[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 ^)|tf\4  
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。 'r-B%D=  
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模型 auY?Cj'"fs  
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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。 eE\T,u5:  
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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. :qShP3^  
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光源 j~9Y0jz_  
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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。 OP_\V8=  
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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。 ]'>jw#|h  
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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。 :r:x|[3.  
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视网膜的散射 !SLfAFcS  
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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。 ;xai JJK{  
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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。 ys7Tq+  
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脚本 ]\ZmK0q<:  
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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： "b)EH/s  
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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。 z\WyL;  
余下的脚本计算与屈光度有关的所有参数。 N6*FlG-  
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分析 T w1&<S  
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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。 <J}JYT  
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脚本代码 YYe=
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. ^i@0P}K<  
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Dim entity As T_ENTITY D'UIxc8  
Dim op As T_OPERATION _]0<G8|Rv  
Dim mat As T_MODELMATERIAL L/N%ft]!T  
Dim A As Double y (%y'xBP  
Dim pupilDiam As Double &}#zG5eu  
Dim eID As Long v*OT[l7  
Dim parID As Long +Je%8jH  
Dim count As Integer < 7*9b  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double *c(YlfeZ#  
Dim tlens As Double, nlens As Double $?;)uoAg  
Dim curv As Double, conic As Double A5s;<d0  
Dim ok As Long pMf ?'l  
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Sub Main r\C"Fx^  
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    '用户输入对话框 ?lU(FK  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 !2.eJ)G  
        TextBox 220,21,40,21,.TextBox1 'default: 0 wOEc~WOd  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 /.t1Ow  
        OKButton 40,91,90,21 Y/L*0M.<  
        CancelButton 190,91,90,21 EO/41O  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 {s:"mkR  
        TextBox 220,49,40,21,.TextBox2 'default: 4 o"p['m*g  
    End Dialog py wc~dWvz  
    Dim dlg As UserDialog |[)pQGw  
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    ok = Dialog (dlg) 79+i4(H  
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    If ok=0 Then    'cancel button was pressed Ns\};j?TU*  
        Print "Execution cancelled." }LoMS<O-[  
        End Qs<L$"L1  
    End If NLt"yD3t  
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    'Assign accommodation and pupil diameter & use defaults if field left empty d@ ]N  
    If dlg.TextBox1 = "" Then -\25&m!+  
        A = 0           'Default accommodation p&
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    Else C4 -y%W"P  
        A = CDbl(dlg.TextBox1) qXoq< |  
    End If VU+=b+B~m  
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    If dlg.TextBox2 = "" Then CF:!  
        pupilDiam = 4   'Default pupil diameter G(bl)p^  
    Else nx%eq,Pq  
        pupilDiam = CDbl(dlg.TextBox2) TQQh:y  
    End If Fx:4d$>;  
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    Print " " Rt@O@oDI  
    Print "Accommodation = " & A & " Diopters" *qFl&*h}  
    Print "Pupil Diameter = " & pupilDiam & " mm" y=AF EP  
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    ' Calculate new parameters with accommodation j_z@VT}y  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness 4,BJK`{  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens B)dG:~  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens 8=g~+<A  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens ;s+3#Py  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens Q
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    tlens = 3.767 + 0.04*A                  'Lens thickness `$3ktQ$  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction 59~mr:*sF  
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    'Adjust parameters to account for accommodation
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    '************************************************************************* aq#F  
    'Aqueous thickness (Position of Lens) e{^^u$C1.e  
    '************************************************************************* -vc ,O77z"  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) e7plL^^`  
    GetCustomElement eID, entity FRXaPod  
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    parID = FindFullName( "Geometry.Arizona Eye" ) 86a,J3C[  
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    ' Delete any shift(s) in z { _Y'%Ggh  
    count = 0 cg9*+]rc  
    While GetOperationCount(eID)>count *w}r:04F  
        GetOperation eID, count, op }ktK*4<k  
        If op.Type="ShiftZ" Then 9_~9?5PU  
            DeleteOperation eID,count N0N%~3  
            count=count-1 qx*N-,M%k(  
        End If 9Q\RCl_1  
        count=count+1 hf;S#.k  
    Wend sejT] rJ  
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    'Set new shift in N,:G5Wx
