[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 #$%9XD3  
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。 !h7`W*::  
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模型 r!yrPwKL  
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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。 zzuDI_,/  
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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. <"/Y`/
 
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光源 [9a0J):w{  
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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。 N7%Jy?-+  
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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。 {gl-tRC3  
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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。 RX>kOp29  
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视网膜的散射 W!I"rdo;V  
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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。 q NU\XO`H  
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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。 kJ>l,AD/  
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脚本 ]ss0~2  
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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： -a]oN:ERb  
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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。 '\l(.N
 
余下的脚本计算与屈光度有关的所有参数。 waQNX7Xdn  
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分析 gx4`pH;B\  
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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。 wX#=l?,K  
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脚本代码 vC$[Zm  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. /t%IU  
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Dim entity As T_ENTITY Yj/S(4(h?  
Dim op As T_OPERATION d'kQE_y2.  
Dim mat As T_MODELMATERIAL pJVzT,poh  
Dim A As Double EHcqj;@m  
Dim pupilDiam As Double &y mfA{s  
Dim eID As Long 6fY(u7m|p  
Dim parID As Long j?+FS`a!  
Dim count As Integer _z)G!_7.>\  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double Y@TZReb  
Dim tlens As Double, nlens As Double TPq5"mco  
Dim curv As Double, conic As Double my[)/'  
Dim ok As Long =JOu
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Sub Main (".`#909  
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    '用户输入对话框 $[VKM|Zjw  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 ZJ 8~f  
        TextBox 220,21,40,21,.TextBox1 'default: 0 }7g\1l\  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 E6NkuBQ((  
        OKButton 40,91,90,21 ,@/b7BVv  
        CancelButton 190,91,90,21 )mB+#T<k-  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 %TPnC'2  
        TextBox 220,49,40,21,.TextBox2 'default: 4 L
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    End Dialog 68*h#&  
    Dim dlg As UserDialog 1V+a;-?  
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    ok = Dialog (dlg) ul?'kuYk  
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    If ok=0 Then    'cancel button was pressed 6QLWF@  
        Print "Execution cancelled." E&#AX:  
        End pTST\0?  
    End If {Lk~O)E  
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    'Assign accommodation and pupil diameter & use defaults if field left empty z=N'evx~  
    If dlg.TextBox1 = "" Then 4G;+ETp  
        A = 0           'Default accommodation 245(ajxHC  
    Else ,`^B!U3m   
        A = CDbl(dlg.TextBox1) Qa5<go{  
    End If yj `b-^$?  
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    If dlg.TextBox2 = "" Then ]V6<h Psi  
        pupilDiam = 4   'Default pupil diameter ..Zuy|?w  
    Else \"V7O'S)&  
        pupilDiam = CDbl(dlg.TextBox2) w[uK3Av  
    End If '6Ybf  
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    Print " " 6$4G&'J  
    Print "Accommodation = " & A & " Diopters" t*.O >$[  
    Print "Pupil Diameter = " & pupilDiam & " mm" ]sd|u[:k  
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    ' Calculate new parameters with accommodation (i.MxGDd  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness 2rB$&>}T  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens `a["`N^  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens G':mc{{  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens )p~\lM}?d  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens E=Ah_zKU  
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    tlens = 3.767 + 0.04*A                  'Lens thickness \wCj$-;Jt  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction y5kqnibh@  
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    'Adjust parameters to account for accommodation +6B(LPxgP  
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    '************************************************************************* U?[a@Hj{  
    'Aqueous thickness (Position of Lens) kUUN2  
    '************************************************************************* YjdCCju  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) fZ`b~ZBwIj  
    GetCustomElement eID, entity <K=:_  
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    parID = FindFullName( "Geometry.Arizona Eye" ) S`8 h]vX  
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    ' Delete any shift(s) in z S)iv k x  
    count = 0 :UoZ`O~  
    While GetOperationCount(eID)>count 94=Wy-  
        GetOperation eID, count, op <ap%+(!I  
        If op.Type="ShiftZ" Then :@y!5[88!  
