[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 &
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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。 tsL ; wT_  
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模型 n1{[CCee@  
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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。 l)*(UZ"  
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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. "+T`{$Z=C  
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光源 JRw,${W  
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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。
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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。 ^)?Wm,{"w  
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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。 L7;~4_M9.V  
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视网膜的散射 OcO/wA(&{  
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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。 T>'O[=UWh  
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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。 babL.Ua8o  
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脚本 XDJE]2^52?  
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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： eZAMV/]jH  
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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。 qWheoyAB  
余下的脚本计算与屈光度有关的所有参数。 sFz0:SqhE  
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分析 e O\72? K  
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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。 9
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脚本代码 } 7 o!  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. ?'6@m86d  
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Dim entity As T_ENTITY H]R/=OYBUh  
Dim op As T_OPERATION )1 T2u  
Dim mat As T_MODELMATERIAL K 77iv  
Dim A As Double NplyvjQN;  
Dim pupilDiam As Double cb /Q<i  
Dim eID As Long S[3"?$3S  
Dim parID As Long q7Hf7^a  
Dim count As Integer F]yB=  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double "jum*<QZz  
Dim tlens As Double, nlens As Double H_$?b  
Dim curv As Double, conic As Double U_"!\lI_yg  
Dim ok As Long a
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Sub Main Gn8sB  
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    '用户输入对话框 EcB !bf  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 d-_V*rYU  
        TextBox 220,21,40,21,.TextBox1 'default: 0 -p_5T*R  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 ML905n u  
        OKButton 40,91,90,21 ~r.R|f]IQ  
        CancelButton 190,91,90,21 &|Duc} t  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 6i[Ts0H%<!  
        TextBox 220,49,40,21,.TextBox2 'default: 4 !{.CGpS ]  
    End Dialog Dm)B? H"  
    Dim dlg As UserDialog P0.cF]<m  
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    ok = Dialog (dlg) tRdf:F\X  
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    If ok=0 Then    'cancel button was pressed OKMdyyO<l  
        Print "Execution cancelled." gPKf8{#%e  
        End 8<C*D".T$  
    End If w.
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    'Assign accommodation and pupil diameter & use defaults if field left empty QgqJ #  
    If dlg.TextBox1 = "" Then "sN%S's  
        A = 0           'Default accommodation G{} 2"/  
    Else jjV'`Vy)  
        A = CDbl(dlg.TextBox1) 754MQK|g  
    End If ki'$P.v{$w  
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    If dlg.TextBox2 = "" Then $v@$C
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        pupilDiam = 4   'Default pupil diameter 031"D*W'i  
    Else eK:?~BI!  
        pupilDiam = CDbl(dlg.TextBox2) >)ekb7  
    End If
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    Print " " uslu-|b!%  
    Print "Accommodation = " & A & " Diopters"  1c0'i  
    Print "Pupil Diameter = " & pupilDiam & " mm" Zt!#KSF7%  
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    ' Calculate new parameters with accommodation bZYayjxZ5i  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness @JbxGi  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens @A1f#Ed<
 
