[技术]Arizona眼睛模型 [复制链接]

简介 o -tc}Aa  
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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。 OgJd^  
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模型 pEk^;  
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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。 85; BS'  
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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. Wz)O,X^  
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光源 a1Q|su{H  
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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。 8wGq:@#=  
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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。 Q!DH8'|4?L  
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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。 5/j7C>  
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视网膜的散射 )cA#2mlS'1  
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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。 lSv?!2  
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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。 m~;fklX S  
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脚本 ? b;_T,S[  
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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： 'n`+R~Kkh  
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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。 C!KxY/*Px  
余下的脚本计算与屈光度有关的所有参数。 +X[+SF)!  
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分析 I&9_F%rX  
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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。 @<]sW*s  
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脚本代码 }Rujh4*  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. Tb~|p_;o  
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Dim entity As T_ENTITY v&t~0jX,  
Dim op As T_OPERATION o+UCu`7e  
Dim mat As T_MODELMATERIAL 7.7aHt0  
Dim A As Double =l6aSr   
Dim pupilDiam As Double }j=UO*|  
Dim eID As Long |C:^BWrU*  
Dim parID As Long Y,1ZvUOB  
Dim count As Integer uw'>tb@  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double "B18|#v  
Dim tlens As Double, nlens As Double '@4Myg* b  
Dim curv As Double, conic As Double y$,K^f  
Dim ok As Long 0#\K9|.  
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Sub Main gc~nT/lfK  
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    '用户输入对话框 P#^-{;B
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    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 5^kLNNum  
        TextBox 220,21,40,21,.TextBox1 'default: 0 VaYL#\;c<  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 <(YE_<F*  
        OKButton 40,91,90,21 % zP]z  
        CancelButton 190,91,90,21 OIi8x? .~]  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 ?`9XFE~a!  
        TextBox 220,49,40,21,.TextBox2 'default: 4 -D=J/5L#5  
    End Dialog Y j[M>v  
    Dim dlg As UserDialog _+c' z  
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    ok = Dialog (dlg) M::  
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    If ok=0 Then    'cancel button was pressed GnAG'.t-Z  
        Print "Execution cancelled." m Acny$u  
        End g]kM7,/M  
    End If g.L~Z1-  
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    'Assign accommodation and pupil diameter & use defaults if field left empty -cDS+*[  
    If dlg.TextBox1 = "" Then 91I6-7# Xt  
        A = 0           'Default accommodation 36]pE<  
    Else x9ll0Ht  
        A = CDbl(dlg.TextBox1) fU/&e^, 's  
    End If P{T\zT  
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    If dlg.TextBox2 = "" Then \
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        pupilDiam = 4   'Default pupil diameter 0.pZlv  
    Else ;_$Q~X  
        pupilDiam = CDbl(dlg.TextBox2) =sm<B^yj  
    End If
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    Print " " }I}/e v  
    Print "Accommodation = " & A & " Diopters" ar&j1""  
    Print "Pupil Diameter = " & pupilDiam & " mm" w!/\dqjv  
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    ' Calculate new parameters with accommodation ON(OYXj  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness t`M4@1S"'  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens <K g=?wb  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens ;s*   
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens _h6j, )  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens bk(q8xR`  
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    tlens = 3.767 + 0.04*A                  'Lens thickness nrBpq  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction /EIQMZuYp  
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    'Adjust parameters to account for accommodation enC/@){~  
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    '************************************************************************* YYE{zU  
    'Aqueous thickness (Position of Lens) g2LY~  
    '************************************************************************* gg0rkg  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) N!PPL"5z  
    GetCustomElement eID, entity R\a6#u3  
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    parID = FindFullName( "Geometry.Arizona Eye" ) f]pHJVgFV  
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    ' Delete any shift(s) in z lGlh/B%  
    count = 0 k~0#Iy_{M  
    While GetOperationCount(eID)>count o5@d1A  
        GetOperation eID, count, op _ez*dE%  
        If op.Type="ShiftZ" Then bI-uF8"  
            DeleteOperation eID,count Ao )\/AR'  
            count=count-1 *M?[Gro/  
        End If uGmv`R_  
        count=count+1 m >Rdsn~l  
    Wend ]x1;uE?1J  
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    'Set new shift in NR>&1aRbyb  
    op.Type = "ShiftZ" !.G knDT  
    op.val1 = taq dEhFuNO<2  
    op.parent = parID +F
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    AddOperation eID, op |EGC1x]j=  
    Print "Set aqueous humor thickness = " & taq-0.55 Zt"#'1  
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    '************************************************************************* Ia[4P8Z  
    'Radius and conic constant of anterior lens 2/iBk'd  
    '************************************************************************* 1!%T<!A.  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) @+6cKP  
    GetConic eID, entity, curv, conic u?F^gIw  
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    SetConic eID, entity, 1/Rant, CCant E5$Fhc  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant /;5/7Bvj  
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    '************************************************************************* aBd>.]l?  
