[技术]Arizona眼睛模型 [复制链接]

简介 Pme`UcE3H  
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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。 wf8vKl#Kfw  
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模型 rj<%_d'Z`  
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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。 ~Bj-n6QDE  
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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. oPre$YT}h  
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光源 0~n=|3*P  
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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。 ;~/  
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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_NlO  
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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。 Hhfqb"2on  
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视网膜的散射 C5;"mo-  
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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。 PT>,:zY  
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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。 S}fIZ1  
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脚本 _3kAN.g  
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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： ))306*X\  
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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。 #?8'Z/1)  
余下的脚本计算与屈光度有关的所有参数。 Pm" ,7  
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分析 Lo9+#ITyx  
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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。 =]etw  
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脚本代码 Hyc19|  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. $yc&f(Tv  
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Dim entity As T_ENTITY |A0kbC.  
Dim op As T_OPERATION qj=12;  
Dim mat As T_MODELMATERIAL IvH0sS`F  
Dim A As Double IsnC_"f  
Dim pupilDiam As Double >&BgF*mm  
Dim eID As Long O+z-6:`  
Dim parID As Long |)GE7y0Q  
Dim count As Integer <R_3;5J%  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double ><^A4s  
Dim tlens As Double, nlens As Double HLTz|P0JZ  
Dim curv As Double, conic As Double QeU>%qKT  
Dim ok As Long [Zgy,j\\  
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Sub Main h:j-Xd$H+  
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    '用户输入对话框 K;S&91V)=  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 zBqr15  
        TextBox 220,21,40,21,.TextBox1 'default: 0 [=..#y!U  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 [wIyW/
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        OKButton 40,91,90,21 1 5rE|m^  
        CancelButton 190,91,90,21 _mFb+8C  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 .6  
        TextBox 220,49,40,21,.TextBox2 'default: 4 D~8f6Ko"m  
    End Dialog Nb(se*Y#  
    Dim dlg As UserDialog aD0w82s]J  
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    ok = Dialog (dlg) kA\;h|Y3  
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    If ok=0 Then    'cancel button was pressed sOVaQ&+y  
        Print "Execution cancelled."
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        End A\k-OP]  
    End If $"x(:  
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    'Assign accommodation and pupil diameter & use defaults if field left empty M>1V3sM  
    If dlg.TextBox1 = "" Then .DCp)&m l;  
        A = 0           'Default accommodation 9lOUE  
    Else )M^;6S  
        A = CDbl(dlg.TextBox1) #`}g?6VHo  
    End If %xWmzdn  
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    If dlg.TextBox2 = "" Then YQe @C  
        pupilDiam = 4   'Default pupil diameter @AVx4,!>[  
    Else d|DIqT~{W  
        pupilDiam = CDbl(dlg.TextBox2) Zw"6-h4  
    End If bncK8SK  
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    Print " " zXZy:SD  
    Print "Accommodation = " & A & " Diopters" )mwY] !  
    Print "Pupil Diameter = " & pupilDiam & " mm" rA{h/T"  
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    ' Calculate new parameters with accommodation u%v^(9z  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness v }P~g  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens ^<sX^V+{  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens ,gD30Pylz  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens [o|]>(tk  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens Ya\G/R
 
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    tlens = 3.767 + 0.04*A                  'Lens thickness x-Xb4?{  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction L{ .r8wSrI  
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    'Adjust parameters to account for accommodation BAqu@F\):  
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    '************************************************************************* bYG}CO  
    'Aqueous thickness (Position of Lens) FKL}6W:  
    '************************************************************************* %'^m6^g;  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) RTF{<,E.UX  
    GetCustomElement eID, entity REFisH-  
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    parID = FindFullName( "Geometry.Arizona Eye" ) zA( 2+e 7  
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    ' Delete any shift(s) in z S,Tm=} wj  
    count = 0 a$;+-Y  
    While GetOperationCount(eID)>count LnR3C:NO k  
        GetOperation eID, count, op t*Lo;]P  
        If op.Type="ShiftZ" Then !.3 MtXr  
            DeleteOperation eID,count S2j7(T;~YB  
            count=count-1 X,T^(p  
        End If uiHlaMf  
        count=count+1 ?9=yo5M}  
    Wend 7W}~c/%  
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    'Set new shift in @,zBZNX y  
    op.Type = "ShiftZ" j-yD;N  
    op.val1 = taq a$9UUH-|  
    op.parent = parID ,9W0fm\t  
    AddOperation eID, op G)b]uX  
    Print "Set aqueous humor thickness = " & taq-0.55 S5bk<8aPP  
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    '************************************************************************* = ng\  
    'Radius and conic constant of anterior lens QC ]z--wu  
    '************************************************************************* E*
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    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) ;Oe6SNquT  
    GetConic eID, entity, curv, conic PB }$.8  
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    SetConic eID, entity, 1/Rant, CCant ?8vjHEE  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant
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    '************************************************************************* Prjl ;[I}  
    'Radius and conic constant of posterior lens )%#hpP M^  
    '*************************************************************************
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    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) 6p1TI1(  
    GetConic eID, entity, curv, conic X Phw0aV  
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    SetConic eID, entity, 1/Rpost, CCpost zRf]SZ(tO  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost 5!y3=.j  
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    '************************************************************************* M~ *
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    'Lens thickness (Position of posterior lens surface) sH+]lTSX6{  
    '************************************************************************* QuF%m^aE  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) U/jJ@8
 
