[技术]Arizona眼睛模型 [复制链接]

简介 %Rm`+  
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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。 Zg=jDPt}  
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模型 oxZXY]$y
 
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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。 JDP/vNq  
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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. hF`Qs  
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光源 Y>Ju$i  
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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。 Aq;WQyZ2  
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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。 J. $U_k  
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在往下看是内置的脚本用来修改屈光度，使其为4（250mm），光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 +<rWYF(ii/  
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视网膜的散射 JIU8~D  
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在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 sh)[|?7
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注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 ZW%;"5uVm)  
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脚本 `h='FJ/!  
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内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： bsv!z\}  
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如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 o]TKL'gW  
余下的脚本计算与屈光度有关的所有参数。 .f-s+J&ED  
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分析 i;fU],aK!  
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屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 2Dw}o;1'  
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脚本代码 d8J(~$tXQN  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. COH9E
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Dim entity As T_ENTITY D]?yGI_  
Dim op As T_OPERATION v,Uu)Z  
Dim mat As T_MODELMATERIAL D_M73s!U  
Dim A As Double *]*0
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Dim pupilDiam As Double Xq%ijo  
Dim eID As Long pM}n)Q!{3"  
Dim parID As Long ,m[#<}xXA  
Dim count As Integer Bmv5yc+;  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double NeR1}W  
Dim tlens As Double, nlens As Double @y8) "m"  
Dim curv As Double, conic As Double ~;vt{pk  
Dim ok As Long "{x+ \Z\  
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Sub Main l,ic-Y1  
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    '用户输入对话框 -cgMf\YF  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 09J,!NN  
        TextBox 220,21,40,21,.TextBox1 'default: 0 qlC4&82=Q  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 g3TqTs  
        OKButton 40,91,90,21 >0S(se
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        CancelButton 190,91,90,21 oT i$@q  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 U*\1d  
        TextBox 220,49,40,21,.TextBox2 'default: 4 ]23+ d/  
    End Dialog Y
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    Dim dlg As UserDialog #D^(dz*  
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    ok = Dialog (dlg) I]Ws
  
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    If ok=0 Then    'cancel button was pressed 4[rX\?^e  
        Print "Execution cancelled." :'T
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        End nZ4@g@e2
 
    End If 4F,RlKHBl  
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    'Assign accommodation and pupil diameter & use defaults if field left empty Da ]zbz%%  
    If dlg.TextBox1 = "" Then H8h,JBg5<F  
        A = 0           'Default accommodation >:|jds#  
    Else o,!W,sx_  
        A = CDbl(dlg.TextBox1) Q1RUmIe_&  
    End If vz^=o'  
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    If dlg.TextBox2 = "" Then 3j\Py'};  
        pupilDiam = 4   'Default pupil diameter &H/3@A3  
    Else rTzXRMv@o  
        pupilDiam = CDbl(dlg.TextBox2) D 4<,YBvV  
    End If I@ D<rjR  
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    Print " " w_*$wVl
 
