[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 )IK%Dg(v  
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。 (W"0c?i|]  
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模型 jX'pUO  
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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。 i)cG  
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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. H/W&a2R^P  
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光源 bg9_$laDi  
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多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 c 3| Lk7Q  
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除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处，并增加了pre-propagation distance= -8。尽管光线在光瞳处创建，规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射，而不是在光瞳处入射。 ZA_~o#0%  
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在往下看是内置的脚本用来修改屈光度，使其为4（250mm），光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 *WzPxQ_  
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视网膜的散射 ,-$%>Uv  
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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。 } -hH2  
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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。 _fj@40i M  
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脚本 f
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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： 1U~'8=-  
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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。 8p~[8}  
余下的脚本计算与屈光度有关的所有参数。 ocp3JR_0  
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分析 aI\>=*HF  
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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。 jI}{0LW&F&  
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脚本代码 V3pn@'pr  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. 7,9zj1<  
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Dim entity As T_ENTITY IP1{gMG  
Dim op As T_OPERATION Q},uM_"+  
Dim mat As T_MODELMATERIAL {
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Dim A As Double \l;H!y[  
Dim pupilDiam As Double 8\Z/mU*4  
Dim eID As Long g5&,l  
Dim parID As Long '-X913eG!  
Dim count As Integer "l09Ae'V  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double J&b&*3   
Dim tlens As Double, nlens As Double xF9PjnWF=  
Dim curv As Double, conic As Double +Mh9Jf  
Dim ok As Long W&k2z,|  
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Sub Main h@?BA<'S  
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    '用户输入对话框 B7qiCX}pD  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 nxYp9,c"  
        TextBox 220,21,40,21,.TextBox1 'default: 0 =gr3a,2  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 2KmPZ&r  
        OKButton 40,91,90,21 .hXdXY  
        CancelButton 190,91,90,21 _9zydtw  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 (hX}O>  
        TextBox 220,49,40,21,.TextBox2 'default: 4 ViT$]Nv  
    End Dialog s*pgR=dZZ  
    Dim dlg As UserDialog Z,Tv8;  
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    ok = Dialog (dlg) 7_#i,|]58  
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    If ok=0 Then    'cancel button was pressed 76*5/J-  
        Print "Execution cancelled." eqE%ofW  
        End 5zBsulRt  
    End If rRZ ,X%  
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    'Assign accommodation and pupil diameter & use defaults if field left empty mI~k@!3  
    If dlg.TextBox1 = "" Then mM7S9^<UH  
        A = 0           'Default accommodation ^Ru/7pw5  
    Else 4 p(KdYc  
        A = CDbl(dlg.TextBox1) Ea*Jl<  
    End If 6,|)%~VUm  
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    If dlg.TextBox2 = "" Then ~FV Z0%+,  
        pupilDiam = 4   'Default pupil diameter bP 2IX  
    Else az]S&\i7T  
        pupilDiam = CDbl(dlg.TextBox2) f[/E $r99J  
    End If 3E361?ubM  
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    Print " " Qy@r&  
    Print "Accommodation = " & A & " Diopters" <4Jo1  
    Print "Pupil Diameter = " & pupilDiam & " mm" uNYHEs6%T$  
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    ' Calculate new parameters with accommodation x+9aTsZ  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness [Hww3+~+  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens lLT;V2=osX  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens *lIK?"mo  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens U>^-Db
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    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens DPNUm<>  
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    tlens = 3.767 + 0.04*A                  'Lens thickness 'N0/;k0ax  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction }cE,&n  
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    'Adjust parameters to account for accommodation ds4)Nk4%O  
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    '************************************************************************* RCq_FY  
    'Aqueous thickness (Position of Lens) a-,BBM8|  
    '************************************************************************* xF_ Y7rw1w  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) QO)Q%K,  
    GetCustomElement eID, entity fO.gfHI  
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    parID = FindFullName( "Geometry.Arizona Eye" ) l 49)Cv/  
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    ' Delete any shift(s) in z C``%<)WC  
    count = 0 swnov[0  
    While GetOperationCount(eID)>count CBTa9|57  
        GetOperation eID, count, op 2Fce| Tn  
        If op.Type="ShiftZ" Then >b0e"eGt  
