[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 #M$[C d I$  
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。 NEa:  
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模型 jA$g0>  
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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。 Gi~p-OS,  
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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. %I9{)'+@x  
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光源 P,k~! F^L  
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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。 "XT7;!  
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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。 S_/9eI~X  
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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。 1uZ[Ewl]  
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视网膜的散射 |iKk'Rta4  
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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。 5XySF #  
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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。 P?p>'avP  
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脚本 oW(lQ'"  
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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： fOJ0#^Z  
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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。 $R(?@B(  
余下的脚本计算与屈光度有关的所有参数。 w`=_|4wFw  
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分析 2+zE|I.  
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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。 'N^\9X0
  
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脚本代码 HM57b>
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. EBlfwFd  
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Dim entity As T_ENTITY 9qN4f8R  
Dim op As T_OPERATION Lh3>xZy"-z  
Dim mat As T_MODELMATERIAL Z?X0:WK  
Dim A As Double `q|&;wP.  
Dim pupilDiam As Double /WlK*8C  
Dim eID As Long |$"2R3  
Dim parID As Long BC*vG=a  
Dim count As Integer rE0?R(_  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double u$ [R>l9  
Dim tlens As Double, nlens As Double n@n608  
Dim curv As Double, conic As Double Ay)q %:qx  
Dim ok As Long u>c\J|K_V  
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Sub Main Rs_0xh  
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    '用户输入对话框 dv=y,q@W  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 !OWPwBm;  
        TextBox 220,21,40,21,.TextBox1 'default: 0 y_O[r1MF  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 !wiW#PR  
        OKButton 40,91,90,21 !Ic;;<
 
