[技术]Arizona眼睛模型 [复制链接]

简介 1
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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。 qbq2Bi'a  
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模型 N*Q*>q  
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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。 O
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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. %1k"K~eu  
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光源 Vbp
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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。 ?SYmsaSr5  
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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。 h~sTi  
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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。 OjffN'a+N  
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视网膜的散射 3:WHC3}W  
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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。 8hww({S2  
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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。 jt6_1^   
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脚本 =[aiW|Y  
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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： _M8'~$Sg  
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如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 <6.`(isph  
余下的脚本计算与屈光度有关的所有参数。 n|H
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分析 6:QlHuy0nH  
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屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 \ 6taC  
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脚本代码 cna%;f.  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. nZYO}bv\  
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Dim entity As T_ENTITY PS!or!m  
Dim op As T_OPERATION #$U/*~m $  
Dim mat As T_MODELMATERIAL WyB^b-QmDh  
Dim A As Double @6!Myez'  
Dim pupilDiam As Double 5sEk rT '  
Dim eID As Long  Jc]k\U  
Dim parID As Long 
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Dim count As Integer QS4~":D/C  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double h4ntjk|{i7  
Dim tlens As Double, nlens As Double ;c|_z 9+  
Dim curv As Double, conic As Double (ruMOKW  
Dim ok As Long VL"Cxs  
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Sub Main W%&s$b(  
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    '用户输入对话框 -~J5aG[@~>  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 rR{KnM  
        TextBox 220,21,40,21,.TextBox1 'default: 0 x@)cj  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 1n6%EC|X  
        OKButton 40,91,90,21 rN.8-  
        CancelButton 190,91,90,21 ' qT\I8%  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 gCRPaF6  
        TextBox 220,49,40,21,.TextBox2 'default: 4 iM1E**WCtv  
    End Dialog 805oV(-  
    Dim dlg As UserDialog L"c.15\  
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    ok = Dialog (dlg) BVus3Y5IJQ  
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    If ok=0 Then    'cancel button was pressed LV$Ko_9eA  
        Print "Execution cancelled." HHgv,bC!  
        End rkdA4'66w  
    End If ]TtID4qL  
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    'Assign accommodation and pupil diameter & use defaults if field left empty 5~[][VV^  
    If dlg.TextBox1 = "" Then 0Q#}:  
        A = 0           'Default accommodation |{,c2Ck:N  
    Else @0tX,Z9  
        A = CDbl(dlg.TextBox1) j}J=ZLr/V"  
    End If I^n,v) 8  
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    If dlg.TextBox2 = "" Then Ix(,gDN  
        pupilDiam = 4   'Default pupil diameter "?iyvzo  
    Else <wd;W;B  
        pupilDiam = CDbl(dlg.TextBox2) E 8$S0u;`  
    End If s`v$r,N0  
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    Print " " pP"j|  
    Print "Accommodation = " & A & " Diopters" QWt3KW8)  
    Print "Pupil Diameter = " & pupilDiam & " mm" kPAg*
 
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    ' Calculate new parameters with accommodation QaA?UzB  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness k`z]l;:  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens z7P~SM  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens *.1#+h/]3  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens '9Q#%
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    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens +`$$^x  
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    tlens = 3.767 + 0.04*A                  'Lens thickness 68<W6z  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction '|Lv-7  
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    'Adjust parameters to account for accommodation zITxJx  
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    '************************************************************************* .SSyW
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    'Aqueous thickness (Position of Lens) (WY9EJ<s,  
    '************************************************************************* 'w<^4/L Q  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) N K@6U_/W  
    GetCustomElement eID, entity t0/Ol'kgs  
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    parID = FindFullName( "Geometry.Arizona Eye" ) (4C)] RHQ  
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    ' Delete any shift(s) in z 0pH$MkQ  
    count = 0 Y;E'gP-J  
    While GetOperationCount(eID)>count '*
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        GetOperation eID, count, op ^Q+z^zlC  
        If op.Type="ShiftZ" Then *mYGs )|  
            DeleteOperation eID,count 
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            count=count-1 ~RBa&Y=Mb  
        End If W+4Bx=Mj  
        count=count+1 Are0Nj&?
 
