[转载]FRED运用：Arizona眼睛模型 [复制链接]

简介 $+JS&k/'m  
人眼光学模型可用来设计眼科用设备，光学系统注定了要与人眼一起使用。本文演示了这样一个模型：Arizona眼睛模型，在Jim Schwiegerling教授的书中有详细描述：《Field Guide to Visual and Ophthalmic Optics》。AZ眼睛模型达到了基于平均临床数据所决定的轴上和轴外像差等级。FRED文件包含了此眼睛模型及几个用来分析它的光源，并包括一个基于想要的屈光度来调整模型的内嵌脚本。 r3E!dTDWq  
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模型 E`int?C!  
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模型的定义如表1种所示，由半径、圆锥常数、折射率、阿贝数、到下一面的距离等一系列表面组成。一些参数由屈光度（A）来决定。 6!x&LoM  
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在FRED中使用0屈光度来创建的，光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. Hnknly  
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光源 -fhN"B)  
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多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 >~%e$a7}+  
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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。 O[tvR:Nh  
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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。 Lbe\@S  
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视网膜的散射 f}g\D#`]/  
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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。 7Q\|=$2  
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注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 F, U*
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脚本 W3`>8v1?o  
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内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： fXrXV~'8  
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如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 U qG .:@T  
余下的脚本计算与屈光度有关的所有参数。 !9 fz(9  
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分析 Aw&tP[N[  
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屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 Y*mbjyt[?X  
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脚本代码 ySI~{YVM  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. %,+leKs  
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Dim entity As T_ENTITY >X*Mio8P#  
Dim op As T_OPERATION 4CGPOc  
Dim mat As T_MODELMATERIAL NcY608C  
Dim A As Double 'X shmZ0&  
Dim pupilDiam As Double N},n `Yl.  
Dim eID As Long Jx'i2&hGN  
Dim parID As Long '\jd#Kn'h  
Dim count As Integer l<M'=-Y  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double mKYeD%Pm*  
Dim tlens As Double, nlens As Double 6e7{Iy  
Dim curv As Double, conic As Double N!*_La=TuH  
Dim ok As Long Z@hD(MS(C  
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Sub Main fu~+8CE.  
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    '用户输入对话框 SNY~9:;]f  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 ~on(3|$  
        TextBox 220,21,40,21,.TextBox1 'default: 0 }NsUnbxT  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 {3&|tk!*  
        OKButton 40,91,90,21 ! !
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        CancelButton 190,91,90,21 {d?$m*YR3`  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 Qt|c1@J  
        TextBox 220,49,40,21,.TextBox2 'default: 4 np~~mdmRK  
    End Dialog "s\L~R.&  
    Dim dlg As UserDialog OgX6'E\E  
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    ok = Dialog (dlg) 7'OtruJ  
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    If ok=0 Then    'cancel button was pressed s: 3z'4oX  
        Print "Execution cancelled." D-,L&R!`  
        End M,ir`"s  
    End If JgHM?AWg|  
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    'Assign accommodation and pupil diameter & use defaults if field left empty 2.d|G`  
    If dlg.TextBox1 = "" Then umd
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        A = 0           'Default accommodation H{t_xL)k.  
    Else @BNEiOAZ#  
        A = CDbl(dlg.TextBox1) KM`eIw>8  
    End If *28pRvY:b  
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    If dlg.TextBox2 = "" Then bO<CR  
        pupilDiam = 4   'Default pupil diameter X6^},C'E.:  
    Else `SVmQSwO[  
        pupilDiam = CDbl(dlg.TextBox2) zq%D/H6J,  
    End If Ux+Q  
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    Print " " \lSU  
    Print "Accommodation = " & A & " Diopters" JAI)Eqqv]  
    Print "Pupil Diameter = " & pupilDiam & " mm" hUm'8)OJ  
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    ' Calculate new parameters with accommodation +&["HoKg}&  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness ,6r{VLN  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens ,k G>?4  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens k#5}\w!  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens D0BI5q  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens 57 #6yXQ  
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    tlens = 3.767 + 0.04*A                  'Lens thickness $U/YR&vcw  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction ~/_SMPLo  
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    'Adjust parameters to account for accommodation j+HHQd7Y  
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    '************************************************************************* kkK kf'  
    'Aqueous thickness (Position of Lens) (< =}]v  
    '************************************************************************* |^9BA-nA  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) ]f1{n  
    GetCustomElement eID, entity 72,rFYvpK  
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    parID = FindFullName( "Geometry.Arizona Eye" ) ]@Sj`J[fd  
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    ' Delete any shift(s) in z $k$4% 7  
    count = 0 _FwK-?4E-  
    While GetOperationCount(eID)>count }=!,o  
        GetOperation eID, count, op KOwOIDt  
        If op.Type="ShiftZ" Then V"!G2&  
            DeleteOperation eID,count <`0h|m'U  
            count=count-1 0T>H)c6:\  
        End If Ig5L$bAM~  
        count=count+1 &
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    Wend wYlf^~#
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    'Set new shift in W}|'#nR  
    op.Type = "ShiftZ" PH{_,X  
    op.val1 = taq z;u  
    op.parent = parID F H1Z2  
    AddOperation eID, op ]#.]/f >-  
    Print "Set aqueous humor thickness = " & taq-0.55 YA&g$
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    '************************************************************************* *~/OOH$"  
    'Radius and conic constant of anterior lens LjU'z#  
    '************************************************************************* =rR~`  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) ?i`l[+G  
    GetConic eID, entity, curv, conic K|oacOF9  
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    SetConic eID, entity, 1/Rant, CCant |!F5.%PY  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant g&n)fF  
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    '************************************************************************* 3R&lqxhg  
    'Radius and conic constant of posterior lens wd/< 8>2X  
    '************************************************************************* . <tq61  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) b}Zd)2G  
    GetConic eID, entity, curv, conic q:<{% U$  
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    SetConic eID, entity, 1/Rpost, CCpost fQP{|+4  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost }(<%`G6N  
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    '************************************************************************* }y%oT P&  
    'Lens thickness (Position of posterior lens surface) !p1qJ
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    '************************************************************************* U?!>Nd  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) ,hVvve,j}  
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    ' Delete any z-shift(s) dik9 >*"|o  
    count = 0 *9p |HX=  
    While GetOperationCount(eID)>count 7n90f2"m  
        GetOperation eID, count, op {-A^g!jT&  
        If op.Type="ShiftZ" Then X";@T.ZGut  
            DeleteOperation eID,count _GKB6e%  
            count=count-1 3/#:~a9Q  
        End If -n0C4kZ2o  
        count=count+1 O+RP3ox"  
    Wend GQ_p-/p R  
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    'Set new z-shift X w.p  
    op.Type = "ShiftZ" zX#%{#9  
    op.val1 = tlens ^;c16  
    op.parent = parID n8hRaNHl2  
    AddOperation eID, op VtOZ%h[#  
    Print "Set lens thickness = " & tlens j|tC@0A  
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    '************************************************************************* IHp_A  
    'Lens index of refraction KQ[!o!%  
    '************************************************************************* ql<rU@  
    eID = FindMaterial( "Lens" ) LB/C-n.`  
    GetModelMaterial eID, mat l6kmS  
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    mat.Nd = nlens VB<Jf'NU  
    SetModelMaterial eID, mat "G:<7oTa  
    Print "Set lens index of refraction = " & nlens V]S1X^
 
