[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 <
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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。 .|[{$&B  
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模型 B=d<L^  
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模型的定义如表1种所示，由半径、圆锥常数、折射率、阿贝数、到下一面的距离等一系列表面组成。一些参数由屈光度（A）来决定。 7o+L  
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在FRED中使用0屈光度来创建的，光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. p}!i_P  
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光源 gP QO
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多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 >M2~p&Si  
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除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处，并增加了pre-propagation distance= -8。尽管光线在光瞳处创建，规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射，而不是在光瞳处入射。 06Wqfzceb  
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在往下看是内置的脚本用来修改屈光度，使其为4（250mm），光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 rlKR <4H  
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视网膜的散射 k)I4m.0a5  
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在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 _" 9 q(1  
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注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 [+D]!&P  
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脚本 GrG'G(NQ  
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内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： _$AM=?P&  
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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。 m)L50ot:/  
余下的脚本计算与屈光度有关的所有参数。 4E.9CjN1>  
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分析 *90dkJZ.  
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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。 0~U%csPHt  
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脚本代码 6,YoP|@0  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. E$ \l57  
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Dim entity As T_ENTITY =.8n K y  
Dim op As T_OPERATION f%EHzm/V  
Dim mat As T_MODELMATERIAL %@C8EFl%3  
Dim A As Double I^A>YJW  
Dim pupilDiam As Double .Qrpz^wdt  
Dim eID As Long ]|!|3lQ  
Dim parID As Long TXi|  
Dim count As Integer -& (iU
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Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double 8:& !F`o  
Dim tlens As Double, nlens As Double Yd4X*Ua  
Dim curv As Double, conic As Double ;7s^slVzF  
Dim ok As Long c#{|sR5  
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Sub Main ZS+m}.,whQ  
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    '用户输入对话框 CjPdN#*l  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 H 0+-$s;f  
        TextBox 220,21,40,21,.TextBox1 'default: 0 lUjZ=3"'
 
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 /b>xQ.G  
        OKButton 40,91,90,21 YT8q0BR]  
        CancelButton 190,91,90,21 GY?u+|Q  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 !T<,fR+8X  
        TextBox 220,49,40,21,.TextBox2 'default: 4 L[2N zwO  
    End Dialog /#vt\I<x  
    Dim dlg As UserDialog H4`>B>\  
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    ok = Dialog (dlg) {v'eP[  
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    If ok=0 Then    'cancel button was pressed nZi&`HjQ  
        Print "Execution cancelled." Zocuc"j  
        End 2 )o2d^^  
    End If wA$?e}  
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    'Assign accommodation and pupil diameter & use defaults if field left empty T&[6  
    If dlg.TextBox1 = "" Then L@O
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        A = 0           'Default accommodation C<teZz8/w  
    Else H^kOwmSzh  
        A = CDbl(dlg.TextBox1) VB905%  
    End If jo&j<3i  
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    If dlg.TextBox2 = "" Then %pjY^tM/  
        pupilDiam = 4   'Default pupil diameter F1BvDplQ>G  
    Else fUf1G{4  
        pupilDiam = CDbl(dlg.TextBox2) Pteti  
    End If N<SW $ o  
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    Print " "  GpTZp#~;  
    Print "Accommodation = " & A & " Diopters" vmNo~clt\  
    Print "Pupil Diameter = " & pupilDiam & " mm" Xbmsq,*]  
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    ' Calculate new parameters with accommodation 8!35 K  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness rNhS\1-  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens r&xIVFPI[  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens GmNCw5F  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens 'eBD/w5U  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens \
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    tlens = 3.767 + 0.04*A                  'Lens thickness LodP,\T  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction 3c#^@Bj(-e  
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    'Adjust parameters to account for accommodation \YJQN3^46>  
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    '************************************************************************* wM[Z
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    'Aqueous thickness (Position of Lens) ^! h3#4  
    '************************************************************************* &bJBsd@Os  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) A?04,l]y  
    GetCustomElement eID, entity 4P?`<K'  
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    parID = FindFullName( "Geometry.Arizona Eye" ) eXsp0!v  
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    ' Delete any shift(s) in z v(0ujfSR0  
    count = 0 ?4wl  
    While GetOperationCount(eID)>count Xk!{UxQKQ  
        GetOperation eID, count, op *6<4ECa7C  
