[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 $'L(}gNv5  
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。 IJS9%m#  
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模型
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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。 [p}J=1S  
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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. \ts:'  
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光源 J:#B,2F+^  
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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。 #OJ^[Zi<  
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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。 "E/F{6NH  
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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。 a3R#Bg(  
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视网膜的散射 1k{ E7eL  
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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。 iknBc-TLD  
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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。 mOGcv_L  
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脚本 ^L]+e  
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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： <X|"5/h  
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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。 1ww|km  
余下的脚本计算与屈光度有关的所有参数。 A){kitx-i)  
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分析 Mgcq'{[~Y=  
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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。 '(^p$=3|@D  
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脚本代码 7lR(6ka&/  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. |I)xK@7  
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Dim entity As T_ENTITY KW+^9&lA  
Dim op As T_OPERATION `!!A;G7Qg  
Dim mat As T_MODELMATERIAL d/P$qMD  
Dim A As Double 9DKmX
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Dim pupilDiam As Double Fypqf|  
Dim eID As Long -uy}]s5Qu  
Dim parID As Long MT
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Dim count As Integer AWD &K!  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double >=C)\Yfu)  
Dim tlens As Double, nlens As Double 2/B(T5PY@  
Dim curv As Double, conic As Double x9-K}s]%  
Dim ok As Long U:_T9!fG  
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Sub Main k?|VF
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    '用户输入对话框 asPD>jc  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 oJ
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        TextBox 220,21,40,21,.TextBox1 'default: 0  78qf  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 -s:JD
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        OKButton 40,91,90,21 uZ<Bfrc  
        CancelButton 190,91,90,21 OK3B6T5w=  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 2kCJqyWy
 
        TextBox 220,49,40,21,.TextBox2 'default: 4 IG
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    End Dialog n$#^gzU4  
    Dim dlg As UserDialog pA+Qb.z5z  
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    ok = Dialog (dlg) Og30&a!~F  
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    If ok=0 Then    'cancel button was pressed YwB5Zqr  
        Print "Execution cancelled." .}
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        End K8284A8v  
    End If O}IS{/^7  
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    'Assign accommodation and pupil diameter & use defaults if field left empty Haq23K  
    If dlg.TextBox1 = "" Then f4!
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        A = 0           'Default accommodation *zz/U (9D  
    Else 2z )h,<D  
        A = CDbl(dlg.TextBox1) g&_0)(a\  
    End If  "thfd"-  
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    If dlg.TextBox2 = "" Then 1(On.Y=   
        pupilDiam = 4   'Default pupil diameter A4(^I u  
    Else P3lNns3  
        pupilDiam = CDbl(dlg.TextBox2) 2eyvY|:Q>  
    End If ]6=cSs!  
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    Print " " c{FvMV2em  
    Print "Accommodation = " & A & " Diopters" yKDg ~zsh  
    Print "Pupil Diameter = " & pupilDiam & " mm" F\,3z7s  
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    ' Calculate new parameters with accommodation }c&Zv#iO6  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness x6:$lZ(  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens W{Nhh3  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens ukG1<j7.  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens IXd&$h]Lq  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens *dUnP{6g  
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    tlens = 3.767 + 0.04*A                  'Lens thickness pjbKMx  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction OP:;?Fs9`  
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    'Adjust parameters to account for accommodation =_ -@1 1a  
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    '************************************************************************* HQf[T@  
    'Aqueous thickness (Position of Lens) atl0#FBd  
    '************************************************************************* 9W'#4  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) |mmIu_  
    GetCustomElement eID, entity QKCk. 0Xe  
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    parID = FindFullName( "Geometry.Arizona Eye" ) W-Hw%bwN/q  
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    ' Delete any shift(s) in z o^DiIoor  
    count = 0 mYa0_P%^  
    While GetOperationCount(eID)>count )O2^?Q quS  
        GetOperation eID, count, op -*?a*q/#nQ  
        If op.Type="ShiftZ" Then A:
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            DeleteOperation eID,count 8iX?4qj{P  
            count=count-1 +yCIA\i#t6  
        End If B;G|2um:$  
        count=count+1 QD"V=}'?  
    Wend =>S5}6  
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    'Set new shift in z KJ6j]m  
    op.Type = "ShiftZ" zFQxW4G  
    op.val1 = taq <(
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    op.parent = parID
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    AddOperation eID, op CXA)Zl5#  
    Print "Set aqueous humor thickness = " & taq-0.55 {u9VHAXCf  
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    '************************************************************************* 4P2)fLmc  
    'Radius and conic constant of anterior lens
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    '************************************************************************* o{zo-:>Jp  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) WOgbz&S?J  
    GetConic eID, entity, curv, conic 6
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    SetConic eID, entity, 1/Rant, CCant N],A&}30  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant (Ptv#LSUX  
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    '************************************************************************* w6#hsRq[C  
    'Radius and conic constant of posterior lens B8B^@   
    '************************************************************************* $!KV]]  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) v*3ezf\  
    GetConic eID, entity, curv, conic _W?}%;  
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    SetConic eID, entity, 1/Rpost, CCpost P8;|>OLZ)  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost t;y>q  
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    '************************************************************************* {\lu; b!  
    'Lens thickness (Position of posterior lens surface) KY4|C05,  
    '************************************************************************* #^Sd r-   

