[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 #K_
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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。 9rA0lqr]5  
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模型 $l
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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。 ~f&E7su-6+  
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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. e }?db  
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光源 z3{G9Np  
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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。 ^KnU4sD  
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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。 wy<S;   
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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。 q<x/Hat)  
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视网膜的散射 pTth}JM>  
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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。 v|)4ocFK  
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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。 Si4!R+
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脚本 *nT<m\C6  
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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： OR P\b  
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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。 ]6k\)#%2  
余下的脚本计算与屈光度有关的所有参数。 hE:9{;Gf  
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分析 WMDl=6  
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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。 6
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脚本代码 ~p6 V,Q  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. ?d\N(s9F  
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Dim entity As T_ENTITY ~f2z]JLr:  
Dim op As T_OPERATION "`/h#np  
Dim mat As T_MODELMATERIAL J/`<!$<c  
Dim A As Double Ot0ap$&  
Dim pupilDiam As Double Xz6<lLb  
Dim eID As Long #Qw0&kM7I  
Dim parID As Long {S]}.7`l9(  
Dim count As Integer @(w@e\Bq  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double +%z>H"J.  
Dim tlens As Double, nlens As Double U7,e/?a  
Dim curv As Double, conic As Double Df-DRi  
Dim ok As Long b}$+H/V
 
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Sub Main 4d4ZT?V[  
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    '用户输入对话框 [C 7^r3w  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 F}yW/  
        TextBox 220,21,40,21,.TextBox1 'default: 0 )bL'[h
 
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 R{`(c/%8  
        OKButton 40,91,90,21 *->W^1eGM  
        CancelButton 190,91,90,21 tPWLg),  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 FW;?s+Uyx  
        TextBox 220,49,40,21,.TextBox2 'default: 4 #b}Z`u?@  
    End Dialog ];$L &5^  
    Dim dlg As UserDialog XAKs0*J>  
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    ok = Dialog (dlg) un"Gozmt5  
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    If ok=0 Then    'cancel button was pressed tyDU @M  
        Print "Execution cancelled." q s!j>x  
        End  #4NaL  
    End If 8mrUotjS  
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    'Assign accommodation and pupil diameter & use defaults if field left empty VR8-&N  
    If dlg.TextBox1 = "" Then 0cH`;!MZ  
        A = 0           'Default accommodation s-!
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    Else ea2ayT  
        A = CDbl(dlg.TextBox1) .WJYQi  
    End If @Sn(lnlB  
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    If dlg.TextBox2 = "" Then ] )\Pqn(  
        pupilDiam = 4   'Default pupil diameter uk:(pZ-uJ  
    Else :K,i\  
        pupilDiam = CDbl(dlg.TextBox2) cGzPI+F  
    End If ,.8KN<A2]'  
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    Print " " ]L.O8  
    Print "Accommodation = " & A & " Diopters" @CL{D:d  
    Print "Pupil Diameter = " & pupilDiam & " mm" !X#OOqPr=  
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    ' Calculate new parameters with accommodation #$07:UJ  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness X=&ET)8-Y  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens `:K
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    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens !sP{gi#=  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens ;?iW%:_,  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens 20h, ^  
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    tlens = 3.767 + 0.04*A                  'Lens thickness N/2T[s_&  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction bl;1i@Z*M  
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    'Adjust parameters to account for accommodation n0 {i&[I~+  
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    '************************************************************************* n5NsmVW\x  
    'Aqueous thickness (Position of Lens) xGg )Y#  
    '************************************************************************* %/.b~|,-  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) !9
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    GetCustomElement eID, entity `iNSr?N.  
