[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 #).$o~1ht!  
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。 cMw<
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模型 gxv^=;2C  
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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。 mlnF,+s  
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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. [n2B6Px  
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光源 wVBKVb9N  
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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。 6hxZ5&;(*  
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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。 `H+"7SO  
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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。 uUH4vUa  
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视网膜的散射 U"PcNQy  
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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。 Ipp_}tl_  
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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。 17LhgZs&  
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脚本 &N~Eu-@b  
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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： ]I?.1X5d0  
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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。 W__ArV2Z_  
余下的脚本计算与屈光度有关的所有参数。 kwI``7g8*e  
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分析 >Bt82ibN  
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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。 u#0snw~)/  
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脚本代码 osW"wh_
  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. dSM\:/t  
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Dim entity As T_ENTITY .wfydu)3  
Dim op As T_OPERATION $J[( 3  
Dim mat As T_MODELMATERIAL VY?9|};f  
Dim A As Double u47<J?!Q  
Dim pupilDiam As Double 8=8hbdy;  
Dim eID As Long kf, &t   
Dim parID As Long X
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Dim count As Integer MpV<E0CmE  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double p.DQ|?  
Dim tlens As Double, nlens As Double 6Yu:v  
Dim curv As Double, conic As Double V6]6KP#D  
Dim ok As Long wlS/(:02  
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Sub Main R9J!}az'  
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    '用户输入对话框 -f+#j
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    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 YT\`R  
        TextBox 220,21,40,21,.TextBox1 'default: 0 F/5&:e?( )  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 R9XU7_3B  
        OKButton 40,91,90,21 .u-a+ac<  
        CancelButton 190,91,90,21 tl#sCf!c  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 m1$tf ^  
        TextBox 220,49,40,21,.TextBox2 'default: 4 (s};MdXIz  
    End Dialog 1`cH EAa  
    Dim dlg As UserDialog 9*qwXU_aV  
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    ok = Dialog (dlg) 9`in r.:  
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    If ok=0 Then    'cancel button was pressed 2]!@)fio`  
        Print "Execution cancelled." D,#UJPyg  
        End atuqo3  
    End If 6o't3Peh  
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    'Assign accommodation and pupil diameter & use defaults if field left empty <BR^Dv07U  
    If dlg.TextBox1 = "" Then 2Tp2{"sB>A  
        A = 0           'Default accommodation |T:R.=R$~  
    Else
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        A = CDbl(dlg.TextBox1) JEjxY&  
    End If $dC`keQM>9  
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    If dlg.TextBox2 = "" Then vDjH $ U  
        pupilDiam = 4   'Default pupil diameter <WXVUEea  
    Else U^m#!hp  
        pupilDiam = CDbl(dlg.TextBox2) m2]N%Y  
    End If F*72g)hVh  
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    Print " " f%G\'q]#F  
    Print "Accommodation = " & A & " Diopters" EX,>V,.UV  
    Print "Pupil Diameter = " & pupilDiam & " mm" q*I*B1p[m  
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    ' Calculate new parameters with accommodation 7|,L{~  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness xyL"U*  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens 1lw%RM  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens Xu$>$D#a  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens mjeJoMvN)H  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens Y
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    tlens = 3.767 + 0.04*A                  'Lens thickness fi?4!h  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction br I;}m  

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    'Adjust parameters to account for accommodation R%UTYRLUn  
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    '************************************************************************* l=?e0d>O  
    'Aqueous thickness (Position of Lens) +,e#uuj$p  
    '************************************************************************* j=r1JV @  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) (W}F\P  
    GetCustomElement eID, entity 3$?6rMl@y  
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    parID = FindFullName( "Geometry.Arizona Eye" ) :ld~9  
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    ' Delete any shift(s) in z 4]o+)d.`(  
    count = 0 qTJhYxm  
    While GetOperationCount(eID)>count -^_2{i  
        GetOperation eID, count, op Xa`Q;J"h  
        If op.Type="ShiftZ" Then z,,"yVk`,  
            DeleteOperation eID,count sN41Bz$q.  
