[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 wf:OK[r9  
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。 1 =M ?GDc  
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模型  {PVWD7  
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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。 LL3#5AA"k|  
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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. [@5Ytv H  
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光源 6BCf:mqP  
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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。 i*@<y/&'  
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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。 j
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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。 FW21 U<  
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视网膜的散射 !;KCU^9  
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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。 'LO^<  
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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。 BZ?
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脚本 =g|IG [V  
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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： K|:@Z  
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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!REygyx  
余下的脚本计算与屈光度有关的所有参数。 `Ch9~*p  
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分析 $h*L=t(  
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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。 T
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脚本代码 yL2o}ZbS  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. 7Z-O_h3;)@  
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Dim entity As T_ENTITY Na?!;1]_  
Dim op As T_OPERATION 8&)DE@W  
Dim mat As T_MODELMATERIAL L 8dc(Z%v  
Dim A As Double Wb?8j M  
Dim pupilDiam As Double >o7n+Rb:  
Dim eID As Long 93` AWg/T  
Dim parID As Long [&#/]Ul'  
Dim count As Integer i03w1pSH,  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double iC98_o_9  
Dim tlens As Double, nlens As Double >VN5`Zlw\C  
Dim curv As Double, conic As Double \v.C]{Gzc  
Dim ok As Long ]y1OFKYv  
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Sub Main :n.f_v}6  
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    '用户输入对话框 a{qM2P(S  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 a*ushB  
        TextBox 220,21,40,21,.TextBox1 'default: 0 =Q+= f  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 bqnNLs<N  
        OKButton 40,91,90,21 k=4N.*#`y  
        CancelButton 190,91,90,21 xx{PespNt  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 ~1W x=  
        TextBox 220,49,40,21,.TextBox2 'default: 4 +KvU$9Ad>  
    End Dialog A.EbXo/  
    Dim dlg As UserDialog K%F,='P}  
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    ok = Dialog (dlg) 9+{G8$Ai  
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    If ok=0 Then    'cancel button was pressed q(.:9A*0  
        Print "Execution cancelled." "F.;Dv9V[0  
        End vfE6Ggz  
    End If -/g B|J  
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    'Assign accommodation and pupil diameter & use defaults if field left empty g'V>_u#(  
    If dlg.TextBox1 = "" Then 7,lq}a8z  
        A = 0           'Default accommodation [ji#U s:h  
    Else [5+}rwm&W  
        A = CDbl(dlg.TextBox1) @]-jl}:]  
    End If 8$;=Uf,x  
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    If dlg.TextBox2 = "" Then sSi6wO$  
        pupilDiam = 4   'Default pupil diameter Z3&_  
    Else cxr=k%~}J  
        pupilDiam = CDbl(dlg.TextBox2) S>]pRV9rT  
    End If hnc@  
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    Print " " gm[z[~
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    Print "Accommodation = " & A & " Diopters" !`M|C?b  
    Print "Pupil Diameter = " & pupilDiam & " mm" w6W}"Uw  
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    ' Calculate new parameters with accommodation Gq }U|Z  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness ;o0&`b?  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens !=:$lzS^  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens TG+VEL |T  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens yX0dbW~@y  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens < 
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    tlens = 3.767 + 0.04*A                  'Lens thickness U2wbvXr5-  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction <-D0u?8  
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    'Adjust parameters to account for accommodation ktdW`R\+  
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    '************************************************************************* 26k LhFS  
    'Aqueous thickness (Position of Lens) /O^RF}  
    '************************************************************************* 82QGS$0V  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) ,]cD  
    GetCustomElement eID, entity o17ekML  
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    parID = FindFullName( "Geometry.Arizona Eye" ) j(k: @  
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    ' Delete any shift(s) in z vOc 9ZE  
    count = 0 A' /KUi  
    While GetOperationCount(eID)>count K?zH35f$  
        GetOperation eID, count, op qASqscO  
        If op.Type="ShiftZ" Then $a"n1ou  
            DeleteOperation eID,count
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            count=count-1 f'aVV!  
        End If T|dY 2  
        count=count+1 HOE_S!N  
    Wend !H irhDN  
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    'Set new shift in NCk r /#!  
    op.Type = "ShiftZ" d~:!#uWyFk  
    op.val1 = taq eL\;Nf+Zp  
    op.parent = parID
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    AddOperation eID, op 'b#0t#|TM  
    Print "Set aqueous humor thickness = " & taq-0.55 ]b%Hy  

