[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 [!U! Z'i  
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。 HrHtA]  
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模型 1'b}Y8YO  
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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。 hZ-?-F?*@  
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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. VCa`|S?2  
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光源 8BX9JoDi  
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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。 N[;R8SP  
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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。 8JU{]Z!G<;  
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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。 a!\^O).pA  
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视网膜的散射 pI( H7 (  
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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。 .qrS[ w  
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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。 ICzcV };$  
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脚本 -=)+)9~G  
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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： )p[Qj58  
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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。 Vn?|\3KY  
余下的脚本计算与屈光度有关的所有参数。 76b2 3|  
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分析 U3t)yr h  
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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。 K[i&!Z&  
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脚本代码 lVgin54Q  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. :
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Dim entity As T_ENTITY G4wJv^6i9  
Dim op As T_OPERATION lQG;WVqW  
Dim mat As T_MODELMATERIAL _g6H&no[  
Dim A As Double =Q4Wr0y><]  
Dim pupilDiam As Double )5w#n1  
Dim eID As Long oWBjPsQ  
Dim parID As Long 6yXN7L==x  
Dim count As Integer ET\rd5Po  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double UDV6 ##$
 
Dim tlens As Double, nlens As Double 4Q~++PKBe  
Dim curv As Double, conic As Double !XO"lS  
Dim ok As Long XF?"G<2  
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Sub Main >[4CQK`U  
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    '用户输入对话框 V@\A<q%jTs  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 Qk].^'\  
        TextBox 220,21,40,21,.TextBox1 'default: 0 s(y=u>  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 #xt-65^  
        OKButton 40,91,90,21 _ECH(  
        CancelButton 190,91,90,21 VF g"AJf  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1
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        TextBox 220,49,40,21,.TextBox2 'default: 4 ?y,z  
    End Dialog }ssL
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    Dim dlg As UserDialog S&MF; E6  
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    ok = Dialog (dlg) oFp4*<\  
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    If ok=0 Then    'cancel button was pressed wa
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        Print "Execution cancelled." -S 0dr8E  
        End ]~\%ANoi  
    End If n(j5dN>]  
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    'Assign accommodation and pupil diameter & use defaults if field left empty tfPe-U  
    If dlg.TextBox1 = "" Then 7:n OAN}%  
        A = 0           'Default accommodation #f }OR
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    Else >!%+)  
        A = CDbl(dlg.TextBox1) 5
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    End If j "e]Ui  
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    If dlg.TextBox2 = "" Then }nMp.7b  
        pupilDiam = 4   'Default pupil diameter jB3Rue:+g  
    Else D4PjE@D"H  
        pupilDiam = CDbl(dlg.TextBox2) ML:H\  
    End If #* Iyvx  
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    Print " " 8Wx7%@^O  
    Print "Accommodation = " & A & " Diopters" `bjPOA(g  
    Print "Pupil Diameter = " & pupilDiam & " mm" [wM]w  
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    ' Calculate new parameters with accommodation lj@ibA]  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness d1u6*&@lf  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens U\(T<WX,  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens 
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens EOG&Xa  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens LteZ7e  
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    tlens = 3.767 + 0.04*A                  'Lens thickness HA3d9`  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction r%xf=};  
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    'Adjust parameters to account for accommodation AO]1`b:  
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    '************************************************************************* 5.F/>?<  
    'Aqueous thickness (Position of Lens) b}Wm-]|+  
    '************************************************************************* q82yh&  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) '%KaAi$  
    GetCustomElement eID, entity @P6*4W  
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    parID = FindFullName( "Geometry.Arizona Eye" ) mC./,a[  
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    ' Delete any shift(s) in z mxmj  
    count = 0 [
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    While GetOperationCount(eID)>count NJPp6RZ%  
        GetOperation eID, count, op >JT^[i8[  
        If op.Type="ShiftZ" Then "1ov<  
            DeleteOperation eID,count S=g E'"LT  
            count=count-1 v6O5n(5,,  
        End If <E\vc6n  
        count=count+1 l'kVi  
    Wend :zsMkdU  
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    'Set new shift in r<EwtO+x  
    op.Type = "ShiftZ" d%Nx/DS)  
    op.val1 = taq xv0y?#`z  
    op.parent = parID 4x?4[J~u[  
    AddOperation eID, op s1 (UOd7}  
    Print "Set aqueous humor thickness = " & taq-0.55 PQ(/1v   
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    '************************************************************************* Z2&7HTz  
    'Radius and conic constant of anterior lens Y>I9o)KR  
    '************************************************************************* Nuc2CB)J  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) l`?4O  
    GetConic eID, entity, curv, conic z?.XVk-  
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    SetConic eID, entity, 1/Rant, CCant p9j2jb,qy  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant Gu#wH  
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    '************************************************************************* QA# 7T3|  
    'Radius and conic constant of posterior lens ZBXn&Gm  
    '************************************************************************* V5S6?V\  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) NU.YL1  
    GetConic eID, entity, curv, conic zd?uMq;w  
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    SetConic eID, entity, 1/Rpost, CCpost *2r(!fJP=^  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost # &Z1d(!  
