[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 Ij,Yuo  
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。 wRi~Yb?  
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模型 %IU4\ZY>  
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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。 2%]t3\XW  
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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. m9I(TOw  
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光源 APOea  
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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。 |
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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。 `>y[wa>9r  
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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。 !,R  

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视网膜的散射 c%b\CP\)W  
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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。 JkJhfFV  
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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。 $Q#?`j  
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脚本 @_(nd57oSs  
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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： HoMQt3C
 
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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。 Hc>([?P%t  
余下的脚本计算与屈光度有关的所有参数。 E=A/4p6\$  
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分析 z=u~]:.1O  
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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。 +Z )`inw  
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脚本代码  h=:*7>}  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. B>1M$3`E  
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Dim entity As T_ENTITY XL=
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Dim op As T_OPERATION hcj{%^p  
Dim mat As T_MODELMATERIAL twAw01".  
Dim A As Double fQ^h{n  
Dim pupilDiam As Double Ua}g  
Dim eID As Long -=@K%\\~5  
Dim parID As Long "sC$%D<oc  
Dim count As Integer _P>
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Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double >3v0yh_3  
Dim tlens As Double, nlens As Double OX'/?B((  
Dim curv As Double, conic As Double k&n\ =tKN  
Dim ok As Long y>?k<)nA{  
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Sub Main SB5@\^  
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    '用户输入对话框 9c#L{in  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 "X\q%%P=?  
        TextBox 220,21,40,21,.TextBox1 'default: 0 bDxPgb7N=  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 \ro~-n+o  
        OKButton 40,91,90,21 cKaL K#~  
        CancelButton 190,91,90,21 7MR:X#2v>  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 &pa)Ee>  
        TextBox 220,49,40,21,.TextBox2 'default: 4 Lx9hq7<  
    End Dialog f:)]FHPB1  
    Dim dlg As UserDialog F^4*|g  
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    ok = Dialog (dlg) |j\eBCnH3  
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    If ok=0 Then    'cancel button was pressed 1Al=v  
        Print "Execution cancelled." jJiCF,m  
        End vbW\~xf  
    End If :==UDVP  
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    'Assign accommodation and pupil diameter & use defaults if field left empty Lqy|DJ%  
    If dlg.TextBox1 = "" Then &Z#Vw.7U  
        A = 0           'Default accommodation $u/8Rp  
    Else uOy\{5s8  
        A = CDbl(dlg.TextBox1) p?EEox  
    End If _p3WE9T  
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    If dlg.TextBox2 = "" Then T1Ln)CS?9  
        pupilDiam = 4   'Default pupil diameter DR#3njjEC  
    Else sIP6GWK$  
        pupilDiam = CDbl(dlg.TextBox2) 9&?tQ"@x  
    End If +9&ulr  
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    Print " " l%vhV&  
    Print "Accommodation = " & A & " Diopters" NpjsZcA  
    Print "Pupil Diameter = " & pupilDiam & " mm" R$~JhcX*l'  
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    ' Calculate new parameters with accommodation ]}*G[[ ^p  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness ^^U)WB  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens qCv}+d)  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens zXA= se0U  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens lW@
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    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens IWSEssP  
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    tlens = 3.767 + 0.04*A                  'Lens thickness `0-m`>1>  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction HvL9;^!  
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    'Adjust parameters to account for accommodation o F,R@f  
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    '************************************************************************* I=Lj_UF4  
    'Aqueous thickness (Position of Lens) )xXrs^  
    '************************************************************************* G+%5V5GS  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) jw&}N6^G  
    GetCustomElement eID, entity }sm56}_  
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    parID = FindFullName( "Geometry.Arizona Eye" ) uvAy#,
  
