[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 b0/YX@  
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。 {1_<\~J  
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模型 .SLpgYFL{  
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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。 q65]bs4M  
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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. peHjKK  
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光源 sH>`eqY
 
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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。 %ZcS"/gf  
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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。 QT5pn5+ z  
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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。 D.-G!0!  
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视网膜的散射 (@qPyM6~}  
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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。 |N^"?bSt  

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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。 `N&*+!O%  
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脚本 IuT)?S7O*k  
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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： i]N<xcF9N*  
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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。 QeC\(4
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余下的脚本计算与屈光度有关的所有参数。 7y&6q`y E  
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分析 J <;xkT1x  
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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。 .ARM~{q6)@  
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脚本代码 %#rtNDi  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. b_ak@LYiu  
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Dim entity As T_ENTITY tkR~(h  
Dim op As T_OPERATION ]hS<"=oj  
Dim mat As T_MODELMATERIAL K!Fem6R  
Dim A As Double -3i(N.)<;  
Dim pupilDiam As Double Y.) QNTh  
Dim eID As Long <" nWGF4d  
Dim parID As Long qD4s?j-9  
Dim count As Integer yf0v,]v[  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double A$N%deb  
Dim tlens As Double, nlens As Double qR!ZtJ5j  
Dim curv As Double, conic As Double m~*qS4  
Dim ok As Long 0 K#|11r  
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Sub Main $u.rO7)  
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    '用户输入对话框 D4@?>ek6U  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 |" WL  
        TextBox 220,21,40,21,.TextBox1 'default: 0 ?8{Os;!je  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 :e=7=|@7  
        OKButton 40,91,90,21 W{.:Cf9  
        CancelButton 190,91,90,21 qb
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        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 yNXYS  
        TextBox 220,49,40,21,.TextBox2 'default: 4 sZCK?  
    End Dialog ] 1pIIX}  
    Dim dlg As UserDialog i8k} B o  
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    ok = Dialog (dlg) :0Jn`Ds4o  
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    If ok=0 Then    'cancel button was pressed AV2Jl"1)z  
        Print "Execution cancelled." w-ald?`  
        End v~Dobk/n  
    End If ~`&4?c3p  
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    'Assign accommodation and pupil diameter & use defaults if field left empty s=-?kcoJ2d  
    If dlg.TextBox1 = "" Then 1Z)P.9c  
        A = 0           'Default accommodation ?i0+h7=6  
    Else ]gVA6B?&9  
        A = CDbl(dlg.TextBox1) .<>t2,Af  
    End If ^|.T\  
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    If dlg.TextBox2 = "" Then 0ZDm[#7z  
        pupilDiam = 4   'Default pupil diameter 0J'Cx&Rg  
    Else kVM*[<k  
        pupilDiam = CDbl(dlg.TextBox2) 9&=%shOc+x  
    End If g]HWaFjc5  
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    Print " " \mGb|aF8  
    Print "Accommodation = " & A & " Diopters" q`{@@[/(y  
    Print "Pupil Diameter = " & pupilDiam & " mm" XchD3p+uB  
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    ' Calculate new parameters with accommodation sj&(O@~R  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness  dnC"`  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens &$CyT6mb^  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens 9NVtvBA  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens rwUhNth-Qh  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens O}cfb4"  
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    tlens = 3.767 + 0.04*A                  'Lens thickness hl**G4z9q  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction DL~! ^fx  
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    'Adjust parameters to account for accommodation Et*LbU  
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    '************************************************************************* uv$5MwKU  
    'Aqueous thickness (Position of Lens) 8i`T?KB  
    '************************************************************************* teDRX13=;  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) `O3#/1+  
    GetCustomElement eID, entity Fczia0@z  
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    parID = FindFullName( "Geometry.Arizona Eye" ) K ~\b+  
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    ' Delete any shift(s) in z AX@bM  
    count = 0 !$iwU3~<  
    While GetOperationCount(eID)>count MJe/ \  
        GetOperation eID, count, op %`G
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        If op.Type="ShiftZ" Then NPBOG1q%  
            DeleteOperation eID,count kH0kf-4\  
            count=count-1 lp$,`Uz`  
        End If e'npa*.e  
        count=count+1 U/U_q-z]  
    Wend .ejC#vB{KM  
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    'Set new shift in E?K(MT&@  
    op.Type = "ShiftZ" U.^
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    op.val1 = taq tJd/uQJ  
    op.parent = parID k~<ORnda  
    AddOperation eID, op 0\ j)!b  
    Print "Set aqueous humor thickness = " & taq-0.55 2V9"{F?  
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    '************************************************************************* yyVJb3n5:!  
    'Radius and conic constant of anterior lens bsc b
 
