[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 i{6wns?KMj  
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。 c9R|0Yn^J  
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模型 LkIbvJCV  
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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。 j-wz7B  
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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. @2)ImgK[  
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光源 Z^yhSbE{5  
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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。 \P7y&`|  
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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。 2x dN0S  
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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。 keL!;q|r-)  
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视网膜的散射 ?br4 wl  
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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。 zV"oB9\9O  
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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。 (GI]Uyn  
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脚本 uw`fC%-xh  
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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： A%c)=(,  
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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。 T&PLvyBL  
余下的脚本计算与屈光度有关的所有参数。 y O
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分析 K]Onb{QY  
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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。 rc9Y:(S1l  
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脚本代码 O FCA~sR  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. "~HV!(dRMC  
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Dim entity As T_ENTITY ^HasT4M+x  
Dim op As T_OPERATION Zc9j_.?*  
Dim mat As T_MODELMATERIAL ]~A<Q{  
Dim A As Double p3YF  
Dim pupilDiam As Double r(::3TF%#q  
Dim eID As Long 7yK1Q_XY>  
Dim parID As Long SJdi*>  
Dim count As Integer c@1q8,  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double #RA3 T[A  
Dim tlens As Double, nlens As Double ko%B`
 
Dim curv As Double, conic As Double @lnM%  
Dim ok As Long +\O[)\  
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Sub Main wuQ>|\Zs  
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    '用户输入对话框 s"solPw  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 )"o+wSI1  
        TextBox 220,21,40,21,.TextBox1 'default: 0 >)IXc<"wq  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 f YuM`O  
        OKButton 40,91,90,21 +#d}3^_]  
        CancelButton 190,91,90,21 (s\":5 C  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 BLvI[b|3gn  
        TextBox 220,49,40,21,.TextBox2 'default: 4 t9Nu4yl  
    End Dialog fx783  
    Dim dlg As UserDialog k v}<u  
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    ok = Dialog (dlg) ?$T39U^  
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    If ok=0 Then    'cancel button was pressed 9C{\=?e;  
        Print "Execution cancelled." j_r7oARL  
        End v8`)h<:W?  
    End If "n3i(sZ  
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    'Assign accommodation and pupil diameter & use defaults if field left empty (3
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    If dlg.TextBox1 = "" Then u8wZ2j4S  
        A = 0           'Default accommodation 8zRb)B+  
    Else Q:x:k+O-  
        A = CDbl(dlg.TextBox1)
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    End If [?$|   
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    If dlg.TextBox2 = "" Then B az:N6u  
        pupilDiam = 4   'Default pupil diameter ($oO, c'z  
    Else ]/+qM)F  
        pupilDiam = CDbl(dlg.TextBox2) $VrKoL\ScA  
    End If <}E^r_NvD  
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    Print " " ; YaR|)B  
    Print "Accommodation = " & A & " Diopters" Qjj:r~l  
    Print "Pupil Diameter = " & pupilDiam & " mm" W].P(A
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    ' Calculate new parameters with accommodation ')9%eBaeK  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness IKK<D'6  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens p.2>
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    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens LaE;{jY  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens {tE/Jv $  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens {1GW,T!#  
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    tlens = 3.767 + 0.04*A                  'Lens thickness a.5s5g)8  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction P#H#@:/3  
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    'Adjust parameters to account for accommodation JXlFo3<  
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    '************************************************************************* eh'mSf^=p  
    'Aqueous thickness (Position of Lens) WRAW%?$  
    '************************************************************************* v.1= TBh  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) >:]fN61#  
    GetCustomElement eID, entity x~GV#c  
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    parID = FindFullName( "Geometry.Arizona Eye" ) ~MY(6P  
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    ' Delete any shift(s) in z 'KGY;8<x]  
    count = 0 $/C<^}A  
    While GetOperationCount(eID)>count 2t { Cpw  
        GetOperation eID, count, op {K'SOhH4?  
