[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 Yo:>m*31  
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。 zf2]|]*xz  
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模型 WKmG
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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。 Y_f6y9?ZE  
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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. 6C) G  
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光源 tS`fG;  
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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。 HtS:'~DYo  
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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。 rWSw1(sAA  
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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。 4JP01lq'\  
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视网膜的散射 -zMXc"'C^k  
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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。 "S)4Cjk  
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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。 E%jOJA  
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脚本 F]SexP4:A  
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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： }q27M  
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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。 7P!/jawxb  
余下的脚本计算与屈光度有关的所有参数。 `h :&H,N  
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分析 ]?mWnEi!z  
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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。 GVn7#0x  
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脚本代码 L{'qZ#N[  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. 5K{(V^88F  
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Dim entity As T_ENTITY "t`r_Aw  
Dim op As T_OPERATION d*8 c,x  
Dim mat As T_MODELMATERIAL 1wqCoDgkp  
Dim A As Double 0O"GI33Mg  
Dim pupilDiam As Double LDr!d1A  
Dim eID As Long JL2IVENWc  
Dim parID As Long D-A#{e _  
Dim count As Integer m7^a4  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double Lm:O vVVB  
Dim tlens As Double, nlens As Double 44RZk|U1J{  
Dim curv As Double, conic As Double U-X  
Dim ok As Long m'oVqA&  
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Sub Main 9j$ OU@N 8  
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    '用户输入对话框 CG$S?  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 ?GB($D=Y'&  
        TextBox 220,21,40,21,.TextBox1 'default: 0 _(J- MCY\  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 DTn=WGm)  
        OKButton 40,91,90,21 +5?sYp\  
        CancelButton 190,91,90,21 [WX+/pm7>  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 6bo,x  
        TextBox 220,49,40,21,.TextBox2 'default: 4 \9@*Jgpd6*  
    End Dialog 0%`\8  
    Dim dlg As UserDialog +J_A*B  
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    ok = Dialog (dlg) fcD$km  
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    If ok=0 Then    'cancel button was pressed <74q]C
 
        Print "Execution cancelled." "{qhk{  
        End r"Pj,}$A  
    End If 2~Gcoda  
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    'Assign accommodation and pupil diameter & use defaults if field left empty g4RkkoZ>)  
    If dlg.TextBox1 = "" Then S)@R4{=e"V  
        A = 0           'Default accommodation bN<c5  
    Else |@Q(~[It  
        A = CDbl(dlg.TextBox1) cJj0`@0f  
    End If Ai(M06P:h  
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    If dlg.TextBox2 = "" Then PIB|&I|p  
        pupilDiam = 4   'Default pupil diameter i "62+  
    Else T1\Xz
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        pupilDiam = CDbl(dlg.TextBox2)
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    End If [UR+G8X21m  
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    Print " " [$8*(d"F'  
    Print "Accommodation = " & A & " Diopters" %w/o#*j<;  
    Print "Pupil Diameter = " & pupilDiam & " mm" W4|1wd}.t  
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    ' Calculate new parameters with accommodation OA4NXl'  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness {BY`Wu:w  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens dH#S69>  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens yY[[)
 
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens mrE^D|  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens H Y.,f_m  
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    tlens = 3.767 + 0.04*A                  'Lens thickness ogip#$A}3  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction ,Xo9gn  
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    'Adjust parameters to account for accommodation Z9~~vf#  
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    '************************************************************************* 7s<v06Wo  
    'Aqueous thickness (Position of Lens) o PR^Z pt  
    '************************************************************************* f.V0uBDN  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) W{1=O)w  
    GetCustomElement eID, entity l \xIGs  
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    parID = FindFullName( "Geometry.Arizona Eye" ) ?u'JhZ  
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    ' Delete any shift(s) in z .fUqsq  
    count = 0 K )KE0/n  
    While GetOperationCount(eID)>count s/`4]B;2U  
        GetOperation eID, count, op O 4l[4,`  
        If op.Type="ShiftZ" Then _GI [SzD  
            DeleteOperation eID,count `@")R-  
            count=count-1 1p+2*c  
        End If czdNqk.kh  
        count=count+1 8 6?D  
    Wend PKwHq<vAsB  
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    'Set new shift in csH1X/3ha\  
    op.Type = "ShiftZ" 2ZNTg@o  
    op.val1 = taq ~Jp\'P7*  
    op.parent = parID .F'Fk=N  
    AddOperation eID, op n KDX=73  
    Print "Set aqueous humor thickness = " & taq-0.55 WTY{sq\' o  
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    '************************************************************************* 76zi)f1f  
    'Radius and conic constant of anterior lens OHp 121  
    '************************************************************************* 8l+\Qyj  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) @6h=O`X>  
    GetConic eID, entity, curv, conic lJR",_  
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    SetConic eID, entity, 1/Rant, CCant vRRi"bo  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant 6
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    '************************************************************************* &P[eA u  
    'Radius and conic constant of posterior lens G)5%f\&
 
