[技术]Arizona眼睛模型 [复制链接]

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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。 V(3=j)#  
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模型 ~X!Z+Vg  
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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。 F;sZc,Y,^  
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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. \x;`8H  
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光源 (rm*KD"]  
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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。 ,u_ Z0S M  
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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。 "kd)dy95H  
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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。 VMIX=gTZ  
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视网膜的散射 Lz{z~xNHW.  
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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。 7!U^?0?/  
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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。 @8*lqV2  
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脚本 Z@,[a  
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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： L Q0e@5  
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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。 %X|u({(zb  
余下的脚本计算与屈光度有关的所有参数。
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分析 [ylRq7^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。 nvQTJ4,,  

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脚本代码 QQJf;p7  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. < 1[K1'7h  
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Dim entity As T_ENTITY jn(%v]
 
Dim op As T_OPERATION CEW1T_1U<\  
Dim mat As T_MODELMATERIAL u4j"U6"]M  
Dim A As Double s'|t2`K("  
Dim pupilDiam As Double X,{ 3_  
Dim eID As Long S$ffTdRz  
Dim parID As Long 2Qt!JXC  
Dim count As Integer E!_3?:[S_  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double "VDMO^  
Dim tlens As Double, nlens As Double u'nQC*iJb  
Dim curv As Double, conic As Double M|NQoQ8q  
Dim ok As Long 1yVhO2`7]  
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Sub Main m*jTvn  
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    '用户输入对话框 2RQ-L  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 }R11G9N.  
        TextBox 220,21,40,21,.TextBox1 'default: 0 e3ce?gk  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 A=3L_ #nO  
        OKButton 40,91,90,21 inip/&P?V  
        CancelButton 190,91,90,21 \
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        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 mRa\ wEg%  
        TextBox 220,49,40,21,.TextBox2 'default: 4 zy5FO<->  
    End Dialog Q8MIpa!:  
    Dim dlg As UserDialog 3{fg3?  
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    ok = Dialog (dlg) w@<II-9L)<  
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    If ok=0 Then    'cancel button was pressed m7DKC,  
        Print "Execution cancelled." tj$[szo  
        End @$~IPg[J  
    End If ?w+ V:
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    'Assign accommodation and pupil diameter & use defaults if field left empty [q Uv|l1  
    If dlg.TextBox1 = "" Then u~aRFQ:  
        A = 0           'Default accommodation }opw_h+/F  
    Else S'5Zy} +x  
        A = CDbl(dlg.TextBox1) (|F.3~Amq  
    End If [}]yJ+)  
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    If dlg.TextBox2 = "" Then ZP5 !O[Ut  
        pupilDiam = 4   'Default pupil diameter r0 )ne|&Hp  
    Else P:t .Nr"  
        pupilDiam = CDbl(dlg.TextBox2) l<BV{Gl  
    End If 3ye  
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    Print " " |?ssHW  
    Print "Accommodation = " & A & " Diopters" ?*%_:fB  
    Print "Pupil Diameter = " & pupilDiam & " mm" bi^?SH\  
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    ' Calculate new parameters with accommodation P.qzP/Ny  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness #K6cBfqI  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens 8'HS$J;C  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens V*{rHp{=p  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens 0'fswa)  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens @J"tM.  
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    tlens = 3.767 + 0.04*A                  'Lens thickness -X~mW  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction ##*]2
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    'Adjust parameters to account for accommodation 6:O<k2=2  
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    '************************************************************************* GD{L$#i!  
    'Aqueous thickness (Position of Lens) IF|6iKCE  
    '************************************************************************* z.!N|"4yr  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) hU8Y&R)=9  
    GetCustomElement eID, entity &J*M  
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    parID = FindFullName( "Geometry.Arizona Eye" ) <"J]u@|  
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    ' Delete any shift(s) in z b1.*cIv}  
    count = 0 8~]D!c8;a  
    While GetOperationCount(eID)>count B-R#?Xn:!I  
        GetOperation eID, count, op U
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        If op.Type="ShiftZ" Then -juG[zn  
            DeleteOperation eID,count LmePJ  
            count=count-1 DS<1"4 b|  
