[技术]Arizona眼睛模型 [复制链接]

简介 ?3nR  
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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。 9{RB{<Se!  
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模型 1;C+$  
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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。 ~D<IB#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. s%qF/70'  
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光源 iL7DRQ1  
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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。 48:>NW  
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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。 D>HOn^   
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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。 mtJ9nC  
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视网膜的散射 .LZwuJ^;  
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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。 GR +[UG  
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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。 d@ i}-;  
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脚本 xC{qV,  
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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： U@HK+C"M|  
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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。 ePr&!Tz#  
余下的脚本计算与屈光度有关的所有参数。 {l>yi  
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分析 CS@FYO  
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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。 mzeY%A<0^  
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脚本代码 X'd9[).  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. qyF{f8pzq  
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Dim entity As T_ENTITY 6kNrYom  
Dim op As T_OPERATION S<VSn}vn  
Dim mat As T_MODELMATERIAL 3on7~*  
Dim A As Double iH/6M  
Dim pupilDiam As Double `+o2DA)#(  
Dim eID As Long LS7, a|  
Dim parID As Long pm_`>3  
Dim count As Integer `Gn50-@  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double Ove<mFI\  
Dim tlens As Double, nlens As Double g+pml*LJ  
Dim curv As Double, conic As Double (Dw,DY9  
Dim ok As Long Y"~gw~7OD  
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Sub Main 8zRP(+&W  
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    '用户输入对话框 #~7ip\Uf[  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 0s/w,?  
        TextBox 220,21,40,21,.TextBox1 'default: 0 >4#)r8;dx  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 *~t6(
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        OKButton 40,91,90,21 OR%'K2C6S  
        CancelButton 190,91,90,21 F<qz[,]|-j  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 t=Xv;=daB  
        TextBox 220,49,40,21,.TextBox2 'default: 4 ~\Hc,5G   
    End Dialog l:j4Ft 8  
    Dim dlg As UserDialog M_"L9^^>N  
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    ok = Dialog (dlg) IFF92VD&  
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    If ok=0 Then    'cancel button was pressed P(+&OoY2  
        Print "Execution cancelled." 2w["aVr =  
        End 3~uW I%I`  
    End If %p2Sh)@M  
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    'Assign accommodation and pupil diameter & use defaults if field left empty "uaMk}[ <!  
    If dlg.TextBox1 = "" Then ]j`c]
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        A = 0           'Default accommodation p-Kz-+A[  
    Else L<ue$'  
        A = CDbl(dlg.TextBox1) wE?'Cl  
    End If GBRa.;Kk  
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    If dlg.TextBox2 = "" Then [co% :xJu  
        pupilDiam = 4   'Default pupil diameter U56G.  
    Else - `p4-J!Fy  
        pupilDiam = CDbl(dlg.TextBox2) H
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    End If 0:9.;x9_  
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    Print " " m 8aITd8  
    Print "Accommodation = " & A & " Diopters" 2QJ{a46}  
    Print "Pupil Diameter = " & pupilDiam & " mm" v":x4!kdX  
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    ' Calculate new parameters with accommodation Urr@a/7  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness YVHm{A1b0  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens 6YGubH7%_  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens 9}PhN<Gd  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens TU:7Df  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens 8B\2Zfe  
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    tlens = 3.767 + 0.04*A                  'Lens thickness X voo=  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction g^}8:,F_  
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    'Adjust parameters to account for accommodation L"o>wYx
 
