[技术]Arizona眼睛模型 [复制链接]

简介 )!=X?fz,O  
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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。 kSjvY&n%  
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模型 4{ED~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。 W!b'nRkq  
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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. \|R
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光源 7k#0EhN1>  
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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。 s[u*~A  
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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。 BBRZlx  
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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。 ^J&}C  
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视网膜的散射 tx}=c5  
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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。 *XluVochrb  
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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。 c#8@>;  
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脚本 /*m6-DC  

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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： 2%~+c|TH.)  
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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。 XOPiwrg%p  
余下的脚本计算与屈光度有关的所有参数。 kFQx7m  
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分析 QT[4\)  
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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。 \kC'y9k  
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脚本代码 He}"e&K  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. F&D,y-CQ  
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Dim entity As T_ENTITY :Oi}X7\  
Dim op As T_OPERATION B1z7r0Rm,  
Dim mat As T_MODELMATERIAL eY3<LVAX  
Dim A As Double 4+F@BxpB  
Dim pupilDiam As Double C@9K`N[*  
Dim eID As Long !>6`+$=U  
Dim parID As Long !s[
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Dim count As Integer km6O3>p5r  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double qDjH^f  
Dim tlens As Double, nlens As Double G(

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Dim curv As Double, conic As Double sxPvi0>  
Dim ok As Long `6pz9j]  
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Sub Main a#+;BH1  
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    '用户输入对话框 e J:#vX86  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 DN|+d{^lN  
        TextBox 220,21,40,21,.TextBox1 'default: 0 Nd**":i$  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 c"NGE  
        OKButton 40,91,90,21 @Qd5a(5WM  
        CancelButton 190,91,90,21 -z>m]YDH  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 cp4~`X  
        TextBox 220,49,40,21,.TextBox2 'default: 4 ,-1d2y  
    End Dialog ^[1Xl7)`  
    Dim dlg As UserDialog MG3xX;  
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    ok = Dialog (dlg) "tmr s_~  
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    If ok=0 Then    'cancel button was pressed L^L.;1  
        Print "Execution cancelled." j/hm)*\io  
        End K9S(Xip  
    End If JUTlJyx8  
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    'Assign accommodation and pupil diameter & use defaults if field left empty g
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    If dlg.TextBox1 = "" Then 0t)5KO  
        A = 0           'Default accommodation j]6YLM@5$  
    Else z<8WN[fB  
        A = CDbl(dlg.TextBox1) 10m`LG  
    End If CjLiLB  
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    If dlg.TextBox2 = "" Then [V41 Gk  
        pupilDiam = 4   'Default pupil diameter ~oeX0l>F  
    Else c1g'l.XL 3  
        pupilDiam = CDbl(dlg.TextBox2) 2.&%mSN  
    End If k<%y+v  
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    Print " " Gvc/o$_  
    Print "Accommodation = " & A & " Diopters" `&SBp }W}  
    Print "Pupil Diameter = " & pupilDiam & " mm" *%2,= p  
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    ' Calculate new parameters with accommodation ,ydn]0SS  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness /^
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens I
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    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens *NQsD C.J^  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens Z xR  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens LO)p2[5#R  
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    tlens = 3.767 + 0.04*A                  'Lens thickness (sEZNo5n  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction 10r9sR  
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    'Adjust parameters to account for accommodation +aRHMH
 
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    '************************************************************************* i{k v$ir!  
    'Aqueous thickness (Position of Lens) QE`u~  
    '************************************************************************* %?!TqJT?{  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) l"9$lF}
 
