[技术]Arizona眼睛模型 [复制链接]

简介 OE(Z)|LF  
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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。 $4\,a^  
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模型 VQ/<MY C  
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模型的定义如表1种所示，由半径、圆锥常数、折射率、阿贝数、到下一面的距离等一系列表面组成。一些参数由屈光度（A）来决定。 T=|oZ  
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在FRED中使用0屈光度来创建的，光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. Htseu`>_$  
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光源 }kaU0 P  
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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。 ON{
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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。 <6=kwV6  
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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。 `b^eRnpR  
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视网膜的散射 Nb2]}; O  
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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。 Tz H*?bpP  
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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。 2 w2JFdm  
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脚本 D}1Z TX_  
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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： Suixk'-  
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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。 SG1fu<Q6J  
余下的脚本计算与屈光度有关的所有参数。 wV- kB4^4
 
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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。 zfDxc3e  
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脚本代码 LOf0_g/  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. _{z.Tu  
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Dim entity As T_ENTITY [,s{/OM  
Dim op As T_OPERATION qkpnXQ  
Dim mat As T_MODELMATERIAL VU7x w  
Dim A As Double +@),
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Dim pupilDiam As Double *Z"9QX  
Dim eID As Long P+!j[X^  
Dim parID As Long (,~gY=E+  
Dim count As Integer H"8fnN=xB  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double LJK<Xen  
Dim tlens As Double, nlens As Double KlbL<9P>  
Dim curv As Double, conic As Double uc@f#(-  
Dim ok As Long u(B0X=B  
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Sub Main 8YJ8_$Z  
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    '用户输入对话框 $Yh7N5XH,  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 ,6U
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        TextBox 220,21,40,21,.TextBox1 'default: 0 PDaD:}9  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 Wu]Dpe  
        OKButton 40,91,90,21 /PbN!r<1  
        CancelButton 190,91,90,21 Zf~Em'g"3  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 "' g*_  
        TextBox 220,49,40,21,.TextBox2 'default: 4 ydOJ^Yty  
    End Dialog ]YcM45x
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    Dim dlg As UserDialog 6;g_}Zx  
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    ok = Dialog (dlg) F;l*@y Tq  
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    If ok=0 Then    'cancel button was pressed 5/-{.g   
        Print "Execution cancelled." :4]^PB@dl  
        End HMT^gmF)  
    End If 3*9<JHu  
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    'Assign accommodation and pupil diameter & use defaults if field left empty {f;]  
    If dlg.TextBox1 = "" Then i;!#:JX  
        A = 0           'Default accommodation k^-HY[Q9  
    Else ~Aul 7[IH  
        A = CDbl(dlg.TextBox1) y'ULhDgq^B  
    End If I_s4Pf[l  
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    If dlg.TextBox2 = "" Then g+Z~"O]$M  
        pupilDiam = 4   'Default pupil diameter d6ZJhxJ  
    Else :e1BQj`R  
        pupilDiam = CDbl(dlg.TextBox2) Z)B5g>  
    End If g7G=ga  
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    Print " " NLZTIZC
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    Print "Accommodation = " & A & " Diopters" bgs2~50  
    Print "Pupil Diameter = " & pupilDiam & " mm" CCp&P5[67  
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    ' Calculate new parameters with accommodation _&s37A&\  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness aKdi  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens ~D1.opj3  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens cX'&J_T+  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens YGb&mD  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens nDLr17  
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    tlens = 3.767 + 0.04*A                  'Lens thickness `* !t<?$i  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction %j9'HtjEa  
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    'Adjust parameters to account for accommodation VY }?Nb<&  
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    '************************************************************************* HS!O;7s'  
    'Aqueous thickness (Position of Lens) I6}ineps  
    '************************************************************************* ooa>~!91P  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) Q)oO*CnM!-  
    GetCustomElement eID, entity FbRq h|  
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    parID = FindFullName( "Geometry.Arizona Eye" ) T@c{5a  
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    ' Delete any shift(s) in z  p]z *  
    count = 0 afEhC0j  
    While GetOperationCount(eID)>count {MK.jw9/  
        GetOperation eID, count, op  )L}6to  
        If op.Type="ShiftZ" Then &_cMbFLBP  
            DeleteOperation eID,count Ys|n9pW  
            count=count-1 a!ao{8#  
        End If E>xd*23+\  
        count=count+1 Ik_u34U  
    Wend P~Cx#`#(V  
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    'Set new shift in &HdzbKO=  
    op.Type = "ShiftZ" 0zR4Kj7EE  
    op.val1 = taq I@x^`^+l  
    op.parent = parID cTW3\S=  
    AddOperation eID, op 6J3:[7k=&  
    Print "Set aqueous humor thickness = " & taq-0.55 Na8%TT>  
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    '************************************************************************* 8P8@i+[]W  
    'Radius and conic constant of anterior lens  +z/_'DE  
    '************************************************************************* RLkP)+t  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" )
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    GetConic eID, entity, curv, conic "PO>@tY  
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    SetConic eID, entity, 1/Rant, CCant 6 Fz?'Xf  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant te e  
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    '************************************************************************* 34lt?6%j  
    'Radius and conic constant of posterior lens Lyjt$i W%  
    '************************************************************************* X"yj
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    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) >cm*_26;I  
    GetConic eID, entity, curv, conic . e' vc  
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    SetConic eID, entity, 1/Rpost, CCpost EC*rd  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost ~/0t<^  
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    '************************************************************************* kaBP&6|Z  
    'Lens thickness (Position of posterior lens surface) }%z {tn  
    '************************************************************************* sB|>\O#-
 
