[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 m.pB]yq&  
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。 ('xIFi  
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模型 >8D!K0?E  
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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。 BaZ$pO^  
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在FRED中使用0屈光度来创建的，光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. @X+m,u  
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光源 0_q8t!<xJw  
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多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 p:Ry F4{b2  
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除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处，并增加了pre-propagation distance= -8。尽管光线在光瞳处创建，规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射，而不是在光瞳处入射。 a$r- U_?  
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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。 `ltc)$  
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视网膜的散射 G d~ v _  
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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。 @&?E3?5ll  
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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。 6D|[3rXr  
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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： Rd'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。 -!;2?6R9{  
余下的脚本计算与屈光度有关的所有参数。 W
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分析 _D~l2M  
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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。 @<kY,ox@~  
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脚本代码 "uCO?hv0  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. GWFF.Mo^  
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Dim entity As T_ENTITY Drm#z05i[g  
Dim op As T_OPERATION /2^"c+/'p  
Dim mat As T_MODELMATERIAL !LI6_Oq  
Dim A As Double JLd-{}A""-  
Dim pupilDiam As Double "5<:Dj/W  
Dim eID As Long
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Dim parID As Long m)AF9#aT2  
Dim count As Integer n*A?>NV  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double 0JFS%Yjw[  
Dim tlens As Double, nlens As Double riR(CJ}Ff  
Dim curv As Double, conic As Double +YZ*>ki  
Dim ok As Long E{;F4wT_@  
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Sub Main Fn>KdoByN  
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    '用户输入对话框 nTsKJX%\  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 '9{`Czc(Gb  
        TextBox 220,21,40,21,.TextBox1 'default: 0 +3uPHpMB-  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 R [ZY;g:p  
        OKButton 40,91,90,21 m)
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        CancelButton 190,91,90,21 Az7 ]qb  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 cwuzi;f  
        TextBox 220,49,40,21,.TextBox2 'default: 4 6am g*=]  
    End Dialog ZnKjU ]m  
    Dim dlg As UserDialog U$yy7}g  
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    ok = Dialog (dlg) R + ~b@  
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    If ok=0 Then    'cancel button was pressed LBxmozT  
        Print "Execution cancelled." ?(Se$iTZ  
        End Ii9[[I  
    End If \sMe2OL#z  
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    'Assign accommodation and pupil diameter & use defaults if field left empty 44NMof8N  
    If dlg.TextBox1 = "" Then HQvJ*U4++  
        A = 0           'Default accommodation GO?hB4 9T  
    Else xi51,y+(5  
        A = CDbl(dlg.TextBox1) 3 ,zW6-}  
    End If 0iYo&q'n  
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    If dlg.TextBox2 = "" Then NSa6\.W)  
        pupilDiam = 4   'Default pupil diameter 5?MaKNm}  
    Else ]_BH"ng}  
        pupilDiam = CDbl(dlg.TextBox2) ZDG~tCh=@  
    End If yky%+@2q  
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    Print " " G9^xv  
    Print "Accommodation = " & A & " Diopters" IRGcE&m  
    Print "Pupil Diameter = " & pupilDiam & " mm" :8K}e]!c1  
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    ' Calculate new parameters with accommodation t"zi'9$t  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness {dXTj7  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens 5(gWK{R)*  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens M8Vc
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens k".kbwcaF  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens <UF0Xc&X'  

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    tlens = 3.767 + 0.04*A                  'Lens thickness nY7gST  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction Esu{c9,  
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    'Adjust parameters to account for accommodation jST4O"DjM  
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    '************************************************************************* /ej[oR  
    'Aqueous thickness (Position of Lens) j+fib} 8}  
    '************************************************************************* W]oa7
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    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) ^2H;  
    GetCustomElement eID, entity 
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    parID = FindFullName( "Geometry.Arizona Eye" ) n$`+03a  
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    ' Delete any shift(s) in z `m#-J;la  
    count = 0 %ufh  
    While GetOperationCount(eID)>count !zvjgDlZv  
        GetOperation eID, count, op 8\"Gs z  
        If op.Type="ShiftZ" Then Fgi`g{N  
            DeleteOperation eID,count ,jEc4ih4  
            count=count-1 L2+cVR  
        End If =\_gT=tZ  
        count=count+1 Q-<Qm?  
    Wend <}:` Y"  
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    'Set new shift in e pp04~  
    op.Type = "ShiftZ" ~+j2a3rv-{  
    op.val1 = taq zz[fkH3  
    op.parent = parID >s
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    AddOperation eID, op &e6UEG  
    Print "Set aqueous humor thickness = " & taq-0.55 UOsK(mB  
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    '************************************************************************* [zBi*%5O  
    'Radius and conic constant of anterior lens 5@%.wb4  
    '************************************************************************* $'I&u  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) 9@ YKx0  
    GetConic eID, entity, curv, conic ff5 gE'  
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    SetConic eID, entity, 1/Rant, CCant 8 eK8-R$  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant 5L:-Xr{
 
