[技术]Arizona眼睛模型 [复制链接]

简介 WO4=Mte?  
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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。 4D%9Rc0 G  
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模型 {CG_P,FO  
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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。 5AS[\CB4  
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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. a {}|Bf<  
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光源 M2x["  
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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。 X{n- N5*  
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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。 \l"&A  
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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。 $WYbm}j  
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视网膜的散射 n?\ nn3  
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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。 qm
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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。 uPYmHA}_/  
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脚本 MS(JR  
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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： [S.ZJUns  
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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。 -U<Upn)2  
余下的脚本计算与屈光度有关的所有参数。 Z3k(P  
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分析 a9n^WOJ6  
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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。 ;fw1
 
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脚本代码 "fg](Cp[z  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. EFpIp4_Y  
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Dim entity As T_ENTITY hlu:=<B  
Dim op As T_OPERATION  hjO*~  
Dim mat As T_MODELMATERIAL ^qCkt1C-M  
Dim A As Double ]M)O YY  
Dim pupilDiam As Double \BWyk
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Dim eID As Long f<+4rHT  
Dim parID As Long hYQ_45Z*?  
Dim count As Integer ,#.9^J  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double  z:d+RMA  
Dim tlens As Double, nlens As Double `;
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Dim curv As Double, conic As Double Mb+CtI_'  
Dim ok As Long \eCQL(_  
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Sub Main  )QB9zl:  
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    '用户输入对话框 $yZ(ws  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 Fv3:J~Yf  
        TextBox 220,21,40,21,.TextBox1 'default: 0 ?mh0^G  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 kOV6O?h  
        OKButton 40,91,90,21 =UV=F/Af^  
        CancelButton 190,91,90,21 71G00@&w9D  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 :Oc&{z?q  
        TextBox 220,49,40,21,.TextBox2 'default: 4 jO5Wemqf  
    End Dialog *h~(LH"tN  
    Dim dlg As UserDialog v]m#+E  
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    ok = Dialog (dlg) JT*Pm"}  
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    If ok=0 Then    'cancel button was pressed s/OXZ<C|  
        Print "Execution cancelled." 8_uh2`+Bvb  
        End ixJwv\6Y  
    End If 7J$Yd976  
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    'Assign accommodation and pupil diameter & use defaults if field left empty }>m3V2>[  
    If dlg.TextBox1 = "" Then }\d3   
        A = 0           'Default accommodation du^r EMb%  
    Else _R;+}1G/  
        A = CDbl(dlg.TextBox1) -
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    End If G2hBJTW  
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    If dlg.TextBox2 = "" Then 5h>t4 [~  
        pupilDiam = 4   'Default pupil diameter .iH#8Z  
    Else l&m'?.gf  
        pupilDiam = CDbl(dlg.TextBox2) ?r}!d2:dX  
    End If zNQ|G1o  
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    Print " " d5
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    Print "Accommodation = " & A & " Diopters" dWhF[q"  
    Print "Pupil Diameter = " & pupilDiam & " mm" x^JjoI2vf  
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    ' Calculate new parameters with accommodation D(gpF85t  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness 0%5x&vx'S  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens *!x/ia9  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens b}jLI_R{  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens o)IcAqN$H  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens 0Z>oiBr4  
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    tlens = 3.767 + 0.04*A                  'Lens thickness m#(ve1E  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction ^Sz?c_<2
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    'Adjust parameters to account for accommodation b{Kw.?85  
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    '************************************************************************* @DYkWivLu  
    'Aqueous thickness (Position of Lens) /WIHG0D  
    '************************************************************************* Gq
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    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) 9=Rj9%  
    GetCustomElement eID, entity UT7"
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    parID = FindFullName( "Geometry.Arizona Eye" ) `)R@\@jt  
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    ' Delete any shift(s) in z "Z6:d"S`  
    count = 0 6">jf #pE  
    While GetOperationCount(eID)>count c~UYs\  
        GetOperation eID, count, op RU'DUf  
        If op.Type="ShiftZ" Then 4c=oAL  
            DeleteOperation eID,count 1f1J'du  
            count=count-1 u!DSyHR '  
        End If #/9(^6f:  
        count=count+1 _"`U.!3*  
    Wend kM\O2ay  
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    'Set new shift in {G%!M+n<  
    op.Type = "ShiftZ" fE/8;v!
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    op.val1 = taq jsvD[\P  
    op.parent = parID &p$SFH?s  
    AddOperation eID, op #YSUPO%F  
    Print "Set aqueous humor thickness = " & taq-0.55 <&'r_m  
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    '************************************************************************* 1H_#5hd  
    'Radius and conic constant of anterior lens <`q|6XWL  
    '************************************************************************* 0Fh*8a}?b  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) b
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    GetConic eID, entity, curv, conic 5i$~1ZC  
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    SetConic eID, entity, 1/Rant, CCant 5yQv(<~*G
 
