[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 6;:D!},'c  
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。 )92(C  
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模型 qD\9h`a  
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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。 6,jCO@!   
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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. dmXfz D  
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光源 Ssz;d&93  
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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 tWMm:(  
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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。 Y DHP-0?  
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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。 0fBw
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视网膜的散射 ^o _J0 ]m  
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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。 gl`J(  
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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。 1;c>#20  
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脚本 #[x*0K-h  
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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： CC"
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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。 'v0rnIsI?  
余下的脚本计算与屈光度有关的所有参数。 gy,)%{,G  
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分析 p.8  
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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。 |4pl}:g/Z  
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脚本代码 VK*`&D<P  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. b+ycEs=_  
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Dim entity As T_ENTITY <+q`Dk  
Dim op As T_OPERATION NrXIaN  
Dim mat As T_MODELMATERIAL \ILNx^$EL  
Dim A As Double '&,p>aM  
Dim pupilDiam As Double :/5GHfyj  
Dim eID As Long ic!% }S?  
Dim parID As Long }AB_i'C0  
Dim count As Integer DBaZcO(U  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double uK(]@H7~!c  
Dim tlens As Double, nlens As Double (n>Gi;u(R  
Dim curv As Double, conic As Double `p* 43nV  
Dim ok As Long J%r:"Jm[y1  
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Sub Main Uvc$&j^k  
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    '用户输入对话框 {j`8XWLZZN  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 S},Cz  
        TextBox 220,21,40,21,.TextBox1 'default: 0 ^J hs/HV  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 k\SqDmv  
        OKButton 40,91,90,21 rA?<\*  
        CancelButton 190,91,90,21 T_UJ?W  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 (j@c946z""  
        TextBox 220,49,40,21,.TextBox2 'default: 4 JCBX?rM/  
    End Dialog O"o|8 l}M/  
    Dim dlg As UserDialog #*y.C[^5{  
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    ok = Dialog (dlg) @VIY=qh  
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    If ok=0 Then    'cancel button was pressed ??.aLeF&  
        Print "Execution cancelled." |X XO0  
        End J| wk})?  
    End If hPz=Ec<zW  
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    'Assign accommodation and pupil diameter & use defaults if field left empty ,66(*\xT  
    If dlg.TextBox1 = "" Then p&<n_b  
        A = 0           'Default accommodation d(RMD  
    Else C:^ :^y  
        A = CDbl(dlg.TextBox1) V*2*5hx  
    End If k1yqerA  
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    If dlg.TextBox2 = "" Then r9M3rj]  
        pupilDiam = 4   'Default pupil diameter ?
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    Else 7\yh(+kN  
        pupilDiam = CDbl(dlg.TextBox2) - uO(qUa#  
    End If 4B[pQlg  
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    Print " " ?,v& o>*  
    Print "Accommodation = " & A & " Diopters" Ho*B<#&(A|  
    Print "Pupil Diameter = " & pupilDiam & " mm" WwWOic2  
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    ' Calculate new parameters with accommodation <<gW`KF   
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness ;3& wO~lW  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens  gsi2  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens *5s*-^'#!  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens baTd;`Pn  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens "x;FE<I  
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    tlens = 3.767 + 0.04*A                  'Lens thickness SQU@JKi;g  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction Ho(}_Q&  
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    'Adjust parameters to account for accommodation A-L)2.M  
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    '************************************************************************* o2$A2L9P  
    'Aqueous thickness (Position of Lens) ZR|s]'  
    '************************************************************************* Wql=PqF  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) 1TfFWlf[B  
    GetCustomElement eID, entity ~~"U[G1  
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    parID = FindFullName( "Geometry.Arizona Eye" ) Ny`SE\B+/  
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    ' Delete any shift(s) in z jJvd!,=)  
    count = 0 @QnKaZ8jW  
    While GetOperationCount(eID)>count 1\/vS$bi(  
        GetOperation eID, count, op Si23w'T  
        If op.Type="ShiftZ" Then ]Y->EME:W  
            DeleteOperation eID,count =I&BO[d  
            count=count-1 v5?)J91  
        End If }c=Y<Cdh  
