[技术]Arizona眼睛模型 [复制链接]

简介 CuYSvW  
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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。 <)$JA  
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模型 !?GW<Rh  
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模型的定义如表1种所示，由半径、圆锥常数、折射率、阿贝数、到下一面的距离等一系列表面组成。一些参数由屈光度（A）来决定。 'dd[=vzK  
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在FRED中使用0屈光度来创建的，光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. 3\?y
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光源 cG4$)q;q  
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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。 ft Rza  
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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。 w4;1 ('  
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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&9pI(3R~  
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视网膜的散射 u\}"l2 r  
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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.6bb4  
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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。 [UYE.$Y#(  
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脚本 @SH$QUM(  
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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： vUgMfy&  
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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。 FKk.BA957h  
余下的脚本计算与屈光度有关的所有参数。  ^#&:-4/  
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分析 H 5'Ke+4.e  
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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。 &bT \4  
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脚本代码 W60C$*h  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. h5VZ-v_j  
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Dim entity As T_ENTITY +:#UU;W  
Dim op As T_OPERATION Zp <^|=D  
Dim mat As T_MODELMATERIAL y:ad%,. C  
Dim A As Double ;]sbz4?  
Dim pupilDiam As Double SH/^qDT'  
Dim eID As Long fFJu]  
Dim parID As Long oS Apa  
Dim count As Integer QK@[b3-h1  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double v
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Dim tlens As Double, nlens As Double 9a3mN(<  
Dim curv As Double, conic As Double rM{V>s:N  
Dim ok As Long RGV}c#  
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Sub Main We?cRb  
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    '用户输入对话框 ?)?}^  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 &(i_s  
        TextBox 220,21,40,21,.TextBox1 'default: 0 /YT _~q=:  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 XCUU(H  
        OKButton 40,91,90,21 4g^Xe-  
        CancelButton 190,91,90,21 u5E\wRn  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 L@>$ Aw  
        TextBox 220,49,40,21,.TextBox2 'default: 4 IAzi:ct  
    End Dialog ?Oyps7hXx  
    Dim dlg As UserDialog 5tQZf'pHfd  
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    ok = Dialog (dlg) 8q_"aa,`  
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    If ok=0 Then    'cancel button was pressed j$Wd[Ja+O  
        Print "Execution cancelled." m)Sdogt_  
        End y,cz;2  
    End If _fE$KaP  
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    'Assign accommodation and pupil diameter & use defaults if field left empty %8$ldNhV  
    If dlg.TextBox1 = "" Then gjDxgNpa  
        A = 0           'Default accommodation 8c^Hfjr0  
    Else VL2+"<  
        A = CDbl(dlg.TextBox1) G%5ZG$as  
    End If K0C3s  
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    If dlg.TextBox2 = "" Then }(/\vTn*1  
        pupilDiam = 4   'Default pupil diameter bK#S
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    Else E)z=85;_p  
        pupilDiam = CDbl(dlg.TextBox2) $i]G'fj  
    End If "'v^X!"  
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    Print " " U2vM|7]VP  
    Print "Accommodation = " & A & " Diopters" Y=\:fa  
    Print "Pupil Diameter = " & pupilDiam & " mm" w:c9Z=KX  
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    ' Calculate new parameters with accommodation Y4Y~ep  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness =:;K nS  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens #b
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    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens 9>T5~C'*  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens 2wwJ>iR`  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens #6*20w_u  
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    tlens = 3.767 + 0.04*A                  'Lens thickness @RXkj-,eC#  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction 0,5)L\{ R  
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    'Adjust parameters to account for accommodation Znd ,FqHk  
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    '************************************************************************* X+kgx!u'y  
    'Aqueous thickness (Position of Lens) dCpDA a3  
    '************************************************************************* 0)rayzv  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) 8F9x2CM-[C  
    GetCustomElement eID, entity qT~a`ou:  
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    parID = FindFullName( "Geometry.Arizona Eye" ) apZPHau6h  
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    ' Delete any shift(s) in z ,Q<mU
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    count = 0 _F
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    While GetOperationCount(eID)>count N;gY5;0m  
        GetOperation eID, count, op $:RR1.Tv  
        If op.Type="ShiftZ" Then (7Ln~J*  
            DeleteOperation eID,count PUmgcMt  
            count=count-1 eY[kUMo  
        End If F-Bj  
        count=count+1 9DdR"r'7  
    Wend \03ZE^H  
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    'Set new shift in *vzEfmN:d  
    op.Type = "ShiftZ" '0w</g  
    op.val1 = taq 7n,=`0{r  
    op.parent = parID -2'1KAk-W  
    AddOperation eID, op 0<93i   
    Print "Set aqueous humor thickness = " & taq-0.55 ![9$ru  
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    '************************************************************************* z(Z7[#.  
