[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 rR^VW^|f  
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。 %(,JBa:G  
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模型 Y]^[|e8  
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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。 pc:~_6S  
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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. RVlC8uJ;P  
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光源 vb\UP&Ip  
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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。 '!b1~+PV  
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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。 87r#;ND  
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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。 lJ:B9n3OzT  
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视网膜的散射 bTb|@  
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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。 A@f`g[q  
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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。 O{%yO=`r  
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脚本 bmGIxBRq  
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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： }BzV<8F  
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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。 K*d+
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余下的脚本计算与屈光度有关的所有参数。 X8GIRL)lJ  
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分析 */u_RJ  
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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。 L^Fni~  
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脚本代码 -V%"i,t  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. ?<%GYdus  
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Dim entity As T_ENTITY >h(n8wTP  
Dim op As T_OPERATION hV)D,oN3  
Dim mat As T_MODELMATERIAL Uz} #.  
Dim A As Double l#Ipo5
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Dim pupilDiam As Double ^yb3L1y  
Dim eID As Long bzF>Efza  
Dim parID As Long tMR&>hM  
Dim count As Integer NhU~'k  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double +? E~F  
Dim tlens As Double, nlens As Double w/IYQC\v  
Dim curv As Double, conic As Double SDwTGQ/0  
Dim ok As Long LPc)-t|p"  
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Sub Main >7V96jL$Y  
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    '用户输入对话框 MX2]Q  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 #^|y0:  
        TextBox 220,21,40,21,.TextBox1 'default: 0 ZX'q-JUv f  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1  LP-~;  
        OKButton 40,91,90,21 T~8==Z{[  
        CancelButton 190,91,90,21 ;wK;  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 A<fKO <d  
        TextBox 220,49,40,21,.TextBox2 'default: 4 <2"'R(4",  
    End Dialog opU=49b  
    Dim dlg As UserDialog ?x1sm"]p'  
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    ok = Dialog (dlg) 6<u=hhL  
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    If ok=0 Then    'cancel button was pressed &kUEnwQ-  
        Print "Execution cancelled." j)xRzImu  
        End [% \>FT[  
    End If )S@e&a|  
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    'Assign accommodation and pupil diameter & use defaults if field left empty
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    If dlg.TextBox1 = "" Then c<bV3,  
        A = 0           'Default accommodation  DA]<30w  
    Else C~-x637/  
        A = CDbl(dlg.TextBox1) `?f6~$1  
    End If ;-sZaU;  
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    If dlg.TextBox2 = "" Then tg-U x  
        pupilDiam = 4   'Default pupil diameter #{K}o}  
    Else ,.DTJ7H+  
        pupilDiam = CDbl(dlg.TextBox2) Oy EOb>  
    End If \kWL:uU  
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    Print " " 
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    Print "Accommodation = " & A & " Diopters" JYbsta  
    Print "Pupil Diameter = " & pupilDiam & " mm" Iue}AGxu:{  
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    ' Calculate new parameters with accommodation }?G([s56  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness ~&HP}Q$#f  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens [x{z}rYH  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens -&q@|h'  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens gxnIur)  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens X1*f#3cm#  
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    tlens = 3.767 + 0.04*A                  'Lens thickness q)j b9e   
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction \ SCi\j/a(  

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    'Adjust parameters to account for accommodation 1Hl-|n  
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    '************************************************************************* gGZ-B<  
    'Aqueous thickness (Position of Lens) M>qqe!c*  
    '************************************************************************* FEY_(70  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) B(|*
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    GetCustomElement eID, entity |7%has3"  
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    parID = FindFullName( "Geometry.Arizona Eye" ) H4B|c42  
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    ' Delete any shift(s) in z `D/<*e,#  
    count = 0 H 48YX(HI  
    While GetOperationCount(eID)>count m^!Kthq  
        GetOperation eID, count, op qu\cU(H|  
        If op.Type="ShiftZ" Then cMs8D  
            DeleteOperation eID,count e5AZU7%.  
