[技术]Arizona眼睛模型 [复制链接]

简介 P,[O32i#  
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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。 :W\xZ  
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模型 <Y9xHn&  
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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。 < <vE.  
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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. u0(PWCi2
 
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光源 0`
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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。 DGwN*>X  
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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。 y2U^7VrO  
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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。 s=+,F<;x.U  
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视网膜的散射 4Em mh=A  
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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。 dT%$"sj5  
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注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 6_m5%c~;+r  
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脚本 * ?a-m\  
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内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： -Cjc~{B>7X  
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如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 G/nSF:rp  
余下的脚本计算与屈光度有关的所有参数。 :@:i*2=  
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分析 :Rh?#yO5  
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屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 }7>r,  
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脚本代码 lLO|,  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. /STFXR1@.u  
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Dim entity As T_ENTITY j {w'#x,  
Dim op As T_OPERATION e`pYO]Z  
Dim mat As T_MODELMATERIAL |gvx^)ro  
Dim A As Double }Fd4; ]  
Dim pupilDiam As Double y9cDPwi:b  
Dim eID As Long !o+Y"* /  
Dim parID As Long 9E/{HNkf  
Dim count As Integer mXd,{b'  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double qB57w:J  
Dim tlens As Double, nlens As Double <9JI@\>  
Dim curv As Double, conic As Double *9#6N2J$M  
Dim ok As Long mR
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Sub Main S+^*rw
  
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    '用户输入对话框 v71j1Q}6  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 u^DfRd&P0  
        TextBox 220,21,40,21,.TextBox1 'default: 0 kdVc;v/5  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 l<5
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        OKButton 40,91,90,21 ;GW[Yw>Rz  
        CancelButton 190,91,90,21 d"K~+<V}  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 {tUjUwhz(  
        TextBox 220,49,40,21,.TextBox2 'default: 4 #wXq'yi  
    End Dialog  `mar-r_m  
    Dim dlg As UserDialog 'R&Y pR  
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    ok = Dialog (dlg) \J*~AT~5q  
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    If ok=0 Then    'cancel button was pressed .lclW0*  
        Print "Execution cancelled." ?b?6/_W~R  
        End Gwyjie9t  
    End If :ud<"I]:  
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    'Assign accommodation and pupil diameter & use defaults if field left empty h^yLmRL  
    If dlg.TextBox1 = "" Then G(g`>' m  
        A = 0           'Default accommodation /.54r/FN')  
    Else i2. +E&3v  
        A = CDbl(dlg.TextBox1)  -&N^S?  
    End If 4R 9lA  
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    If dlg.TextBox2 = "" Then 0GEM3~~D.?  
        pupilDiam = 4   'Default pupil diameter 'R'P^  
    Else <>=A6
 