    '************************************************************************* m7>)p]]  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) M#],#o*G  
    GetConic eID, entity, curv, conic |9CPT%A#  
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    SetConic eID, entity, 1/Rant, CCant )J\ JAUj  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant M _Lj
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    '************************************************************************* 0R+<^6^l)  
    'Radius and conic constant of posterior lens i}:^<jDv?  
    '************************************************************************* i"!j:YEo  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) 1RQM-0W,  
    GetConic eID, entity, curv, conic QA!'p1{#  
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    SetConic eID, entity, 1/Rpost, CCpost +>mU4Fwp  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost Y-DHW/Z~  
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    '************************************************************************* c&L|e$C]  
    'Lens thickness (Position of posterior lens surface) :(jovse\  
    '************************************************************************* ]CnT4[f!  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) [py/\zkn  
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    ' Delete any z-shift(s) $>l65)(E\  
    count = 0 ve/|"RB  
    While GetOperationCount(eID)>count Qo["K}Ty  
        GetOperation eID, count, op <^A1.o<GN  
        If op.Type="ShiftZ" Then /Q9iO&Vu  
            DeleteOperation eID,count kvt"7;(  
            count=count-1 wAF#N1-k  
        End If >RmL0d#B  
        count=count+1 6k\8ulHw  
    Wend $xj>j  
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    'Set new z-shift +u7nx  
    op.Type = "ShiftZ" \G]vTK3  
    op.val1 = tlens 6$$ku  
    op.parent = parID <m?/yREK2  
    AddOperation eID, op ~c GH+M@  
    Print "Set lens thickness = " & tlens @z.HyQ_v  
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    '************************************************************************* +Xr87x;  
    'Lens index of refraction O:O +Q!58  
    '************************************************************************* Nf{tC9l  
    eID = FindMaterial( "Lens" ) p8u-
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    GetModelMaterial eID, mat Rwz (20n\^  
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    mat.Nd = nlens yy3-Xu4  
    SetModelMaterial eID, mat {W#VUB  
    Print "Set lens index of refraction = " & nlens Q pbzx/2h  
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    '************************************************************************* yB^_dE  
    'Pupil diameter *e-+~/9~  
    '************************************************************************* 7(= 09z  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) o4pe>hn  
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    'Adjust pupil diameter (trimming volume inner hole) 0j|JyS:}G  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" iYxpIqWw  
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    ' Adjust pupil location to just in front of the lens $5/lU }To  
    parID = FindFullName( "Geometry.Arizona Eye" ) 41`&/9:"_M  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) "@)9$-g  
    count = 0 '&$xLZ8  
    While GetOperationCount(eID)>count HBnnIbEtF'  
        GetOperation eID, count, op p8MPn>h<  
        If op.Type="ShiftZ" Then :s OsG&y  
            DeleteOperation eID,count VpkkiN  
            count=count-1 -gKo@I  
        End If U: Q&sq8U  
        count=count+1 q
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    Wend aC2\C=ru_  
    op.Type = "ShiftZ" `[Xff24(eb  
    op.val1 = taq-0.01 (>\w8]  
    op.parent = parID }EZd=_kAq~  
    AddOperation eID, op Z6`[dAo  
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    Print "Set pupil diameter = " & pupilDiam 2aUy1*aM  
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    'Update AZ Eye subassembly Description XZFM|=%X  
    eID = FindFullName( "Geometry.Arizona Eye" ) ! uyC$8V*l  
    GetEntity eID, entity *^&2L,w  
    entity.Description = "Accommodation = " & A & "D" Bzw!,(u/ "  
    SetEntity eID, entity Z>H y+Q4  
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    Update B@W`AD1^{  
    Print "DONE!" <X_I`  
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End Sub AG$S;)Yl9c  
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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： \We\*7^E  
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Accommodation = 4 Diopters ZsP
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Pupil Diameter = 4 mm p|z\L}0  
Set aqueous humor thickness = 2.81 Y&Sk/8  
Set anterior lens radius = 10.4 and conic constant = -2.375869 /i#~#Bn|  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 m*MfGj(  
Set lens thickness = 3.927 CcZ\QOet&C  
Set lens index of refraction = 1.42672 b!R\u1b  
Set pupil diameter = 4 OA_Bz"  
DONE! ?m?DAd~ZY  
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