[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。 Y"G$^3% (]  
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模型 Ab8~'<F$B  
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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。 {ZN{$Ad3/  
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在FRED中使用0屈光度来创建的，光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. gO_^{>2  
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光源 *)g*5kKN  
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多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 0Rrz   
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除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处，并增加了pre-propagation distance= -8。尽管光线在光瞳处创建，规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射，而不是在光瞳处入射。 E8#y
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在往下看是内置的脚本用来修改屈光度，使其为4（250mm），光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 3l<)|!f]g  
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视网膜的散射 .oAg (@^6  
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在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 CDoZv""  
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注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 >Py;6K  
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脚本 oPm1`x  
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内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： ax7ub  
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如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 rbQA6_U 5A  
余下的脚本计算与屈光度有关的所有参数。 aH,0+|  
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分析 nb(#;3DQ  
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屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 j$N`JiKM  
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脚本代码 78y4nRQ*  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. 1B,RRHXn6  
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Dim entity As T_ENTITY Vk{0)W7  
Dim op As T_OPERATION NVJvCs)3f  
Dim mat As T_MODELMATERIAL 0y2iS't  
Dim A As Double 2$\Du9+  
Dim pupilDiam As Double B@.U\.  
Dim eID As Long +%
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Dim parID As Long mZMLDs:  
Dim count As Integer qhLe[[>  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double EDL<J1%  
Dim tlens As Double, nlens As Double f<0-'fGJd  
Dim curv As Double, conic As Double e,:@c3I  
Dim ok As Long +#'exgGU^[  
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Sub Main \HTXl]  
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    '用户输入对话框 CNfeHMT  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 G)'cd D1  
        TextBox 220,21,40,21,.TextBox1 'default: 0 {Qlvj.Xw  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 HO&#Lv  
        OKButton 40,91,90,21 8~}Ti*Urc  
        CancelButton 190,91,90,21 %|l*=v  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 w9i1ag  
        TextBox 220,49,40,21,.TextBox2 'default: 4 ]>*Z 1g;
  
    End Dialog :mY(d6#A>  
    Dim dlg As UserDialog \u",bMQF  
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    ok = Dialog (dlg) !mq+Oz~  
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    If ok=0 Then    'cancel button was pressed j/dNRleab  
        Print "Execution cancelled."
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        End o`hF1*yp  
    End If %UgyGQeo  
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    'Assign accommodation and pupil diameter & use defaults if field left empty M0"xDvQ  
    If dlg.TextBox1 = "" Then $p}7CP  
        A = 0           'Default accommodation S(9fGh  
    Else /v=MGX@r  
        A = CDbl(dlg.TextBox1) XZIj' a0d  
    End If C
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    If dlg.TextBox2 = "" Then Q6"r^wWx  
        pupilDiam = 4   'Default pupil diameter )P\ec  
    Else UT]LF#.(  
        pupilDiam = CDbl(dlg.TextBox2) ^EM##Ss_  
    End If DkQy.  
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    Print " " e9N"{kDs6  
    Print "Accommodation = " & A & " Diopters" \BUr2]  
    Print "Pupil Diameter = " & pupilDiam & " mm" M nH4p  
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    ' Calculate new parameters with accommodation /R 2:Js  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness VT;$:>!+  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens hPD2/M  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens ~qco -b  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens o;
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    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens kCLz@9>FQ  
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    tlens = 3.767 + 0.04*A                  'Lens thickness h]vA%VuE'E  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction 4CfPa6_  
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    'Adjust parameters to account for accommodation |HhUU1!  
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    '************************************************************************* I>b!4?h  
    'Aqueous thickness (Position of Lens) ?_}[@x  
    '************************************************************************* 9m%[ y1v0  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) 7L? ~;;L$  
    GetCustomElement eID, entity "qR qEpD%  
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    parID = FindFullName( "Geometry.Arizona Eye" ) |jO&qT]{  
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    ' Delete any shift(s) in z W?5^cEF  
    count = 0 -HS(<V=a?k  
    While GetOperationCount(eID)>count yG2j!D  
        GetOperation eID, count, op P*)}ENY  
        If op.Type="ShiftZ" Then )TBBYCL3  
            DeleteOperation eID,count u])N^AY"sj  
            count=count-1 aQ46e
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        End If Ef:.)!;jy  
        count=count+1 E@Q+[~H}  
    Wend [#M^:Q  
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    'Set new shift in ^e8~e
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    op.Type = "ShiftZ" s(r(! FZ  
    op.val1 = taq =Y?M#3P.I  
    op.parent = parID -[".km  
    AddOperation eID, op %Z}A+Rv+*m  
    Print "Set aqueous humor thickness = " & taq-0.55 'k{pWfn=<  
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    '************************************************************************* pg [F{T<  
    'Radius and conic constant of anterior lens gj0gs  
    '************************************************************************* CES^ c-. k  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) DnMfHG[<  
    GetConic eID, entity, curv, conic /P Qz$e-!Y  
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    SetConic eID, entity, 1/Rant, CCant #Bj.#5  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant "z1\I\ ^  
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    '************************************************************************* @M?;~M?B]J  
    'Radius and conic constant of posterior lens WIa4!\Ky!  