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    '************************************************************************* .MW/XnCYs4  
    'Lens thickness (Position of posterior lens surface) JeU1r-i  
    '************************************************************************* 'Ad|*
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) R6qC0@*  
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    ' Delete any z-shift(s) -ei+r#  
    count = 0 ANXN.V  
    While GetOperationCount(eID)>count okLheF  
        GetOperation eID, count, op uAv'%/  
        If op.Type="ShiftZ" Then !sav~dB)  
            DeleteOperation eID,count ?tf<AZ=+^L  
            count=count-1 `&g1`vg  
        End If a'B 5m]%  
        count=count+1 \zV'YeG  
    Wend );L+)UV  
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    'Set new z-shift ^1`T_+#[s  
    op.Type = "ShiftZ" jQY^[A  
    op.val1 = tlens x}H%NzR  
    op.parent = parID xoNn
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    AddOperation eID, op sH\h{^  
    Print "Set lens thickness = " & tlens #4ii!ev  
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    '************************************************************************* H?)?(t7@  
    'Lens index of refraction Mx=L lC)  
    '************************************************************************* }
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    eID = FindMaterial( "Lens" ) Oy~X@A  
    GetModelMaterial eID, mat 2jH&@g$cl;  
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    mat.Nd = nlens  q{RT~,%  
    SetModelMaterial eID, mat VMV~K7%0  
    Print "Set lens index of refraction = " & nlens bb"x^DtT  
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    '************************************************************************* Nj;G%KAP  
    'Pupil diameter 5vjtF4}7!  
    '************************************************************************* yMBFw:/o  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) $/;<~Pzi  
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    'Adjust pupil diameter (trimming volume inner hole) {b90c'8?a  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" :qO)^~x  
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    ' Adjust pupil location to just in front of the lens iT&Y9  
    parID = FindFullName( "Geometry.Arizona Eye" ) =-8y=  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) >}>cJh6  
    count = 0 E>w|i  
    While GetOperationCount(eID)>count n<66 7 <  
        GetOperation eID, count, op S}XVr?l2O  
        If op.Type="ShiftZ" Then lr&O@ 5"oy  
            DeleteOperation eID,count R9O[`~BA2  
            count=count-1 1JO@G3,  
        End If 0vi\o`**Mj  
        count=count+1 L+d4&x  
    Wend ?)'+l   
    op.Type = "ShiftZ" <[<]+r&*  
    op.val1 = taq-0.01 ]>k>Z#8E*  
    op.parent = parID iJ 8I# j+N  
    AddOperation eID, op `KzNBH,W  
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    Print "Set pupil diameter = " & pupilDiam %eLf6|1x  
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    'Update AZ Eye subassembly Description +hKH\]  
    eID = FindFullName( "Geometry.Arizona Eye" ) 8cv[|`<  
    GetEntity eID, entity (S#nA:E  
    entity.Description = "Accommodation = " & A & "D" E
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    SetEntity eID, entity L(i0d[F  
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    Update f1}b;JJTsv  
    Print "DONE!" Yeb-u+23  
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End Sub M8iI e:{ c  
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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： 0I \l_St@  
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Accommodation = 4 Diopters k4Ub+F  
Pupil Diameter = 4 mm lpHz*NZ0  
Set aqueous humor thickness = 2.81 u[2B0a  
Set anterior lens radius = 10.4 and conic constant = -2.375869 k&8&D  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 3tIno!|  
Set lens thickness = 3.927 [d/uy>z,  
Set lens index of refraction = 1.42672 C'Z6l^{>  
Set pupil diameter = 4 ,zU7UL^I  
DONE! ums*EKjs97  
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