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    '************************************************************************* @g$Gti  
    'Radius and conic constant of anterior lens :SGF45>B@  
    '************************************************************************* %y|)=cm[  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) k=B]&F  
    GetConic eID, entity, curv, conic t$xY #:  
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    SetConic eID, entity, 1/Rant, CCant , 'ZD=4_  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant G_k~X"  
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    '************************************************************************* o;=l^-  
    'Radius and conic constant of posterior lens 2GWMlI  
    '************************************************************************* 3`B6w$z>(  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) hDcEGU_  
    GetConic eID, entity, curv, conic IuOgxm~Y  
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    SetConic eID, entity, 1/Rpost, CCpost ?F6pEt4  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost C0 /g1;p(  
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    '************************************************************************* AQ+]|XYo_  
    'Lens thickness (Position of posterior lens surface) M5*{  
    '************************************************************************* C_n9T{k  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) 3'c0#h@VD  
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    ' Delete any z-shift(s) KA){''>8  
    count = 0 P~G1EK|4  
    While GetOperationCount(eID)>count )YX 'N<[  
        GetOperation eID, count, op ZP;j9T!  
        If op.Type="ShiftZ" Then p"FW&Q=PN  
            DeleteOperation eID,count |kvC H<F'  
            count=count-1 FFH_d <q  
        End If F^5?\  
        count=count+1 :L1dyVA{  
    Wend &/uu)v  
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    'Set new z-shift .GsO.#p{  
    op.Type = "ShiftZ" n%k!vJ)]  
    op.val1 = tlens &g.+V/<[  
    op.parent = parID 5o6>T!
 
    AddOperation eID, op GF>'\@Th  
    Print "Set lens thickness = " & tlens ( @3\`\X  
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    '************************************************************************* ;Ww7"-=sw  
    'Lens index of refraction l"!Ko G7  
    '************************************************************************* u6MzRC  
    eID = FindMaterial( "Lens" ) #ssN027  
    GetModelMaterial eID, mat A
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    mat.Nd = nlens :k3Nt5t!  
    SetModelMaterial eID, mat ;
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    Print "Set lens index of refraction = " & nlens V\{tmDE  
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    '************************************************************************* (vB<%l.&  
    'Pupil diameter 6X\ 2GC9  
    '************************************************************************* E6,4RuCK  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) C%U`"-%n@7  
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    'Adjust pupil diameter (trimming volume inner hole) >9f%@uSM$3  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" sPpsq  
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    ' Adjust pupil location to just in front of the lens 3Te^  
    parID = FindFullName( "Geometry.Arizona Eye" ) y /BJIQ  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) 5i-Rglo  
    count = 0 2OwV^-OG  
    While GetOperationCount(eID)>count q-`RI*1]  
        GetOperation eID, count, op 9!Ar`Io2@  
        If op.Type="ShiftZ" Then ]ZoD'-,  
            DeleteOperation eID,count pFm=y#!t  
            count=count-1 DF g,Xa#  
        End If .-IkL|M  
        count=count+1 XO9M_*Va  
    Wend 9&2Vm;F_  
    op.Type = "ShiftZ"
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    op.val1 = taq-0.01 WJ d%2pO]  
    op.parent = parID X5khCLHi  
    AddOperation eID, op Ezi-VGjr]  
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    Print "Set pupil diameter = " & pupilDiam mCWhUBghR  
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    'Update AZ Eye subassembly Description E^rbcGJ  
    eID = FindFullName( "Geometry.Arizona Eye" ) !TP@- X;  
    GetEntity eID, entity E%'~'[Q
 
    entity.Description = "Accommodation = " & A & "D" [b/k3&O'  
    SetEntity eID, entity .(X lg-H,  
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    Update .!6>oL/iF  
    Print "DONE!" NFr:y<0>z  
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End Sub 8UMFq  
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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： nD0}wiL{  
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Accommodation = 4 Diopters Kv@eI$t5  
Pupil Diameter = 4 mm [Cb`{  
Set aqueous humor thickness = 2.81 )'
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Set anterior lens radius = 10.4 and conic constant = -2.375869 #9
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Set posterior lens radius = -4.424557 and conic constant = -3.081019 )OLq_':^@  
Set lens thickness = 3.927 xESjM1A)  
Set lens index of refraction = 1.42672 )$&dg2[  
Set pupil diameter = 4 `g_"GE  
DONE! Yyfq  
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