    '************************************************************************* kpxd+w  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) E-.M+[   
    GetConic eID, entity, curv, conic m`4Sp#m  
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    SetConic eID, entity, 1/Rpost, CCpost Q4CxtY  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost HQQc<7c",  
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    '************************************************************************* jP@H$$-=wH  
    'Lens thickness (Position of posterior lens surface) v(h   
    '************************************************************************* fo4j^,`  

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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) 5a5I+* c  
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    ' Delete any z-shift(s) uDQ d48>  
    count = 0 H5^'J`0\  
    While GetOperationCount(eID)>count Co[  r
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        GetOperation eID, count, op B=u@u([.  
        If op.Type="ShiftZ" Then /NMd GKr  
            DeleteOperation eID,count }yx'U 3  
            count=count-1 PZeVjL?E  
        End If JV(|7Sk  
        count=count+1 hgfCM  
    Wend 5~aSkg,MD  
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    'Set new z-shift E
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    op.Type = "ShiftZ" /DQoM@X  
    op.val1 = tlens z"=#<C  
    op.parent = parID "Z&{  
    AddOperation eID, op hi`\3B  
    Print "Set lens thickness = " & tlens -P(q<T2MV'  
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    '************************************************************************* ! Hdg $,  
    'Lens index of refraction HGh`O\f8  
    '************************************************************************* 2/E3~X7  
    eID = FindMaterial( "Lens" ) Z+(V'e;  
    GetModelMaterial eID, mat O292JA  
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    mat.Nd = nlens '7u#uL,pa1  
    SetModelMaterial eID, mat P7 H-Dw  
    Print "Set lens index of refraction = " & nlens aVM@^n  
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    '************************************************************************* dfO@Yo-?*'  
    'Pupil diameter Ke~a  
    '************************************************************************* Ex&f}/F  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) 7'J}|m{7  

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    'Adjust pupil diameter (trimming volume inner hole) !3kyPoq+  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" V[HHP_  
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    ' Adjust pupil location to just in front of the lens Jc-0.^]E}  
    parID = FindFullName( "Geometry.Arizona Eye" ) C-@@`EP  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) df&d+jY  
    count = 0 IgG@v9'  
    While GetOperationCount(eID)>count M})2y+  
        GetOperation eID, count, op {h7*a=  
        If op.Type="ShiftZ" Then *jCXH<?R  
            DeleteOperation eID,count rgRh ySud  
            count=count-1 4 "@BbVYR  
        End If NMJ230?  
        count=count+1 v,KH2 (N  
    Wend vaxNF%^~yN  
    op.Type = "ShiftZ" zq8z#FN  
    op.val1 = taq-0.01 4IG'Tm  
    op.parent = parID y9=/kFPRm  
    AddOperation eID, op B&0-~o3WP  
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    Print "Set pupil diameter = " & pupilDiam ZgcA[P  
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    'Update AZ Eye subassembly Description : N>5{  
    eID = FindFullName( "Geometry.Arizona Eye" ) ]mn(lK  
    GetEntity eID, entity Fm#4;'x5E  
    entity.Description = "Accommodation = " & A & "D" B=(m;A#G  
    SetEntity eID, entity s~6?p% 2]  
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    Update ujXC#r&  
    Print "DONE!" sG%Q?&-
 
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End Sub /E2
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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： S@k4k^Vg  
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Accommodation = 4 Diopters 2w$o;zz1  
Pupil Diameter = 4 mm 9} :n  
Set aqueous humor thickness = 2.81 ;4z6="<Y  
Set anterior lens radius = 10.4 and conic constant = -2.375869 _Su? VxU  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 W=M]1hy  
Set lens thickness = 3.927 pfe9n[  
Set lens index of refraction = 1.42672 $-|`#|CBd  
Set pupil diameter = 4 Z
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DONE! xm6=l".%z  
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