[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 7\eN8+  
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。 wS#.Wzp.w  
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模型 q*,];j/>k  
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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。 g6+}'MN:5  
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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. <Jv %}r  
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光源 B<x)^[<v  
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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。 fHdPav f,S  
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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。 UJ<eF/KSmG  
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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。 9=89)TrY  
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视网膜的散射 cK"b0K/M?B  
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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。 xQ=[0!p+  
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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。 ayTEQS  
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脚本 VnAJOR7lrx  
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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： 3V>2N)3`A  
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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。 ?kMG!stgp}  
余下的脚本计算与屈光度有关的所有参数。 QK)"-y}"g  
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分析 O'a Srjl  
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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。 TL lR"L5  
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脚本代码 why;1z>V  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. nSdta'6  
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Dim entity As T_ENTITY zZE 2%fqM  
Dim op As T_OPERATION l$=Y(Xk  
Dim mat As T_MODELMATERIAL R]L|&{  
Dim A As Double W7r1!/ccj  
Dim pupilDiam As Double q^ lx03   
Dim eID As Long q|xJ)[AO  
Dim parID As Long -*t4(wT|j  
Dim count As Integer ZbD_
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Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double ve;#o<  
Dim tlens As Double, nlens As Double zBg>I=hiG  
Dim curv As Double, conic As Double \x\_I1|  
Dim ok As Long 2A'!kd$2  
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Sub Main rw/WD(  
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    '用户输入对话框 W=fs"
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    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 JFf*v6:,  
        TextBox 220,21,40,21,.TextBox1 'default: 0 ;dgxeP;mp  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 c~bi ~ f  
        OKButton 40,91,90,21 sJu^deX  
        CancelButton 190,91,90,21 /V}>v
  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 4 qM
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        TextBox 220,49,40,21,.TextBox2 'default: 4 ,*ZdMw!  
    End Dialog A82Bn|J  
    Dim dlg As UserDialog huVw+vAA  
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    ok = Dialog (dlg) 6B>1"h%Wf  
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    If ok=0 Then    'cancel button was pressed Jv(9
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        Print "Execution cancelled." *;b.x"  
        End xrb %-vT  
    End If
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    'Assign accommodation and pupil diameter & use defaults if field left empty "|<6bA  
    If dlg.TextBox1 = "" Then A<-Prvryt  
        A = 0           'Default accommodation 7 $AEh+f  
    Else L7oLV?k  
        A = CDbl(dlg.TextBox1) x|C[yu^c  
    End If g_'F(An  
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    If dlg.TextBox2 = "" Then MR:GH.uM:  
        pupilDiam = 4   'Default pupil diameter WrWJ!   
    Else &s m7R i  
        pupilDiam = CDbl(dlg.TextBox2) DL0jA/f  
    End If V}<Hx3!  
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    Print " " $qOV#,@  
    Print "Accommodation = " & A & " Diopters" '@OqWdaR  
    Print "Pupil Diameter = " & pupilDiam & " mm" )c~1
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    ' Calculate new parameters with accommodation a|aRUxa0"  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness R1$O)A}k  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens :6R0=oz  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens 2ZHeOKJ-  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens OT-!n  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens Np$peT[  
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    tlens = 3.767 + 0.04*A                  'Lens thickness FnkB z5D  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction w D|p'N  
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    'Adjust parameters to account for accommodation }<?1\k  
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    '************************************************************************* (pY'v/a-  
    'Aqueous thickness (Position of Lens) F<SCW+>z2a  
    '************************************************************************* qm30,$\c`~  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) X;$g7A  
    GetCustomElement eID, entity ^@
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    parID = FindFullName( "Geometry.Arizona Eye" ) F!v`._]  
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    ' Delete any shift(s) in z 43_;Z| T  
    count = 0 hCXSC*;  
    While GetOperationCount(eID)>count r2:n wlG  
        GetOperation eID, count, op Z:F5cXt<  
        If op.Type="ShiftZ" Then d GEMrjx  
            DeleteOperation eID,count UuDT=_1Sh  
            count=count-1 WSA;p=_  
        End If _"BYnPq@wb  
        count=count+1 fAx7_}k/ m  
    Wend +RIG8w]  
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    'Set new shift in c,WRgXL  
    op.Type = "ShiftZ" 9Z! j
 