    GetCustomElement eID, entity -FQS5Zb.!  
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    parID = FindFullName( "Geometry.Arizona Eye" ) 5} 1qo7;  
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    ' Delete any shift(s) in z CMHg]la  
    count = 0 0]l9x}  
    While GetOperationCount(eID)>count t&rr;W]  
        GetOperation eID, count, op h($Jo  
        If op.Type="ShiftZ" Then #v:A-u  
            DeleteOperation eID,count <}1GYeP  
            count=count-1 l#|M.V6G  
        End If | @p  
        count=count+1 Px?0)^"2  
    Wend 2G}@s.iE  
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    'Set new shift in G3de<?K.[V  
    op.Type = "ShiftZ" AI3\
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    op.val1 = taq c.h_&~0qf  
    op.parent = parID $TavvO%#  
    AddOperation eID, op pcPRkYT[M  
    Print "Set aqueous humor thickness = " & taq-0.55 $>=w<=r|;  
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    '************************************************************************* Y,d|b V*FH  
    'Radius and conic constant of anterior lens o.>Yj)U  
    '************************************************************************* PsI{y&.  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) KZwzQ"Hl  
    GetConic eID, entity, curv, conic ^tl&FWF  
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    SetConic eID, entity, 1/Rant, CCant &%@>S.  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant A9M/n^61  
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    '************************************************************************* DWu~%U8  
    'Radius and conic constant of posterior lens q4ej7T8  
    '************************************************************************* qgsw8O&  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) s:Z1 ZAxv  
    GetConic eID, entity, curv, conic u|\K kk  
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    SetConic eID, entity, 1/Rpost, CCpost No(S#,vJ;  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost mcSZ1d~,(  
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    '************************************************************************* ^j]"5@f  
    'Lens thickness (Position of posterior lens surface) =8x-+u5}rK  
    '************************************************************************* ]8EkZC  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) ((tWgSZ3  
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    ' Delete any z-shift(s)
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    count = 0 lK #~lC  
    While GetOperationCount(eID)>count 2T}FX4'  
        GetOperation eID, count, op Z n]e2  
        If op.Type="ShiftZ" Then a|@1RH>7H  
            DeleteOperation eID,count WvHy}1W  
            count=count-1 <^B!.zQ  
        End If JL&ni]m  
        count=count+1 dF0:'y  
    Wend jX 6+~  
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    'Set new z-shift "aeKrMgc6V  
    op.Type = "ShiftZ" ? p^':@=  
    op.val1 = tlens &6@e9ff0  
    op.parent = parID }}~ t!/x  
    AddOperation eID, op p|R]/C0f  
    Print "Set lens thickness = " & tlens DqlspT  
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    '************************************************************************* wq`\p['Q,  
    'Lens index of refraction 'C\knQ  
    '************************************************************************* bL18G(5  
    eID = FindMaterial( "Lens" ) D_Cd^;b  
    GetModelMaterial eID, mat C$fQ[@  
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    mat.Nd = nlens 4p_@f^v~QH  
    SetModelMaterial eID, mat [[d@P%X&  
    Print "Set lens index of refraction = " & nlens E9n7P'8  
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    '************************************************************************* 3W}xYYs]^  
    'Pupil diameter Wy,Tf*[  
    '************************************************************************* vCtag]H2@  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) ShRkL<  
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    'Adjust pupil diameter (trimming volume inner hole) NuKx{y}P  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" OL)M`eVQ'  
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    ' Adjust pupil location to just in front of the lens h;sdm/  
    parID = FindFullName( "Geometry.Arizona Eye" ) B|n<{g[-cM  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) 'Z(4Wuwb  
    count = 0 9:jZ3U  
    While GetOperationCount(eID)>count \m;"KyP+  
        GetOperation eID, count, op [!E~pW%|n  
        If op.Type="ShiftZ" Then *FEY"W+bY  
            DeleteOperation eID,count >VWH bo  
            count=count-1 haMt2S2_B:  
        End If dLI`\e<r&[  
        count=count+1 _w>9Z>PR  
    Wend J#'+&DH  
    op.Type = "ShiftZ" Gr?[s'Ze  
    op.val1 = taq-0.01 1ssEJ;#s  
    op.parent = parID h*-j  
    AddOperation eID, op fr<, LC.  
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    Print "Set pupil diameter = " & pupilDiam A1,- qv1s  
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    'Update AZ Eye subassembly Description bbO1`b-  
    eID = FindFullName( "Geometry.Arizona Eye" ) B?tO&$s  
    GetEntity eID, entity y-c2tF@'v  
    entity.Description = "Accommodation = " & A & "D" 7T3ub3\  
    SetEntity eID, entity /^z5;aG  
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    Update saaN$tU7  
    Print "DONE!" /N&)r wc  
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End Sub Hc{0O7  
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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： ;eRYgC  
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Accommodation = 4 Diopters 7}<057Xn'  
Pupil Diameter = 4 mm 9}2E+  
Set aqueous humor thickness = 2.81 *0`oFTJ  
Set anterior lens radius = 10.4 and conic constant = -2.375869 4W''j[Y/  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 Ih.6"ISK}  
Set lens thickness = 3.927 a jCx"J  
Set lens index of refraction = 1.42672 ;9hi2_luV  
Set pupil diameter = 4 C%csQ m  
DONE! DEw_dOJ(