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant WLWE%bDP  
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    '************************************************************************* hoihdVjv  
    'Radius and conic constant of posterior lens ~Rcd  
    '************************************************************************* m!:7ur:Y  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) ^F~e?^s  
    GetConic eID, entity, curv, conic #?i#q%q  
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    SetConic eID, entity, 1/Rpost, CCpost WU1o4&OF  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost oA~m*|  
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    '************************************************************************* q9oF8&O,  
    'Lens thickness (Position of posterior lens surface) = sIR[V'(  
    '************************************************************************* j78xMGKO  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) 9kP!O_  
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    ' Delete any z-shift(s) K.R2)o`  
    count = 0 +c\s%Gzrh  
    While GetOperationCount(eID)>count 64\ZOG\,  
        GetOperation eID, count, op tb0XXEE  
        If op.Type="ShiftZ" Then 3_T'TzQu  
            DeleteOperation eID,count 4ij`  
            count=count-1 ;?2vW8{p<  
        End If VSZ6;&2^  
        count=count+1 VJCh5t*  
    Wend ^;s`[f|w  
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    'Set new z-shift %TG$5')0  
    op.Type = "ShiftZ" X{#@ :z$  
    op.val1 = tlens Ai->,<Ig]  
    op.parent = parID Mn~A;=%qF  
    AddOperation eID, op 9$Mi/eLG2N  
    Print "Set lens thickness = " & tlens 45j+n.9=  
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    '************************************************************************* .3|9 ~]  
    'Lens index of refraction R/^JyL  
    '************************************************************************* sp**Sg)  
    eID = FindMaterial( "Lens" )  A]U]  
    GetModelMaterial eID, mat MmWJYF=  
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    mat.Nd = nlens `6mHt6"h  
    SetModelMaterial eID, mat : 6>H\  
    Print "Set lens index of refraction = " & nlens [k'Ph33c  
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    '************************************************************************* -'PpY302  
    'Pupil diameter `FJnR~d  
    '************************************************************************* Xq>e]#gR  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) ;7`<.y  
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    'Adjust pupil diameter (trimming volume inner hole) BE"nyTQ  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" ){YPP!8cI  
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    ' Adjust pupil location to just in front of the lens ~2H7_+.#  
    parID = FindFullName( "Geometry.Arizona Eye" ) ($S{td;  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) BRD'5 1]|  
    count = 0 [V)sCAW  
    While GetOperationCount(eID)>count )E7A,ZW,  
        GetOperation eID, count, op u\e#_*>  
        If op.Type="ShiftZ" Then -/gS s<"  
            DeleteOperation eID,count Gr6ma*)y~t  
            count=count-1 !7xp<=  
        End If (J$A  
        count=count+1 "}OFwes
  
    Wend Y$ChMf  
    op.Type = "ShiftZ" Oq[E\8Wn  
    op.val1 = taq-0.01 jujx3rnK?  
    op.parent = parID =` i 7?  
    AddOperation eID, op S-rqrbr|AT  
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    Print "Set pupil diameter = " & pupilDiam bg HaheU  
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    'Update AZ Eye subassembly Description *}_/:\v  
    eID = FindFullName( "Geometry.Arizona Eye" ) y2+a2  
    GetEntity eID, entity Nr[Rp  
    entity.Description = "Accommodation = " & A & "D" k( g$_ ]X  
    SetEntity eID, entity _"sRL}-Z  
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    Update nUd\4;J#  
    Print "DONE!" sd[QtK^  
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End Sub Agi1r]W  
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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： zJnVO$A'  
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Accommodation = 4 Diopters {;4PP463  
Pupil Diameter = 4 mm _#gsR"FZ$  
Set aqueous humor thickness = 2.81 aqM_t  
Set anterior lens radius = 10.4 and conic constant = -2.375869 t~M<j|]k  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 vv0zUvmT  
Set lens thickness = 3.927 WvJ?e  
Set lens index of refraction = 1.42672 +E [bLz^  
Set pupil diameter = 4 yQA[X}  
DONE! (Z$6JNkz