[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 ($!g= 7  
人眼光学模型可用来设计眼科用设备，光学系统注定了要与人眼一起使用。本文演示了这样一个模型：Arizona眼睛模型，在Jim Schwiegerling教授的书中有详细描述：《Field Guide to Visual and Ophthalmic Optics》。AZ眼睛模型达到了基于平均临床数据所决定的轴上和轴外像差等级。FRED文件包含了此眼睛模型及几个用来分析它的光源，并包括一个基于想要的屈光度来调整模型的内嵌脚本。 _y:aPn  
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模型 `j'gt&  
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模型的定义如表1种所示，由半径、圆锥常数、折射率、阿贝数、到下一面的距离等一系列表面组成。一些参数由屈光度（A）来决定。 eI@G B  
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在FRED中使用0屈光度来创建的，光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. lr[&*v?h  
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光源 Mn*5oH  
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多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 UoJMOw[  
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除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处，并增加了pre-propagation distance= -8。尽管光线在光瞳处创建，规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射，而不是在光瞳处入射。 ~2UmX'  
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在往下看是内置的脚本用来修改屈光度，使其为4（250mm），光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 ,]4.|A_[Rq  
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视网膜的散射 N8Un42  
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在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 Mvk#$:8e  
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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。 _2eL3xXha.  
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脚本 .-:6L2  
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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： #Y>d@  
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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。 ntF#x.1Pm  
余下的脚本计算与屈光度有关的所有参数。 <PQ[N[SU  
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分析 7 P]Sc  
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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。 7@i2Mz/eV  
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脚本代码 )h(yh50 B  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. zyFbu=d|O:  
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Dim entity As T_ENTITY ^i~'aq  
Dim op As T_OPERATION rVx?Yo1F'  
Dim mat As T_MODELMATERIAL *!+?%e{;b  
Dim A As Double _xXDvBU  
Dim pupilDiam As Double |p+ xM  
Dim eID As Long 7 m!e\x8  
Dim parID As Long (?zZvW8  
Dim count As Integer "a>a "Ei  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double veGRwir  
Dim tlens As Double, nlens As Double ZBfB4<M9xS  
Dim curv As Double, conic As Double O:G-I$F|  
Dim ok As Long %GDs/9  
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Sub Main %D}]Z=gp  
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    '用户输入对话框 `'<
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    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1  W,)qE^+  
        TextBox 220,21,40,21,.TextBox1 'default: 0 @y`7csbp  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 s&*s9F  
        OKButton 40,91,90,21 u<{uUui}$v  
        CancelButton 190,91,90,21 %O3 r>o=  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 o*WI*Fb'  
        TextBox 220,49,40,21,.TextBox2 'default: 4 qbe9 CF'@_  
    End Dialog ?{I]!gI  
    Dim dlg As UserDialog TJp0^&Q  
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    ok = Dialog (dlg) kzLtI w&.  
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    If ok=0 Then    'cancel button was pressed Y+I`XeY  
        Print "Execution cancelled." 6~v|pA jY  
        End Sud5F4S  
    End If l~Sn`%PgA  
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    'Assign accommodation and pupil diameter & use defaults if field left empty }nJG<rY  
    If dlg.TextBox1 = "" Then a<K@rgQ  
        A = 0           'Default accommodation #0j,1NpL  
    Else P9D'L{yS/x  
        A = CDbl(dlg.TextBox1) JRj%d&^}  
    End If MM%c  
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    If dlg.TextBox2 = "" Then [bvIT]Z  
        pupilDiam = 4   'Default pupil diameter ` 
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    Else OVm $  
        pupilDiam = CDbl(dlg.TextBox2) eqze7EY  
    End If *xOrt)D=  
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    Print " " Pc4FEH/  
    Print "Accommodation = " & A & " Diopters" [UHDN:y  
    Print "Pupil Diameter = " & pupilDiam & " mm" nP>*0Fq  
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    ' Calculate new parameters with accommodation W@x UR-}51  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness 7=ZB?@bU~  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens fH7o,U|  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens 81|Xg5g)b  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens mSzBNvci  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens -)tu$W*  
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    tlens = 3.767 + 0.04*A                  'Lens thickness +`x8[A)-  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction 98os4}r  
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    'Adjust parameters to account for accommodation lc=C  
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    '************************************************************************* yjVPaEu]aU  
    'Aqueous thickness (Position of Lens) D/Y.'P:j  
    '************************************************************************* \gL H_$}  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) %jY/jp=R  
    GetCustomElement eID, entity <;.Zms${@  
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    parID = FindFullName( "Geometry.Arizona Eye" ) xh\{ dUPA  
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    ' Delete any shift(s) in z 1Q6WpS  
    count = 0 XnQo0 R.PW  
    While GetOperationCount(eID)>count oO|zRK1;/  
        GetOperation eID, count, op Yo c N
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        If op.Type="ShiftZ" Then ":*PC[)W  
            DeleteOperation eID,count ~:f9,  
            count=count-1 N(@'L43$V  
        End If 5[M?O4
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        count=count+1 pI |;  
    Wend b$nXljV4?  