            DeleteOperation eID,count F[c;iM(^  
            count=count-1 Q<r O5 -K  
        End If eGblQGRS  
        count=count+1 h?DMrYk_%#  
    Wend $_l@k=  
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    'Set new shift in |_%|  
    op.Type = "ShiftZ" #oi4!%*M  
    op.val1 = taq gR(*lXm5w  
    op.parent = parID Vcl"qz@Fj  
    AddOperation eID, op oG5JJpLT  
    Print "Set aqueous humor thickness = " & taq-0.55 ab' f:  
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    '************************************************************************* o;\0xuM@  
    'Radius and conic constant of anterior lens BRV /7ao="  
    '************************************************************************* 9QI\[lT&  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) Q4Q*5>  
    GetConic eID, entity, curv, conic HlY4%M5q/  
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    SetConic eID, entity, 1/Rant, CCant (9$/r/-a  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant q0w5ADd
 
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    '************************************************************************* r%$-F
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    'Radius and conic constant of posterior lens |jaUVE_2[  
    '************************************************************************* {`~{%2ayq7  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) dLal15Pb  
    GetConic eID, entity, curv, conic 6$b"tdP  
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    SetConic eID, entity, 1/Rpost, CCpost ."PR Z,  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost :j vx-jQ  
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    '************************************************************************* z(3mhMJY  
    'Lens thickness (Position of posterior lens surface) #=b_!~:%  
    '************************************************************************* sN7I~  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) Y1Bj++?2  
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    ' Delete any z-shift(s) or~o'  
    count = 0 WUdKj  
    While GetOperationCount(eID)>count g^^%4Y  
        GetOperation eID, count, op #v')iR"  
        If op.Type="ShiftZ" Then `t:7&$>T  
            DeleteOperation eID,count <2ffcBv  
            count=count-1 HPCgv?E3  
        End If {{[).o/  
        count=count+1 .?_wcp=  
    Wend |VlAt#E  
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    'Set new z-shift '9*wr*  
    op.Type = "ShiftZ" zY\v|l
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    op.val1 = tlens Cr4shdN34  
    op.parent = parID *WfOB2rU  
    AddOperation eID, op eP'e_E  
    Print "Set lens thickness = " & tlens p2!x8`IB*  
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    '************************************************************************* )wpBxJ;dB}  
    'Lens index of refraction 8:L%-  
    '************************************************************************* ZHICpL  
    eID = FindMaterial( "Lens" ) W&z.O  
    GetModelMaterial eID, mat Gc4N)oq)}b  
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    mat.Nd = nlens U-3KuR+0  
    SetModelMaterial eID, mat 1F/`*z
 
    Print "Set lens index of refraction = " & nlens {+z+6i  
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    '************************************************************************* !o:RIwS3  
    'Pupil diameter OWB^24Z&3  
    '************************************************************************* 0UWLs_k:  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) W8yr06{]  
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    'Adjust pupil diameter (trimming volume inner hole) EZIMp8^  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" #TZYe4#f  
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    ' Adjust pupil location to just in front of the lens g*- K!X6l  
    parID = FindFullName( "Geometry.Arizona Eye" ) uc=-+*D'I  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) ,, ]y 8P  
    count = 0 [ #A!B#`  
    While GetOperationCount(eID)>count #rzxFMA"  
        GetOperation eID, count, op (LTm!"Q  
        If op.Type="ShiftZ" Then /qo.Z  
            DeleteOperation eID,count eAu3,qoM  
            count=count-1 6g@j,iFy  
        End If HHWB_QaL  
        count=count+1 ',kYZay  
    Wend V{{b^y  
    op.Type = "ShiftZ" I@+dE V`Lf  
    op.val1 = taq-0.01 He)v:AH  
    op.parent = parID g?^o++  
    AddOperation eID, op eO(VSjo'`  
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    Print "Set pupil diameter = " & pupilDiam S<88>|&n]  
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    'Update AZ Eye subassembly Description +S^Uw'L$=T  
    eID = FindFullName( "Geometry.Arizona Eye" ) jp=^$rS6[  
    GetEntity eID, entity )3'/g`c  
    entity.Description = "Accommodation = " & A & "D" lsY5QE:Qrp  
    SetEntity eID, entity %Ni)^   
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    Update *1ku2e]z  
    Print "DONE!" *vCJTz  
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End Sub }j+ZF'#  
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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： ,hT t]w  
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Accommodation = 4 Diopters 4}W*
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Pupil Diameter = 4 mm ,D+pGxbr   
Set aqueous humor thickness = 2.81 TN.mNl%  
Set anterior lens radius = 10.4 and conic constant = -2.375869 IObGmc  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 zK k;&y|{  
Set lens thickness = 3.927 db@i*Bf  
Set lens index of refraction = 1.42672 (/v(.t  
Set pupil diameter = 4 Cbx/  
DONE! lDCoYX_  
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