[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 #pK" ^O*!  
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。 GP %hf{  
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模型 wYV>Qd Z  
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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。 L1DH9wiQi  
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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. f^"pZS  
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光源 nP*%N|0  
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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。 k 9z9{  
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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。 Xxd]j]  
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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。 
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视网膜的散射 T{f$S  
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在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 02*qf:kTnA  
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注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 #C?M-  
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脚本 |Rhqi  
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内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： -rm[.  
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如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 C}Kl!  
余下的脚本计算与屈光度有关的所有参数。 GfEWms8z  
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分析 y*-_  
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屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 ^rP]B-)  
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脚本代码 :Ez,GAk  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. 5h6o}  
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Dim entity As T_ENTITY flFdoEV.U)  
Dim op As T_OPERATION 15<? [`:6  
Dim mat As T_MODELMATERIAL [p`5$\e  
Dim A As Double B#SVN Lv  
Dim pupilDiam As Double }shxEsq  
Dim eID As Long [{BY$"b#:  
Dim parID As Long fTvm2+.nX  
Dim count As Integer 'EAskA]*  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double wL 4Y%g  
Dim tlens As Double, nlens As Double V<H9KA  
Dim curv As Double, conic As Double 9iZio3m  
Dim ok As Long n%J=!z3  
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Sub Main <TRhnz  
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    '用户输入对话框 RE%f'y  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 4<F z![>  
        TextBox 220,21,40,21,.TextBox1 'default: 0 X4!7/&  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 #H>{>0q  
        OKButton 40,91,90,21 {a:05Y  
        CancelButton 190,91,90,21 f=R+]XPzz  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 &o;0%QgF  
        TextBox 220,49,40,21,.TextBox2 'default: 4 "}fweCBgo  
    End Dialog 8aP/vToa  
    Dim dlg As UserDialog K\F0nToJ.  
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    ok = Dialog (dlg) e;6KxvX~  
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    If ok=0 Then    'cancel button was pressed 8v& \F  
        Print "Execution cancelled." DdgiY9a.  
        End !`Rh2g*o9  
    End If L
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    'Assign accommodation and pupil diameter & use defaults if field left empty 2(xC|  
    If dlg.TextBox1 = "" Then 2Kz+COP+  
        A = 0           'Default accommodation :OY~Q3 @  
    Else 2L^)k?9>g+  
        A = CDbl(dlg.TextBox1) yS\&2"o  
    End If "S%t\  
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    If dlg.TextBox2 = "" Then ;Y`Y1  
        pupilDiam = 4   'Default pupil diameter tUJRNEg  
    Else |HAJDhM,l  
        pupilDiam = CDbl(dlg.TextBox2) e /JQ #A  
    End If ;[sW\Ou  
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    Print " " ssi7)0  
    Print "Accommodation = " & A & " Diopters" "n!yK
  
    Print "Pupil Diameter = " & pupilDiam & " mm" cqNK`3:.j  
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    ' Calculate new parameters with accommodation ~.m<`~u  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness m.e]tTe  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens )#}>,,S  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens -1g:3'% P  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens dw bR,K  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens V0\[|E;F  
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    tlens = 3.767 + 0.04*A                  'Lens thickness Ic#xz;elM  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction 18>cfDh;N  
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    'Adjust parameters to account for accommodation 9Yx(u2PQ  
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    '************************************************************************* L_8zZ8 o  
    'Aqueous thickness (Position of Lens) _IDZ.\'>$  
    '************************************************************************* 6Xlzdt  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) xAQtX=FoX+  
    GetCustomElement eID, entity @c3xUK  
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    parID = FindFullName( "Geometry.Arizona Eye" ) iq(PC3e`V  
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    ' Delete any shift(s) in z 11[lc2  
    count = 0 :S+K\  
    While GetOperationCount(eID)>count #<im?  