            count=count-1 G&Fe2&5!w  
        End If e"#QUc(  
        count=count+1 p=!12t  
    Wend #| pn,/  
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    'Set new shift in <-6f}wN  
    op.Type = "ShiftZ" $E/N  
    op.val1 = taq S>Z07d6&  
    op.parent = parID Q~R%|Q{&  
    AddOperation eID, op %1mIngW
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    Print "Set aqueous humor thickness = " & taq-0.55 [][ze2+b  
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    '************************************************************************* t|urvoz  
    'Radius and conic constant of anterior lens )\KU:_l  
    '************************************************************************* bL`>#M_^  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) ^jbjHI&  
    GetConic eID, entity, curv, conic ]z O6ESH  
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    SetConic eID, entity, 1/Rant, CCant %i6/= 'u  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant 23d*;ri5  
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    '************************************************************************* |&"/u7^  
    'Radius and conic constant of posterior lens mxnu\@}(  
    '************************************************************************* P3!JA)p6a  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) 2= Y8$-  
    GetConic eID, entity, curv, conic 8-_atL  
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    SetConic eID, entity, 1/Rpost, CCpost 1l5'N=hL  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost U5 ia|V  
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    '************************************************************************* B&QEt[=s  
    'Lens thickness (Position of posterior lens surface) $D='NzE/  
    '************************************************************************* p;qFMzyS9  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) %I=/ y  
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    ' Delete any z-shift(s) 8d?%9# p-)  
    count = 0 !hFzIp  
    While GetOperationCount(eID)>count pocXQEg$]  
        GetOperation eID, count, op O7
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        If op.Type="ShiftZ" Then mlYkn  
            DeleteOperation eID,count ce3``W/H3  
            count=count-1 63(XCO  
        End If i#NtiZ.t=  
        count=count+1 5yyc0UG  
    Wend AJ>$`=  
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    'Set new z-shift 1#3eY?Nb  
    op.Type = "ShiftZ" QFK'r\3pU  
    op.val1 = tlens $O&N  
    op.parent = parID m 7S`u  
    AddOperation eID, op U2r[.Ru  
    Print "Set lens thickness = " & tlens ~g9~D}48k'  
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    '************************************************************************* j u&v4]  
    'Lens index of refraction 6i;q=N$'  
    '************************************************************************* ~W-l|-eogz  
    eID = FindMaterial( "Lens" ) `z`=!1  
    GetModelMaterial eID, mat K8
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    mat.Nd = nlens Scug wSB  
    SetModelMaterial eID, mat 9K;g\? 3  
    Print "Set lens index of refraction = " & nlens R|k:8v{V=  
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    '************************************************************************* p1[|5r5Day  
    'Pupil diameter 2%v6h  
    '************************************************************************* 8>G5VhCm~o  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) 1Vkb}A,'  
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    'Adjust pupil diameter (trimming volume inner hole) >(_2'c*[w  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" G5|'uKz2"  
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    ' Adjust pupil location to just in front of the lens .:XXc  
    parID = FindFullName( "Geometry.Arizona Eye" ) Q8A+\LR~)  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) ]heVR&bQ  
    count = 0 Lxn-M5RPQ  
    While GetOperationCount(eID)>count d} 5  
        GetOperation eID, count, op S(Z\h_m(  
        If op.Type="ShiftZ" Then -aLM*nIoe  
            DeleteOperation eID,count G*=&yx."E  
            count=count-1 Xq_hC"s  
        End If A8QUfg@uK~  
        count=count+1 uP$i2Cy  
    Wend tJ*/5k &  
    op.Type = "ShiftZ" 1cx%+-  
    op.val1 = taq-0.01 $WE=u9m  
    op.parent = parID Y O|hwhe_  
    AddOperation eID, op ,gW$m
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    Print "Set pupil diameter = " & pupilDiam  )y6  
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    'Update AZ Eye subassembly Description fLeHn,*,"  
    eID = FindFullName( "Geometry.Arizona Eye" ) 1;+77<  
    GetEntity eID, entity EuA352x  
    entity.Description = "Accommodation = " & A & "D" 'K}2m  
    SetEntity eID, entity _dECAk &b  
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    Update @Z7s3b  
    Print "DONE!" xb"e'Zh  
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End Sub GY5JPl  
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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： ny!80I  
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Accommodation = 4 Diopters <Fv7JPN%  
Pupil Diameter = 4 mm Z"KrirZ  
Set aqueous humor thickness = 2.81 foBF]7Bz?  
Set anterior lens radius = 10.4 and conic constant = -2.375869 Q<DXDvL  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 s'd\"WaQV  
Set lens thickness = 3.927 ~
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Set lens index of refraction = 1.42672 ;\f0II3  
Set pupil diameter = 4 JaR!9GVN7  
DONE! RH$l?j6  
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