[技术]Arizona眼睛模型 [复制链接]

简介 o?`FjZ6;x  
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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。 ;*A'2ymXUT  
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模型 OW7  
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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。 ,2@o`R.27  
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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. WR;1  
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光源 |5&+VI  
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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。 Q+:y  
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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。 ij"~]I  
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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。 Abc{<4 z0?  
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视网膜的散射 |
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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。 T &ZQie/  
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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。 w#A)B<Y/"  
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脚本 cgnNO&  
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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： ]C_+u_9  
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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。 T{{:p\<]_  
余下的脚本计算与屈光度有关的所有参数。 Y|Iq~
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分析 mZ)>^.N6  
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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。 !T6R[  
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脚本代码 D#;7S'C  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. N} EKV  
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Dim entity As T_ENTITY ,9&cIUH  
Dim op As T_OPERATION fY<#KM6X  
Dim mat As T_MODELMATERIAL XwH>F7HPe  
Dim A As Double Kz HYh  
Dim pupilDiam As Double !eX0Q 2  
Dim eID As Long Q\Ek U.[I  
Dim parID As Long !fOPYgAGKn  
Dim count As Integer zsL@0]e&  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double HC iRk1  
Dim tlens As Double, nlens As Double fz'qB-F Y  
Dim curv As Double, conic As Double c_8&4  
Dim ok As Long 0ho;L0Nr'  
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Sub Main %:3XYO.w-  
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    '用户输入对话框 n0(Q/  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 >0^<<=m  
        TextBox 220,21,40,21,.TextBox1 'default: 0 HNzxFnh  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 pH'_k k  
        OKButton 40,91,90,21 4X
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        CancelButton 190,91,90,21 *22Vc2[i;  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 p9v:T1?  
        TextBox 220,49,40,21,.TextBox2 'default: 4 jJ$\WUQ.  
    End Dialog kK&w5'  
    Dim dlg As UserDialog ?sN{U\  
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    ok = Dialog (dlg) -Vn#Ab_C  
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    If ok=0 Then    'cancel button was pressed mU5Ox4>&9  
        Print "Execution cancelled." W+h2rv  
        End BgQEd@cN  
    End If mixsJ}
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    'Assign accommodation and pupil diameter & use defaults if field left empty >kXscbRL7  
    If dlg.TextBox1 = "" Then abo=v<mR  
        A = 0           'Default accommodation ;V,
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    Else ,#Z%0NLe  
        A = CDbl(dlg.TextBox1) aOD
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    End If kwjO5OC8  
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    If dlg.TextBox2 = "" Then #U:|
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        pupilDiam = 4   'Default pupil diameter ,s8/6n#  
    Else 10SI&O  
        pupilDiam = CDbl(dlg.TextBox2) erH,EE^-x<  
    End If -.Wcz|  
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    Print " " VF`!ks  
    Print "Accommodation = " & A & " Diopters" 7^d
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    Print "Pupil Diameter = " & pupilDiam & " mm" Xf u0d1b  
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    ' Calculate new parameters with accommodation #Oka7.yz  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness aTcz5g0"  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens G6p gG+w  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens ;cMQ0e  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens ]Lv3XMa  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens MK1\  
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    tlens = 3.767 + 0.04*A                  'Lens thickness $d<NN2  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction q5;dQ8Y?  
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    'Adjust parameters to account for accommodation VYG@_fd!x  
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    '************************************************************************* s"jvO>[  
    'Aqueous thickness (Position of Lens) =gVMt  
    '************************************************************************* 2!#
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    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) Xm#W}Y'  
    GetCustomElement eID, entity ZJDV'mC}  
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    parID = FindFullName( "Geometry.Arizona Eye" ) +|/0sPW(  
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    ' Delete any shift(s) in z Ci`o;KVj  
    count = 0 #`iEbiSq  
    While GetOperationCount(eID)>count <K CI@  
        GetOperation eID, count, op QAkK5,`vV.  
