[技术]Arizona眼睛模型 [复制链接]

简介 WR"p2=  
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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。 Cqk6Igw  
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模型 rW3fd.;kss  
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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。 "A9 c]  
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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. PK* $  
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光源 I^6z
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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。 KcjP39@I  
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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。 ];go?.*C  
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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。 z<mU$<  
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视网膜的散射 : LI*#~'Ka  
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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。 Sc*O_c3D  
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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。 U{o0P
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脚本 Ui7S8c#tH  
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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： xAD: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。 ``}EbOMG  
余下的脚本计算与屈光度有关的所有参数。 amIG9:-1'  
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分析 (;'?56  
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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。 ?8n`4yO0  
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脚本代码 p/xxoU  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. </|I
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Dim entity As T_ENTITY :'!,L0I|t  
Dim op As T_OPERATION C_Y^
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Dim mat As T_MODELMATERIAL YzSUJ=0/  
Dim A As Double D`LcL|nmH  
Dim pupilDiam As Double <w.W[ak  
Dim eID As Long ucyz>TL0  
Dim parID As Long =LS?:Mhm  
Dim count As Integer 1 {dhGX  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double ]v3 9ag_hu  
Dim tlens As Double, nlens As Double :0j9  
Dim curv As Double, conic As Double 9Ay*'   
Dim ok As Long ZUb6d*B  
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Sub Main V7!x-E/  
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    '用户输入对话框 wz5xJ:Tj  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 E3y"  
        TextBox 220,21,40,21,.TextBox1 'default: 0 <Vr"  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 h\b]>q@  
        OKButton 40,91,90,21 G_g~-[O  
        CancelButton 190,91,90,21 Y6/'gg'&5  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 INsc!xOQ  
        TextBox 220,49,40,21,.TextBox2 'default: 4 {b[8x   
    End Dialog XS]=sfN  
    Dim dlg As UserDialog VC\43A,9  
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    ok = Dialog (dlg) AW4N#gt8',  
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    If ok=0 Then    'cancel button was pressed -#H>kbs  
        Print "Execution cancelled." C XZm/^  
        End 1GVJ3VXt  
    End If 16[>af0<g  
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    'Assign accommodation and pupil diameter & use defaults if field left empty 7E4=\vM  
    If dlg.TextBox1 = "" Then `(<XdlOj  
        A = 0           'Default accommodation J.mEOo!>  
    Else Iw8;",e2  
        A = CDbl(dlg.TextBox1) xjiMM>|n  
    End If 7M<Ae D%  
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    If dlg.TextBox2 = "" Then SEF/D0  
        pupilDiam = 4   'Default pupil diameter MVK='  
    Else r>sk@[4h  
        pupilDiam = CDbl(dlg.TextBox2) _) 2fXG!  
    End If IM}T2\tZ}  
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    Print " " 0m6Vf x  
    Print "Accommodation = " & A & " Diopters" UwrinkoeE  
    Print "Pupil Diameter = " & pupilDiam & " mm"  a= ;7  
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    ' Calculate new parameters with accommodation >Qz#;HI
 
