[技术]Arizona眼睛模型 [复制链接]

简介 Xq`|'6]/  
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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。 FHpS?htRy  
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模型 S;#S3?G  
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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。 7PG&G5  
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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. !yAlb#yu  
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光源 {E*dDv  
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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。 A:$Qt%c  
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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。 ?+-uF}  
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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。 MY>mP  
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视网膜的散射 wZ7O
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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。  ismx evD  
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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。 ? <b>2j  
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脚本 eUP.:(E  
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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： Zpfsh2`  
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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。 d/I,`  
余下的脚本计算与屈光度有关的所有参数。 3[mVPV  
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分析 W&E?#=*X  
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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。 a<%Ivqni  
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脚本代码 3>60_:+Zb  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. \F`%vZrKR  
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Dim entity As T_ENTITY zx:Qz  
Dim op As T_OPERATION h-)tWJ c  
Dim mat As T_MODELMATERIAL WI@l2`X  
Dim A As Double v|DgRPY  
Dim pupilDiam As Double ft |W  
Dim eID As Long nPlg5&E  
Dim parID As Long Y3%_IwSJ|  
Dim count As Integer Jz"Yb  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double IRWVoCc9/\  
Dim tlens As Double, nlens As Double
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Dim curv As Double, conic As Double b+b].,  
Dim ok As Long >@Vap  
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Sub Main F3)w('h9c  
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    '用户输入对话框 j
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    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 HLYog+?  
        TextBox 220,21,40,21,.TextBox1 'default: 0 {tE9m@[AF  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 _JEe]  
        OKButton 40,91,90,21 _]oNbcbt(  
        CancelButton 190,91,90,21 _x+)Tv  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 B!
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        TextBox 220,49,40,21,.TextBox2 'default: 4 X ? eCK,  
    End Dialog iX]tL:,~i  
    Dim dlg As UserDialog $,I%g<  
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    ok = Dialog (dlg) SM?r
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    If ok=0 Then    'cancel button was pressed 5/w4[d  
        Print "Execution cancelled." (FVHtZi7  
        End KE$I!$zO  
    End If zE,1zBS<  
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    'Assign accommodation and pupil diameter & use defaults if field left empty &9j*Y  
    If dlg.TextBox1 = "" Then TUy 25E  
        A = 0           'Default accommodation W!Qaa(o?  
    Else pB(|Y]3A  
        A = CDbl(dlg.TextBox1) g"}j  
    End If 8'<RPU}M  
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    If dlg.TextBox2 = "" Then 4:zyZu3fm  
        pupilDiam = 4   'Default pupil diameter !-tP\%'  
    Else Zb&5)&'
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        pupilDiam = CDbl(dlg.TextBox2) /#Fz K  
    End If UlNx5l+k  
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    Print " " u{J\X$]  
    Print "Accommodation = " & A & " Diopters" f%[0}.
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    Print "Pupil Diameter = " & pupilDiam & " mm" }5b,u6  
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    ' Calculate new parameters with accommodation /mK."5-cm  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness ~rfUqM]I   
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens e'dx Y(  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens }q?*13iy(  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens zkm#w  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens G=(ja?d  
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    tlens = 3.767 + 0.04*A                  'Lens thickness 7W.z8>p  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction JTcE{i  
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    'Adjust parameters to account for accommodation N2uTWT>  
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    '************************************************************************* 8+mu'RZ X  
    'Aqueous thickness (Position of Lens) wl Nl|+ K  
    '************************************************************************* INNTp[  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) J;5G]$s  
    GetCustomElement eID, entity :"Gd;~p.  
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    parID = FindFullName( "Geometry.Arizona Eye" ) pP)> x*1  
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    ' Delete any shift(s) in z k &6$S9  
    count = 0 =`EVg>+^  
    While GetOperationCount(eID)>count ]N^>>k  
        GetOperation eID, count, op mV;)V8'  
        If op.Type="ShiftZ" Then ' JAcN@q~z  
            DeleteOperation eID,count CyKupJ.Fq  
            count=count-1 N"Cd{3  
        End If lPA:ho/`:  
        count=count+1 zbZN-j#  
    Wend j&l2n2z  
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    'Set new shift in ;mauA#vd  
    op.Type = "ShiftZ" 7Um3myXU  
    op.val1 = taq ;\54(x}|K  
    op.parent = parID S{S.H?{F  
    AddOperation eID, op 1Gp|_8  
    Print "Set aqueous humor thickness = " & taq-0.55 xX~; /e&,  
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    '************************************************************************* f-5}`)`.+  
    'Radius and conic constant of anterior lens AiUK#I  
    '************************************************************************* JPM W|JT  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) js[H $  
    GetConic eID, entity, curv, conic +nKf ^rG  
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    SetConic eID, entity, 1/Rant, CCant @u1mC\
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    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant ;@/vKA3l.  
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    '************************************************************************* %Hpz^<`  
    'Radius and conic constant of posterior lens 8C4v  
    '************************************************************************* pKhV<MFB  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) NGAjajB  
    GetConic eID, entity, curv, conic - -ZSl  
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    SetConic eID, entity, 1/Rpost, CCpost G]E-2 _t7  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost Uq=!>C8  
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    '************************************************************************* +<7a$/L?4  
    'Lens thickness (Position of posterior lens surface) OcZ8:`=%  
    '************************************************************************* K)nn;j=  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) +7$zL;ph=n  
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    ' Delete any z-shift(s) D`@*udn=  
    count = 0 ^ jT1q_0  
    While GetOperationCount(eID)>count Wu U_RE  
        GetOperation eID, count, op JAS!eF  
        If op.Type="ShiftZ" Then 0
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            DeleteOperation eID,count ?T7ndXX  
            count=count-1 YnwP\Arfq  
        End If 95^-ptO{1`  
        count=count+1 -n]E
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    Wend Y5\=5r/  
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    'Set new z-shift O_|p{65
  