    'Radius and conic constant of posterior lens `t>A~.f  
    '************************************************************************* h+c
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    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) z j F'CY  
    GetConic eID, entity, curv, conic )Z*nm<=  
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    SetConic eID, entity, 1/Rpost, CCpost dw-o71(1d  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost X:/7#fcG8  
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    '************************************************************************* fB)S:f|  
    'Lens thickness (Position of posterior lens surface) KY%LqcC  
    '************************************************************************* &R))c|>OT&  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) #Q1 |]  
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    ' Delete any z-shift(s) FfC\uuRe  
    count = 0 Eb7GiRT#  
    While GetOperationCount(eID)>count M+VAol}1  
        GetOperation eID, count, op 1{<r~  
        If op.Type="ShiftZ" Then )zydD=,bu  
            DeleteOperation eID,count  K,o&gY  
            count=count-1 Fr_6pEH]}  
        End If Hva/C{Y  
        count=count+1 "?G?G'yK>  
    Wend P#|}]oG%  

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    'Set new z-shift p4@0[z'  
    op.Type = "ShiftZ" ]P96-x  
    op.val1 = tlens goOw.~dZ'  
    op.parent = parID hvc3n> Y[}  
    AddOperation eID, op KRM:h`+-.-  
    Print "Set lens thickness = " & tlens wzF%R{;  
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    '************************************************************************* $T6+6<  
    'Lens index of refraction I uC7Hx`z  
    '************************************************************************* -br): }f  
    eID = FindMaterial( "Lens" ) d5"rCd[  
    GetModelMaterial eID, mat +} y"S-  
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    mat.Nd = nlens N<O<wtXIj  
    SetModelMaterial eID, mat cEIs9;  
    Print "Set lens index of refraction = " & nlens k+zskfo  
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    '************************************************************************* #fDM{f0]R  
    'Pupil diameter \cdns;  
    '************************************************************************* RgVnx]IF  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) !tSh9L;<O  
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    'Adjust pupil diameter (trimming volume inner hole) 9TZ6c  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" j XYr&F  
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    ' Adjust pupil location to just in front of the lens "H]R\xp  
    parID = FindFullName( "Geometry.Arizona Eye" ) ? U* `!-  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) M6j~`KSE  
    count = 0 3:>hHQi  
    While GetOperationCount(eID)>count 3U'l'H,  
        GetOperation eID, count, op >=86*U~  
        If op.Type="ShiftZ" Then lHFk~Qp[  
            DeleteOperation eID,count "|BSGV!8  
            count=count-1 uQ%3?bx)T  
        End If }nptmc  
        count=count+1 -56gg^Pnr  
    Wend C%|m[,Gx  
    op.Type = "ShiftZ" m%b#B>J,n  
    op.val1 = taq-0.01 !gcea?I  
    op.parent = parID ZcN#jnb0/  
    AddOperation eID, op rN,T}M=2  
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    Print "Set pupil diameter = " & pupilDiam a+j"8tHu$  
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    'Update AZ Eye subassembly Description 0]zMb^wo  
    eID = FindFullName( "Geometry.Arizona Eye" ) lx7]rkWo|a  
    GetEntity eID, entity 4HpKKhv"  
    entity.Description = "Accommodation = " & A & "D" et/v/Hvw1  
    SetEntity eID, entity yG;@S8zC  
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    Update aMGyV"6(-6  
    Print "DONE!" i v.G  
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End Sub i.^:xZ  
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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： yY]E~  
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Accommodation = 4 Diopters '.jYu7   
Pupil Diameter = 4 mm @)wsHW%cjz  
Set aqueous humor thickness = 2.81 =mSu^q(l  
Set anterior lens radius = 10.4 and conic constant = -2.375869 \uO^wJ}  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 vpC?JXz=H  
Set lens thickness = 3.927 LQR^lD+_=  
Set lens index of refraction = 1.42672 "ji+~%`^[t  
Set pupil diameter = 4 =G !]_d0  
DONE! mW~*GD~r