        If op.Type="ShiftZ" Then *w0!C:mL&  
            DeleteOperation eID,count orjtwF>^  
            count=count-1 OAXA<  
        End If JSL&` `  
        count=count+1 '{ <RX  
    Wend $Cz2b/O  
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    'Set new shift in 9]eG|LFD  
    op.Type = "ShiftZ" oJa}NH   
    op.val1 = taq ^yW['H6V  
    op.parent = parID ,p|Q/M^  
    AddOperation eID, op "
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    Print "Set aqueous humor thickness = " & taq-0.55 coXg]bUKo  
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    '************************************************************************* |dR}S!fmG  
    'Radius and conic constant of anterior lens \,13mB6  
    '************************************************************************* (OiV IH  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) wUaWF$~y  
    GetConic eID, entity, curv, conic f&<+45JI  
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    SetConic eID, entity, 1/Rant, CCant "^&H9.z,v  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant {Z2nc)|7C  
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    '************************************************************************* iq' PeVo  
    'Radius and conic constant of posterior lens +jhzE%  
    '************************************************************************* n.g-%4\q  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) t?"(Zb  
    GetConic eID, entity, curv, conic @&?(XY 'M%  
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    SetConic eID, entity, 1/Rpost, CCpost fXMY.X>f  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost k2 Ju*W&  
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    '************************************************************************* t+v%%N_  
    'Lens thickness (Position of posterior lens surface) ==Egy:<:Q  
    '************************************************************************* G2|jS@L#  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) %SC Jmn2  
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    ' Delete any z-shift(s) LDQ
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    count = 0  26p[x'W  
    While GetOperationCount(eID)>count YZ>L_$:q  
        GetOperation eID, count, op {D[6=\F  
        If op.Type="ShiftZ" Then ]@ruizb8  
            DeleteOperation eID,count =\lw.59  
            count=count-1 xf&[QG+Ef  
        End If DKf(igw  
        count=count+1 >@7$=Y>D  
    Wend [W3X$r~-  
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    'Set new z-shift lpXGsKH2  
    op.Type = "ShiftZ" [gT}<W  
    op.val1 = tlens pVc+}Wzh  
    op.parent = parID j&X&&=   
    AddOperation eID, op fG1iq<~  
    Print "Set lens thickness = " & tlens {wC*61@1  
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    '************************************************************************* @eJ8wf]  
    'Lens index of refraction {dZ]+2Z~+  
    '************************************************************************* U;W9`JT<.f  
    eID = FindMaterial( "Lens" ) Q0(6n8i  
    GetModelMaterial eID, mat t+a.,$U  
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    mat.Nd = nlens 6FzB-],  
    SetModelMaterial eID, mat [2-n*a(q  
    Print "Set lens index of refraction = " & nlens -)(5^OQ  
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    '************************************************************************* lWY
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    'Pupil diameter %rrA]\C'  
    '************************************************************************* ,!_6X9N-h  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) +%YBa'Lk  
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    'Adjust pupil diameter (trimming volume inner hole) 9^F3r]bH  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder"  !64Tx  
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    ' Adjust pupil location to just in front of the lens Wh i#Ii~  
    parID = FindFullName( "Geometry.Arizona Eye" ) k\[(;9sf.  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) HaVhdv3L  
    count = 0 l~"T>=jq3  
    While GetOperationCount(eID)>count Q3WI@4  
        GetOperation eID, count, op Imv#7{ndq  
        If op.Type="ShiftZ" Then %rb$tKk  
            DeleteOperation eID,count "`ftcJUd  
            count=count-1 )I&.6l!#  
        End If "jAd.x?X7e  
        count=count+1 ~1+6gG  
    Wend }gQ2\6o2g  
    op.Type = "ShiftZ" nsI+04[F  
    op.val1 = taq-0.01 \'Ae,q|w  
    op.parent = parID vu0Ue  
    AddOperation eID, op > T*`Y0P  
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    Print "Set pupil diameter = " & pupilDiam ASHU0v  
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    'Update AZ Eye subassembly Description T)gulP  
    eID = FindFullName( "Geometry.Arizona Eye" ) ?5EH/yV;  
    GetEntity eID, entity e%[*NX/  
    entity.Description = "Accommodation = " & A & "D" *:yG)J 3F  
    SetEntity eID, entity
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    Update *#YZm>h  
    Print "DONE!" J[<Zy^"Y;  
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End Sub Mm$\j*f/  
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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： v\,N"X(,  
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Accommodation = 4 Diopters >>J3"XHX  
Pupil Diameter = 4 mm KZjh<sjX|  
Set aqueous humor thickness = 2.81 *U^Y@""a  
Set anterior lens radius = 10.4 and conic constant = -2.375869 d AcSG  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 r+bGZ  
Set lens thickness = 3.927 {[2o  
Set lens index of refraction = 1.42672 5z_d$.CIc  
Set pupil diameter = 4 8)0]cX  
DONE! ?z1v_Jh