[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 W\>^[c/  
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。 2-6.r_  
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模型 /h7>Z9T  
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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。 D0#T-B\#  
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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. $&=4.7Yt  
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光源 AJ>BF.>  
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多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 W>?f^C!+m  
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除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处，并增加了pre-propagation distance= -8。尽管光线在光瞳处创建，规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射，而不是在光瞳处入射。 +Q SxYV  
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在往下看是内置的脚本用来修改屈光度，使其为4（250mm），光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 _Sly7_  
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视网膜的散射 U^[cYT
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在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 &547`
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注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 u8-a-k5<  
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脚本 }g>dn  
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内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： 5T$
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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。 ~/j$TT"  
余下的脚本计算与屈光度有关的所有参数。 !Qv5"_  
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分析 ]> nPqL  
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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。 2YL`3cgfb  
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脚本代码 x r-;,W  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. Y brx%  
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Dim entity As T_ENTITY
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Dim op As T_OPERATION |7svA<<[  
Dim mat As T_MODELMATERIAL 5~@?>)TBv  
Dim A As Double o2
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Dim pupilDiam As Double p//T7rs  
Dim eID As Long lo cW_/  
Dim parID As Long ! 9d_Gf-  
Dim count As Integer ~gu=x&{  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double y=[gQJ6~r  
Dim tlens As Double, nlens As Double W3D
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Dim curv As Double, conic As Double SV
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Dim ok As Long i/NDWVFD  
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Sub Main Qo'yS"g<9)  
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    '用户输入对话框 O{PW  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 x1t{SQ-C  
        TextBox 220,21,40,21,.TextBox1 'default: 0 S-isL4D.Z  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 9.xvV|Sp  
        OKButton 40,91,90,21 }TSgAwsbC  
        CancelButton 190,91,90,21 Kb^>X{  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 vTpStoUM  
        TextBox 220,49,40,21,.TextBox2 'default: 4 fx<FIj7  
    End Dialog J4YT)-  
    Dim dlg As UserDialog SXQ@;=]xV  
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    ok = Dialog (dlg) X6Un;UL  
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    If ok=0 Then    'cancel button was pressed +C'XS{K,#  
        Print "Execution cancelled." }-d)ms!  
        End T36x=LX  
    End If wAw42{M  
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    'Assign accommodation and pupil diameter & use defaults if field left empty zm3-C%:Bw  
    If dlg.TextBox1 = "" Then 34z_+  
        A = 0           'Default accommodation Y!Drb-U?;  
    Else E_~x==cb  
        A = CDbl(dlg.TextBox1) doBNghS  
    End If 0|ZVA+  
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    If dlg.TextBox2 = "" Then @cZ\*,T  
        pupilDiam = 4   'Default pupil diameter VKy5=2&  
    Else auRY|j  
        pupilDiam = CDbl(dlg.TextBox2) /?Vdqci  
    End If eI^gV'UK  
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    Print " " ?KCivf  
    Print "Accommodation = " & A & " Diopters" )u0O_R  
    Print "Pupil Diameter = " & pupilDiam & " mm" 69Nw/$  
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    ' Calculate new parameters with accommodation @M=$qO_$9  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness Dzr e'  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens #EJP(wXa  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens 6a*83G,k  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens \QGa4_#  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens wZjlHe  
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    tlens = 3.767 + 0.04*A                  'Lens thickness B52yaG8C  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction fz3lR2~G  
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    'Adjust parameters to account for accommodation Q/py qe G  
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    '************************************************************************* ^LVk5l)\>g  
    'Aqueous thickness (Position of Lens)
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    '************************************************************************* $eBQH  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) yAG+] r  
    GetCustomElement eID, entity vM(Xip7  
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    parID = FindFullName( "Geometry.Arizona Eye" ) !"E-\cc'  
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    ' Delete any shift(s) in z 0/Z !5-.  
    count = 0 oxfF`L"  
    While GetOperationCount(eID)>count J=iRul^S  
        GetOperation eID, count, op Ux}W&K/?'  
        If op.Type="ShiftZ" Then B`{mdjMy  
            DeleteOperation eID,count 2 z7}+lH  
            count=count-1 \0?$wIH?  
        End If U;U08/y  
        count=count+1 u]M\3V.  