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens [~{F(Le  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens  :RnUNz  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens u8zL[]>  
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    tlens = 3.767 + 0.04*A                  'Lens thickness wb.yGfJ  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction eC!=4_lx)  
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    'Adjust parameters to account for accommodation zo
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    '************************************************************************* s>J5.Z7"'j  
    'Aqueous thickness (Position of Lens) E5^\]`9P  
    '************************************************************************* OvX&5Q5  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) d0 )725Ia  
    GetCustomElement eID, entity h< r(:.%!}  
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    parID = FindFullName( "Geometry.Arizona Eye" ) |jiIx5qr  
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    ' Delete any shift(s) in z fmuh9Z  
    count = 0 A]|w1nq  
    While GetOperationCount(eID)>count }%u#TwZ  
        GetOperation eID, count, op L(;$(k-/(  
        If op.Type="ShiftZ" Then \\dUp>1=  
            DeleteOperation eID,count \t!~s^Oox  
            count=count-1 9)oi_U.  
        End If <r#FI8P;X  
        count=count+1 oy8jc];SO  
    Wend v?VDASR2`  
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    'Set new shift in r'*$'QY-N  
    op.Type = "ShiftZ" /i,n75/y?  
    op.val1 = taq ZHNL~=r}  
    op.parent = parID gQPw+0w  
    AddOperation eID, op %hSQ\T<8[o  
    Print "Set aqueous humor thickness = " & taq-0.55 4QA~@pBX^{  
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    '************************************************************************* qzZ/%{Ak  
    'Radius and conic constant of anterior lens 3>h2W  
    '************************************************************************* 8%,#TMOg  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) L?h?LZnq  
    GetConic eID, entity, curv, conic ~,}|~  
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    SetConic eID, entity, 1/Rant, CCant 9f! M1  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant e-rlk5k%f  
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    '************************************************************************* ]6e(-v!U  
    'Radius and conic constant of posterior lens 76tn`4NIP  
    '************************************************************************* OIPY,cj~  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) |6Q5bV  
    GetConic eID, entity, curv, conic e`n ZiM>  
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    SetConic eID, entity, 1/Rpost, CCpost zFjz%:0  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost K83'`W^  
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    '************************************************************************* T`E0_ZU
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    'Lens thickness (Position of posterior lens surface) HEVjK$  
    '************************************************************************* \\R}3 >Wc  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) "9_$7.q<y  
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    ' Delete any z-shift(s) fmixWL7.Zg  
    count = 0 D&):2F^9.  
    While GetOperationCount(eID)>count N0p6xg~  
        GetOperation eID, count, op p}QDX*/sSu  
        If op.Type="ShiftZ" Then (I$%6JO:  
            DeleteOperation eID,count T]%-Ri  
            count=count-1 ]Kt@F0U<o  
        End If o-=|}u]mz  
        count=count+1 %&6QUv^  
    Wend @:?[R&`  
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    'Set new z-shift >=0]7k;  
    op.Type = "ShiftZ" 5?^#v  
    op.val1 = tlens vxZ'-&;t  
    op.parent = parID &x1A{j_  
    AddOperation eID, op p-iFe\+  
    Print "Set lens thickness = " & tlens 67(s\  
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    '************************************************************************* \ivxi<SR  
    'Lens index of refraction ;M.Q=#;E  
    '************************************************************************* t1w]L  
    eID = FindMaterial( "Lens" ) DC h !Z{I  
    GetModelMaterial eID, mat \#,2#BmO"E  
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    mat.Nd = nlens #KiJ{w'  
    SetModelMaterial eID, mat [`@M!G.  
    Print "Set lens index of refraction = " & nlens w x]?D%l  
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    '************************************************************************* RHFRN&RU$  
    'Pupil diameter
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    '************************************************************************* qKD  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) 4G,FJjE`p  
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    'Adjust pupil diameter (trimming volume inner hole) "kP,v&n  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" 1L!;lP2  
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    ' Adjust pupil location to just in front of the lens 7Vy_Cec1  
    parID = FindFullName( "Geometry.Arizona Eye" ) DT`HS/~fH  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) -*k2:i`  
    count = 0 ~s+vJvWz  
    While GetOperationCount(eID)>count bh@CtnO  
        GetOperation eID, count, op Yk|6?e{+)  
        If op.Type="ShiftZ" Then b,^ "-r  
            DeleteOperation eID,count =_`q;Tu=  
            count=count-1 jQV[zcM  
        End If _-C/sp^  
        count=count+1 xfeED^?  
    Wend VZt%cq  
    op.Type = "ShiftZ" mS'Ad<  
    op.val1 = taq-0.01 OWibmX
 
    op.parent = parID [P+kQBLpL  
    AddOperation eID, op !\7M7  
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    Print "Set pupil diameter = " & pupilDiam ',R%Q0Q  
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    'Update AZ Eye subassembly Description IB&G#2M<  
    eID = FindFullName( "Geometry.Arizona Eye" ) >T]9.`xhK  
    GetEntity eID, entity h,$CJdDY]  
    entity.Description = "Accommodation = " & A & "D" GKFRZWXdT  
    SetEntity eID, entity P*!`AWn  
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    Update j;`pAN('  
    Print "DONE!" r<ww%2HTS
 
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End Sub cjL)M=pIS  
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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： [e` |<  
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Accommodation = 4 Diopters S9!KI)  
Pupil Diameter = 4 mm %/uLyCUZ  
Set aqueous humor thickness = 2.81 #HgNwM  
Set anterior lens radius = 10.4 and conic constant = -2.375869 [ iTP:8  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 +A?P4}  
Set lens thickness = 3.927 aM $2lR])J  
Set lens index of refraction = 1.42672 =p4n@C  
Set pupil diameter = 4 xmnBG4,f  
DONE! c?CD;Pk  
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