    op.val1 = taq G/Ll4 :  
    op.parent = parID :^ 9sy  
    AddOperation eID, op IYtM'!u  
    Print "Set aqueous humor thickness = " & taq-0.55 WxNPAJ6YH  
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    '************************************************************************* %EC{O@EAk  
    'Radius and conic constant of anterior lens 53y,eLf  
    '************************************************************************* bj6-0`  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) ]-  
    GetConic eID, entity, curv, conic $L|YllD%  
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    SetConic eID, entity, 1/Rant, CCant K@ZK@++  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant /SLAg&  
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    '************************************************************************* 8<z]rLQw?%  
    'Radius and conic constant of posterior lens R
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    '************************************************************************* q2qbbQ6H  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) <@;Y.76~  
    GetConic eID, entity, curv, conic ZY%]F,Y  
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    SetConic eID, entity, 1/Rpost, CCpost ,`<w#  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost j\V9o9D  
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    '************************************************************************* AEj
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    'Lens thickness (Position of posterior lens surface) NzRpI5\.  
    '************************************************************************* JryCL]  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) h-"c )?p  
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    ' Delete any z-shift(s) vIk;x
  
    count = 0 -C9_gZ  
    While GetOperationCount(eID)>count JN5<=x5r  
        GetOperation eID, count, op yn;h.m[):  
        If op.Type="ShiftZ" Then g.CUo:c  
            DeleteOperation eID,count !E\xn^  
            count=count-1 =F>@z4[P-  
        End If .gPE Qc+D  
        count=count+1 {~=Edf  
    Wend NL})_.Og  
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    'Set new z-shift kYxb@Zn=|  
    op.Type = "ShiftZ" qPgLSZv  
    op.val1 = tlens  T~I5W=y  
    op.parent = parID {Vz.| a[T  
    AddOperation eID, op K]mR9$/  
    Print "Set lens thickness = " & tlens :*GLLjS;  
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    '************************************************************************* 3?Ckk{)&  
    'Lens index of refraction YyR)2j1O  
    '************************************************************************* MPt:bf#  
    eID = FindMaterial( "Lens" ) >
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    GetModelMaterial eID, mat 11Kbj`sRZ  
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    mat.Nd = nlens Fv n:V\eb  
    SetModelMaterial eID, mat *2O4*Q1  
    Print "Set lens index of refraction = " & nlens 7I~Ww{  
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    '************************************************************************* _D9`L&X}  
    'Pupil diameter [zp v3Uw  
    '************************************************************************* >*ey 7g  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" )  SJY<#_b  
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    'Adjust pupil diameter (trimming volume inner hole) (17%/80-J  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" .k5 TQt  
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    ' Adjust pupil location to just in front of the lens [t55Kz*cD  
    parID = FindFullName( "Geometry.Arizona Eye" ) fm2,Mx6  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) @=o1q=5@8  
    count = 0 b-e3i;T!}~  
    While GetOperationCount(eID)>count $x&@!/&|pv  
        GetOperation eID, count, op /{pVYY  
        If op.Type="ShiftZ" Then 41luFtE9  
            DeleteOperation eID,count %AbA(F  
            count=count-1 /60`
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        End If [u[`!L=  
        count=count+1 +W+O7SK\y  
    Wend @-dM'R6C  
    op.Type = "ShiftZ" tjZ.p.IlG  
    op.val1 = taq-0.01 (uG.s%I  
    op.parent = parID \-kX-Tq  
    AddOperation eID, op `+17x<N  
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    Print "Set pupil diameter = " & pupilDiam SX)giQLU  
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    'Update AZ Eye subassembly Description |He,v/r  
    eID = FindFullName( "Geometry.Arizona Eye" ) 7 }`c:u~j  
    GetEntity eID, entity #yZZ$XOk  
    entity.Description = "Accommodation = " & A & "D" "@!z+x[8  
    SetEntity eID, entity $"[1yQ<p  
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    Update T^h;T{H2  
    Print "DONE!" O@[c
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End Sub R }M'D15  
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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：
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Accommodation = 4 Diopters QC.WR'.  
Pupil Diameter = 4 mm /G$8j$  
Set aqueous humor thickness = 2.81 0T2h3,  
Set anterior lens radius = 10.4 and conic constant = -2.375869 gwk$|aT@  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 }K,:aN,44\  
Set lens thickness = 3.927 c;_GZ}8  
Set lens index of refraction = 1.42672 Tyu]14L  
Set pupil diameter = 4 [\CQ_qs|  
DONE! Pxu!,Mi[d  

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