    '************************************************************************* N3!x7J7A  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) h%8[];*DpN  
    GetConic eID, entity, curv, conic %J5zfNe)&  
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    SetConic eID, entity, 1/Rpost, CCpost nNSq6 Cj  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost \/xWsbG\  
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    '************************************************************************* Pe6MDWR  
    'Lens thickness (Position of posterior lens surface) 4nN%5c~=  
    '************************************************************************* ' jf$3  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) 1 `hj]@.]  
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    ' Delete any z-shift(s) A36dj  
    count = 0 ps\A\aggML  
    While GetOperationCount(eID)>count U7bbJ>U_|  
        GetOperation eID, count, op $Y5R^Y  
        If op.Type="ShiftZ" Then p-POg%|&<  
            DeleteOperation eID,count \tc4DS  
            count=count-1 Z@nWx]iz  
        End If Y6~/H  
        count=count+1 k|(uIU* ]  
    Wend ,B_Nz}\8  
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    'Set new z-shift PHU#$LG  
    op.Type = "ShiftZ" dMK|l   
    op.val1 = tlens rvgArFf}]  
    op.parent = parID Ikv@}^p 7  
    AddOperation eID, op }1=V`N(  
    Print "Set lens thickness = " & tlens OSY$qL2  
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    '************************************************************************* b_+dNoB  
    'Lens index of refraction 2Dgulx5kGZ  
    '************************************************************************* >k)}R|tJ  
    eID = FindMaterial( "Lens" ) kq&xH;9=.  
    GetModelMaterial eID, mat u(iEuF;7  
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    mat.Nd = nlens *p0n{F9  
    SetModelMaterial eID, mat P1tc*2Z  
    Print "Set lens index of refraction = " & nlens FH:^<^M  
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    '************************************************************************* *8{PoD   
    'Pupil diameter A Ch!D>C1  
    '************************************************************************* SIQ7oxS4  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) fTQRn  
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    'Adjust pupil diameter (trimming volume inner hole) _+73Y'  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" wQ-pIi{G  
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    ' Adjust pupil location to just in front of the lens BV_rk^}Ur  
    parID = FindFullName( "Geometry.Arizona Eye" ) >={?H?C  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) VSns_>o  
    count = 0 ZZ|a`U  
    While GetOperationCount(eID)>count M*li;  
        GetOperation eID, count, op nQbF~  
        If op.Type="ShiftZ" Then AWsy9  
            DeleteOperation eID,count ElLDSo@WvR  
            count=count-1 M+4>l\  
        End If 30cZz  
        count=count+1 4&]Sb}  
    Wend rV;X1x}l  
    op.Type = "ShiftZ" B'<k*9=Nv8  
    op.val1 = taq-0.01 Jse;@K5y  
    op.parent = parID 3Run.Gv\  
    AddOperation eID, op mNhVLB  
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    Print "Set pupil diameter = " & pupilDiam @)nxX))a  
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    'Update AZ Eye subassembly Description r: Ij\YQ  
    eID = FindFullName( "Geometry.Arizona Eye" ) O_-Lm4g?4  
    GetEntity eID, entity {6}H}_(]  
    entity.Description = "Accommodation = " & A & "D" P|c[EUT  
    SetEntity eID, entity B q/<kEgM  
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    Update O)v?GQRj  
    Print "DONE!" Nmu;+{19M  
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End Sub hdW}._  
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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： ;QZ}$8D6Q  
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Accommodation = 4 Diopters W%$sA}O  
Pupil Diameter = 4 mm 5MU-Eu|*>  
Set aqueous humor thickness = 2.81 :g@H=W  
Set anterior lens radius = 10.4 and conic constant = -2.375869 }C6RgE.6<  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 SbrKNADH%  
Set lens thickness = 3.927 y$-;6zk\]  
Set lens index of refraction = 1.42672 )g;*u,C  
Set pupil diameter = 4 P[Q3z$I}  
DONE! R1A|g=kF  
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