[技术]Arizona眼睛模型 [复制链接]

简介 >Wz;ySEz  
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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。 :O(^w}sle  
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模型 `[C!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。 
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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. q7"7
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光源 92^w8Z.  
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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。 ATR!7i\|  
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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。 qG<$Ajiin  
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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。 %Qj;,#z  

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视网膜的散射 @'|)~,"bx  
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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。 1bH;!J  
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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 aL)  
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脚本 O9r>E3-q  
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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： {Lm~r+ U  
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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。 (7r<''  
余下的脚本计算与屈光度有关的所有参数。 Q_t`.
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分析 L =8rH5  
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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。 xe*aC  
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脚本代码 HvVts\f  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. 65Cg]Dt71  
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Dim entity As T_ENTITY kSDZZx  
Dim op As T_OPERATION xl#LrvxI  
Dim mat As T_MODELMATERIAL D#o}cC.  
Dim A As Double 8)4P Ll  
Dim pupilDiam As Double g]c6&Y,#  
Dim eID As Long oIefw:FE,a  
Dim parID As Long ^g`&7tX  
Dim count As Integer d,=r9.  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double BN4_:  
Dim tlens As Double, nlens As Double kP?KXT3y  
Dim curv As Double, conic As Double xQ@^$_  
Dim ok As Long w.0qp)}  
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Sub Main *;fw%PW  
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    '用户输入对话框
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    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 dX)GPC-D7  
        TextBox 220,21,40,21,.TextBox1 'default: 0 /;
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        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 AqV7\gdOC  
        OKButton 40,91,90,21 uxzze~_+C  
        CancelButton 190,91,90,21 E~_]Lfs)  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 OdB?_.+$  
        TextBox 220,49,40,21,.TextBox2 'default: 4 dx+hhg\L  
    End Dialog UNkCL4N  
    Dim dlg As UserDialog 7=DjI ~  
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    ok = Dialog (dlg) k0Uyf~p~  
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    If ok=0 Then    'cancel button was pressed 9t#S= DP  
        Print "Execution cancelled." 9s_,crq5  
        End f?'JAC*  
    End If 1Q.\s_2  
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    'Assign accommodation and pupil diameter & use defaults if field left empty uIDuGrt  
    If dlg.TextBox1 = "" Then %C=]1Q=T)  
        A = 0           'Default accommodation pe{;~-|6  
    Else XQ~Ke-QW)  
        A = CDbl(dlg.TextBox1) &Ky_v^  
    End If ~mR'Q-hi<  
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    If dlg.TextBox2 = "" Then %Pqf{*d8  
        pupilDiam = 4   'Default pupil diameter 4M^G`WA}t9  
    Else *Otg*,\  
        pupilDiam = CDbl(dlg.TextBox2) S!sqbLrBn  
    End If Vl2XDkhq  
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    Print " " Co3:*nbRv  
    Print "Accommodation = " & A & " Diopters" @`,1:
 
    Print "Pupil Diameter = " & pupilDiam & " mm" C|?o*fQ  
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    ' Calculate new parameters with accommodation al[n,u  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness ;JRs?1<='  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens xSBc-u#< G  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens QurW
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens <bD>m[8,  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens NZ3/5%We/  
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    tlens = 3.767 + 0.04*A                  'Lens thickness p+Y>F\r&w  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction XZ5 /=z  
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    'Adjust parameters to account for accommodation +tD[9b! m  
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    '************************************************************************* %bdjBa}  
    'Aqueous thickness (Position of Lens) ?Sb8@S&J  
    '************************************************************************* ? mhs$g>  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) tu5*Qp\  
    GetCustomElement eID, entity q/4 [3
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    parID = FindFullName( "Geometry.Arizona Eye" ) ~D|5u\D-  
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    ' Delete any shift(s) in z m-jHze`D3  
    count = 0 fhCc! \  
    While GetOperationCount(eID)>count /AQMFx4-5  
        GetOperation eID, count, op :hI@AA>g  
        If op.Type="ShiftZ" Then &wB\ ~Ie-  
            DeleteOperation eID,count 1\r|g2Z :  
            count=count-1 yZWoN&  
        End If fu9Cx  
        count=count+1 MW+b;0U`#  
    Wend xrN &N_K#  
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    'Set new shift in 41_SRh7N  
    op.Type = "ShiftZ" N72Yq)(  
    op.val1 = taq EFc-foN  
    op.parent = parID 1DA1N<'  
    AddOperation eID, op 3S&U!  
    Print "Set aqueous humor thickness = " & taq-0.55 Tdc3_<1  
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    '************************************************************************* .%82P(  
    'Radius and conic constant of anterior lens bUY>st'  
    '************************************************************************* jU5}\o
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    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) r lKlpl  
    GetConic eID, entity, curv, conic -D^}S"'  
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    SetConic eID, entity, 1/Rant, CCant mB0l "# F  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant .E@|D6$D
 