        pupilDiam = CDbl(dlg.TextBox2)
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    End If 0;Lt  
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    Print " " =ttvC"4?  
    Print "Accommodation = " & A & " Diopters" _ELuQ>zM]+  
    Print "Pupil Diameter = " & pupilDiam & " mm" iLQFce7d|&  
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    ' Calculate new parameters with accommodation YJBlF2uD  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness <OX_6d*@  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens (T290a9y>  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens I},]Y~Y3  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens )4nf={iM  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens I&2)@Zw  
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    tlens = 3.767 + 0.04*A                  'Lens thickness ;Jh=7w
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction xIOYwVC  
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    'Adjust parameters to account for accommodation HuVx^y` @  
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    '************************************************************************* c(@(j8@S  
    'Aqueous thickness (Position of Lens) y\a@'LFL  
    '************************************************************************* 3shRrCL0mf  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) ID{62>R  
    GetCustomElement eID, entity %4bGI/\/  
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    parID = FindFullName( "Geometry.Arizona Eye" ) wwvS05=[T  
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    ' Delete any shift(s) in z L1Hk[j]X|  
    count = 0 dBWi1vTF  
    While GetOperationCount(eID)>count ILN Yh3  
        GetOperation eID, count, op nj90`O.K  
        If op.Type="ShiftZ" Then AVn?86ri  
            DeleteOperation eID,count 3np |\i  
            count=count-1 ?*{Vn5aX{  
        End If u&M:w5EM  
        count=count+1 U4$}8~o4  
    Wend `G@(Z:]f,t  
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    'Set new shift in sKg IKYG}T  
    op.Type = "ShiftZ" U"qR6  
    op.val1 = taq K2Z]MpLD  
    op.parent = parID \!51I./Q/  
    AddOperation eID, op j1Ns|oph1  
    Print "Set aqueous humor thickness = " & taq-0.55 -`f 1l8LD2  
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    '************************************************************************* [=EmDP:@  
    'Radius and conic constant of anterior lens q PveG1+25  
    '************************************************************************* KbXENz&C  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) *GZ7S m  
    GetConic eID, entity, curv, conic bMA\_?  
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    SetConic eID, entity, 1/Rant, CCant .!`y(N0hc  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant pdw;SIoC  
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    '************************************************************************* fb=[gK#*,  
    'Radius and conic constant of posterior lens C:9a$  
    '************************************************************************* dED&-e#  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) VYo2m  
    GetConic eID, entity, curv, conic (r
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    SetConic eID, entity, 1/Rpost, CCpost zObrp  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost j^T i6F>f  
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    '************************************************************************* S^c;
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    'Lens thickness (Position of posterior lens surface) )N'-Ap$g  
    '************************************************************************* `Eg~;E:  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) BO%aCK&  
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    ' Delete any z-shift(s) kSfNu{YS  
    count = 0 .4cVX|T  
    While GetOperationCount(eID)>count EyDH-}Y  
        GetOperation eID, count, op fG,)`[eD!_  
        If op.Type="ShiftZ" Then }2]m]D@%7  
            DeleteOperation eID,count FoW|BGA~  
            count=count-1 KsDovy<  
        End If C}=9m A  
        count=count+1 Q/%]%d  
    Wend ]kir@NMv>  
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    'Set new z-shift GlOSCJZ  
    op.Type = "ShiftZ" 0% zy 6{  
    op.val1 = tlens kQ99{lH,5  
    op.parent = parID dr gCr:Gf  
    AddOperation eID, op [r0`D^*=  
    Print "Set lens thickness = " & tlens e6i m_ Tk  
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    '************************************************************************* ws([bS2h  
    'Lens index of refraction m85Hx1!p.  
    '************************************************************************* d "%6S*dL  
    eID = FindMaterial( "Lens" ) c>b{/92%  
    GetModelMaterial eID, mat oIv\Xdc81  
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    mat.Nd = nlens M`49ydh&  
    SetModelMaterial eID, mat nc9sfH3  
    Print "Set lens index of refraction = " & nlens /4YxB,  
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    '************************************************************************* L(q~
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    'Pupil diameter [;pL15-}4  
    '************************************************************************* ^u+#x2$Mg  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) ~F.kgX  
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    'Adjust pupil diameter (trimming volume inner hole) X<<FS%:+  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" eE5j6`5i
 
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    ' Adjust pupil location to just in front of the lens 'j$
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    parID = FindFullName( "Geometry.Arizona Eye" ) Ya29t98Pk  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) <T`&NA@%~$  
    count = 0 jL0=a.;  
    While GetOperationCount(eID)>count 6^sH3=#  
        GetOperation eID, count, op .W51Cup@&  
        If op.Type="ShiftZ" Then *:Uq ;)*  
            DeleteOperation eID,count I#:Dk?"O2  
            count=count-1 @y/!`Ziw  
        End If }q=tg9  
        count=count+1 4O7 {a  
    Wend ?>DwNz^.!  
    op.Type = "ShiftZ" CE7{>pl  
    op.val1 = taq-0.01 qkA8q@Y4|  
    op.parent = parID w^^8*b<  
    AddOperation eID, op .\7AJB
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    Print "Set pupil diameter = " & pupilDiam "J{A}g[  
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    'Update AZ Eye subassembly Description M:t"is
 
    eID = FindFullName( "Geometry.Arizona Eye" ) >9,LN;Ic
 
    GetEntity eID, entity ke2}@|?t  
    entity.Description = "Accommodation = " & A & "D" MogIQ  
    SetEntity eID, entity l}~9xa}:D|  
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    Update I.- I4F)D  
    Print "DONE!" _Jn@+NoO  
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End Sub 3/Dis) v8  
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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： kC iOcl*$  
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Accommodation = 4 Diopters vT#m 8Kg  
Pupil Diameter = 4 mm ?nwg.
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Set aqueous humor thickness = 2.81 N
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Set anterior lens radius = 10.4 and conic constant = -2.375869 /Zg4JQ~  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 ,[[Xo;q  
Set lens thickness = 3.927 W?gelu]  
Set lens index of refraction = 1.42672 "DSRyD0M  
Set pupil diameter = 4 ^L-; S  
DONE! M%2w[<-8c