        GetOperation eID, count, op %BqaVOKJ"f  
        If op.Type="ShiftZ" Then :HkBP90o  
            DeleteOperation eID,count 7RAB"T;?Q  
            count=count-1 N@q}eGe  
        End If dj0; tQ=C  
        count=count+1 kmI0V
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    Wend 7F
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    'Set new shift in <uH8Fivb  
    op.Type = "ShiftZ" }]?Si6_ZZ  
    op.val1 = taq Ifj&S'():  
    op.parent = parID kSQ8kU_w+  
    AddOperation eID, op <B"sp r&1  
    Print "Set aqueous humor thickness = " & taq-0.55 [VCC+_  
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    '************************************************************************* c7Z4u|G  
    'Radius and conic constant of anterior lens _FLEz|%~  
    '************************************************************************* I2ek`t]  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) Y?VbgOM)  
    GetConic eID, entity, curv, conic )*,/L <  
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    SetConic eID, entity, 1/Rant, CCant R?2sbK4Cz  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant a^|DD#5  
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    '************************************************************************* o\AnM5  
    'Radius and conic constant of posterior lens 7io["zW  
    '************************************************************************* --$o$EP`  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" )
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    GetConic eID, entity, curv, conic 1gEH~Jmj  
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    SetConic eID, entity, 1/Rpost, CCpost c8qr-x1HG  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost ^
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    '************************************************************************* TOYK'|lwM  
    'Lens thickness (Position of posterior lens surface) ]Z JoC!u  
    '************************************************************************* P:qmg"i@3  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) X'9.fKp  
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    ' Delete any z-shift(s) YeX*IZX8  
    count = 0 }2A6W%^>]  
    While GetOperationCount(eID)>count "cH RGJG#  
        GetOperation eID, count, op ]|;+2@kDR  
        If op.Type="ShiftZ" Then ) "#'  
            DeleteOperation eID,count "}]`64?  
            count=count-1 2EY"[xK|  
        End If o9?@jjqH  
        count=count+1 ntiS7g e1  
    Wend o<2GtF1"o  
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    'Set new z-shift t<%0eu|  
    op.Type = "ShiftZ" uGKjZi  
    op.val1 = tlens (z?HyxRT  
    op.parent = parID >%JPgr/ 8  
    AddOperation eID, op y!e]bvN  
    Print "Set lens thickness = " & tlens Ae)xFnuq3  
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    '************************************************************************* 4p_C+4  
    'Lens index of refraction )oEVafNsT  
    '************************************************************************* z(PUoV:?  
    eID = FindMaterial( "Lens" ) r@r%qkh(.@  
    GetModelMaterial eID, mat -@uFRQt  
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    mat.Nd = nlens ?@V R%z  
    SetModelMaterial eID, mat e_BG%+;G,  
    Print "Set lens index of refraction = " & nlens N,ht<l\  
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    '************************************************************************* fF:57*ys  
    'Pupil diameter e4X df>B  
    '************************************************************************* ^-;S&=  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) vccWe7rh  
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    'Adjust pupil diameter (trimming volume inner hole) x_PO;  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" 4"@<bKx  
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    ' Adjust pupil location to just in front of the lens (su,=Z  
    parID = FindFullName( "Geometry.Arizona Eye" ) z,HhSW?&^  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) L aTcBcI  
    count = 0 c0Ug
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    While GetOperationCount(eID)>count owVvbC2<b(  
        GetOperation eID, count, op t2&kGf"  
        If op.Type="ShiftZ" Then K/4@2vF  
            DeleteOperation eID,count vwR_2u  
            count=count-1 >WLPE6E  
        End If ?z ,!iK`  
        count=count+1 _sjS'*]  
    Wend !U`&a=k  
    op.Type = "ShiftZ" {f*Y}/@  
    op.val1 = taq-0.01 AZ:7_4jz  
    op.parent = parID F<4rn  
    AddOperation eID, op I-v} DuM  
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    Print "Set pupil diameter = " & pupilDiam :XKYfc_y  
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    'Update AZ Eye subassembly Description ,(jJOFf  
    eID = FindFullName( "Geometry.Arizona Eye" ) /iW+<@Mas  
    GetEntity eID, entity sYTz6-  
    entity.Description = "Accommodation = " & A & "D" vz^ ] g  
    SetEntity eID, entity e8a^"Z`a  
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    Update 'Kelq$dn#  
    Print "DONE!" zal]t$z>  
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End Sub D{9a'0J  
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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： kuY^o,u-1e  
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Accommodation = 4 Diopters o$_0Qs$  
Pupil Diameter = 4 mm B5\l&4X  
Set aqueous humor thickness = 2.81 +)jUA]hJ/  
Set anterior lens radius = 10.4 and conic constant = -2.375869 o<g?*"TRh  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 .5JIQWE(  
Set lens thickness = 3.927 b3NIFKw  
Set lens index of refraction = 1.42672 1nVQYqT_  
Set pupil diameter = 4 ]l7W5$26 @  
DONE! "tEp8m  
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