    op.Type = "ShiftZ" nhI1`l&
 
    op.val1 = tlens {PQ!o^7y  
    op.parent = parID )jm u*D5N  
    AddOperation eID, op &/{x7;e  
    Print "Set lens thickness = " & tlens hgI;^ia  
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    '************************************************************************* tN&_f==e  
    'Lens index of refraction FW,@.CX  
    '************************************************************************* ehr,+GX  
    eID = FindMaterial( "Lens" ) {+x;J4  
    GetModelMaterial eID, mat @1tv/W  
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    mat.Nd = nlens x[1(cj  
    SetModelMaterial eID, mat 6dQ]=];  
    Print "Set lens index of refraction = " & nlens JB(P-Y#yyA  
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    '************************************************************************* Q??nw^8Hi  
    'Pupil diameter VQ'DNv| 9  
    '************************************************************************* MP%pEUomev  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) 2[TssJQ  
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    'Adjust pupil diameter (trimming volume inner hole) -?PX
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" c(!8L\69V}  
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    ' Adjust pupil location to just in front of the lens #`b5kqQm  
    parID = FindFullName( "Geometry.Arizona Eye" ) 2kQa3Pan  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) q3$;lLsb;j  
    count = 0 7) e
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    While GetOperationCount(eID)>count AZ& ]@Ao  
        GetOperation eID, count, op ?R\:6x<  
        If op.Type="ShiftZ" Then u<a =TPAU  
            DeleteOperation eID,count }5a$Ka-  
            count=count-1 [I4&E >  
        End If #vBS7
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        count=count+1 Kvf
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    Wend ,?ci+M)  
    op.Type = "ShiftZ" BHEZ<K[U   
    op.val1 = taq-0.01 b.sRB1  
    op.parent = parID P},d`4Ty@  
    AddOperation eID, op Y
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    Print "Set pupil diameter = " & pupilDiam _M9-n  
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    'Update AZ Eye subassembly Description K_t!P  
    eID = FindFullName( "Geometry.Arizona Eye" ) _$YT*o@0J  
    GetEntity eID, entity Q^z&;%q1  
    entity.Description = "Accommodation = " & A & "D" M~#% [?iU  
    SetEntity eID, entity CxW-lU3G`  
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    Update =x3ZQA  
    Print "DONE!" 9;k!dM  
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End Sub )Y:9sd8g7  
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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&8kORz;?  
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Accommodation = 4 Diopters x0dO^D  
Pupil Diameter = 4 mm b+qdl`Vd  
Set aqueous humor thickness = 2.81 sU}.2k  
Set anterior lens radius = 10.4 and conic constant = -2.375869 6fr@y=s2:  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 #pm0T1+jW  
Set lens thickness = 3.927 soi.`xE  
Set lens index of refraction = 1.42672 {^qp
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Set pupil diameter = 4 N&'05uWY}  
DONE! f}U@e0Lsb