[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 M}c_KFMV  
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。 &K4o8Qz  
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模型 saZ;ixV  
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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。 r1\.Jz  
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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. 48DsRy  

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光源 4qMHVPJv\  
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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。 Vs"Z9p$U  
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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。 ,s2.l/5r;C  
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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。 u+V;r)J{  
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视网膜的散射 9O)>>1}*S  
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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。 oacY-&  
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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。 f8j^a?d|
  
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脚本 {/Cd^CK  
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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： ~% c->\Q  
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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。 =_86{wlk  
余下的脚本计算与屈光度有关的所有参数。 @4|/| !  
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分析 l{R)yTO  
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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。 3l^pY18H'  
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脚本代码 Fzu{,b  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. ,>^~u  
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Dim entity As T_ENTITY  l g
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Dim op As T_OPERATION ?m!F
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Dim mat As T_MODELMATERIAL ~RJg.9V  
Dim A As Double n>Ei1  
Dim pupilDiam As Double /<C=9?Ok  
Dim eID As Long !9 F+uc5  
Dim parID As Long Gl:ASPZ6  
Dim count As Integer s,RS}ek~|  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double 7^L&YVW  
Dim tlens As Double, nlens As Double %Xl@o  
Dim curv As Double, conic As Double BCbW;w8aI  
Dim ok As Long Yem
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Sub Main jt3SA [cy  
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    '用户输入对话框 L:<'TXsRA  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 *v9G#[gG  
        TextBox 220,21,40,21,.TextBox1 'default: 0 . ~<+  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 _=MWt_A '3  
        OKButton 40,91,90,21 ,aJrN!fzU  
        CancelButton 190,91,90,21 DH^^$)  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 9V&LJhDQ  
        TextBox 220,49,40,21,.TextBox2 'default: 4 v^tKT&  
    End Dialog |
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    Dim dlg As UserDialog 9 2EMDKJ  
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    ok = Dialog (dlg) .phQ7":`  
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    If ok=0 Then    'cancel button was pressed ($s{em4L  
        Print "Execution cancelled." _X[c19q  
        End *pMA V[^  
    End If &u8c!;y$b  
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    'Assign accommodation and pupil diameter & use defaults if field left empty Ba6xkEd  
    If dlg.TextBox1 = "" Then Pz 'Hqvd  
        A = 0           'Default accommodation J[
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    Else BP6Shc|C  
        A = CDbl(dlg.TextBox1) Fo#*_y5\  
    End If gUp0RPs  
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    If dlg.TextBox2 = "" Then s__g*%@B b  
        pupilDiam = 4   'Default pupil diameter 7L*`nU|h  
    Else
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        pupilDiam = CDbl(dlg.TextBox2) 6,PLzZ5  
    End If i1 &'Zh  
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    Print " " u W T[6R  
    Print "Accommodation = " & A & " Diopters" GLyh1qNX  
    Print "Pupil Diameter = " & pupilDiam & " mm" qZh~Ay6I  
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    ' Calculate new parameters with accommodation vknFtpx  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness UZra'+Wb  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens 4lCm(#T{,  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens .Q@"];wH  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens R{vPn8X6g  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens j`B{w   
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    tlens = 3.767 + 0.04*A                  'Lens thickness SfUUo9R(sm  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction  ZsZ1  
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    'Adjust parameters to account for accommodation @_3$(*n$~  
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    '************************************************************************* DlI5} Jh  
    'Aqueous thickness (Position of Lens) Vm.@qO*=  
    '************************************************************************* "[yiNJ"kt  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) T*yveo&j  
    GetCustomElement eID, entity Kf#!IY][  
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    parID = FindFullName( "Geometry.Arizona Eye" ) \<**SSN  
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    ' Delete any shift(s) in z R:?vY!  
    count = 0 46Nf|~
 