            DeleteOperation eID,count |g;hXr#~  
            count=count-1 `J|bGf#  
        End If |_&vW
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        count=count+1 "o*(i7T=n  
    Wend :XxsDD  
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    'Set new shift in &?"(al?  
    op.Type = "ShiftZ" VU J*\Sg  
    op.val1 = taq \EuMzb"G9p  
    op.parent = parID )'?3%$EM  
    AddOperation eID, op \rn:/  
    Print "Set aqueous humor thickness = " & taq-0.55 )[|TxXz d  
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    '************************************************************************* ^q-]."W]t~  
    'Radius and conic constant of anterior lens dT4?8:  
    '************************************************************************* *IG} /O.VT  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) Y #E/"x%+  
    GetConic eID, entity, curv, conic 2 DJs'"8  
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    SetConic eID, entity, 1/Rant, CCant ;{[&&qMwU  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant eU&[^  
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    '************************************************************************* pUutI|mt/  
    'Radius and conic constant of posterior lens 8iaP(*J  
    '************************************************************************* Cp`)*P2  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) % 3d59O  
    GetConic eID, entity, curv, conic b
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    SetConic eID, entity, 1/Rpost, CCpost \2KwF}[m  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost Au<NUc 2  
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    '************************************************************************* .;&c<c|  
    'Lens thickness (Position of posterior lens surface) Vr@I9W;D#  
    '************************************************************************* ~,3+]ts='\  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) T}d%XMXq  
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    ' Delete any z-shift(s) '=C)Hj[D  
    count = 0 8;K'77h  
    While GetOperationCount(eID)>count bHZXMUewC  
        GetOperation eID, count, op O W`yv  
        If op.Type="ShiftZ" Then UfIH!6Q  
            DeleteOperation eID,count Mhp6,JL  
            count=count-1 MWTzJGRT  
        End If +NWhvs  
        count=count+1 vncLB&@7  
    Wend Q
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    'Set new z-shift &v9*D`7L  
    op.Type = "ShiftZ" uv,&/,;S  
    op.val1 = tlens kEiWE|  
    op.parent = parID w6FtDl$  
    AddOperation eID, op KYBoGCS>  
    Print "Set lens thickness = " & tlens {[&$W8Li  
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    '************************************************************************* q$IgkL  
    'Lens index of refraction 1?+%*uoPX  
    '************************************************************************* W Cz+  
    eID = FindMaterial( "Lens" ) >F7v'-*{  
    GetModelMaterial eID, mat vt8z=O  
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    mat.Nd = nlens d0ZbusHHb  
    SetModelMaterial eID, mat S 2vjjS  
    Print "Set lens index of refraction = " & nlens t
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    '************************************************************************* /DLgE7iU%  
    'Pupil diameter (b!`klQ  
    '************************************************************************* -aj)
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    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) f-]5Z
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    'Adjust pupil diameter (trimming volume inner hole) o+-G@16  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" SA3!a.*c  
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    ' Adjust pupil location to just in front of the lens R/5@*mv{  
    parID = FindFullName( "Geometry.Arizona Eye" ) :x*#RnRr.  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) +E5EOo{ `|  
    count = 0 ZDffR:An  
    While GetOperationCount(eID)>count DX|yL!4[  
        GetOperation eID, count, op )Pj8{.t4  
        If op.Type="ShiftZ" Then R8"qDj  
            DeleteOperation eID,count 2o5Pbdel  
            count=count-1 L`"B;a
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        End If %N.qu_,IZ  
        count=count+1 -%I 0Q  
    Wend #0*OkZMt  
    op.Type = "ShiftZ" (>.+tq}  
    op.val1 = taq-0.01 JY6&CL`C  
    op.parent = parID *.g@6IkAQ  
    AddOperation eID, op j=>:{`*c  
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    Print "Set pupil diameter = " & pupilDiam 8y$c\Eu(mF  
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    'Update AZ Eye subassembly Description )wFr%wNe  
    eID = FindFullName( "Geometry.Arizona Eye" ) 9pY`_lxa>  
    GetEntity eID, entity 
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    entity.Description = "Accommodation = " & A & "D" P%%[_6<%M  
    SetEntity eID, entity A~Uqw8n$\  
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    Update Wu:@+~J.h  
    Print "DONE!" m`3Mev  
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End Sub kuEB  
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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： 4=b{k,kzgA  
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Accommodation = 4 Diopters yEvuTgDv  
Pupil Diameter = 4 mm qYi<GI*|@  
Set aqueous humor thickness = 2.81 d|~A>YZ  
Set anterior lens radius = 10.4 and conic constant = -2.375869 B^{87YR  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 Hf^Tok^6@]  
Set lens thickness = 3.927 W5#5RK"uX  
Set lens index of refraction = 1.42672 d7O\p(M1  
Set pupil diameter = 4 Td6Gu"  
DONE! N=?! ~n9Q-  
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