[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 6Xz d>5x  
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。 6#AEVRJKU@  
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模型 SME9hS$4  
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模型的定义如表1种所示，由半径、圆锥常数、折射率、阿贝数、到下一面的距离等一系列表面组成。一些参数由屈光度（A）来决定。 6O,:I  
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在FRED中使用0屈光度来创建的，光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. ~ g-(  
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光源 Qwt0~9n(  
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多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 {6WG  
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除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处，并增加了pre-propagation distance= -8。尽管光线在光瞳处创建，规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射，而不是在光瞳处入射。 :p,|6~b$  
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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。 #0vda'q=j  
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视网膜的散射 Kc95yt  
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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。 sQj]#/yK:  
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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。 :V5 Co!/+  
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脚本 |!9xL*A  
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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：
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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。 s+v9H10R
 
余下的脚本计算与屈光度有关的所有参数。 [5p3:D  
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分析 jrFPd  
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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@ SUu7o  
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脚本代码 Z{BK@Q4z  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. @'}2xw[eU  
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Dim entity As T_ENTITY C4$P#DZT^  
Dim op As T_OPERATION xT_"` @  
Dim mat As T_MODELMATERIAL .:f ao'  
Dim A As Double O
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Dim pupilDiam As Double >qB`03>  
Dim eID As Long $x`HmL3Sb  
Dim parID As Long i+mU(/l2{  
Dim count As Integer JZ`SV}\`  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double sZCK?  
Dim tlens As Double, nlens As Double >!@D^3PPA  
Dim curv As Double, conic As Double 2w3LK2`ZL  
Dim ok As Long vT0Op e6m  
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Sub Main 8^+|I,  
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    '用户输入对话框 nvf5a-C+q  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 JyTETf,y  
        TextBox 220,21,40,21,.TextBox1 'default: 0 s7sd(f]=  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 j@(S7=^C6%  
        OKButton 40,91,90,21 e-P{)L<s5  
        CancelButton 190,91,90,21 T@.+bD  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 U5N|2  
        TextBox 220,49,40,21,.TextBox2 'default: 4 S$hxR  
    End Dialog ^8~TsK~  
    Dim dlg As UserDialog P8ej9ULX,  
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    ok = Dialog (dlg) PvV\b<Pe+  
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    If ok=0 Then    'cancel button was pressed zA6C{L G3  
        Print "Execution cancelled." SF*mY=1  
        End [[^r;XKQ  
    End If hNZ_= <D!  
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    'Assign accommodation and pupil diameter & use defaults if field left empty CHv n8tk  
    If dlg.TextBox1 = "" Then NpZ'pBl  
        A = 0           'Default accommodation 5]]QW3  
    Else Bf00&PE;  
        A = CDbl(dlg.TextBox1) -M6vg4gf  
    End If Lf^ 7|  
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    If dlg.TextBox2 = "" Then #aC&!Rei{  
        pupilDiam = 4   'Default pupil diameter "?6*W"N9  
    Else hs;|,r  
        pupilDiam = CDbl(dlg.TextBox2) vb0Ca+}}  
    End If q1 q~%+Jy  
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    Print " " D[@-`F  
    Print "Accommodation = " & A & " Diopters" ,B/TqPP
  
    Print "Pupil Diameter = " & pupilDiam & " mm" ~I>|f  
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    ' Calculate new parameters with accommodation 6Zw$F3 <  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness rtvLLOIO  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens [7`S`\_NK  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens dfVI*5[Z  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens |n,O!29  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens lmoYQFkYP  
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    tlens = 3.767 + 0.04*A                  'Lens thickness B &Z0ZWx  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction [*)2Ou  
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    'Adjust parameters to account for accommodation p +JOUW  
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    '************************************************************************* N/{=j  
    'Aqueous thickness (Position of Lens) 79)iv+nf\l  
    '************************************************************************* lxXF8c>U  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) 8sDw:wTC  
    GetCustomElement eID, entity kH0kf-4\  
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    parID = FindFullName( "Geometry.Arizona Eye" ) b9.7j!W  
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    ' Delete any shift(s) in z nrpbQ(zI*  
    count = 0 j yp.2c  
    While GetOperationCount(eID)>count NODE`VFu  
        GetOperation eID, count, op r7U[QTM%  
        If op.Type="ShiftZ" Then _pS)bxw  
            DeleteOperation eID,count -y&>&D  
            count=count-1 x51p'bNy  
        End If <Vyl*a{%  
        count=count+1  :5^5l  
    Wend }VH`\g}  
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    'Set new shift in :8)3t! A  
    op.Type = "ShiftZ" ezJ^ r,D|  
    op.val1 = taq f]Z9=  
    op.parent = parID uX7"u*@Q*~  
    AddOperation eID, op y>UQm|o<W  
    Print "Set aqueous humor thickness = " & taq-0.55 %kBrxf  
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    '************************************************************************* O'~^wu.  