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    'Set new shift in 0!rU,74I=  
    op.Type = "ShiftZ" -tSWYp{  
    op.val1 = taq ;PJWd|3  
    op.parent = parID $Tt@Xu  
    AddOperation eID, op DEaO=p|  
    Print "Set aqueous humor thickness = " & taq-0.55 ZN|DR|cUY  
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    '************************************************************************* d(w $! $"h  
    'Radius and conic constant of anterior lens
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    '************************************************************************* lkV% k1w  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) tgDmHxB]0  
    GetConic eID, entity, curv, conic |8h<Ls_  
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    SetConic eID, entity, 1/Rant, CCant S?%V o* Y  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant ?MuM _6  
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    '************************************************************************* sf]y\_zU  
    'Radius and conic constant of posterior lens k'wF+>  
    '************************************************************************* E)>~0jv  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) 0yXUVKq3  
    GetConic eID, entity, curv, conic >>wbyj8  
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    SetConic eID, entity, 1/Rpost, CCpost !J[3U   
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost BSG_),AH  
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    '************************************************************************* R)t"
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    'Lens thickness (Position of posterior lens surface) rSB"0W7  
    '************************************************************************* {SW104nb&#  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) S)z jfJR  
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    ' Delete any z-shift(s) !'B.ad  
    count = 0 J}TS-j0  
    While GetOperationCount(eID)>count Y*3qH
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        GetOperation eID, count, op Fm{Ri=X<:  
        If op.Type="ShiftZ" Then tsU.c"^n  
            DeleteOperation eID,count s
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            count=count-1 $# @G!  
        End If g||{Qmr=1  
        count=count+1 '@wYr|s4  
    Wend =+97VO(w]G  
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    'Set new z-shift X^?<, Y)1.  
    op.Type = "ShiftZ" G!oq ;<  
    op.val1 = tlens ];^A8?  
    op.parent = parID 6J6MR<5'  
    AddOperation eID, op 42:\1B#[  
    Print "Set lens thickness = " & tlens B>t$Z5Q^X  
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    '************************************************************************* ?.IT!M}DR  
    'Lens index of refraction pQ*9)C   
    '************************************************************************* $uawQf+S  
    eID = FindMaterial( "Lens" ) r`i<XGPJ%  
    GetModelMaterial eID, mat ss%ahs  
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    mat.Nd = nlens J+[&:]=P  
    SetModelMaterial eID, mat vd SV6p.d  
    Print "Set lens index of refraction = " & nlens 9]VUQl9gh  
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    '************************************************************************* ;)5d wq  
    'Pupil diameter 7h<Q{X<A  
    '************************************************************************* >yg mE`g  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) AASw^A3p  
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    'Adjust pupil diameter (trimming volume inner hole) 2K!3+D"  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" bec n$R  
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    ' Adjust pupil location to just in front of the lens &'N{v@Oi)  
    parID = FindFullName( "Geometry.Arizona Eye" ) <G{m=  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) A0cC)bd&  
    count = 0 `&4L'1eF{  
    While GetOperationCount(eID)>count mgL~ $  
        GetOperation eID, count, op vO%n~l=  
        If op.Type="ShiftZ" Then iRS )Z)  
            DeleteOperation eID,count 8uM>UpX  
            count=count-1 |J'@-*5?[8  
        End If 5iz]3]}%  
        count=count+1 b~Op
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    Wend 4gb2$"!  
    op.Type = "ShiftZ" \ZigG{  
    op.val1 = taq-0.01 E08FUAth]#  
    op.parent = parID 2Auhv!xV  
    AddOperation eID, op k8F<j)"  
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    Print "Set pupil diameter = " & pupilDiam +b.<bb6  
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    'Update AZ Eye subassembly Description {xW?v;  
    eID = FindFullName( "Geometry.Arizona Eye" ) 36*"oD=@  
    GetEntity eID, entity @R_a'v-  
    entity.Description = "Accommodation = " & A & "D" Q'~kWmLf  
    SetEntity eID, entity
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    Update sczN0*w&C  
    Print "DONE!" xpxUn8.  
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End Sub hq6fDR
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如果屈光度是4，光瞳直径是4，则会输出如下数据： 8s/gjEwA  
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Accommodation = 4 Diopters [pUw(KV2m  
Pupil Diameter = 4 mm h +.8Rl  
Set aqueous humor thickness = 2.81 )y\^5>p[  
Set anterior lens radius = 10.4 and conic constant = -2.375869 gYA|JFi  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 am{f<v,EI  
Set lens thickness = 3.927 OKNA36cU'  
Set lens index of refraction = 1.42672 c$rkbbf~V  
Set pupil diameter = 4 X]U,`oE)9  
DONE! 8V>j-C  
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