        End If BzP,Tu{,  
        count=count+1 hlaN'j <C  
    Wend -f)fiQ-<  
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    'Set new shift in rNii,_  
    op.Type = "ShiftZ" x8PT+KC  
    op.val1 = taq jdP
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    op.parent = parID jC9us>b  
    AddOperation eID, op 7{L4a\JzT  
    Print "Set aqueous humor thickness = " & taq-0.55 G @..?>  
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    '************************************************************************* ,erf{"Nh  
    'Radius and conic constant of anterior lens (~=.[Y  
    '************************************************************************* :TH cI;PG8  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) ff\~`n~WZ  
    GetConic eID, entity, curv, conic kI^* '=:  
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    SetConic eID, entity, 1/Rant, CCant //q(v,D%Q  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant EiL#Dwx  
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    '************************************************************************* sjr,)|#[  
    'Radius and conic constant of posterior lens =_7wd*,  
    '************************************************************************* }}JMwT  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) d;Vy59}eY  
    GetConic eID, entity, curv, conic H\67Pd(Z6  
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    SetConic eID, entity, 1/Rpost, CCpost Ymk?@mV4  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost Ke\\B o,  
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    '************************************************************************* }02`ve*   
    'Lens thickness (Position of posterior lens surface) l_vGp  
    '************************************************************************* 7A)\:k  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) nT6y6F_e  
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    ' Delete any z-shift(s) 21uK&nVf^l  
    count = 0 :v&[!  
    While GetOperationCount(eID)>count 2$JGhgDI  
        GetOperation eID, count, op /4:bx#;A  
        If op.Type="ShiftZ" Then ,
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            DeleteOperation eID,count 1 em,/>"  
            count=count-1 XO <wK  
        End If iC gZ3M]  
        count=count+1 m&UP@hUV-  
    Wend uJ!&T  
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    'Set new z-shift HN5m%R&`  
    op.Type = "ShiftZ" Kg[OUBv  
    op.val1 = tlens {"y/;x/  
    op.parent = parID Xn6#q3;^|  
    AddOperation eID, op Ys"wG B>  
    Print "Set lens thickness = " & tlens c/;;zc  
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    '************************************************************************* x84!/n^z  
    'Lens index of refraction 4xy\  
    '************************************************************************* WE<?y_0y&  
    eID = FindMaterial( "Lens" ) iNO>'7s7  
    GetModelMaterial eID, mat q2qi~}l  
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    mat.Nd = nlens :QE5 7.  
    SetModelMaterial eID, mat oaY_
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    Print "Set lens index of refraction = " & nlens NB-dlv1  
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    '************************************************************************* @T'^V0!-q:  
    'Pupil diameter Hq3|>OqC2Q  
    '************************************************************************* bjZJP\6  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) 7
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    'Adjust pupil diameter (trimming volume inner hole) a~$XD(w^  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" D tsZP (  
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    ' Adjust pupil location to just in front of the lens &OMlW_FHR  
    parID = FindFullName( "Geometry.Arizona Eye" ) Wh[QR-7Ew  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) 44]s`QyG  
    count = 0 =$>=EBH,cm  
    While GetOperationCount(eID)>count `KJ(.m  
        GetOperation eID, count, op ( xs'D4  
        If op.Type="ShiftZ" Then i! .]U@{k  
            DeleteOperation eID,count FXQWT9Kk~_  
            count=count-1 +&GV-z~o  
        End If YW}$eW*  
        count=count+1 \Z-th,t  
    Wend iSW2I~PD  
    op.Type = "ShiftZ" ^_7|b[Bt  
    op.val1 = taq-0.01 }K{1Bm@S  
    op.parent = parID O[@!1SKT0  
    AddOperation eID, op 9:j?Jvw$  
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    Print "Set pupil diameter = " & pupilDiam <Xf6?nyZ(  
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    'Update AZ Eye subassembly Description mypV[  
    eID = FindFullName( "Geometry.Arizona Eye" ) sS D8Sx/  
    GetEntity eID, entity aukcO;oG<  
    entity.Description = "Accommodation = " & A & "D" S|85g1}t  
    SetEntity eID, entity +;N]34>S7  
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    Update L^J4wYFTO  
    Print "DONE!" yx-{PjX  
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End Sub c[dSO(=  
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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： /K=OsMl2b8  
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Accommodation = 4 Diopters 18&"j 8'm  
Pupil Diameter = 4 mm *"%TAe7?~+  
Set aqueous humor thickness = 2.81 144Y.  
Set anterior lens radius = 10.4 and conic constant = -2.375869 _`$Q6!Z)l  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 @rl5k(  
Set lens thickness = 3.927 Od1\$\4Z  
Set lens index of refraction = 1.42672 j=WxtMS  
Set pupil diameter = 4 |OeyPD#  
DONE! L9b.D<