[技术]Arizona眼睛模型 [复制链接]

简介 qM F'
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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。 Wj
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模型 )&di c6r  
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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。 %Kd&A*  
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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. %+oWW5
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光源 _+0l+a*D  
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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。 <)y44x|S'  
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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。 <apsG7(7
 
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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。 g~_cYy  
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视网膜的散射 (gBP`*2  
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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。 E",s]  
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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。 m`C(y$8fU  
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脚本 KquHc-fzqr  
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内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： jEfrxlj  
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如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 P8!Vcy938  
余下的脚本计算与屈光度有关的所有参数。 k:PO"<-U  
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分析 dA>t  
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屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 &'V_80vA  
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脚本代码 I z~#G6]M  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. 6XUcJ0  
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Dim entity As T_ENTITY 1C+Y|p?KA  
Dim op As T_OPERATION '-3AWBWI1  
Dim mat As T_MODELMATERIAL &H,5f#  
Dim A As Double /Ik_U?$*  
Dim pupilDiam As Double s<'^ @Y  
Dim eID As Long OQaM47"  
Dim parID As Long o!L1Qrh  
Dim count As Integer ,eOOV@3C  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double 6~?7CK  
Dim tlens As Double, nlens As Double o
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Dim curv As Double, conic As Double 1B=vrGq  
Dim ok As Long 3;~1rw=$<  
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Sub Main +o(t5O[G  
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    '用户输入对话框 0z/tceW'F  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 Lx,"jA/  
        TextBox 220,21,40,21,.TextBox1 'default: 0 hXM8`iFW5  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 xksQMS2#  
        OKButton 40,91,90,21 C$oY,A,  
        CancelButton 190,91,90,21 w_pEup\`  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 MBs]<(RJZ  
        TextBox 220,49,40,21,.TextBox2 'default: 4 &#v^y3r  
    End Dialog UBqA[9  
    Dim dlg As UserDialog ZT4._|2
 
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    ok = Dialog (dlg) Fwyv>U  
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    If ok=0 Then    'cancel button was pressed r4dG83qg  
        Print "Execution cancelled." ,)'!E^n  
        End |M#b`g$JO,  
    End If _I
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    'Assign accommodation and pupil diameter & use defaults if field left empty QZef=  
    If dlg.TextBox1 = "" Then X'.}#R1  
        A = 0           'Default accommodation QD]Vfj4+  
    Else o,9E~Q'`{  
        A = CDbl(dlg.TextBox1) 5 g99t$p9  
    End If ?H eC+=/Z  
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    If dlg.TextBox2 = "" Then ^tsIgK^9H  
        pupilDiam = 4   'Default pupil diameter LdI
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    Else 6[wej$u  
        pupilDiam = CDbl(dlg.TextBox2) yxQxc5/X)  
    End If 4Cke(G  
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    Print " " 'Kxs>/y3  
    Print "Accommodation = " & A & " Diopters" \.myLkm  
    Print "Pupil Diameter = " & pupilDiam & " mm" !vfjo[v  
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    ' Calculate new parameters with accommodation \6)l(b;  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness H&E c*MT  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens v3Tr6[9  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens 0`"]mYH  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens 6hXL`A&},  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens 1lfkb1BM  
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    tlens = 3.767 + 0.04*A                  'Lens thickness X/lLM`  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction \E9Z
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    'Adjust parameters to account for accommodation D^=_408\  
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    '************************************************************************* -Vn9YeH+  
    'Aqueous thickness (Position of Lens) AnU,2[(  
    '************************************************************************* Vi23pDZ5  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) /tc*jXB  
    GetCustomElement eID, entity F)j-D(c4  
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    parID = FindFullName( "Geometry.Arizona Eye" ) :g2?)Er-  
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    ' Delete any shift(s) in z Bt[`p\p@  
    count = 0 %Z 9<La  
    While GetOperationCount(eID)>count 8/U
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        GetOperation eID, count, op Ah='E$t  
        If op.Type="ShiftZ" Then Hhr/o~?;}#  
            DeleteOperation eID,count {\ P$5O{%  
            count=count-1 { >{|3  
        End If cn v4!c0  
        count=count+1 l^:m!SA_  
    Wend m'KY;C  
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    'Set new shift in kwMuL>5  
    op.Type = "ShiftZ" = PcmJG]  
    op.val1 = taq 'M|W nR  
    op.parent = parID 
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    AddOperation eID, op kCL)F\v"iT  
    Print "Set aqueous humor thickness = " & taq-0.55 a k@0M[d  
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    '************************************************************************* m/|>4~  
    'Radius and conic constant of anterior lens 4wX{N   
    '************************************************************************* chQt8Ar3  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) ^-w:
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    GetConic eID, entity, curv, conic 7e/Uc!&*  
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    SetConic eID, entity, 1/Rant, CCant }+nC}A"BC  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant ! o:m*:  
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    '************************************************************************* lInq=  
    'Radius and conic constant of posterior lens 24:;vcb  
    '************************************************************************* ; @ h{-@  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) +)^F9LPl  
    GetConic eID, entity, curv, conic >1`FRw<  
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    SetConic eID, entity, 1/Rpost, CCpost 2"~!Pu^.j  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost ;/N[tO?Q  
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    '************************************************************************* `FHHh  
    'Lens thickness (Position of posterior lens surface) 0AY23/  
    '************************************************************************* S]KcAz(fX  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) o\@1\#a  
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    ' Delete any z-shift(s) ^b~&}uU  
    count = 0 }pbyC  
    While GetOperationCount(eID)>count W'E!5T^  
        GetOperation eID, count, op Vl{CD>$,  
        If op.Type="ShiftZ" Then <^UB@'lCm  
            DeleteOperation eID,count p^&' C_?  
            count=count-1 4;M  
        End If mn{8"@Z  
        count=count+1 nZfTK>)A0  
    Wend +uM1#-+h  
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    'Set new z-shift Bz_['7D  
    op.Type = "ShiftZ" COOazXtW  
    op.val1 = tlens ?g}n$%*5y!  
    op.parent = parID +Q_X,gZ  
    AddOperation eID, op Y$--Hp4  
    Print "Set lens thickness = " & tlens /"- k ;jz  
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    '************************************************************************* n>Y3hY  
    'Lens index of refraction
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    '************************************************************************* lN,b@;  
    eID = FindMaterial( "Lens" ) !aeL*`;  
    GetModelMaterial eID, mat d0>V^cB'?  
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    mat.Nd = nlens RecA?-0  
    SetModelMaterial eID, mat ~2 T_)l?  
    Print "Set lens index of refraction = " & nlens LXVm0IOFF  
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    '************************************************************************* q+x4Od3  
    'Pupil diameter P0Ds7xh]h  
    '************************************************************************* WVftLIJ  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) Fla[YWS  
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    'Adjust pupil diameter (trimming volume inner hole) "monuErg&  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" si/F\NDT
 