    Wend K(VW%hV1  
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    'Set new shift in 5/?P|T  
    op.Type = "ShiftZ" OxQYNi2  
    op.val1 = taq N*_"8LIfi_  
    op.parent = parID Xwq]f:@V  
    AddOperation eID, op .'j29 6[u  
    Print "Set aqueous humor thickness = " & taq-0.55 #!})3_Qc(y  
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    '************************************************************************* b7Oj<!Wo`  
    'Radius and conic constant of anterior lens ubbnFE&PD  
    '************************************************************************* :Fe_,[FR  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) {x
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    GetConic eID, entity, curv, conic Vb!O8xV4;+  
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    SetConic eID, entity, 1/Rant, CCant n@ [  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant ar$*a>'?  
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    '************************************************************************* yMxT
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    'Radius and conic constant of posterior lens {eQWO
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    '************************************************************************* %;|
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    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) W~ruN4q.  
    GetConic eID, entity, curv, conic YQd:M%$  
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    SetConic eID, entity, 1/Rpost, CCpost SK R1E];4  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost 1e}8LH7  
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    '************************************************************************* e |V]  
    'Lens thickness (Position of posterior lens surface) C6jR=@42Q  
    '************************************************************************* 7-*=|gl+  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) D4Etl5k  
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    ' Delete any z-shift(s) KX4],B5 +  
    count = 0 ss iokLE  
    While GetOperationCount(eID)>count (D7$$!}  
        GetOperation eID, count, op 9Ah[rK*}  
        If op.Type="ShiftZ" Then !{Z~<Ky  
            DeleteOperation eID,count <f>akT,W  
            count=count-1 wK!~tYxP  
        End If zT#`qCbT'J  
        count=count+1 38IMxd9v  
    Wend jc:s` 4  
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    'Set new z-shift _#C()Ro*P  
    op.Type = "ShiftZ" +L%IG  
    op.val1 = tlens wtH~-xSB|  
    op.parent = parID p&Ed\aQ%z;  
    AddOperation eID, op 3BQ!qO17^d  
    Print "Set lens thickness = " & tlens _}gtcyx  
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    '************************************************************************* ,}SCa'PB  
    'Lens index of refraction M.[
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    '************************************************************************* T!|=El>  
    eID = FindMaterial( "Lens" ) ig!7BxM)<h  
    GetModelMaterial eID, mat Z?G&.# :  
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    mat.Nd = nlens GJA`l8`SQ  
    SetModelMaterial eID, mat I#rubAl  
    Print "Set lens index of refraction = " & nlens ",Cr,;]  
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    '************************************************************************* bt/ =Kq#  
    'Pupil diameter r 
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    '*************************************************************************
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    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) (u1m]WYL  
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    'Adjust pupil diameter (trimming volume inner hole) z=Cr7-  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" jZ*WN|FK?  
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    ' Adjust pupil location to just in front of the lens kg97S  
    parID = FindFullName( "Geometry.Arizona Eye" ) $XnPwOj  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) s1j{x&OSq  
    count = 0 #0Ds'
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    While GetOperationCount(eID)>count ,5Vt]#F5@  
        GetOperation eID, count, op gl%`qf6:O  
        If op.Type="ShiftZ" Then 8|^CK|m6*  
            DeleteOperation eID,count ]9 w76Z  
            count=count-1 \cJa;WM>  
        End If Rl~T$ Ey  
        count=count+1 3'`dFY,  
    Wend 9 ;i\g=  
    op.Type = "ShiftZ" ]d}0l6  
    op.val1 = taq-0.01 9i q""  
    op.parent = parID p{$p $/A  
    AddOperation eID, op wq!iV |  
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    Print "Set pupil diameter = " & pupilDiam <n"C,  
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    'Update AZ Eye subassembly Description 4,p;Km&  
    eID = FindFullName( "Geometry.Arizona Eye" ) Fr2N[\>s  
    GetEntity eID, entity Cfu=u *u  
    entity.Description = "Accommodation = " & A & "D" V^s0fWa  
    SetEntity eID, entity qQ]]~F  
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    Update ~a9W3b4j  
    Print "DONE!" ,E )|y4  
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End Sub 8hanzwoJ:  
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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： Dh4 6o|P  
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Accommodation = 4 Diopters Z~  
Pupil Diameter = 4 mm t<iEj"5  
Set aqueous humor thickness = 2.81 OX]V)QHVZ  
Set anterior lens radius = 10.4 and conic constant = -2.375869 >o,^b\  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 R"v 3!P  
Set lens thickness = 3.927 o`S?  
Set lens index of refraction = 1.42672 rZXrT}Xh{W  
Set pupil diameter = 4 1Tp/MV/>  
DONE! da!P0x9p  
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