    Print "Accommodation = " & A & " Diopters" wUH:l  
    Print "Pupil Diameter = " & pupilDiam & " mm" ;-VXp80J  
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    ' Calculate new parameters with accommodation 6c*QBzNL  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness /J!~0~F  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens 9PG3cCr?  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens }i52MI1-XP  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens ?tkd5kE  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens 9,$ n6t;  
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    tlens = 3.767 + 0.04*A                  'Lens thickness KP CZiu7  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction /U=?D(>x  
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    'Adjust parameters to account for accommodation 6A-nhvDP  
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    '************************************************************************* iz2;xa*  
    'Aqueous thickness (Position of Lens) LDdgI  
    '************************************************************************* ;M5]XCPk  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) 7o9[cq w  
    GetCustomElement eID, entity wj\kx\+  
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    parID = FindFullName( "Geometry.Arizona Eye" ) s}?QA cC  
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    ' Delete any shift(s) in z i.''\  
    count = 0 CPJ%<+4%b  
    While GetOperationCount(eID)>count _FzA
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        GetOperation eID, count, op ^F87gow%`B  
        If op.Type="ShiftZ" Then 7w?N-Q$y  
            DeleteOperation eID,count (#rhD}  
            count=count-1 Iy@6cd,)S  
        End If sK7b4gmK  
        count=count+1 JxlZ,FF$@  
    Wend Ha~}NO  
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    'Set new shift in tw&biLM5T  
    op.Type = "ShiftZ" ?;DzWCL~9  
    op.val1 = taq ZQ[s/  
    op.parent = parID J"Nn.iVq  
    AddOperation eID, op {$'oKJy*  
    Print "Set aqueous humor thickness = " & taq-0.55 % {A%SDh  
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    '************************************************************************* trlZ  
    'Radius and conic constant of anterior lens 2Jqr"|sw  
    '************************************************************************* 9C:V i  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) ~/;shs<9EM  
    GetConic eID, entity, curv, conic PF:'
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    SetConic eID, entity, 1/Rant, CCant cfL:#IM  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant W@61rT}c  
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    '************************************************************************* Ns.{$'ll  
    'Radius and conic constant of posterior lens wcW}Sv[r  
    '************************************************************************* \+)AQ!E  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) %[fZ@!B  
    GetConic eID, entity, curv, conic 9KMtPBZ  
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    SetConic eID, entity, 1/Rpost, CCpost :CG;:( |  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost 9C|-|mo  
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    '************************************************************************* #<yKG\X?  
    'Lens thickness (Position of posterior lens surface) '|nA
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    '************************************************************************* zI'c'X1,  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) %RXFgm!{f  
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    ' Delete any z-shift(s) 5/i]Jni  
    count = 0 j\2q2_f  
    While GetOperationCount(eID)>count }c'T]h\S  
        GetOperation eID, count, op /086qB|  
        If op.Type="ShiftZ" Then 9tIE+RD  
            DeleteOperation eID,count n@9R|biO  
            count=count-1 YH{FTVOt{C  
        End If cT#R B7  
        count=count+1 8v\^,'@  
    Wend 47^
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    'Set new z-shift "@rXN"4  
    op.Type = "ShiftZ" }N@+bNh~  
    op.val1 = tlens E 7"`D\*  
    op.parent = parID ^Dys#
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    AddOperation eID, op 7z3YzQ=Kg  
    Print "Set lens thickness = " & tlens Ui}%T]  
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    '************************************************************************* -{eI6#z|\A  
    'Lens index of refraction _+. )8   
    '************************************************************************* J;Veza  
    eID = FindMaterial( "Lens" ) Fd>e
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    GetModelMaterial eID, mat U46Z~B  
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    mat.Nd = nlens YI),yj  
    SetModelMaterial eID, mat AHn Yfxv_  
    Print "Set lens index of refraction = " & nlens N6!$V7oT  
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    '************************************************************************* bw OG|\  
    'Pupil diameter VHx:3G  
    '************************************************************************* Og(|bs!6  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) 1IWP~G  
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    'Adjust pupil diameter (trimming volume inner hole) ?Z"<&ts
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" /xkF9  
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    ' Adjust pupil location to just in front of the lens ^MUvd  
    parID = FindFullName( "Geometry.Arizona Eye" ) ;g_<i_*x#  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) *hkNJ  
    count = 0 GqD_6cdh  
    While GetOperationCount(eID)>count Io7o*::6iw  
        GetOperation eID, count, op +XL|bdK  
        If op.Type="ShiftZ" Then F'^?s= QX  
            DeleteOperation eID,count 48n7<M;I  
            count=count-1 JI|MR#_u  
        End If YF<U'EVU-  
        count=count+1 YCo qe,5  
    Wend =J^FV_1rJ  
    op.Type = "ShiftZ" L] !M1\  
    op.val1 = taq-0.01 0Y9fK? (  
    op.parent = parID I'%ASZ  
    AddOperation eID, op \Culf'iX  
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    Print "Set pupil diameter = " & pupilDiam )H-y  
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    'Update AZ Eye subassembly Description ?m dGMf)  
    eID = FindFullName( "Geometry.Arizona Eye" ) @Jr@ fF}  
    GetEntity eID, entity f"0?_cG{%  
    entity.Description = "Accommodation = " & A & "D" 3Jw}MFFV  
    SetEntity eID, entity c_FnJ_++f  
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    Update *&~wl(+O=  
    Print "DONE!" '+E\-X  
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End Sub BHJS.o*j~  
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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： z;6,,  
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Accommodation = 4 Diopters U$ 22r b  
Pupil Diameter = 4 mm !r`/vQ#  
Set aqueous humor thickness = 2.81 v}BXH4&Y  
Set anterior lens radius = 10.4 and conic constant = -2.375869 C vWt  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 s)j3+@:#  
Set lens thickness = 3.927 [.c'22R6  
Set lens index of refraction = 1.42672 T{zz3@2?  
Set pupil diameter = 4 J|:Zs1.<d  
DONE! < <]uniZ\