[技术]Arizona眼睛模型 [复制链接]

简介 y:457R2F  
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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。 [1s B  
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模型 LOp<c<+aW  
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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。 l{;vD=D  
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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. FzNs >*  
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光源 d/"e3S1  
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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。 VPf=LSxJe  
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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。 GUMO;rZs  
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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。 f 1]1ZOb  
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视网膜的散射 oKzLt  
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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。 V,lz}&3L  
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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。 *_@8v?  
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脚本 &_G^=Nc,H  
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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： tK0?9M.)  
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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$~>e .  
余下的脚本计算与屈光度有关的所有参数。 )nQA) uz  
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分析 S}mqK|!
 
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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。 (@[c;+x  
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脚本代码 0escp~\Z  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. }HRM6fR1S  
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Dim entity As T_ENTITY ]+Ik/+Nz  
Dim op As T_OPERATION [HLXWu3  
Dim mat As T_MODELMATERIAL @WEDXB  
Dim A As Double 5Ay\s:hb[u  
Dim pupilDiam As Double ET.c8K1f  
Dim eID As Long 7G zf>n  
Dim parID As Long <XDYnWz  
Dim count As Integer :/A3l=}iV  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double TldqF BX  
Dim tlens As Double, nlens As Double unY+/p $  
Dim curv As Double, conic As Double oF7o"NHaWa  
Dim ok As Long Db3#;  
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Sub Main Yi:@>A<#  
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    '用户输入对话框 6
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    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 m:_'r"o  
        TextBox 220,21,40,21,.TextBox1 'default: 0 ]rY:C "#  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 +`'=K ;{U  
        OKButton 40,91,90,21 {$5?[KD  
        CancelButton 190,91,90,21 OTwIR<_B+  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 B~xT:r  
        TextBox 220,49,40,21,.TextBox2 'default: 4 dTcrJ|/Y  
    End Dialog =K
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    Dim dlg As UserDialog .ww~'5b0  
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    ok = Dialog (dlg) 
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    If ok=0 Then    'cancel button was pressed Jga;
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        Print "Execution cancelled." 8=\}#F  
        End j%%& G$Tfu  
    End If
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    'Assign accommodation and pupil diameter & use defaults if field left empty &BxDS .  
    If dlg.TextBox1 = "" Then <MdIQ;I8  
        A = 0           'Default accommodation {^(h*zxn  
    Else 0[E}[{t`  
        A = CDbl(dlg.TextBox1) apy9B6%PJ+  
    End If !79eF)  
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    If dlg.TextBox2 = "" Then d%?$
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        pupilDiam = 4   'Default pupil diameter N5K\h}'%  
    Else -,YoVB!T  
        pupilDiam = CDbl(dlg.TextBox2) ]40@yr
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    End If !:BmDX[<n  
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    Print " " gZ!q  
    Print "Accommodation = " & A & " Diopters" y
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    Print "Pupil Diameter = " & pupilDiam & " mm" -}:; EGUtd  
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    ' Calculate new parameters with accommodation sQ"; t=yC  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness \%BII>VS  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens o|`%>&jP  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens v=8sj{g3,3  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens Rq`d I~5!b  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens Nl$b;~u  
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    tlens = 3.767 + 0.04*A                  'Lens thickness 6>DmcG:.  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction ^K3Bn  
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    'Adjust parameters to account for accommodation <Dk6o`7^N  
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    '************************************************************************* K&'Vd@  
    'Aqueous thickness (Position of Lens) `En>o~L;  
    '************************************************************************* nF1}?  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) H3#rFO"C*  
    GetCustomElement eID, entity {J~VB~('  
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    parID = FindFullName( "Geometry.Arizona Eye" ) Ht4A   
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    ' Delete any shift(s) in z 3sD/4 ?  
    count = 0 eHE?#r16Z  
    While GetOperationCount(eID)>count &RB{0Q
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        GetOperation eID, count, op `=%mU/v  
        If op.Type="ShiftZ" Then g>*P}r~;^b  
            DeleteOperation eID,count +?9. &<?  
            count=count-1 O= 84ZP%  
        End If i+@t_pxc  
        count=count+1 A<p6]#t#X)  
    Wend }}b &IA#  
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    'Set new shift in Eg+z(m$M  
    op.Type = "ShiftZ" HRg< f= oz  
    op.val1 = taq AGGNJ4m  
    op.parent = parID CNM
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    AddOperation eID, op n?mV(?N  
    Print "Set aqueous humor thickness = " & taq-0.55 |V-)3#c  
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    '************************************************************************* zvOSQxGQ  
    'Radius and conic constant of anterior lens }rA _4%  
    '************************************************************************* |C`.m
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    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) kO}QOL4  
    GetConic eID, entity, curv, conic k#"}oI{< 6  
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    SetConic eID, entity, 1/Rant, CCant
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    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant $s<bKju  
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    '************************************************************************* $:IEpV{  
    'Radius and conic constant of posterior lens ?#gYu%7DN  
    '************************************************************************* tB#-}Gf  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" )
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    GetConic eID, entity, curv, conic ?4sF:Y+\  
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    SetConic eID, entity, 1/Rpost, CCpost =bh.V@*  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost }J+\o~  
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    '************************************************************************* QHPC?a6CD  
    'Lens thickness (Position of posterior lens surface) f9a_:]F   
    '************************************************************************* BvqypLI  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) F.$NYr/|y  
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    ' Delete any z-shift(s) u(C?\HaH  
    count = 0 JW9U&Bj
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    While GetOperationCount(eID)>count ;@s'JSPt  
        GetOperation eID, count, op ICm/9Onh&  
        If op.Type="ShiftZ" Then EZ)$lw/!J  
            DeleteOperation eID,count ;oivG)hJl  
            count=count-1 HwxME%w  
        End If (aX6jdvo  
        count=count+1 8dCa@r&tz  
    Wend dPb@[k  
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    'Set new z-shift Dl=qss~g+  
    op.Type = "ShiftZ"
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    op.val1 = tlens ~T:L0||.%9  
    op.parent = parID i1ss}JJp*  
    AddOperation eID, op ]:n! \G  
    Print "Set lens thickness = " & tlens "!z9UiA  
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    '************************************************************************* g3kF&+2i  
    'Lens index of refraction XHYVcwmDz-  
    '************************************************************************* &-2i+KjEX  
    eID = FindMaterial( "Lens" ) U( (F<  
    GetModelMaterial eID, mat g/BlTi
 