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    '*************************************************************************  ]@M5&  
    'Radius and conic constant of posterior lens Q*XE h  
    '************************************************************************* 8+Bu+|c%f  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) bTSL<"(]N  
    GetConic eID, entity, curv, conic C8L'si  
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    SetConic eID, entity, 1/Rpost, CCpost w2xG_q  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost |0,vQv  
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    '*************************************************************************
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    'Lens thickness (Position of posterior lens surface) K2<~(78C  
    '************************************************************************* M+!x}$&v  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) 1>Q'R  
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    ' Delete any z-shift(s) ^bL
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    count = 0 U/NBFc:[y:  
    While GetOperationCount(eID)>count Rl6\#C*  
        GetOperation eID, count, op z7-k`(l4  
        If op.Type="ShiftZ" Then Bu]t*$  
            DeleteOperation eID,count T{}fHfM  
            count=count-1 9Ok9bC'?8@  
        End If 9*:gr#(5  
        count=count+1 %AW4.3()8  
    Wend AE@NOM7u  
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    'Set new z-shift 4c+$%pq5  
    op.Type = "ShiftZ" /Ky__l
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    op.val1 = tlens j8K,jZ  
    op.parent = parID m~'? /!!  
    AddOperation eID, op _Zc%z@}  
    Print "Set lens thickness = " & tlens tV/Z)fpyH  
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    '************************************************************************* T%Pp*1/m7  
    'Lens index of refraction x|KWyfOS  
    '************************************************************************* s9oO%e<  
    eID = FindMaterial( "Lens" ) j(#%tIv  
    GetModelMaterial eID, mat 9,]5v+  
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    mat.Nd = nlens ~3RC>8*Qw  
    SetModelMaterial eID, mat 6/ `.(fL1  
    Print "Set lens index of refraction = " & nlens KL'zXkS  
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    '************************************************************************* nmjm<Bu  
    'Pupil diameter ggb|Ew  
    '************************************************************************* #?B%Ja% ;W  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" )  d^|0R  
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    'Adjust pupil diameter (trimming volume inner hole) z}Jr^>  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" \.gEh1HW  
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    ' Adjust pupil location to just in front of the lens V|MY!uV  
    parID = FindFullName( "Geometry.Arizona Eye" ) tD$lNh^  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) ~svO*o Wa  
    count = 0 5y4u5Tm-%  
    While GetOperationCount(eID)>count 
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        GetOperation eID, count, op #&,H"?"  
        If op.Type="ShiftZ" Then 5f:DN
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            DeleteOperation eID,count <ale$[  
            count=count-1 rgcWRt  
        End If M*pRv  
        count=count+1 fMf&?`V  
    Wend P6U%=xaC  
    op.Type = "ShiftZ" [XlB<P=|>  
    op.val1 = taq-0.01 4O{Avt7C  
    op.parent = parID YH:8<O,{-  
    AddOperation eID, op k6\^p;!Y  
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    Print "Set pupil diameter = " & pupilDiam )fU(AXSP  
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    'Update AZ Eye subassembly Description 9j|gdfb%ml  
    eID = FindFullName( "Geometry.Arizona Eye" ) Cpx+qQt0  
    GetEntity eID, entity q\9d6u=Gm  
    entity.Description = "Accommodation = " & A & "D" 4-v6=gz.  
    SetEntity eID, entity R UTnc  
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    Update g2p"LWex-  
    Print "DONE!" gd6Dm4q(  
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End Sub X21dX`eMN  
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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： D!TZI  
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Accommodation = 4 Diopters v vE\  
Pupil Diameter = 4 mm D>wZ0p b-  
Set aqueous humor thickness = 2.81 ^O%9yEo
  
Set anterior lens radius = 10.4 and conic constant = -2.375869 q9}m!*8e  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 v@u<Ww;=@  
Set lens thickness = 3.927 3 EYiQ`  
Set lens index of refraction = 1.42672 S-Ai3)t6  
Set pupil diameter = 4 ^i_Iqph=  
DONE! ^lO76Dz~a