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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) -Z6ot{%  
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    ' Delete any z-shift(s) }$iH3#E8  
    count = 0 hc~--[1c:  
    While GetOperationCount(eID)>count JH<q7Y6!y  
        GetOperation eID, count, op PTL52+
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        If op.Type="ShiftZ" Then - n11L  
            DeleteOperation eID,count bk#u0N  
            count=count-1 HOu<,9?>Q  
        End If \JN<"/  
        count=count+1 "R):B~8|H{  
    Wend y;#p=,r  
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    'Set new z-shift <7)Vj*VxC  
    op.Type = "ShiftZ"  h}+,]^  
    op.val1 = tlens $WTu7lVV[1  
    op.parent = parID uX`Jc:1q3  
    AddOperation eID, op / ^!(rHf  
    Print "Set lens thickness = " & tlens BflF*-s ^  
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    '************************************************************************* 3(vI{[yhT  
    'Lens index of refraction _|H]X+|  
    '************************************************************************* fN
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    eID = FindMaterial( "Lens" ) vbFY}  
    GetModelMaterial eID, mat i3#]_ p{  
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    mat.Nd = nlens #4d0/28b  
    SetModelMaterial eID, mat !BK^5,4?--  
    Print "Set lens index of refraction = " & nlens F"a,[i,[W  
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    '************************************************************************* <8jn_6  
    'Pupil diameter y . AN0  
    '************************************************************************* 5#WZXhlc}  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) CEI#x~Oq  
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    'Adjust pupil diameter (trimming volume inner hole) 5/neV&VcB  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" ]iPTB  
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    ' Adjust pupil location to just in front of the lens d{9jd{ _#G  
    parID = FindFullName( "Geometry.Arizona Eye" ) qK(?\t$  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) Yxi.A$g  
    count = 0 C7)].vUN  
    While GetOperationCount(eID)>count yK[~(!c5  
        GetOperation eID, count, op U .e Urzu  
        If op.Type="ShiftZ" Then Q.vtU%T  
            DeleteOperation eID,count nFxogCn
 
            count=count-1 *B@<{x r  
        End If kk^KaD4dA  
        count=count+1 n;2W=N?y  
    Wend D>LdDhNn,`  
    op.Type = "ShiftZ" srg#<oH|{c  
    op.val1 = taq-0.01 eQzSWn[  
    op.parent = parID +F+jC9j(<  
    AddOperation eID, op 5 _] i==M  
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    Print "Set pupil diameter = " & pupilDiam t'R&$;z@b  
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    'Update AZ Eye subassembly Description ii{5z;I]X  
    eID = FindFullName( "Geometry.Arizona Eye" ) Eepy%-\  
    GetEntity eID, entity U_oMR$/Z  
    entity.Description = "Accommodation = " & A & "D" 3%k@,Vvt  
    SetEntity eID, entity :c<C;.  
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    Update syBYH5  
    Print "DONE!" ~TurYvf  
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End Sub % sT=>\  
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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： @I_A(cr  
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Accommodation = 4 Diopters 4sROMk=l
  
Pupil Diameter = 4 mm /5zzzaj{  
Set aqueous humor thickness = 2.81 rK)%n!Z  
Set anterior lens radius = 10.4 and conic constant = -2.375869 &bA;>Lu#|o  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 YwHnDV
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Set lens thickness = 3.927 sF(U?)48  
Set lens index of refraction = 1.42672 &ec_jxF  
Set pupil diameter = 4 fZXd<Fg+  
DONE! >Li ~Og@  
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