[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 0;x&\x7K
 
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。 ok6t| 7sq  
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模型 kmW/{I9,ua  
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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。 <IIz-6*V  
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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. @=G[mc\  
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光源 S?Cd,WxT  
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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。 ,fiV xnQ  
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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。 kJ%a;p`O  
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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。 gs+nJ+b  
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视网膜的散射 B4HMs$>   
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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。 3w>1R>7  
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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。 y%9Hu
  
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脚本 6i+AJCkC  
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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： H/*sl
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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。 ,Y| ;V  
余下的脚本计算与屈光度有关的所有参数。 p<pGqW  
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分析 CXuMNa  
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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。 a;a1>1  
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脚本代码 b%x=7SMXO  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. Pxkh;:agD  
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Dim entity As T_ENTITY "5ISKuL  
Dim op As T_OPERATION O9<oq  
Dim mat As T_MODELMATERIAL
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Dim A As Double X%og}Cfi  
Dim pupilDiam As Double 7wY0JS$fz  
Dim eID As Long #y"LFoJn  
Dim parID As Long pKLNBR|  
Dim count As Integer oV9{{  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double M<=e~';H  
Dim tlens As Double, nlens As Double =
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Dim curv As Double, conic As Double cM,
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Dim ok As Long f8UJ3vB  
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Sub Main Z:<w
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    '用户输入对话框 BaUuDo/ZO  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 U|QP]6v  
        TextBox 220,21,40,21,.TextBox1 'default: 0 p1.3)=T  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 )p#L"r^)  
        OKButton 40,91,90,21 9GT}_ ^fb  
        CancelButton 190,91,90,21 2dB]Lw@s  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 Wwr  
        TextBox 220,49,40,21,.TextBox2 'default: 4 B>I:KGkV  
    End Dialog u|\?6fz  
    Dim dlg As UserDialog GpO*As_2  
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    ok = Dialog (dlg) x|c_(  
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    If ok=0 Then    'cancel button was pressed sV0NDM0  
        Print "Execution cancelled." N9*QQ0  
        End {:\LFB_  
    End If II=!E  
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    'Assign accommodation and pupil diameter & use defaults if field left empty @.)[U:N  
    If dlg.TextBox1 = "" Then /<-=1XJI  
        A = 0           'Default accommodation oxUBlye  
    Else WCk. K  
        A = CDbl(dlg.TextBox1) rXBCM  
    End If c4Q9foE   
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    If dlg.TextBox2 = "" Then  !I&,!$  
        pupilDiam = 4   'Default pupil diameter 9&6P,ts%Q  
    Else mQSn*;9\T3  
        pupilDiam = CDbl(dlg.TextBox2) QUZ+#*:s  
    End If 'mm>
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    Print " " mfffOG  
    Print "Accommodation = " & A & " Diopters" k!bJ&} Q(b  
    Print "Pupil Diameter = " & pupilDiam & " mm" 19[!9ci  
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    ' Calculate new parameters with accommodation 8X278^ #  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness B~@Gfb>`'  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens l,3,$  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens p*T[(\8{n  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens h qhX  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens 9%"\s2T  
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    tlens = 3.767 + 0.04*A                  'Lens thickness (J%>{?"ij  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction $b7@S`5  
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    'Adjust parameters to account for accommodation *WFd[cKE  
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    '************************************************************************* K:Z(jF!j  
    'Aqueous thickness (Position of Lens) nqTOAL9FF  
    '************************************************************************* B[#n,ay  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) ;kR=vv  
    GetCustomElement eID, entity a0PU&o1EF  
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    parID = FindFullName( "Geometry.Arizona Eye" ) F!4V!VWA}  
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    ' Delete any shift(s) in z 1A#/70Mo  
    count = 0 ^-|~c`&}B  
    While GetOperationCount(eID)>count G+k wG)K  
        GetOperation eID, count, op ;KEie@Ry  
        If op.Type="ShiftZ" Then 
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            DeleteOperation eID,count $"MVr5q6  
