[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 9 !V,++j  
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。 7E;`1lh7  
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模型 '}F..w/  
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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。 D;6C2>U~L  
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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. zin'&G>l  
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光源 S%o6cl=  
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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。 `bW0Va N  
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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。 ORFi0gFbA  
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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。 NGkWr  
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视网膜的散射  ja^  
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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。 sq+cF/jo6  
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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。 a@m  64l)  
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脚本 G@rV9  
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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： :xC1Ka%~  
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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。 WTUC\}#E\  
余下的脚本计算与屈光度有关的所有参数。 IQ5'4zQg=  
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分析 /<CgSW}  
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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。 ?F9c6$|  
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脚本代码 QQQN}!xPj  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. ]~\%ANoi  
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Dim entity As T_ENTITY ,9~qLQ0O  
Dim op As T_OPERATION ~--F?KUnL  
Dim mat As T_MODELMATERIAL `9Q O'^)  
Dim A As Double W&e}*  
Dim pupilDiam As Double &o7"L;  
Dim eID As Long VIuzBmR|\  
Dim parID As Long .`/6[Zp

 
Dim count As Integer 4td9=dNA+l  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double j9*5Kj  
Dim tlens As Double, nlens As Double SlD7 \X&~  
Dim curv As Double, conic As Double AIt;~x  
Dim ok As Long !0Eo9bU%@  
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Sub Main isor%R!  
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    '用户输入对话框 A<[BR*n  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 +]0/:
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        TextBox 220,21,40,21,.TextBox1 'default: 0 b.QL\$a &  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 d1u6*&@lf  
        OKButton 40,91,90,21 R&MetQ~-{  
        CancelButton 190,91,90,21 U\(T<WX,  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 |[MtUWEW  
        TextBox 220,49,40,21,.TextBox2 'default: 4 ~) vz`bD1  
    End Dialog *q0vp^?  
    Dim dlg As UserDialog SD]rYIu+  
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    ok = Dialog (dlg) \'>d.'d  
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    If ok=0 Then    'cancel button was pressed T;{"lp.  
        Print "Execution cancelled." C$^WW}S  
        End $mut v=IO  
    End If DB.)/(zWQ  
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    'Assign accommodation and pupil diameter & use defaults if field left empty z{A~d  
    If dlg.TextBox1 = "" Then ""x>-j4  
        A = 0           'Default accommodation IAb-O  
    Else _PGS"O?j  
        A = CDbl(dlg.TextBox1) 9bu1Ax1M  
    End If f<*-;  
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    If dlg.TextBox2 = "" Then `0Xs!f  
        pupilDiam = 4   'Default pupil diameter g!
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    Else epxbTJfc  
        pupilDiam = CDbl(dlg.TextBox2) [Ee <SB{  
    End If
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    Print " " )X'ln  
    Print "Accommodation = " & A & " Diopters" 3(=QY)  
    Print "Pupil Diameter = " & pupilDiam & " mm" pu Z0_1uN  
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    ' Calculate new parameters with accommodation K'S\$  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness zQx6r .  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens s+6tdBvzs  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens ;6{{hc4  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens F3&:KZ!V&m  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens {lNG:o  
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    tlens = 3.767 + 0.04*A                  'Lens thickness _t@9WA;+\  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction mjJ/rx{kbw  
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    'Adjust parameters to account for accommodation jYnP)xX;  
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    '************************************************************************* x(y=.4Yf+  
    'Aqueous thickness (Position of Lens) (?kCo  
    '************************************************************************* DUyUA'*4n|  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) #s|,oIm  
    GetCustomElement eID, entity ?EA
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    parID = FindFullName( "Geometry.Arizona Eye" ) ad`=A V]  
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    ' Delete any shift(s) in z C&&33L  
    count = 0 #gRtCoew  
    While GetOperationCount(eID)>count ky@DH(^>  
        GetOperation eID, count, op xHWD1>  
        If op.Type="ShiftZ" Then &ej|DM6  
            DeleteOperation eID,count $QJ,V~  
            count=count-1 CC XOxd  
        End If Ls{]ohP  