            count=count-1 Fp\;j\pfw  
        End If wGy
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        count=count+1 \jfK']P/H  
    Wend ~I||"$R  
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    'Set new shift in *Fy6-
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    op.Type = "ShiftZ" mnm ZO}  
    op.val1 = taq VLXA6+  
    op.parent = parID JK$3qUDnI  
    AddOperation eID, op 8$IKQNS  
    Print "Set aqueous humor thickness = " & taq-0.55 L FWp}#%  
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    '************************************************************************* WvfP9(-  
    'Radius and conic constant of anterior lens 8~Cmn%  
    '************************************************************************* $Q*R/MY  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) A \/~u"Y  
    GetConic eID, entity, curv, conic uu6 JZp  
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    SetConic eID, entity, 1/Rant, CCant -1Q24jrO-  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant q T6y&  
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    '************************************************************************* [F6)Z[uG  
    'Radius and conic constant of posterior lens ^4`aONydl  
    '************************************************************************* 6KddHyFz  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) D ,kxB~  
    GetConic eID, entity, curv, conic u W]gBhO$O  
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    SetConic eID, entity, 1/Rpost, CCpost {$8+n::  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost a_b#hM/c;  
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    '************************************************************************* +>PsQ^^x  
    'Lens thickness (Position of posterior lens surface) Yq ]sPE92  
    '************************************************************************* ;\K]~  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) FX!KX/OE)  
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    ' Delete any z-shift(s) 5}%R  
    count = 0 9&sb,^4  
    While GetOperationCount(eID)>count z|pt)Xl  
        GetOperation eID, count, op xJ>5 ol  
        If op.Type="ShiftZ" Then 
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            DeleteOperation eID,count wV )\M]@  
            count=count-1 Im6gWDdq@6  
        End If A4zI1QF  
        count=count+1 MT!Y!*-5  
    Wend k[f2`o=  
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    'Set new z-shift y8YsS4E^Q  
    op.Type = "ShiftZ" KElEGW  
    op.val1 = tlens 8dR `T}  
    op.parent = parID }+@!c%TCx~  
    AddOperation eID, op 8UU
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    Print "Set lens thickness = " & tlens KKC%!Xy  
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    '************************************************************************* 30vxOkS
 
    'Lens index of refraction l`"?KD  
    '************************************************************************* /?;'y,(Q  
    eID = FindMaterial( "Lens" ) .jJD$FC  
    GetModelMaterial eID, mat -riX=K>$  
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    mat.Nd = nlens Lg<h54X  
    SetModelMaterial eID, mat 7(}'
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    Print "Set lens index of refraction = " & nlens -Cyo2wk  
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    '************************************************************************* V1'otQH2l  
    'Pupil diameter Jg$<2CR&  
    '************************************************************************* #LR4%}mg  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) ),yar9C  
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    'Adjust pupil diameter (trimming volume inner hole)
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" 8&U Mmbgy  
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    ' Adjust pupil location to just in front of the lens lJ;Wi  
    parID = FindFullName( "Geometry.Arizona Eye" ) sJZ2e6?n  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) *QQeK#$s  
    count = 0 t*hy"e{*a  
    While GetOperationCount(eID)>count =mXC,<]  
        GetOperation eID, count, op Y\9}LgIvr  
        If op.Type="ShiftZ" Then h^g0|p5  
            DeleteOperation eID,count h/n(  
            count=count-1 jfG of*  
        End If JOuyEPy  
        count=count+1 !dT+cZsf  
    Wend Xqw}O2QQ1  
    op.Type = "ShiftZ" _^W;J/He  
    op.val1 = taq-0.01 JlYZ\  
    op.parent = parID OjhX:{"59  
    AddOperation eID, op _tHhS@  
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    Print "Set pupil diameter = " & pupilDiam 4Kch=jt4#  
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    'Update AZ Eye subassembly Description >e {1e  
    eID = FindFullName( "Geometry.Arizona Eye" ) Qa,
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    GetEntity eID, entity !S=YM<Ad  
    entity.Description = "Accommodation = " & A & "D" d3:GmB .  
    SetEntity eID, entity K T0t4XPM  
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    Update R%KF/1;/  
    Print "DONE!" S L 5k^|  
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End Sub s|WwB
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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： <yipy[D  
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Accommodation = 4 Diopters &:l-;7d  
Pupil Diameter = 4 mm Y'iI_cg  
Set aqueous humor thickness = 2.81 yMWh#[phH  
Set anterior lens radius = 10.4 and conic constant = -2.375869 2 `>a(  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 +51h
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Set lens thickness = 3.927 cTGd<  
Set lens index of refraction = 1.42672 36{GZDGQ  
Set pupil diameter = 4 Wu 0:X*>}p  
DONE! d#E&,^@M  
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