    While GetOperationCount(eID)>count fx:KH:q3  
        GetOperation eID, count, op VWt'Kx"  
        If op.Type="ShiftZ" Then BtChG] N|  
            DeleteOperation eID,count M7,MxwZ0k  
            count=count-1 ;0}2@Q2@ZK  
        End If :g#it@  
        count=count+1 8[;oUVb
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    Wend A#&qo
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    'Set new shift in (14kR  
    op.Type = "ShiftZ" N1~$ +  
    op.val1 = taq nX%'o`f  
    op.parent = parID [dlH t;S  
    AddOperation eID, op <9a_wGs  
    Print "Set aqueous humor thickness = " & taq-0.55 ecpUp39\  
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    '************************************************************************* GK?R76d  
    'Radius and conic constant of anterior lens J5_Y\@  
    '************************************************************************* F t/ x5  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) 9P
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    GetConic eID, entity, curv, conic 389.&`Q%Ut  
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    SetConic eID, entity, 1/Rant, CCant 2-!Mao"^  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant +|)1_NK  
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    '************************************************************************* KxmPL  
    'Radius and conic constant of posterior lens z.&%>%TPP  
    '*************************************************************************
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    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) myOX:K*  
    GetConic eID, entity, curv, conic )=nPM`Jn.  
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    SetConic eID, entity, 1/Rpost, CCpost eZ5}O0sfp  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost [.xk
 
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    '************************************************************************* OKP_3Ns  
    'Lens thickness (Position of posterior lens surface) wn|@D<  
    '************************************************************************* #aY<J:Nx  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) U9.=Ik  
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    ' Delete any z-shift(s) 'O2#1SWe  
    count = 0 PJ'lZu8?x  
    While GetOperationCount(eID)>count tW"ptU^9)
 
        GetOperation eID, count, op (L:Fb  
        If op.Type="ShiftZ" Then K6*UFO4}i  
            DeleteOperation eID,count LiD |4(3  
            count=count-1 pkfOM"5'  
        End If 1 lCikS^c  
        count=count+1 -s%-*K+,W  
    Wend 8Gl5)=2  
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    'Set new z-shift ro^6:w3O^  
    op.Type = "ShiftZ" %_R|@cyD  
    op.val1 = tlens dN\P&"`  
    op.parent = parID gq_7_Y/  
    AddOperation eID, op R5&$h$[/  
    Print "Set lens thickness = " & tlens GHC?Tp  
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    '************************************************************************* P,;b'-5C  
    'Lens index of refraction 4:eq{n  
    '************************************************************************* C:GHP$/}  
    eID = FindMaterial( "Lens" ) ?V)C9@bp  
    GetModelMaterial eID, mat MRg\FR2>1  
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    mat.Nd = nlens `TD%M`a  
    SetModelMaterial eID, mat }d3N`TT  
    Print "Set lens index of refraction = " & nlens 4 ^~zN"6]  
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    '************************************************************************* w^rb|mKo  
    'Pupil diameter 5Jhbf2-  
    '************************************************************************* opcR~tg@r  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) gUH'DS]{  
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    'Adjust pupil diameter (trimming volume inner hole) g t^]32$  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" nl-t<#z[  
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    ' Adjust pupil location to just in front of the lens WW[`E  
    parID = FindFullName( "Geometry.Arizona Eye" ) ELrZ8&5G  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) ]Z$TzT&@%  
    count = 0 cbu nq"  
    While GetOperationCount(eID)>count `mKlv~$1^  
        GetOperation eID, count, op XAU_SPAjiw  
        If op.Type="ShiftZ" Then 7Z`Mt9:Ht  
            DeleteOperation eID,count vpeBQ=2\  
            count=count-1 y@kcXlY  
        End If 6}i&6@Snq?  
        count=count+1 >^H'ZYzw  
    Wend I`"-$99|t1  
    op.Type = "ShiftZ" Ku0H?qft(  
    op.val1 = taq-0.01 3Zaq#uA  
    op.parent = parID >FY&-4+v  
    AddOperation eID, op qJX+[PJ  
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    Print "Set pupil diameter = " & pupilDiam dE5 5  
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    'Update AZ Eye subassembly Description OC?Zw@  
    eID = FindFullName( "Geometry.Arizona Eye" ) Sqdc1zC
 
    GetEntity eID, entity $(KIB82&  
    entity.Description = "Accommodation = " & A & "D" 3b|7[7}&  
    SetEntity eID, entity
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    Update 2Ft8dfdm`  
    Print "DONE!" !c4)pMd  
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End Sub 9
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如果屈光度是4，光瞳直径是4，则会输出如下数据： |{7e#ww]  
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Accommodation = 4 Diopters Evr2|4|O~  
Pupil Diameter = 4 mm 2AXF$YjY
 
Set aqueous humor thickness = 2.81
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Set anterior lens radius = 10.4 and conic constant = -2.375869 :cXIO  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 &Rt+LN0qB0  
Set lens thickness = 3.927 6K4`;  
Set lens index of refraction = 1.42672 x1m8~F  
Set pupil diameter = 4 qPXANx<^  
DONE! ?JXBWB4  
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