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    '************************************************************************* xKuRh}^K  
    'Aqueous thickness (Position of Lens) ykV 5  
    '************************************************************************* Y]/%t{Y  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) 6W]9$n\"?  
    GetCustomElement eID, entity gcdlT7F)b-  
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    parID = FindFullName( "Geometry.Arizona Eye" ) =a@j=  
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    ' Delete any shift(s) in z }:us:%  
    count = 0 :h\Q;?  
    While GetOperationCount(eID)>count H!5\v
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        GetOperation eID, count, op w5Ay)lz  
        If op.Type="ShiftZ" Then 9~]~#Uj  
            DeleteOperation eID,count YjxF}VI~<  
            count=count-1 @+Si?8\  
        End If 4dO~C  
        count=count+1 MvK !u  
    Wend ]rWgSID  
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    'Set new shift in "alyfyBu'M  
    op.Type = "ShiftZ" '98VYCL  
    op.val1 = taq A OISs4  
    op.parent = parID |iE50,  
    AddOperation eID, op T 6)bD&  
    Print "Set aqueous humor thickness = " & taq-0.55 1.D,W1s  
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    '************************************************************************* iOU6V  
    'Radius and conic constant of anterior lens 1FlX'[vh  
    '************************************************************************* 8ZM&(Lz7u  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) pEBM3r!X  
    GetConic eID, entity, curv, conic E"qRw_ ~t  
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    SetConic eID, entity, 1/Rant, CCant f&BY/ n,  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant 9 7GV2]-M  
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    '************************************************************************* 8$6
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    'Radius and conic constant of posterior lens o4m\~as)Y  
    '************************************************************************* ^(vs.U^U<  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) OSs&r$  
    GetConic eID, entity, curv, conic }001K  
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    SetConic eID, entity, 1/Rpost, CCpost g.BdlVB\  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost Si8p
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    '************************************************************************* _F>CBG  
    'Lens thickness (Position of posterior lens surface) K@I D/]PF  
    '************************************************************************* "e.jZcN*  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) ,w{e  
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    ' Delete any z-shift(s) 9^oKtkoDZ  
    count = 0 @;*Ksy@1O  
    While GetOperationCount(eID)>count LAB=Vp1y3[  
        GetOperation eID, count, op #Y

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        If op.Type="ShiftZ" Then {:6r;TB  
            DeleteOperation eID,count 2oVSn"  
            count=count-1 &J[:awQX  
        End If 6:b!F  
        count=count+1 `uOT+B%R  
    Wend 1S{D6#bE  
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    'Set new z-shift L2\#w<d  
    op.Type = "ShiftZ" `[f*Z
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    op.val1 = tlens r[|Xy>Zj
 
    op.parent = parID A\4D79>x  
    AddOperation eID, op 1eS&&J5  
    Print "Set lens thickness = " & tlens 3{'Ne}5%I  
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    '************************************************************************* [k.tWA,&  
    'Lens index of refraction Q# ~Q=T'<  
    '************************************************************************* mk.9OhYY  
    eID = FindMaterial( "Lens" ) ) i;1*jK  
    GetModelMaterial eID, mat u+Y\6~
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    mat.Nd = nlens _Gn2o2T  
    SetModelMaterial eID, mat Q-_N2W?  
    Print "Set lens index of refraction = " & nlens QoI3>Oj=  
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    '************************************************************************* $ `ov4W  
    'Pupil diameter C'9Cr}cZ.  
    '************************************************************************* f.D?sHAn  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) 6n,i0W  
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    'Adjust pupil diameter (trimming volume inner hole) \y97W&AN  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" LInz<bc<(  
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    ' Adjust pupil location to just in front of the lens Vc 1\i  
    parID = FindFullName( "Geometry.Arizona Eye" ) %RTBV9LIXr  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) >")Tf6zw&  
    count = 0 3eb%OEMYk  
    While GetOperationCount(eID)>count 95ZyP!  
        GetOperation eID, count, op LhA*F[6$M  
        If op.Type="ShiftZ" Then gZN8!#h}B  
            DeleteOperation eID,count e%svrJ2   
            count=count-1 c/D+|X*  
        End If c23oCfB>  
        count=count+1 j_K
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    Wend ^]H5h]U'  
    op.Type = "ShiftZ" ). <-X^@  
    op.val1 = taq-0.01 ^X=ar
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    op.parent = parID B^1>PE  
    AddOperation eID, op p)`{Sos  
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    Print "Set pupil diameter = " & pupilDiam BL0 {HV!  
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    'Update AZ Eye subassembly Description Lf16j*}-Q  
    eID = FindFullName( "Geometry.Arizona Eye" ) Zq^At+8+  
    GetEntity eID, entity *1uKr9  
    entity.Description = "Accommodation = " & A & "D" o)h_H;  
    SetEntity eID, entity CuFSeRe  
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    Update U_Vs.M.p  
    Print "DONE!" C_( *>!Z%  
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End Sub }u\])I3  
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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： 6"wlg!k8  
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Accommodation = 4 Diopters YJ^] u}  
Pupil Diameter = 4 mm gR&Q3jlIV  
Set aqueous humor thickness = 2.81 'H3^e}   
Set anterior lens radius = 10.4 and conic constant = -2.375869 3_ r*y9l  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 34`'M+3  
Set lens thickness = 3.927 { d=^}-^   
Set lens index of refraction = 1.42672 ^|/TC!v]M  
Set pupil diameter = 4 EMh7z7}Rr  
DONE! :G [|CPm-