    'Radius and conic constant of anterior lens QE;,mC>  
    '************************************************************************* i}:^<jDv?  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) r)qow.+&  
    GetConic eID, entity, curv, conic czo*_q%  
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    SetConic eID, entity, 1/Rant, CCant [9CBTSr  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant Y5IQhV.  
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    '************************************************************************* |oOA;JC)(  
    'Radius and conic constant of posterior lens +{e2TY  
    '************************************************************************* 
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    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) jA%R8hdr_  
    GetConic eID, entity, curv, conic ",E$}= ,Z  
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    SetConic eID, entity, 1/Rpost, CCpost :bp8S@  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost olDzmy(=W*  
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    '************************************************************************* #k)J);&ZA  
    'Lens thickness (Position of posterior lens surface) /EM=!@ka  
    '************************************************************************* ?O e,  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) P.t7_v>  
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    ' Delete any z-shift(s) {1wjIo"ptg  
    count = 0 ~rz%TDX0\  
    While GetOperationCount(eID)>count _H2%6t/V  
        GetOperation eID, count, op !Ie={BpzbZ  
        If op.Type="ShiftZ" Then +u7nx  
            DeleteOperation eID,count 8bEii1EM  
            count=count-1 DVyxe
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        End If z"@UNypc,  
        count=count+1 ,?!4P+ob  
    Wend pXxpEv  
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    'Set new z-shift :+S~N)0j^  
    op.Type = "ShiftZ" '%A*Z,f  
    op.val1 = tlens UazUr=|e  
    op.parent = parID [E%Ov0OC  
    AddOperation eID, op v/7iu*u  
    Print "Set lens thickness = " & tlens 7;:Uv=  
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    '************************************************************************* a s?)6  
    'Lens index of refraction DKf:0E8  
    '************************************************************************* Jp`qE  
    eID = FindMaterial( "Lens" ) Y)v_O_`  
    GetModelMaterial eID, mat !Ry4w|w  
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    mat.Nd = nlens m&r?z%  
    SetModelMaterial eID, mat 6Y
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    Print "Set lens index of refraction = " & nlens lMBXD?,,J  
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    '************************************************************************* ]^CNC0  
    'Pupil diameter @460r  
    '************************************************************************* 7q _.@J  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) q]o^Y  
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    'Adjust pupil diameter (trimming volume inner hole) .EoLJHL }  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" APucA  
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    ' Adjust pupil location to just in front of the lens }xM >F%  
    parID = FindFullName( "Geometry.Arizona Eye" ) Vam4/6  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) ;O7<lF\7o  
    count = 0 CR<Nau>  
    While GetOperationCount(eID)>count rYMHc@a9(  
        GetOperation eID, count, op U: Q&sq8U  
        If op.Type="ShiftZ" Then q
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            DeleteOperation eID,count Od:,r  
            count=count-1 <jvSV5%  
        End If 07L1 "  
        count=count+1 >w"k:O17  
    Wend 9nPc>O$  
    op.Type = "ShiftZ" 2oFHP_HVfu  
    op.val1 = taq-0.01 /?j vv&  
    op.parent = parID nE3'm[)  
    AddOperation eID, op iv/!c Mb  
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    Print "Set pupil diameter = " & pupilDiam tk <R|i  
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    'Update AZ Eye subassembly Description |H'4];>R?  
    eID = FindFullName( "Geometry.Arizona Eye" ) gf8DhiB  
    GetEntity eID, entity 8E| Nf  
    entity.Description = "Accommodation = " & A & "D" jQiKof>  
    SetEntity eID, entity JW4~Qwx  
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    Update amn\#_(  
    Print "DONE!" $fwv'  
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End Sub yJ&`@gB  
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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： ,:QzF"MV  
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Accommodation = 4 Diopters Xn'{g  
Pupil Diameter = 4 mm j[fVF3v  
Set aqueous humor thickness = 2.81 (hn@+hc  
Set anterior lens radius = 10.4 and conic constant = -2.375869 crt )}L8-  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 5@6%/='I q  
Set lens thickness = 3.927 !V6O~#  
Set lens index of refraction = 1.42672 ]HK|xO(  
Set pupil diameter = 4 <Yk#MeiEp  
DONE! xmEmdOoD  
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