    'Radius and conic constant of anterior lens AuT:snCzR  
    '*************************************************************************  |A\o  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) Qk >
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    GetConic eID, entity, curv, conic C8x9 Jrc  
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    SetConic eID, entity, 1/Rant, CCant /cT6X]o8  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant ny
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    '*************************************************************************
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    'Radius and conic constant of posterior lens WLA&K]  
    '************************************************************************* 4n"6<cO5q  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) \)?+6D'#  
    GetConic eID, entity, curv, conic 7>=
 
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    SetConic eID, entity, 1/Rpost, CCpost }?o4MiLB  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost ?)T@qn+  
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    '************************************************************************* .yDGwLry  
    'Lens thickness (Position of posterior lens surface) 9khMG$  
    '************************************************************************* IXG@$O?y/  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) -y>~ :.  
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    ' Delete any z-shift(s) tW a'[2L  
    count = 0 4jSYR#Hqp`  
    While GetOperationCount(eID)>count {1qr6P,"  
        GetOperation eID, count, op icb*L~qm  
        If op.Type="ShiftZ" Then Zl>dB
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            DeleteOperation eID,count Npi)R)  
            count=count-1
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        End If .9N7`  
        count=count+1 zk"8mTg  
    Wend RL$%Vy0  
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    'Set new z-shift ~>N63I6  
    op.Type = "ShiftZ" I\x9xJ4x  
    op.val1 = tlens :t<S  
    op.parent = parID G$2@N6  
    AddOperation eID, op ,i1BoG  
    Print "Set lens thickness = " & tlens ?O3d Sxi  
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    '************************************************************************* @%G?Nht]o  
    'Lens index of refraction k'k}/Hxub  
    '************************************************************************* 8*x=Fm,Ok  
    eID = FindMaterial( "Lens" ) DVVyWn[  
    GetModelMaterial eID, mat U1HG{u,"y  
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    mat.Nd = nlens jJ-C\ v  
    SetModelMaterial eID, mat iEZ+Znon  
    Print "Set lens index of refraction = " & nlens C<3<,~gI  
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    '************************************************************************* IxS%V31  
    'Pupil diameter H%XF~tF:  
    '************************************************************************* Dk>6PBl  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) "l9aBBiu  
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    'Adjust pupil diameter (trimming volume inner hole) JSi0-S[Y{  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" @"MQ6u G>  
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    ' Adjust pupil location to just in front of the lens tv.<pP9-C  
    parID = FindFullName( "Geometry.Arizona Eye" ) G<Eb~].1'  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) m./PRV1$x  
    count = 0 S<-nlBs.  
    While GetOperationCount(eID)>count ;Xy=;Z.]
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        GetOperation eID, count, op M;,$
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        If op.Type="ShiftZ" Then XL^05  
            DeleteOperation eID,count \ ZE[7Ae  
            count=count-1 jeJgDAUv  
        End If S,nELV~!  
        count=count+1 U: Wet,  
    Wend @aZTx/  
    op.Type = "ShiftZ" (y
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    op.val1 = taq-0.01 ?h&?`WO(  
    op.parent = parID )S(Ly.  
    AddOperation eID, op "I)zi]vk  
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    Print "Set pupil diameter = " & pupilDiam *=2W:,$  
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    'Update AZ Eye subassembly Description (nt`8 0  
    eID = FindFullName( "Geometry.Arizona Eye" ) xsn=Ji2 F  
    GetEntity eID, entity QcW8A ,\q  
    entity.Description = "Accommodation = " & A & "D" @anjjC5a~  
    SetEntity eID, entity gWGDm~+  
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    Update %ACW"2#(  
    Print "DONE!" @
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End Sub >*8V]{f9  
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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： T1$E][@Iv  
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Accommodation = 4 Diopters Q`<{cFsU  
Pupil Diameter = 4 mm UGI<
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Set aqueous humor thickness = 2.81 cQyN@W  
Set anterior lens radius = 10.4 and conic constant = -2.375869 .Mb[j1L^  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 o~IAZU39  
Set lens thickness = 3.927 7>__ fQu  
Set lens index of refraction = 1.42672 , :#bo]3  
Set pupil diameter = 4 {9U!0h-2"  
DONE! ;_e9v,