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness CeoK@y=o  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens z,[4BM  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens gR"'|c   
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens V6?ku6k  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens Glcl7f"<^  
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    tlens = 3.767 + 0.04*A                  'Lens thickness Id(o6j^J_  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction hV])\t=yf  
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    'Adjust parameters to account for accommodation 1+v&SU  
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    '************************************************************************* snOd 3Bw  
    'Aqueous thickness (Position of Lens) k:Sxs+)?1  
    '************************************************************************* L"A,7@:Vd  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) h.ojj$f,  
    GetCustomElement eID, entity mHB*4L  
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    parID = FindFullName( "Geometry.Arizona Eye" ) \B8tGog  
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    ' Delete any shift(s) in z T~7i:<E^  
    count = 0 3:7J@>  
    While GetOperationCount(eID)>count mS5'q q;t  
        GetOperation eID, count, op Wc ]BQn  
        If op.Type="ShiftZ" Then t/LQ|/xo  
            DeleteOperation eID,count LCx{7bN1ro  
            count=count-1 @*e|{;X]hy  
        End If j1%o+#df  
        count=count+1 A&rk5y;  
    Wend j|TcmZGO  
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    'Set new shift in wd2GKq!  
    op.Type = "ShiftZ" ^&buX_nlO  
    op.val1 = taq B>*zQb2:  
    op.parent = parID V
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    AddOperation eID, op |} ;&xI  
    Print "Set aqueous humor thickness = " & taq-0.55 NypM+y  
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    '************************************************************************* #'fh'$5"  
    'Radius and conic constant of anterior lens VliX'.-  
    '************************************************************************* R7}=k)U?d@  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) Yb\t0:_  
    GetConic eID, entity, curv, conic oa$-o/DhB  
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    SetConic eID, entity, 1/Rant, CCant O*xC}$OOn  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant B:#5U85m  
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    '************************************************************************* ;= ^kTb`X  
    'Radius and conic constant of posterior lens gR}>q4b  
    '************************************************************************* NFw7g&1;Kp  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) EjW3_ %  
    GetConic eID, entity, curv, conic <0T5W#H`D  
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    SetConic eID, entity, 1/Rpost, CCpost 0YK`wuZGS  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost (|+Sbq(o  
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    '************************************************************************* 9o5W\.A7[D  
    'Lens thickness (Position of posterior lens surface) oU`8\n](  
    '************************************************************************* X-2rC  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) qniP
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    ' Delete any z-shift(s) =<Q_&_.60  
    count = 0 ap;?[B~Ga  
    While GetOperationCount(eID)>count )@+lfIE(l  
        GetOperation eID, count, op vFKX@wV S  
        If op.Type="ShiftZ" Then /{@^
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            DeleteOperation eID,count QP/%+[E.  
            count=count-1 };;\&#  
        End If Bu
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        count=count+1 C_xOk'091  
    Wend !lQGoXQ'4  
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    'Set new z-shift ZI.;7G@|  
    op.Type = "ShiftZ"  .>?h  
    op.val1 = tlens o zg%-  
    op.parent = parID !_EL{/ko  
    AddOperation eID, op CR8a)X4j#  
    Print "Set lens thickness = " & tlens y.,S}7l:
 
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    '************************************************************************* 8 Z|c!QIU  
    'Lens index of refraction M]9oSi  
    '************************************************************************* "9F]Wv/  
    eID = FindMaterial( "Lens" ) )Dn~e#  
    GetModelMaterial eID, mat L(Ww6
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    mat.Nd = nlens $p_FrN{  
    SetModelMaterial eID, mat T.ZPpxY  
    Print "Set lens index of refraction = " & nlens &"X6s%ZH|  
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    '************************************************************************* kg@D?VqJP  
    'Pupil diameter 6x18g(KbP  
    '************************************************************************* dLA'cQId  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) ]MI>"hn  
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    'Adjust pupil diameter (trimming volume inner hole) 'zYKG5A  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" p#-ov-znp  
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    ' Adjust pupil location to just in front of the lens iMgfF_r  
    parID = FindFullName( "Geometry.Arizona Eye" ) [HEqMBX=;  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) Xxl>,QUA  
    count = 0 oh%kuO T[  
    While GetOperationCount(eID)>count ~vf&JH'!  
        GetOperation eID, count, op WY=RJe2  
        If op.Type="ShiftZ" Then z^(6>U ?  
            DeleteOperation eID,count 31BN ?q  
            count=count-1 ?gZJ v  
        End If 5<0d2bK$  
        count=count+1 P<+y%g(({  
    Wend In
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    op.Type = "ShiftZ" !sF! (u7  
    op.val1 = taq-0.01 1\v$8pP+  
    op.parent = parID wLa^pI4p ^  
    AddOperation eID, op M:m-iX  
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    Print "Set pupil diameter = " & pupilDiam
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    'Update AZ Eye subassembly Description |.bp  
    eID = FindFullName( "Geometry.Arizona Eye" ) G5^gwG+  
    GetEntity eID, entity "|1MJuY_6  
    entity.Description = "Accommodation = " & A & "D" @G/':N   
    SetEntity eID, entity # SmM5%  
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    Update %}z/_QZ  
    Print "DONE!" 7ko7)"N  
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End Sub ETu7G5?  
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如果屈光度是4，光瞳直径是4，则会输出如下数据： Y`FGD25`  
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Accommodation = 4 Diopters Lh=~3  
Pupil Diameter = 4 mm ^$][ah  
Set aqueous humor thickness = 2.81 7f4R5
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Set anterior lens radius = 10.4 and conic constant = -2.375869 C,C=W]G  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 eO,  
Set lens thickness = 3.927 gbc^Lb  
Set lens index of refraction = 1.42672 h]Zc&&+8{  
Set pupil diameter = 4 ;qI5GQ {  
DONE! &}Y_EHj}