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    ' Adjust pupil location to just in front of the lens eE>3=1d]w  
    parID = FindFullName( "Geometry.Arizona Eye" ) f/Grem  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) =9\=5_V  
    count = 0 S&6}9r  
    While GetOperationCount(eID)>count $e+@9LNK  
        GetOperation eID, count, op %aaOws  
        If op.Type="ShiftZ" Then W2wDSP-   
            DeleteOperation eID,count Umm_FEU#]  
            count=count-1 Q0gO1T  
        End If ,vrdtL  
        count=count+1 ""^9WLH4g-  
    Wend Vt5%A}.VQ  
    op.Type = "ShiftZ" hAOXOj1  
    op.val1 = taq-0.01 Gc~A,_(  
    op.parent = parID $.QnM  
    AddOperation eID, op fm;1Iu#  
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    Print "Set pupil diameter = " & pupilDiam V{HZ/p_Y  
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    'Update AZ Eye subassembly Description itm;,Sbg  
    eID = FindFullName( "Geometry.Arizona Eye" ) q+~z#
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    GetEntity eID, entity GLwL'C'591  
    entity.Description = "Accommodation = " & A & "D" =P'=P0G  
    SetEntity eID, entity +;C|5y  
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    Update 3HO4h\mp  
    Print "DONE!" ~`#.ZMO  
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End Sub 56G5JSB=\  
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如果屈光度是4，光瞳直径是4，则会输出如下数据： MQQiQ 2  
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Accommodation = 4 Diopters {Xwin$C  
Pupil Diameter = 4 mm <z#r3J  
Set aqueous humor thickness = 2.81 %N/I;`  
Set anterior lens radius = 10.4 and conic constant = -2.375869 B6 x5E  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 `y;&M8.  
Set lens thickness = 3.927 b[uTt'p}  
Set lens index of refraction = 1.42672 nkS6A}i3o  
Set pupil diameter = 4 }C/}8<  
DONE! ?b#/*T}ac