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    ' Delete any shift(s) in z nY.Umj  
    count = 0 3vEjf  
    While GetOperationCount(eID)>count 5}(YMsUb  
        GetOperation eID, count, op iKCTYXN1(  
        If op.Type="ShiftZ" Then ff2.|20  
            DeleteOperation eID,count
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            count=count-1 0L
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        End If ^~hhdwu3a  
        count=count+1 x#!{5;V&K  
    Wend 7~k~S>sO  
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    'Set new shift in %d~9at6-B  
    op.Type = "ShiftZ" *~MiL9m+?  
    op.val1 = taq A/W7;D  
    op.parent = parID 2v; 7ohK  
    AddOperation eID, op TPmZ/c^  
    Print "Set aqueous humor thickness = " & taq-0.55 LxYM"_1A;  
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    '************************************************************************* H;"N|pBy  
    'Radius and conic constant of anterior lens _yXeX  
    '************************************************************************* rSFXchD/  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) _S7M5{U_  
    GetConic eID, entity, curv, conic ;Bc<u[G  
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    SetConic eID, entity, 1/Rant, CCant Z~.]ZWj-  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant QK/+*hr;  
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    '************************************************************************* WSX@0A.&)  
    'Radius and conic constant of posterior lens g{f>jd  
    '************************************************************************* Hi 0df3t  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) ^_"q`71Dk  
    GetConic eID, entity, curv, conic `0i}}Zo  
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    SetConic eID, entity, 1/Rpost, CCpost s9Q)6=mE  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost X;[zfEB  
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    '************************************************************************* 113x9+w[  
    'Lens thickness (Position of posterior lens surface) \(v
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    '************************************************************************* bT6)(lm  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) 'V1 -iJj9  
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    ' Delete any z-shift(s) X9BBnZ  
    count = 0 i{x0#6_Y  
    While GetOperationCount(eID)>count WoT z'  
        GetOperation eID, count, op XQoT},C  
        If op.Type="ShiftZ" Then UK9MWC5g9  
            DeleteOperation eID,count #;KG6IE  
            count=count-1 &+|4(d1  
        End If ,0u0 '  
        count=count+1 !/lYq;$R  
    Wend %<o$ J~l~  
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    'Set new z-shift ;.[$  
    op.Type = "ShiftZ" kIZdND&  
    op.val1 = tlens 4oEq,o_  
    op.parent = parID ~m=%a  
    AddOperation eID, op !`Yi{}1_  
    Print "Set lens thickness = " & tlens ^+l\YB7pD  
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    '************************************************************************* -{sv3|P>  
    'Lens index of refraction 5x'y{S<  
    '************************************************************************* g.sV$.T2K  
    eID = FindMaterial( "Lens" ) ,$(v#Tz  
    GetModelMaterial eID, mat 3
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    mat.Nd = nlens COJ!b  
    SetModelMaterial eID, mat 10C91/  
    Print "Set lens index of refraction = " & nlens gBS#Z.  
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    '************************************************************************* sWCm[HpG  
    'Pupil diameter Q]'!FmXf  
    '************************************************************************* '{*>hj5.8  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) J7] 60H#P  
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    'Adjust pupil diameter (trimming volume inner hole) <;Z3 5{  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" DyTk<L  
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    ' Adjust pupil location to just in front of the lens c\ *OId1{;  
    parID = FindFullName( "Geometry.Arizona Eye" ) nAC#_\  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) JX<W[P>M  
    count = 0 @{a-IW3  
    While GetOperationCount(eID)>count WQC6{^/4[1  
        GetOperation eID, count, op T1di$8  
        If op.Type="ShiftZ" Then oVsazYJ|?  
            DeleteOperation eID,count #E@i@'T  
            count=count-1 (`Mz.VN  
        End If A)\DPLAG  
        count=count+1 Bx!` UdRn  
    Wend ~,1q :Kue  
    op.Type = "ShiftZ" %$KO]   
    op.val1 = taq-0.01 Ax*~[$$~%  
    op.parent = parID YY
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    AddOperation eID, op L2$L.@  
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    Print "Set pupil diameter = " & pupilDiam Y--8v#t  

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    'Update AZ Eye subassembly Description ?0%TE\I8  
    eID = FindFullName( "Geometry.Arizona Eye" ) 6+z]MT  
    GetEntity eID, entity GK%ovK  
    entity.Description = "Accommodation = " & A & "D" gQDK?aQX  
    SetEntity eID, entity \ \}/2#1=c  
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    Update I@M^Wu]wW  
    Print "DONE!" ~B\:  
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End Sub OF
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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： mnjA8@1  
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Accommodation = 4 Diopters f~9Y1|6  
Pupil Diameter = 4 mm IW_D$pq  
Set aqueous humor thickness = 2.81 Rw 8o]  
Set anterior lens radius = 10.4 and conic constant = -2.375869 +eXfT*=u5  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 Acv{XnB  
Set lens thickness = 3.927 rv%[?Ml  
Set lens index of refraction = 1.42672 d~8~RT2m  
Set pupil diameter = 4 p
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DONE! 1iDo$]TEK  
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