        If op.Type="ShiftZ" Then WYRC_U7  
            DeleteOperation eID,count 4E=QO!pVv  
            count=count-1 RLex#j  
        End If 1F>8#+B/W  
        count=count+1 ye(av&Hn  
    Wend Ys_LGfK  
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    'Set new shift in _l] 0V g`  
    op.Type = "ShiftZ" lAG@nh^  
    op.val1 = taq *GYLj
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    op.parent = parID Muq~p~m}  
    AddOperation eID, op ?{ \7th37  
    Print "Set aqueous humor thickness = " & taq-0.55 5{+>3J  
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    '************************************************************************* =3% GLj  
    'Radius and conic constant of anterior lens qYVeFSS  
    '************************************************************************* }vx 46  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) POc<XLZB  
    GetConic eID, entity, curv, conic /T {R\  
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    SetConic eID, entity, 1/Rant, CCant I m-M2n  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant %j@/Tx/  
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    '************************************************************************* si~zg\uY  
    'Radius and conic constant of posterior lens _d7;Z%  
    '************************************************************************* %&H^UxC  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) @6|0H`kv  
    GetConic eID, entity, curv, conic )@U~Li/+  
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    SetConic eID, entity, 1/Rpost, CCpost E0HE@pqr  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost /Dc54Un  
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    '************************************************************************* ;B2&#kot7  
    'Lens thickness (Position of posterior lens surface)
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    '************************************************************************* =Gj~:|;$  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) Lwm /[  
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    ' Delete any z-shift(s) ZvXw#0)v  
    count = 0 1x/R  
    While GetOperationCount(eID)>count 9X1vL  
        GetOperation eID, count, op Jk`l{N  
        If op.Type="ShiftZ" Then ('uUf!h?\  
            DeleteOperation eID,count $z)egh(z  
            count=count-1 3qu?qD  
        End If GU1
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        count=count+1 < fe.  
    Wend dR>$vbjh1Z  
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    'Set new z-shift X-bM`7'H  
    op.Type = "ShiftZ" o,_F;ZhE  
    op.val1 = tlens n/BoK6g  
    op.parent = parID bx6=LK  
    AddOperation eID, op e{4e<hd  
    Print "Set lens thickness = " & tlens 1PWi~1q{Q  
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    '************************************************************************* #@V<{/;49  
    'Lens index of refraction DuAix)#FN9  
    '************************************************************************* RxPD44jVA  
    eID = FindMaterial( "Lens" ) tNqSCjQ~_c  
    GetModelMaterial eID, mat P A*U\  
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    mat.Nd = nlens 4u0?[v[Hu  
    SetModelMaterial eID, mat 3*7klu  
    Print "Set lens index of refraction = " & nlens 8In~qf  
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    '************************************************************************* Xa"I  
    'Pupil diameter 8{icY|:MTN  
    '************************************************************************* 0[uOKFgE  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) >x~Qa@s;  
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    'Adjust pupil diameter (trimming volume inner hole) 8OS^3JS3"  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" >*^SQ
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    ' Adjust pupil location to just in front of the lens +>Y]1IlI  
    parID = FindFullName( "Geometry.Arizona Eye" ) J5f}-W@  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) ?%Q=l;W.  
    count = 0 QR-pji y  
    While GetOperationCount(eID)>count sQrM"i0Y>  
        GetOperation eID, count, op \SgBI/L^  
        If op.Type="ShiftZ" Then j,i)ecZ>  
            DeleteOperation eID,count "9vL+Hh  
            count=count-1 &`]T#">  
        End If :UKc:JVNM  
        count=count+1 }U}ppq0Eo  
    Wend dgByl-8Q  
    op.Type = "ShiftZ" z-]ND  
    op.val1 = taq-0.01 bVZAf  
    op.parent = parID ,a2=OV  
    AddOperation eID, op va#].4_  
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    Print "Set pupil diameter = " & pupilDiam AS4oz:B  
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    'Update AZ Eye subassembly Description r#}o +3*  
    eID = FindFullName( "Geometry.Arizona Eye" ) Cnu])R  
    GetEntity eID, entity I&&;a.  
    entity.Description = "Accommodation = " & A & "D" 04Uyr;y  
    SetEntity eID, entity N /;Vg^Wx  
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    Update VhnIr#L+  
    Print "DONE!"  Lo)T  
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End Sub 0d0ga^O  
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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： Xoq
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Accommodation = 4 Diopters 9m"EY@-  
Pupil Diameter = 4 mm }1a(*s,s-^  
Set aqueous humor thickness = 2.81 i8*(J-M  
Set anterior lens radius = 10.4 and conic constant = -2.375869 &-vHb  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 [*H h6  
Set lens thickness = 3.927 ^%U`|GBZp  
Set lens index of refraction = 1.42672 vZqW,GDfXo  
Set pupil diameter = 4 :hf%6N='kI  
DONE! wr>6Go%  
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