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    ' Delete any z-shift(s) gs0,-)  
    count = 0 }m0Lr:vq<r  
    While GetOperationCount(eID)>count wBeOMA  
        GetOperation eID, count, op %M'"%Yn@(y  
        If op.Type="ShiftZ" Then Kz^aW  
            DeleteOperation eID,count
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            count=count-1 M_*w)<  
        End If ` qt4~rD  
        count=count+1 u6B (f;  
    Wend 0*t
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    'Set new z-shift (<8T*Xo  
    op.Type = "ShiftZ" ?w<x_Lo  
    op.val1 = tlens U][.ioc  
    op.parent = parID @?e;Jp9  
    AddOperation eID, op IXzad  
    Print "Set lens thickness = " & tlens q
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    '************************************************************************* 4&`66\p;  
    'Lens index of refraction zb;2xTH+  
    '************************************************************************* dB_\,%vAd  
    eID = FindMaterial( "Lens" ) 7Y#b7H  
    GetModelMaterial eID, mat YW/<. 0rI  
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    mat.Nd = nlens e3(0L I  
    SetModelMaterial eID, mat QjQJ "  
    Print "Set lens index of refraction = " & nlens B]]M?pS  
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    '************************************************************************* T-<^mX[}  
    'Pupil diameter %|-Rh^H[JK  
    '************************************************************************* TOBAh.1  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) Ex@#!fz{%  
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    'Adjust pupil diameter (trimming volume inner hole) TFM}
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" oh:t ex<  
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    ' Adjust pupil location to just in front of the lens +vYm:  
    parID = FindFullName( "Geometry.Arizona Eye" ) m{V
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    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) )<3WVvB  
    count = 0 # ^%'*/z  
    While GetOperationCount(eID)>count VQ}=7oe%q  
        GetOperation eID, count, op :uI}"Bp  
        If op.Type="ShiftZ" Then jl7e6#zu  
            DeleteOperation eID,count [{Y$]3?}  
            count=count-1 yGN<.IP75  
        End If `qfVgT=2  
        count=count+1 'fg`td  
    Wend BJ&>'rc  
    op.Type = "ShiftZ" 67n1s  
    op.val1 = taq-0.01 if`/LJsa  
    op.parent = parID qv,|7yw{  
    AddOperation eID, op S++}kR);  
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    Print "Set pupil diameter = " & pupilDiam 4!monaB"e  
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    'Update AZ Eye subassembly Description lhxhAe  
    eID = FindFullName( "Geometry.Arizona Eye" ) 0~FX!1;  
    GetEntity eID, entity ?rv+ydR/q  
    entity.Description = "Accommodation = " & A & "D" G=b`w;oL:  
    SetEntity eID, entity mBnC]$<R  
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    Update _ -?)-L&g  
    Print "DONE!" \(;5YCCE  
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End Sub vn kktD'n  
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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： @c{Z?>dUc#  
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Accommodation = 4 Diopters 9VP|a-  
Pupil Diameter = 4 mm NIYAcLa@n8  
Set aqueous humor thickness = 2.81 *^NC5=A(
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Set anterior lens radius = 10.4 and conic constant = -2.375869 S&R~*  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 qed; UyN  
Set lens thickness = 3.927 )Wc#?K  
Set lens index of refraction = 1.42672 ~xXB !K~C  
Set pupil diameter = 4 Xbap'/t  
DONE! l+T\DZ