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" )
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    ' Delete any z-shift(s) BJzNh>-#=  
    count = 0 4{!7T  
    While GetOperationCount(eID)>count u(W
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        GetOperation eID, count, op O
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        If op.Type="ShiftZ" Then g8<Ja
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            DeleteOperation eID,count 0OJBC~?{\  
            count=count-1 R2uekpP  
        End If d51.Tbt#%7  
        count=count+1 ^{L/) Xy5  
    Wend sdkKvo.y0  
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    'Set new z-shift ,9T-\)sT  
    op.Type = "ShiftZ" w9QY2v,U  
    op.val1 = tlens i"eUacBz/-  
    op.parent = parID MXy~kb&  
    AddOperation eID, op y7[D9ZvZ  
    Print "Set lens thickness = " & tlens :by EXe;3  
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    '************************************************************************* S
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    'Lens index of refraction BEn,py7  
    '************************************************************************* [l;9](\8O  
    eID = FindMaterial( "Lens" ) *;(wtMg  
    GetModelMaterial eID, mat S.,om;`  
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    mat.Nd = nlens SJ/($3GkBd  
    SetModelMaterial eID, mat P+tnXT>nE  
    Print "Set lens index of refraction = " & nlens l/|bU9o /u  
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    '************************************************************************* ;MD6iBD  
    'Pupil diameter {(o$? =  
    '************************************************************************* |8xu*dVAp4  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) R
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    'Adjust pupil diameter (trimming volume inner hole) h_O6Z2J1  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" nP9zTa  
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    ' Adjust pupil location to just in front of the lens & ,KxE(C  
    parID = FindFullName( "Geometry.Arizona Eye" ) 9~AAdD  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) .<GU2&;!  
    count = 0 &
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    While GetOperationCount(eID)>count ?OW!zE:  
        GetOperation eID, count, op 37:\X5)z/  
        If op.Type="ShiftZ" Then 'q+CL&D  
            DeleteOperation eID,count 7WuhYJbf  
            count=count-1 Aqi9@BH  
        End If LP_w6fjT  
        count=count+1 K0681_bp  
    Wend 9?4EM^-  
    op.Type = "ShiftZ" 8KQD w:  
    op.val1 = taq-0.01 }jF67c->  
    op.parent = parID lRIS&9vA3  
    AddOperation eID, op IF"-{@  

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    Print "Set pupil diameter = " & pupilDiam B?;!j)FUtt  
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    'Update AZ Eye subassembly Description vjfV??XSU  
    eID = FindFullName( "Geometry.Arizona Eye" ) V/ a!&_""  
    GetEntity eID, entity LV$@J  
    entity.Description = "Accommodation = " & A & "D" 6xLLIby,  
    SetEntity eID, entity I/F3%'O  
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    Update XeGtge/}T  
    Print "DONE!" h]|E,!H  
    
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End Sub bf9LR1  
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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： BQ\o?={  
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Accommodation = 4 Diopters -UJ; =/  
Pupil Diameter = 4 mm j?5s/  
Set aqueous humor thickness = 2.81 +W{ELdup%q  
Set anterior lens radius = 10.4 and conic constant = -2.375869 &W'X3!Te  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 znNJ?  
Set lens thickness = 3.927 s<}d)
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Set lens index of refraction = 1.42672 t%xD epFQ  
Set pupil diameter = 4 rD7L==Ld  
DONE! ynWF Y<VX