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    op.Type = "ShiftZ" nswhYSX  
    op.val1 = taq 1K'cT\aFm  
    op.parent = parID nGur2}>n  
    AddOperation eID, op PfGiJ]:V-u  
    Print "Set aqueous humor thickness = " & taq-0.55 P/Y)Yx_(  
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    '************************************************************************* x'SIHV4M@Q  
    'Radius and conic constant of anterior lens !(3[z>  
    '************************************************************************* lA
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    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) n#B}p*G  
    GetConic eID, entity, curv, conic V}Oz!  O  
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    SetConic eID, entity, 1/Rant, CCant 6z'0fi|EN  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant WcpH="vm  
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    '************************************************************************* LvU/,.$  
    'Radius and conic constant of posterior lens @moaa}1  
    '************************************************************************* xn)F(P 0kv  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) vG=Pi'4XXo  
    GetConic eID, entity, curv, conic )Lk2tvr  
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    SetConic eID, entity, 1/Rpost, CCpost #Yy5@A}`o  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost eKU4"XTk  
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    '*************************************************************************

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    'Lens thickness (Position of posterior lens surface) jwI1 I{x  
    '************************************************************************* v "[<pFj^  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) Y^|15ek  
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    ' Delete any z-shift(s) [g{fz3 O6  
    count = 0 % 3fpIzm  
    While GetOperationCount(eID)>count B%o%%A8*g  
        GetOperation eID, count, op <,H/7Ba  
        If op.Type="ShiftZ" Then ~
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            DeleteOperation eID,count v[?gM.SF  
            count=count-1 nFro#qx  
        End If {7v|\6@e3  
        count=count+1 rxZk!- t)L  
    Wend FRQkD%k  
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    'Set new z-shift %f(4jQ0I  
    op.Type = "ShiftZ" dkg+_V!  
    op.val1 = tlens 0XE(vc!  
    op.parent = parID ;#*.@Or@Ah  
    AddOperation eID, op t*Z-]P  
    Print "Set lens thickness = " & tlens A}3E)Qo=G  
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    '************************************************************************* 7dlMDHp\Y  
    'Lens index of refraction n"R$b:  
    '************************************************************************* YYvX@f  
    eID = FindMaterial( "Lens" ) |@?='E?h  
    GetModelMaterial eID, mat "'>fTk_  
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    mat.Nd = nlens dLf ;g}W  
    SetModelMaterial eID, mat r 2{7h>  
    Print "Set lens index of refraction = " & nlens `G>|g^6%i  
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    '************************************************************************* EAF\7J*  
    'Pupil diameter t=[/L]!  
    '************************************************************************* =sS=  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) 1o)<23q`)  
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    'Adjust pupil diameter (trimming volume inner hole) lHu/pSu@k  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" Z(J 1A x  
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    ' Adjust pupil location to just in front of the lens \`8F.oZ^)  
    parID = FindFullName( "Geometry.Arizona Eye" ) !'>#!S~h3  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) gUp9yV  
    count = 0 ^Je*k)COn  
    While GetOperationCount(eID)>count )F0
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        GetOperation eID, count, op U/7jK40  
        If op.Type="ShiftZ" Then A\ tBmL_s  
            DeleteOperation eID,count O[=W%2I!i  
            count=count-1 >PG
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        End If 0bGQO&s [  
        count=count+1 0BOL0<Wq  
    Wend V0gu0+u~R  
    op.Type = "ShiftZ" UZgrSX {  
    op.val1 = taq-0.01 zS?DXE  
    op.parent = parID {|e7^_ke  
    AddOperation eID, op ?1X7jn`,+  
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    Print "Set pupil diameter = " & pupilDiam V.o*`V  
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    'Update AZ Eye subassembly Description AP?m,nd6  
    eID = FindFullName( "Geometry.Arizona Eye" ) /EvT%h?p  
    GetEntity eID, entity Q%t _Epe  
    entity.Description = "Accommodation = " & A & "D" \/r]Ra  
    SetEntity eID, entity 4 @9cO)m  
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    Update [bN_0T.YI  
    Print "DONE!" eBe5H =I@  
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End Sub Ge76/T%{Q  
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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： h:vI:V[/X  
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Accommodation = 4 Diopters _Aw-{HE'  
Pupil Diameter = 4 mm 1rh2!4)7  
Set aqueous humor thickness = 2.81 QX9['B<  
Set anterior lens radius = 10.4 and conic constant = -2.375869 EFs\zWF  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 y$L&N0z  
Set lens thickness = 3.927 {|Fn<&G  
Set lens index of refraction = 1.42672 5)M#hx%]#  
Set pupil diameter = 4 "+BuFhSLf  
DONE! `iwGPG!  
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