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    '************************************************************************* Gc"
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    'Radius and conic constant of posterior lens WB?HY?[r  
    '************************************************************************* %0}^M1  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) }04mJY[  
    GetConic eID, entity, curv, conic w6Nnx5Ay  
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    SetConic eID, entity, 1/Rpost, CCpost qxb]UV,R  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost G~o!u8^;  
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    '************************************************************************* #H w(w  
    'Lens thickness (Position of posterior lens surface) C6[W/,eS  
    '************************************************************************* )PTvw>  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) #kASy 2t  
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    ' Delete any z-shift(s) 6_4B!  
    count = 0 Fu_I0z  
    While GetOperationCount(eID)>count ,#UZp\zZ*  
        GetOperation eID, count, op RzjUrt  
        If op.Type="ShiftZ" Then ?T2>juf]5~  
            DeleteOperation eID,count E#!!tH`lgg  
            count=count-1 5\MC5us3  
        End If UPU$SZAIx  
        count=count+1 z,G_&5|f%  
    Wend kFwFPK%B  
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    'Set new z-shift H:]cBk^[,  
    op.Type = "ShiftZ" P2a5<#_|  
    op.val1 = tlens [K.1 X=O}  
    op.parent = parID >4jE[$p]"  
    AddOperation eID, op Bj1%}B  
    Print "Set lens thickness = " & tlens LXK!4(xaW  

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    '************************************************************************* WA8<:#{e  
    'Lens index of refraction /7 Tm2Vj8  
    '************************************************************************* IgG[Pr'D  
    eID = FindMaterial( "Lens" ) v^b4WS+.:  
    GetModelMaterial eID, mat :R,M Y"(  

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    mat.Nd = nlens 7Hr_ZwO/^  
    SetModelMaterial eID, mat u1$6:"2@5k  
    Print "Set lens index of refraction = " & nlens QM F 
 
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    '************************************************************************* +T$Olz  
    'Pupil diameter _ \6v
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    '************************************************************************* n?.;*:  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) );h(D!D,  
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    'Adjust pupil diameter (trimming volume inner hole) l,7& z  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" 5,1<A@H  
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    ' Adjust pupil location to just in front of the lens  f\<r1  
    parID = FindFullName( "Geometry.Arizona Eye" ) (QiA5!wg  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) e~SK*vR%]  
    count = 0 !k)6r6  
    While GetOperationCount(eID)>count +:.Jl:fx4  
        GetOperation eID, count, op aDKb78 1d  
        If op.Type="ShiftZ" Then 8|i'~BFHs  
            DeleteOperation eID,count $V(]z`b&  
            count=count-1 I_ mus<sE  
        End If JcR|{9ghT  
        count=count+1 jW\:+Taq  
    Wend ~\_VWXXvIW  
    op.Type = "ShiftZ" ;o!p9MEpz;  
    op.val1 = taq-0.01 1.cP3kl  
    op.parent = parID 'RMUjJ-!  
    AddOperation eID, op 'q-q4QCB  
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    Print "Set pupil diameter = " & pupilDiam N&NBn(  
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    'Update AZ Eye subassembly Description [CI&4)#  
    eID = FindFullName( "Geometry.Arizona Eye" ) @'R)$:I%L  
    GetEntity eID, entity .>B'oD  
    entity.Description = "Accommodation = " & A & "D" h=7q;-@7  
    SetEntity eID, entity 'Rn-SD~gIr  
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    Update VI2lwE3  
    Print "DONE!" /I`TN5~  
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End Sub E5&Z={  
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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： 6{y7e L3!  
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Accommodation = 4 Diopters %#x4wi  
Pupil Diameter = 4 mm gJ6`Kl985O  
Set aqueous humor thickness = 2.81 pLB2! +  
Set anterior lens radius = 10.4 and conic constant = -2.375869 h<G4tjtk  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 q-JTGCFl  
Set lens thickness = 3.927 n%&L&G  
Set lens index of refraction = 1.42672 _!03;zrO  
Set pupil diameter = 4 Sa= tiOv  
DONE! +~^S'6yB  
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