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    '************************************************************************* VzJ5.mRQ  
    'Pupil diameter oQ=>'w  
    '************************************************************************* -{ u*qtp  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) 1.q_f<
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    'Adjust pupil diameter (trimming volume inner hole) VGqa)ri"  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" _owjTo}  
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    ' Adjust pupil location to just in front of the lens umLb+GbI4  
    parID = FindFullName( "Geometry.Arizona Eye" ) xug)aE
 
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) pb0E@C/R  
    count = 0 )~jqW=d 2  
    While GetOperationCount(eID)>count
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        GetOperation eID, count, op 'lZ.j&  
        If op.Type="ShiftZ" Then !AJ]j|@VBd  
            DeleteOperation eID,count @/UfDye  
            count=count-1 iK{T^vvk  
        End If }`yiT<z  
        count=count+1 s/Xb^XjS1  
    Wend &L^CCi  
    op.Type = "ShiftZ" &6Il(3-^  
    op.val1 = taq-0.01 #0;HOeIiH  
    op.parent = parID zX{.^|  
    AddOperation eID, op ESb ]}c:  
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    Print "Set pupil diameter = " & pupilDiam X5 ITF)&  
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    'Update AZ Eye subassembly Description 8dK0o>|}  
    eID = FindFullName( "Geometry.Arizona Eye" ) *^ \FIUd  
    GetEntity eID, entity  uIMe  
    entity.Description = "Accommodation = " & A & "D" S'B6jJK2x  
    SetEntity eID, entity >5T_g2pkv  
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    Update nU`Lhh8y  
    Print "DONE!" ji
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End Sub W4YE~  
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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： dRvin[R8  
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Accommodation = 4 Diopters q6`GI6  
Pupil Diameter = 4 mm }jF+`!*
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Set aqueous humor thickness = 2.81 GJ'spgz  
Set anterior lens radius = 10.4 and conic constant = -2.375869 3kmeD".  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 ep(g`e  
Set lens thickness = 3.927 VF0dE  
Set lens index of refraction = 1.42672 8n4V cu  
Set pupil diameter = 4 #G3N(wV3  
DONE! /-0' Qa+*  
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