        CancelButton 190,91,90,21 +Go(yS  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 _Gs*4:  
        TextBox 220,49,40,21,.TextBox2 'default: 4 piYv}4;:(  
    End Dialog Td#D\d\R  
    Dim dlg As UserDialog mr:;Wwd  
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    ok = Dialog (dlg) o?nlnoe  
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    If ok=0 Then    'cancel button was pressed dmh6o
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        Print "Execution cancelled." $YZsaw  
        End
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    End If sX&.8  
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    'Assign accommodation and pupil diameter & use defaults if field left empty VBc[(8o  
    If dlg.TextBox1 = "" Then &v!=\Fig4  
        A = 0           'Default accommodation \b{Aj,6,  
    Else V3;4,^=6Dd  
        A = CDbl(dlg.TextBox1) nQ|4.e;  
    End If Bz}Dgbb  
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    If dlg.TextBox2 = "" Then *r!f! eA:  
        pupilDiam = 4   'Default pupil diameter bqugo  
    Else ]zp5 6U|xa  
        pupilDiam = CDbl(dlg.TextBox2) 9pPb]v,6  
    End If _XT],"  
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    Print " " W{E22J}  
    Print "Accommodation = " & A & " Diopters" 7#n<d879e%  
    Print "Pupil Diameter = " & pupilDiam & " mm" JFax
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    ' Calculate new parameters with accommodation e&[
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    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness 0_yE74i  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens eUQ.,mP  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens =4GJYhj  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens WelB+P2  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens %M8Egr2|0  
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    tlens = 3.767 + 0.04*A                  'Lens thickness 2m.RM&TdB  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction u#5/s8  
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    'Adjust parameters to account for accommodation xGbr>OqkTX  
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    '************************************************************************* iO=xx|d  
    'Aqueous thickness (Position of Lens) I(BG%CO9  
    '************************************************************************* lhg3 }dW  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) =jD[A>3I  
    GetCustomElement eID, entity  j`^':!  
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    parID = FindFullName( "Geometry.Arizona Eye" ) 3nuf3)  
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    ' Delete any shift(s) in z '$Jt
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    count = 0 N/)mw/?i  
    While GetOperationCount(eID)>count ja$>>5<q  
        GetOperation eID, count, op ?7-#iC`  
        If op.Type="ShiftZ" Then Mq) n=M  
            DeleteOperation eID,count lJ]r%YlF  
            count=count-1 1"46OCu{  
        End If $w%oLI@kl  
        count=count+1 ,oe e'  
    Wend BmYU#h  
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    'Set new shift in 2rHw5Wn]~  
    op.Type = "ShiftZ" Cw?AP6f%  
    op.val1 = taq SCeZt [  
    op.parent = parID A/N*Nc  
    AddOperation eID, op J#*Uf>5NY  
    Print "Set aqueous humor thickness = " & taq-0.55 O<4i)Lx2  
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    '************************************************************************* )hk=wu6  
    'Radius and conic constant of anterior lens TI}H(XL(  
    '************************************************************************* 4zghM<  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) kFv\V   
    GetConic eID, entity, curv, conic ih`/1n  
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    SetConic eID, entity, 1/Rant, CCant L1BpkB  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant L5T)_iQ5  
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    '************************************************************************* ..FUg"sSO  
    'Radius and conic constant of posterior lens wI>JOV7  
    '************************************************************************* ,2JqX>On>Y  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) fLI@;*hL0  
    GetConic eID, entity, curv, conic >0 !J]gK  
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    SetConic eID, entity, 1/Rpost, CCpost +lJuF/sS8m  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost !Go(8`>  
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    '************************************************************************* CW\o>yh  
    'Lens thickness (Position of posterior lens surface) =@pm-rI|-  
    '************************************************************************* (m;P,*  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) ("/*k  
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    ' Delete any z-shift(s) 344,mnAd  
    count = 0 /
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    While GetOperationCount(eID)>count 'IfM~9'D  
        GetOperation eID, count, op jLr8?Hyf  
        If op.Type="ShiftZ" Then 6FEtq,;0w  
            DeleteOperation eID,count 6/4OFvL1  
            count=count-1 eBU\&z[  
        End If F!]UaEmV  
        count=count+1 {h9#JMIA  
    Wend @TgCI`E  
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    'Set new z-shift
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    op.Type = "ShiftZ" I$f:K]|.m!  
    op.val1 = tlens (59<Zo  
    op.parent = parID Q]6nW[@j'  
    AddOperation eID, op -^#Ix;%  
    Print "Set lens thickness = " & tlens |:!0`p{R  
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    '************************************************************************* O')Ivm,E  
    'Lens index of refraction f7s]:n*Ih  
    '************************************************************************* $%1[<}<  
    eID = FindMaterial( "Lens" ) 5j]}/Aq  
    GetModelMaterial eID, mat N#,4BU  
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    mat.Nd = nlens 3N]pN<3@  
    SetModelMaterial eID, mat Mm6 (Q  
    Print "Set lens index of refraction = " & nlens Opjt? ]  
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    '************************************************************************* m%Ef]({I  
    'Pupil diameter &)bar.vw/  
    '************************************************************************* 8|d[45*q  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) JWn9&WK  
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    'Adjust pupil diameter (trimming volume inner hole) {g @ *jo&  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" BV!Kiw  
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    ' Adjust pupil location to just in front of the lens 5mFi)0={y  
    parID = FindFullName( "Geometry.Arizona Eye" ) 7PisX!c,h  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) N`zHe*=[~  
    count = 0 qA"
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    While GetOperationCount(eID)>count hG ]jm  
        GetOperation eID, count, op c3 wu&*p{  
        If op.Type="ShiftZ" Then Jhj]rsGk  
            DeleteOperation eID,count SA/0Z=  
            count=count-1 ?v")Z0 ~  
        End If @C!q S7k)  
        count=count+1 2#E;5UYu  
    Wend >Y\4v}-  
    op.Type = "ShiftZ" R 7{rY  
    op.val1 = taq-0.01 #Kh`ATme  
    op.parent = parID db4&?55Q  
    AddOperation eID, op +
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    Print "Set pupil diameter = " & pupilDiam k,@1rOf  
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    'Update AZ Eye subassembly Description F_21`Hj  
    eID = FindFullName( "Geometry.Arizona Eye" ) }>OE"#si  
    GetEntity eID, entity J`x9XWYw  
    entity.Description = "Accommodation = " & A & "D" snK9']WXo  
    SetEntity eID, entity 3$kZu  
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    Update ~}M{[6!  
    Print "DONE!" S3=J1R,  
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End Sub bZlAK)  
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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： P`oR-D  
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Accommodation = 4 Diopters jxoEOEA  
Pupil Diameter = 4 mm tou^p-)GQ|  
Set aqueous humor thickness = 2.81 I3L1|!  
Set anterior lens radius = 10.4 and conic constant = -2.375869 '+eP%Y[W%  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 %kUJ:lg;d  
Set lens thickness = 3.927 L*l( ~t)vF  
Set lens index of refraction = 1.42672 1";~"p2(  
Set pupil diameter = 4 MUo?ajbqOd  
DONE! ~kHir]jc
 
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