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    mat.Nd = nlens :FWo,fq?:{  
    SetModelMaterial eID, mat zOT(>1'  
    Print "Set lens index of refraction = " & nlens ~]C m  
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    '************************************************************************* `%Jq^uW  
    'Pupil diameter _su$]s  
    '************************************************************************* <j&LC /]o  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) Y4,LXuQ
 
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    'Adjust pupil diameter (trimming volume inner hole) MClvmv^  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" ![hVTZ,hyZ  
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    ' Adjust pupil location to just in front of the lens NTy0NH  
    parID = FindFullName( "Geometry.Arizona Eye" ) i5CBLv  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) /p
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    count = 0 5~E'21hJ  
    While GetOperationCount(eID)>count M
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        GetOperation eID, count, op d'*:2;)g^  
        If op.Type="ShiftZ" Then MNVOloA  
            DeleteOperation eID,count |z]--h  
            count=count-1 <L>$Y#wU  
        End If 9vw0box  
        count=count+1 qJq2Z.>hy  
    Wend ht5eb"c+8  
    op.Type = "ShiftZ" * vW#XDx  
    op.val1 = taq-0.01 %eQw\o,a  
    op.parent = parID e sDd>W  
    AddOperation eID, op #b5V/)K  
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    Print "Set pupil diameter = " & pupilDiam 5,u'p8}.  
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    'Update AZ Eye subassembly Description 7^*[XH  
    eID = FindFullName( "Geometry.Arizona Eye" ) XfYhLE  
    GetEntity eID, entity w//L2.  
    entity.Description = "Accommodation = " & A & "D" #t?tt,nc}  
    SetEntity eID, entity eZk4$y  
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    Update s6.#uT7h  
    Print "DONE!" cr"AK"TQ  
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End Sub C3z#A3&J  
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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： 7qT>wCVT  
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Accommodation = 4 Diopters 9>1Gj-S2:  
Pupil Diameter = 4 mm 4Y:[YlfD.  
Set aqueous humor thickness = 2.81 ,+hH|$  
Set anterior lens radius = 10.4 and conic constant = -2.375869 m[%
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Set posterior lens radius = -4.424557 and conic constant = -3.081019 M73d^
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Set lens thickness = 3.927 >nOU 8  
Set lens index of refraction = 1.42672 w|0w<K  
Set pupil diameter = 4 & U6bOH%P  
DONE! ">hOD'PG