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    parID = FindFullName( "Geometry.Arizona Eye" ) _C?hHWSf"  
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    ' Delete any shift(s) in z "?xHlYj@+  
    count = 0 (m/G(wg  
    While GetOperationCount(eID)>count v>)"HL"XG  
        GetOperation eID, count, op PiIpnoM  
        If op.Type="ShiftZ" Then HCs?iJ  
            DeleteOperation eID,count Jhhb7uU+  
            count=count-1 )9`qG:b'  
        End If 0R'?~`aTt  
        count=count+1 g|yvF-+  
    Wend 'Aq{UGN  
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    'Set new shift in IueFx u  
    op.Type = "ShiftZ" J @1!Oq>  
    op.val1 = taq .}TZxla0Zr  
    op.parent = parID <uw9DU7G  
    AddOperation eID, op m8hk:4Ae  
    Print "Set aqueous humor thickness = " & taq-0.55 ?mxMk6w  
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    '************************************************************************* k"zv~`i'  
    'Radius and conic constant of anterior lens c9u`!'g`i  
    '************************************************************************* >W+%8e  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) c9 _rmz8  
    GetConic eID, entity, curv, conic mnX2a  
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    SetConic eID, entity, 1/Rant, CCant k)=s>&hl  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant 051E6-  
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    '************************************************************************* C1n>M}b  
    'Radius and conic constant of posterior lens 1
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    '************************************************************************* @,my7?::oM  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) u^I|T.w<r6  
    GetConic eID, entity, curv, conic g@!V3V  
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    SetConic eID, entity, 1/Rpost, CCpost 0-Ku7<a  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost fxHH;hRfv  
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    '************************************************************************* L\"d  
    'Lens thickness (Position of posterior lens surface) !PQ<04jA!  
    '************************************************************************* +lcbi  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) -zeG1gr3  
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    ' Delete any z-shift(s) s-Tv8goNV  
    count = 0 AH7}/Rc  
    While GetOperationCount(eID)>count pO3SUOP  
        GetOperation eID, count, op 5e^ChK0Q  
        If op.Type="ShiftZ" Then 2eY_%Y0  
            DeleteOperation eID,count jLm ;ty2;  
            count=count-1 ;$wVu|&  
        End If N5 6g+,w%)  
        count=count+1 Fk7')?  
    Wend z$. 88^  
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    'Set new z-shift &@OT*pNna  
    op.Type = "ShiftZ" =X:Y,?  
    op.val1 = tlens dcN22A3  
    op.parent = parID N S[l/0F&  
    AddOperation eID, op QlU8uI[dk  
    Print "Set lens thickness = " & tlens :':s@gqr  
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    '************************************************************************* \Uq(Zga4)  
    'Lens index of refraction 33B]RGq  
    '************************************************************************* VjZ|$k  
    eID = FindMaterial( "Lens" ) tg4pyW<  
    GetModelMaterial eID, mat $uVHSH5l  
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    mat.Nd = nlens hhc,uJ">!  
    SetModelMaterial eID, mat VuZuS6~#J  
    Print "Set lens index of refraction = " & nlens ;iL#7NG-R  
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    '************************************************************************* F{;((VboN  
    'Pupil diameter RMu~l@  
    '************************************************************************* yYA$I'Bm\  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) M%P:n/j  
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    'Adjust pupil diameter (trimming volume inner hole) tl^9WG  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" i$6ypuc  
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    ' Adjust pupil location to just in front of the lens |t#)~Oo  
    parID = FindFullName( "Geometry.Arizona Eye" ) (gWm,fI RZ  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) VTY 5]|;  
    count = 0 R8Fv{7]c  
    While GetOperationCount(eID)>count ;"-&1qHN  
        GetOperation eID, count, op ope^~+c~\  
        If op.Type="ShiftZ" Then z_4J)?3  
            DeleteOperation eID,count .Rs^YZF  
            count=count-1 ?J>  
        End If LBDjIpR6  
        count=count+1 T!)(Dv8@F  
    Wend MeZf*' J  
    op.Type = "ShiftZ" r0% D58  
    op.val1 = taq-0.01 5D//*}b,  
    op.parent = parID `1IgzKL9  
    AddOperation eID, op ^9:Z7 >Z  
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    Print "Set pupil diameter = " & pupilDiam :nOFR$W  
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    'Update AZ Eye subassembly Description DT&@^$?  
    eID = FindFullName( "Geometry.Arizona Eye" )
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    GetEntity eID, entity 5vnrA'BhBU  
    entity.Description = "Accommodation = " & A & "D" <bEbweQrgm  
    SetEntity eID, entity e^1Twz3z  
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    Update #5o(h+w)  
    Print "DONE!" bq0zxg%  
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End Sub -r]W  
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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： @_}P-h  
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Accommodation = 4 Diopters NyNXP_8  
Pupil Diameter = 4 mm 1tFNM[R  
Set aqueous humor thickness = 2.81 )MTO
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Set anterior lens radius = 10.4 and conic constant = -2.375869 WOL:IZX%  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 qF;|bF  
Set lens thickness = 3.927
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Set lens index of refraction = 1.42672 > /caXvS  
Set pupil diameter = 4 ]N F[>uiW  
DONE! &gx%b*;`L0  
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