        If op.Type="ShiftZ" Then 81_3{OrE<  
            DeleteOperation eID,count N,ik&NIWy  
            count=count-1 S'-<p<;D\B  
        End If uz4mHyS6  
        count=count+1 .Qh8I+Q%  
    Wend Hcd>\0  
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    'Set new shift in (W/jkm  
    op.Type = "ShiftZ" >*}qGk  
    op.val1 = taq y`Pp"!P"O  
    op.parent = parID 1TQ$(bI  
    AddOperation eID, op W7A'5  
    Print "Set aqueous humor thickness = " & taq-0.55 (r[<g*+3  
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    '************************************************************************* VP4t~$"  
    'Radius and conic constant of anterior lens FA^x|C=$  
    '************************************************************************* %Z{J=  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) d L%
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    GetConic eID, entity, curv, conic Xs?7Whc6  
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    SetConic eID, entity, 1/Rant, CCant ;(0:6P8I  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant X}zKV  
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    '************************************************************************* Dlj=$25  
    'Radius and conic constant of posterior lens W,{`)NWg  
    '************************************************************************* H5RHA^p|  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) ($(1KE  
    GetConic eID, entity, curv, conic \>=YxB q  
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    SetConic eID, entity, 1/Rpost, CCpost K[sM)_I  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost x}x@_w   
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    '************************************************************************* 'fAD Dh}  
    'Lens thickness (Position of posterior lens surface) jZ 
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    '************************************************************************* vWkKNB  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) x>8f#B\Mr  
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    ' Delete any z-shift(s) hTG d Uw]  
    count = 0 |C&eH$?~=R  
    While GetOperationCount(eID)>count ^LU[{HZV  
        GetOperation eID, count, op uBE,z>/,;  
        If op.Type="ShiftZ" Then H4:TYh  
            DeleteOperation eID,count sId5pY!  
            count=count-1 @J<B^_+Se  
        End If Na~_=3+a  
        count=count+1 ;5|EpoM  
    Wend NUnP'X=J,  
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    'Set new z-shift ONGe/CEXT  
    op.Type = "ShiftZ" x b0
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    op.val1 = tlens =hs@W)-O  
    op.parent = parID @E>^\!nH  
    AddOperation eID, op _@OYC<  
    Print "Set lens thickness = " & tlens /MU<)[*Ro  
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    '************************************************************************* t!u*6W|@  
    'Lens index of refraction 4a @iR2e  
    '************************************************************************* sMS`-,37u  
    eID = FindMaterial( "Lens" ) -mkync3  
    GetModelMaterial eID, mat H);'\]_'x  
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    mat.Nd = nlens " }ZD)7K  
    SetModelMaterial eID, mat B7PmG f)b  
    Print "Set lens index of refraction = " & nlens B)Q'a3d#  
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    '************************************************************************* aBI]' D;  
    'Pupil diameter ww,c)$  
    '************************************************************************* l46F3C|  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) @Hf}PBb  
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    'Adjust pupil diameter (trimming volume inner hole) K?tk&0  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" j
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    ' Adjust pupil location to just in front of the lens Ji!-G4.n"  
    parID = FindFullName( "Geometry.Arizona Eye" ) -0X> y  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) J9 =gv0
 
    count = 0 @ tIB'|O  
    While GetOperationCount(eID)>count "n6Y^  
        GetOperation eID, count, op +n,BD C;  
        If op.Type="ShiftZ" Then %KA/  
            DeleteOperation eID,count X2uX+}h*tA  
            count=count-1 Xdq, =;  
        End If mCGcM^21-x  
        count=count+1 vRq xZN  
    Wend bevT`D  
    op.Type = "ShiftZ" H+;wnI>@  
    op.val1 = taq-0.01 LbR-uc?x  
    op.parent = parID +Y~+o-_  
    AddOperation eID, op m#nxw  
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    Print "Set pupil diameter = " & pupilDiam =eqI]rVj^  
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    'Update AZ Eye subassembly Description AVr!e   
    eID = FindFullName( "Geometry.Arizona Eye" ) K*Jtyy}r  
    GetEntity eID, entity 9^ r  
    entity.Description = "Accommodation = " & A & "D" Ng"vBycy  
    SetEntity eID, entity &XsLp&Do2  
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    Update j1F+,   
    Print "DONE!" x
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End Sub "AouiZkh  
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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： doc  
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Accommodation = 4 Diopters \v
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Pupil Diameter = 4 mm X^Y9T`mQ}  
Set aqueous humor thickness = 2.81 (@E#O$'  
Set anterior lens radius = 10.4 and conic constant = -2.375869 :6?
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Set posterior lens radius = -4.424557 and conic constant = -3.081019 =.E(p)fz  
Set lens thickness = 3.927 y^=oYL  
Set lens index of refraction = 1.42672 kkB
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Set pupil diameter = 4 5uo(z,WLR  
DONE! FA9e(Ha   
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