            count=count-1 p&)d]oV>  
        End If cnw+^8  
        count=count+1 1,]FLsuy  
    Wend Je2&7uR0  
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    'Set new shift in L 8;H_:~_'  
    op.Type = "ShiftZ" Tow!5VAM  
    op.val1 = taq hn/yX|4c(  
    op.parent = parID sX*L[3!vN  
    AddOperation eID, op l%?4L/J)#  
    Print "Set aqueous humor thickness = " & taq-0.55 c5 AaUza  
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    '************************************************************************* ^SsnCn-e  
    'Radius and conic constant of anterior lens y9LO;{(  
    '************************************************************************* [?qzMFb  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) KK6z3"tk5  
    GetConic eID, entity, curv, conic  s_+.xIZ  
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    SetConic eID, entity, 1/Rant, CCant C~"UOFX  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant V\e1NS  
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    '************************************************************************* cu'(Hj  
    'Radius and conic constant of posterior lens iWFtb)3B  
    '************************************************************************* /`nkz  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) -Lb7=98  
    GetConic eID, entity, curv, conic j(K)CHH  
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    SetConic eID, entity, 1/Rpost, CCpost ~3Zz.!F  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost [F;\NJp6?^  
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    '************************************************************************* \7#w@3*  
    'Lens thickness (Position of posterior lens surface) x2r.4  
    '************************************************************************* 'Nuy/\[{\  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) FKL@,>!<e  
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    ' Delete any z-shift(s) j8PeO&n>  
    count = 0 9}Z;(,6/.\  
    While GetOperationCount(eID)>count fE&s 6w&  
        GetOperation eID, count, op ,oSn<$%/q  
        If op.Type="ShiftZ" Then +xsGa{`  
            DeleteOperation eID,count 6BEpnw>p(  
            count=count-1 F< 5kcu#iL  
        End If j
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        count=count+1 =1(7T.t  
    Wend v}
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    'Set new z-shift )R?uzX^qf  
    op.Type = "ShiftZ" a~LdcUYs  
    op.val1 = tlens /"m#mhL  
    op.parent = parID *PB/I4>{  
    AddOperation eID, op }bdoJ5  
    Print "Set lens thickness = " & tlens BafNFPc  
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    '************************************************************************* yGrnzB6|  
    'Lens index of refraction "L1LL iS  
    '************************************************************************* bb\XZ~)F  
    eID = FindMaterial( "Lens" ) ZU`~@.`i  
    GetModelMaterial eID, mat Bt5 P][<  
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    mat.Nd = nlens ,O:p`"3`0=  
    SetModelMaterial eID, mat \*qradgx$  
    Print "Set lens index of refraction = " & nlens PApr8Xe  
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    '************************************************************************* ^,vFxN--q  
    'Pupil diameter PYs0w6o  
    '************************************************************************* L;L_$hu)  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) Z(tO]tQE  
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    'Adjust pupil diameter (trimming volume inner hole) I.|b:c xN  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" v<)&JlR  
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    ' Adjust pupil location to just in front of the lens o"L8n(\  
    parID = FindFullName( "Geometry.Arizona Eye" ) Qt_KUtD  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) jq8TfJ|  
    count = 0 2Q@Jp`#,4  
    While GetOperationCount(eID)>count -)Vy)hD,  
        GetOperation eID, count, op D+! S\~u  
        If op.Type="ShiftZ" Then =OV5DmVmQ  
            DeleteOperation eID,count V>E7!LIn.  
            count=count-1 \w1',"l`  
        End If l,(:~KH|  
        count=count+1 #.fJ M:"tG  
    Wend dn?'06TD  
    op.Type = "ShiftZ" V=5*)i/  
    op.val1 = taq-0.01 +|8.ymvm  
    op.parent = parID D
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    AddOperation eID, op < .e4  
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    Print "Set pupil diameter = " & pupilDiam fkX86  
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    'Update AZ Eye subassembly Description $]}K;  
    eID = FindFullName( "Geometry.Arizona Eye" ) TgDT  
    GetEntity eID, entity M6qNh`+HO
 
    entity.Description = "Accommodation = " & A & "D" Mw-L?j0o[k  
    SetEntity eID, entity .]zZwB  
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    Update -'d`(G"  
    Print "DONE!" 4x4[  
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End Sub iyr8*L\  
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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： 1|ddG010  
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Accommodation = 4 Diopters z[R dM#L  
Pupil Diameter = 4 mm n@"<NKzh  
Set aqueous humor thickness = 2.81 ;V?(j3b[  
Set anterior lens radius = 10.4 and conic constant = -2.375869 COw!a\Jl  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 q+<,FdG  
Set lens thickness = 3.927 4MW oGV9  
Set lens index of refraction = 1.42672 tQUKw@@Q  
Set pupil diameter = 4 Otq1CD9  
DONE! KD+&5=Y  
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