        count=count+1 #E@X'jwu  
    Wend K#a_7/!v/  
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    'Set new shift in GFgh{'|  
    op.Type = "ShiftZ" [_zoJ  
    op.val1 = taq js)I%Z  
    op.parent = parID !E_RD,_  
    AddOperation eID, op `lN Z|U  
    Print "Set aqueous humor thickness = " & taq-0.55 ?oQAxb&  
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    '************************************************************************* B}npom\tC  
    'Radius and conic constant of anterior lens Zksow}%  
    '************************************************************************* n/Dk~Q)  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) vff`Xh>k(  
    GetConic eID, entity, curv, conic UszR. Z  
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    SetConic eID, entity, 1/Rant, CCant wPH1g*U  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant S<"`9r)av  
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    '************************************************************************* &1ss @-  
    'Radius and conic constant of posterior lens |n\(I$  
    '************************************************************************* SAGECK[Ix  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) &z%DX   
    GetConic eID, entity, curv, conic Wj\< )cH]  
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    SetConic eID, entity, 1/Rpost, CCpost xI^nA2g  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost L+TM3*a*  
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    '************************************************************************* &-4SA j  
    'Lens thickness (Position of posterior lens surface) JsbH'l  
    '************************************************************************* GM>Ms!Y  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) q?Av5TFf  
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    ' Delete any z-shift(s) Z*lZl8(`  
    count = 0 dJUI.!hv;  
    While GetOperationCount(eID)>count @BS7Gyw  
        GetOperation eID, count, op &*!) d"  
        If op.Type="ShiftZ" Then n]J;BW&Av  
            DeleteOperation eID,count 7g
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            count=count-1 v#Y
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        End If c`4i#R
 
        count=count+1 +B-;.]L T  
    Wend `~{0  
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    'Set new z-shift #;9n_)  
    op.Type = "ShiftZ" 1[H1l;  
    op.val1 = tlens Y<9Lqc.i  
    op.parent = parID =%$BFg1a(  
    AddOperation eID, op \z)` pno  
    Print "Set lens thickness = " & tlens Kgu#Mi~  
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    '************************************************************************* %<Kw  
    'Lens index of refraction Acx
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    '************************************************************************* Z<n%~z^  
    eID = FindMaterial( "Lens" ) +hKH\]  
    GetModelMaterial eID, mat 8cv[|`<  
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    mat.Nd = nlens  h@"u==0  
    SetModelMaterial eID, mat 'Z ,T,zW  
    Print "Set lens index of refraction = " & nlens &P3ep[]j  
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    '************************************************************************* &?j]L4%  
    'Pupil diameter 5W~-|8m  
    '************************************************************************* coFQu ;i  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) =}Xw}X+[WY  
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    'Adjust pupil diameter (trimming volume inner hole) 8lcB.M  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" u&s>UkR  
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    ' Adjust pupil location to just in front of the lens T*8rR"  
    parID = FindFullName( "Geometry.Arizona Eye" ) )A H)*Mg  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) ? {vY3~  
    count = 0 8.R~Y
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    While GetOperationCount(eID)>count +^v]d_~w_  
        GetOperation eID, count, op mzh7E[S_,i  
        If op.Type="ShiftZ" Then t+`>zux5(T  
            DeleteOperation eID,count 8ECBi(  
            count=count-1 !JC!GS"M5  
        End If ]@bu%_s"  
        count=count+1 A~7q=
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    Wend >Lrud{  
    op.Type = "ShiftZ" !K319 eE  
    op.val1 = taq-0.01 p{k^)5CR/  
    op.parent = parID yM-3nwk  
    AddOperation eID, op _/ Uer}  
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    Print "Set pupil diameter = " & pupilDiam o?\v 8.n  
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    'Update AZ Eye subassembly Description Af%#&r7W  
    eID = FindFullName( "Geometry.Arizona Eye" ) $2+(|VG4F  
    GetEntity eID, entity ]v{TSP^/  
    entity.Description = "Accommodation = " & A & "D" ?3) IzzO  
    SetEntity eID, entity 4+j:]poYG{  
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    Update Ko|p&-Z;  
    Print "DONE!" BPkqC>w  
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End Sub m^rrbU+HM?  
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如果屈光度是4，光瞳直径是4，则会输出如下数据： ]t|-  
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Accommodation = 4 Diopters +rA:/!b)Y  
Pupil Diameter = 4 mm K!a4>Du{  
Set aqueous humor thickness = 2.81 8rwXbYx x  
Set anterior lens radius = 10.4 and conic constant = -2.375869 f-b#F2I  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 |w7D&p$  
Set lens thickness = 3.927 3"XS#~l%  
Set lens index of refraction = 1.42672 ;YK{[$F  
Set pupil diameter = 4 Zc Y* TGx  
DONE! |?KdQeL  
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