    Wend &%(SkL_]  
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    'Set new shift in <QaUq`,  
    op.Type = "ShiftZ" 7:JGrO  
    op.val1 = taq 9JILK9mVO  
    op.parent = parID 4/ q BD  
    AddOperation eID, op S&'s/jB  
    Print "Set aqueous humor thickness = " & taq-0.55 e(&u3 #7Nn  
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    '************************************************************************* yWT1CID  
    'Radius and conic constant of anterior lens qa8?bNd'f  
    '************************************************************************* &wu1Zz[qcz  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) )U]q{0`  
    GetConic eID, entity, curv, conic PTXS8e4  
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    SetConic eID, entity, 1/Rant, CCant 0r!F]Rm-^  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant *o(bB!q"c  
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    '************************************************************************* CkV -L4Jq  
    'Radius and conic constant of posterior lens 9Gx`[{wI9<  
    '************************************************************************* "W9z>ezp  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) ``{GU}n  
    GetConic eID, entity, curv, conic ,&* BhUC  
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    SetConic eID, entity, 1/Rpost, CCpost I,]q;lEMt  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost (b"q(:5oX  
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    '************************************************************************* t9lf=+%s  
    'Lens thickness (Position of posterior lens surface) ]j$(so"  
    '************************************************************************* j*GS')Cm  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) A ;|P
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    ' Delete any z-shift(s) 'b
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    count = 0 oBo |eRIt|  
    While GetOperationCount(eID)>count K]dR%j  
        GetOperation eID, count, op s8';4z  
        If op.Type="ShiftZ" Then T+%P+  
            DeleteOperation eID,count Wu8zK=Ve(  
            count=count-1 z XUr34jF  
        End If XSh[#qJ  
        count=count+1 ;W\?lGOs{  
    Wend   
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    'Set new z-shift =
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    op.Type = "ShiftZ" Wk!<P" nHd  
    op.val1 = tlens V<ilv<  
    op.parent = parID zq3f@xOK  
    AddOperation eID, op 53bVhPGv  
    Print "Set lens thickness = " & tlens axN\ZXU  
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    '************************************************************************* UDgX A  
    'Lens index of refraction l%2 gM7WMY  
    '************************************************************************* hyhm{RC?[  
    eID = FindMaterial( "Lens" ) f9d{{u  
    GetModelMaterial eID, mat # |OA>[  
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    mat.Nd = nlens Cyo:Da A  
    SetModelMaterial eID, mat 6/"#pe^  
    Print "Set lens index of refraction = " & nlens E!L_"GW  
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    '************************************************************************* y*=Ipdj  
    'Pupil diameter .}(X19R  
    '************************************************************************* L{&Yh|}  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) g!cW`B'  
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    'Adjust pupil diameter (trimming volume inner hole) _C|j"f/}  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" ]U}B~Y  
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    ' Adjust pupil location to just in front of the lens 79h'sp6;  
    parID = FindFullName( "Geometry.Arizona Eye" ) PO:sF]5  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) N]\)Ok  
    count = 0 nD!t*P  
    While GetOperationCount(eID)>count <$K7f  
        GetOperation eID, count, op 7m:TY>{  
        If op.Type="ShiftZ" Then ~|LAe-e"  
            DeleteOperation eID,count b"OHXu  
            count=count-1 .VohW=D3  
        End If J?hs\nA  
        count=count+1 p )WRsJ8  
    Wend ;sx4w!Y,  
    op.Type = "ShiftZ" 0;4 YU%u  
    op.val1 = taq-0.01 d-8{}Q  
    op.parent = parID WKwYSbs(  
    AddOperation eID, op 152LdZevF  
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    Print "Set pupil diameter = " & pupilDiam /R>YDout}  
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    'Update AZ Eye subassembly Description C+dz0u3s  
    eID = FindFullName( "Geometry.Arizona Eye" ) 7d+0'3%  
    GetEntity eID, entity FiXqypT_(  
    entity.Description = "Accommodation = " & A & "D" )XoMOz  
    SetEntity eID, entity :EH>&vm  
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    Update Fw#1?/K
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    Print "DONE!" 0+.<BOcW5  
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End Sub i8f+woZL  
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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： XdnpL$0  
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Accommodation = 4 Diopters `f<w+u  
Pupil Diameter = 4 mm ]]y,FQ,r  
Set aqueous humor thickness = 2.81 vV"I}L  
Set anterior lens radius = 10.4 and conic constant = -2.375869 b S'dXP  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 w U1[/  
Set lens thickness = 3.927 6:Y2z!MLO  
Set lens index of refraction = 1.42672 j'lC]}kH  
Set pupil diameter = 4 wbg?IvY[  
DONE! /fU-0a8