry.Arizona Eye" ) 8-3]Bm!  
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    ' Delete any shift(s) in z ='a[(C&Y  
    count = 0 yt}Ve6 m  
    While GetOperationCount(eID)>count L,M=ogdb  
        GetOperation eID, count, op pca `nN!  
        If op.Type="ShiftZ" Then &eKnLGKD  
            DeleteOperation eID,count URdCV{@42  
            count=count-1 =<MSM\Rb  
        End If 4*< x0  
        count=count+1 ET;YAa*  
    Wend O{SP4|0JV  
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    'Set new shift in 1p=^I'#  
    op.Type = "ShiftZ" .w/w] Eq  
    op.val1 = taq S\b[Bq  
    op.parent = parID fmrd7*MW  
    AddOperation eID, op
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    Print "Set aqueous humor thickness = " & taq-0.55 ZpvURp,I  
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    '************************************************************************* / E}L%OvE  
    'Radius and conic constant of anterior lens C?m2R(RF  
    '************************************************************************* 4<[,"<G~3  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) T'B43Q  
    GetConic eID, entity, curv, conic "c` $U]M%  
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    SetConic eID, entity, 1/Rant, CCant f]Z%,'1^  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant :_V9Jw
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    '************************************************************************* k=!lPIx  
    'Radius and conic constant of posterior lens KM li!.(b  
    '************************************************************************* nb d
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    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) KtTv0[66  
    GetConic eID, entity, curv, conic 7.mY@  

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    SetConic eID, entity, 1/Rpost, CCpost BBuI|lr  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost 1c8Nr&Jl  
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    '************************************************************************* " O0p.o  
    'Lens thickness (Position of posterior lens surface) .UX`@Q:Gp  
    '************************************************************************* zGgPW  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) 9MP_#M
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    ' Delete any z-shift(s) 9/2VU< K  
    count = 0 @9#l3  
    While GetOperationCount(eID)>count y0s=yN_  
        GetOperation eID, count, op Z 0&=Lw  
        If op.Type="ShiftZ" Then ?1Os%9D*  
            DeleteOperation eID,count 9#(Nd, m})  
            count=count-1 JC6?*R  
        End If 1OI/!!t1$  
        count=count+1 @cYb37)q=  
    Wend cG!\P:re  
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    'Set new z-shift DR]=\HQ  
    op.Type = "ShiftZ" M;2@<,rM  
    op.val1 = tlens EZs"?A  
    op.parent = parID @7S* ]  
    AddOperation eID, op >^Rkk{cc  
    Print "Set lens thickness = " & tlens }fC=  
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    '************************************************************************* rnAQwm-8O%  
    'Lens index of refraction `>ppDQaS)W  
    '************************************************************************* rfo7\'yk  
    eID = FindMaterial( "Lens" ) WSEw:pln  
    GetModelMaterial eID, mat }jE[vVlRw  
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    mat.Nd = nlens LH}]& >F  
    SetModelMaterial eID, mat |WP}y-Au
 
    Print "Set lens index of refraction = " & nlens qAI%6d  
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    '************************************************************************* /EP RgRX  
    'Pupil diameter ;f?suawMv  
    '************************************************************************* 8MQb5( !  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) trx y3k;  
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    'Adjust pupil diameter (trimming volume inner hole) XXDLbT'J  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" Q DVk7ks  
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    ' Adjust pupil location to just in front of the lens XoNBq9Iu  
    parID = FindFullName( "Geometry.Arizona Eye" ) gOy
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    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) 
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    count = 0 OsT|MX  
    While GetOperationCount(eID)>count c-VIpA1  
        GetOperation eID, count, op
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        If op.Type="ShiftZ" Then !
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            DeleteOperation eID,count )4#YS$B$@)  
            count=count-1 )L/0X40<.  
        End If ]\Z8MxFD  
        count=count+1 U9"(jl/o  
    Wend v<3KxP'a  
    op.Type = "ShiftZ" !!k^M"e2  
    op.val1 = taq-0.01  CK+t6Gp  
    op.parent = parID Fy 1-
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    AddOperation eID, op +'|nsIx,  
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    Print "Set pupil diameter = " & pupilDiam lrjVD(R=g  
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    'Update AZ Eye subassembly Description q6PG=9d0B  
    eID = FindFullName( "Geometry.Arizona Eye" ) 5,R4:y ?cK  
    GetEntity eID, entity X5pb9zRq  
    entity.Description = "Accommodation = " & A & "D" R53^3"q~  
    SetEntity eID, entity =`ZRPA!aY  
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    Update r2*8.j51  
    Print "DONE!" $b~[>S-Q  
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End Sub iE?yvtr8  
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如果屈光度是4，光瞳直径是4，则会输出如下数据： h% eGtd$n  
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Accommodation = 4 Diopters 1xEFMHjy  
Pupil Diameter = 4 mm p#%
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Set aqueous humor thickness = 2.81 %*NED zy  
Set anterior lens radius = 10.4 and conic constant = -2.375869 [l/!&6  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 #w3J+U 6r  
Set lens thickness = 3.927 &,P; 7R  
Set lens index of refraction = 1.42672 .07"I7  
Set pupil diameter = 4 = GyABK  
DONE! [D+,I1u2h