        count=count+1 [z7]@v6b  
    Wend zd$iDi($  
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    'Set new shift in = 4|"<8'  
    op.Type = "ShiftZ" &jg>X+;  
    op.val1 = taq ]0(ZlpT  
    op.parent = parID S_??G:i  
    AddOperation eID, op pV:44  
    Print "Set aqueous humor thickness = " & taq-0.55 wM;=^br  
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    '************************************************************************* &E!m(|6?+  
    'Radius and conic constant of anterior lens B2_fCSlg  
    '************************************************************************* ,.=7{y~  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) ?/@XJcm+  
    GetConic eID, entity, curv, conic ;.$vDin6  
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    SetConic eID, entity, 1/Rant, CCant x2b t^!t.  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant MX!N?k#KhP  
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    '************************************************************************* ZtGkMd$  
    'Radius and conic constant of posterior lens ,|zwY~lt5  
    '************************************************************************* /9D mK%d  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) Ho&f[T(  
    GetConic eID, entity, curv, conic |?f~T"|>  
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    SetConic eID, entity, 1/Rpost, CCpost i"DyXIrk2  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost 6y?uH;SL  
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    '************************************************************************* [(8s\>T  
    'Lens thickness (Position of posterior lens surface) H#nJWe_9A  
    '************************************************************************* &g*1
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) J=O_nup6C  
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    ' Delete any z-shift(s) g86^Z%c(k  
    count = 0 :Us+u-~  
    While GetOperationCount(eID)>count x @9rc,by  
        GetOperation eID, count, op q!5`9u6  
        If op.Type="ShiftZ" Then !@T~m1L eY  
            DeleteOperation eID,count z<yqQ[  
            count=count-1 v`7~#Avhz  
        End If Fy6Lz.baB  
        count=count+1 (Nf!E[}Z  
    Wend Ck/w:i@>?  
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    'Set new z-shift jEP'jib%  
    op.Type = "ShiftZ" i{HzY[  
    op.val1 = tlens gKWUHlQY  
    op.parent = parID :2A-;P4  
    AddOperation eID, op ):L0{W{  
    Print "Set lens thickness = " & tlens 3|URlz  
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    '************************************************************************* {e[~1]j3  
    'Lens index of refraction 9r
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    '************************************************************************* 6s
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    eID = FindMaterial( "Lens" ) A*]sN8  
    GetModelMaterial eID, mat ojIGfQV  
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    mat.Nd = nlens <hgfgk7<  
    SetModelMaterial eID, mat N{Pa&/V  
    Print "Set lens index of refraction = " & nlens zrC1/%T  
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    '************************************************************************* I "R<XX  
    'Pupil diameter kidv^`.H$w  
    '************************************************************************* m^tf=O<  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) #Qu|9Q[QH  
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    'Adjust pupil diameter (trimming volume inner hole) PvxU.  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" ]0}NF  
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    ' Adjust pupil location to just in front of the lens `@<)#9'A  
    parID = FindFullName( "Geometry.Arizona Eye" ) eQ=6< ^KZ  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) )@.0ai  
    count = 0 U[ogtfv`
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    While GetOperationCount(eID)>count Jb7^'P  
        GetOperation eID, count, op [bBPs&7u  
        If op.Type="ShiftZ" Then !}"PHby5N  
            DeleteOperation eID,count 2P|j<~JS  
            count=count-1 t6%zfm   
        End If j4(f1  
        count=count+1 'H1k  
    Wend sA,2gbW  
    op.Type = "ShiftZ" I$fm"N  
    op.val1 = taq-0.01 .;:dG  
    op.parent = parID Z
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    AddOperation eID, op RAxp2uif  
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    Print "Set pupil diameter = " & pupilDiam *Oh]I|?  
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    'Update AZ Eye subassembly Description lBG"COu  
    eID = FindFullName( "Geometry.Arizona Eye" ) ,@8*c0Y~<!  
    GetEntity eID, entity e{ZS"e`!  
    entity.Description = "Accommodation = " & A & "D" `] Zil8n  
    SetEntity eID, entity 4tp}  
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    Update };>~P%u32  
    Print "DONE!" ~8lB#NuN  
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End Sub %^;rYn3  
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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： Xc
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Accommodation = 4 Diopters |Tk'H&  
Pupil Diameter = 4 mm 7)x788Z6  
Set aqueous humor thickness = 2.81 +,4u1`c|$  
Set anterior lens radius = 10.4 and conic constant = -2.375869 )JR&  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 s)kr=zdyo  
Set lens thickness = 3.927 A+"'8%o9}  
Set lens index of refraction = 1.42672 $69d9g8-(!  
Set pupil diameter = 4  ByjgM`
 
DONE! FMqes5\ 3  
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