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The University of Glasgow (Uni-G) ECG Analysis Program
PW Macfarlane, B Devine, E Clark
University of Glasgow, Section of Cardiology and Exercise Medicine, Royal Infirmary, Glasgow
Abstract ------摘要
The University of Glasgow 12/15 lead ECG analysis program has been in continuous development for over 20 years. It has been adapted to meet the needs of different users and keep abreast of changes in terminology as well as new morphological features described in the literature.It is applicable to neonates as well as adults and takes account of racial variation in wave amplitudes. It has
capability for comparing serially recorded ECGs using one of two different approaches. The many varying features of the software have led to the introduction of the descriptor Uni-G (unique) ECG analysis program.
格拉斯哥大學12/15導ECG分析程序已連續開發超過20年。它滿足不同用戶的需要並且使用最新的術語及最新的文獻中描述的形態特徵。適用於新生兒及成人，考慮到波形幅度上種族差異。能夠用兩種不同的方法比較連續記錄的ECG。很多軟件特徵的改變引出本文對Uni-G（獨有的）ECG分析程序描述性的介紹。
1. Introduction ----------引言
Methods for the analysis of electrocardiograms using automated techniques were first investigated in the University of Glasgow in the late 1960’s. The earliest of publications introduced methods for processing waveforms recorded in groups of three leads
simultaneously, whether they were from X, Y, Z orthogonal leads or carefully selected groups of three leads from the 12-lead ECG, e.g. I, aVF, V1 (1,2). At the end of the 1970’s, a decision was made to move to develop a 12-lead ECG analysis program where all leads
were recorded simultaneously. A digital electrocardiograph was designed and built locally (3) and with this, ECGs could be collected in digital form to permit further development of software for analysis and interpretation. Indeed, this instrument was capable of acquiring 11 leads simultaneously so that a complete 12-lead plus an orthogonal 3-lead ECG could be obtained simultaneously.
在二十世紀六十年代末，格拉斯哥大學最先研究使用自動技術分析心電圖的方法。最早的文獻引入的方法用來處理同步記錄的三導波形，它們是X，Y，Z正交導聯或是從12導ECG中精心選擇的三個導聯，如I，aVF，V1。在二十世紀七十年代末，決定開發同步12導ECG分析程序。設計製造了一個數字心電圖機，利用它可以數字形式收集ECG，以供進一步開發分析和解釋軟件。實際上，這個儀器能同步獲取11導波形，因此完整的12導加正交3導ECG可以同步獲取。
Throughout the 1980’s, there was a major effort to collect databases from apparently healthy individuals of all ages from birth onwards and various publications presenting these data have appeared previously (4, 5). Full details will be published in a new edition of
Comprehensive Electrocardiology (6). Diagnostic criteria evolved therefrom in a variety of ways and a comprehensive 12-lead ECG analysis program was introduced for worldwide interpretation of ECGs (7).
整個二十世紀八十年代，投入很大的努力 從明顯健康的所用年齡段的個體，從剛一出生的個體 收集數據，發表了多種介紹這些數據的出版物。全部詳情將在新版《綜合心電學》中發表出來。診斷標準以多種方式向前演變，綜合12導ECG分析程序可在世界範圍內解釋ECG。
2. Methods ----------方法
2.1. Signal processing --------信號處理
The University of Glasgow (Uni-G) ECG interpretation program is based on an analysis of 8 or 11 simultaneously recorded leads acquired at 500 samples per second. The first stage in analysis is to apply a 50 Hz or 60 Hz notch filter to remove AC interference if this has not already been done by the electrocardiograph itself.Thereafter, methods for detection of excessive artefact are used and if leads are found to have an unacceptable quality of recording, the five seconds in which this is found, i.e. the first or second half of the recording is set to be a continuous value. It was found that it could be beneficial to retain five seconds of a lead given that noise
very often occurs in short, one or two second bursts.The next stage in the analytical process is QRS detection and typing. Effectively, a function based on a combination of available leads is formed from which putative QRS complexes are determined. Thereafter,
wave typing is undertaken using an iterative process whereby the first complex in Lead I is compared with the second to look for any differences. The technique is extended to include all complexes in this lead and then repeated for four other leads, as often it is only one or two leads which clearly show an aberrantly conducted complex.
Uni-G ECG解釋程序分析8個或11個同步記錄導聯，採樣率500 sps。分析第一步，如果心電圖機自己沒有去除50 或60Hz 交流乾擾，應用陷波去除。然後，檢測過度的僞跡，如果發現一些導聯上記錄質量差到無法接受，將發現噪聲大的5秒波形，即前5秒或後5秒，設置爲連續值。發現保留5秒波形是有益處的，這是考慮到噪聲出現的時間常常很短，一秒或兩秒時間內突然劇烈的出現噪聲。分析過程的下一步是QRS檢測和歸類。在結合可用導聯基礎上形成有效的檢測QRS複合波的函數。然後，使用迭代過程將波形歸類，I 導上第一個複合波和第二個複合波比較找出不同。這個技術擴展到這個導聯的所有複合波，然後在其它四個導聯上重複該過程，因爲常常只在一個或兩個導聯上異常傳導複合波清晰可見。
A complex selection procedure then decides which class of beat will be selected for averaging and subsequent interpretation. At this stage, cognisance has to be taken of whether or not any beats are paced and although the software itself has routines for detecting and
removing pacemaker stimuli, this is best achieved by front end processing with signals sampled at a much higher rate, e.g. 8,000 samples per second within the electrocardiograph firmware itself. If this is done, a list of pacemaker spike locations is forwarded to the Uni-G program and the spike artifacts are removed from the data.
複合波選擇程序確定哪一類心拍將用來疊加平均和接下來的解釋。在這一步，必須識別每個心拍是否是起搏心拍，儘管軟件自身有檢測和去除起搏脈衝的程序，最好在心電圖機自身固件裏面使用非常高的採樣率，例如8000sps，通過前端處理完成起搏脈衝檢測。如果檢測完成，起搏釘位置列表會被送到Uni-G程序，釘狀的僞跡會被從數據中去除。
The program has optional approaches to computing the average QRS cycle including a simple mean, a weighted mean and a median beat. In different commercial versions, manufacturers may utilise their own proprietary software for beat averaging if desired.
程序有幾種方法計算平均QRS週期，包括簡單的平均，加權平均，中間心拍。在本軟件不同的商業版中，如果需要製造商可以使用他們自己的軟件做心拍平均。
Different approaches to finding fiducial points have been tried, including a simple form of threshold crossing to a more complex template matching technique.Ultimately, a combination of these approaches has been adopted where, for example, QRS onset was found to
perform best with respect to a noisy test set using a threshold technique. On the other hand, T-end performed best using a template matching method. All QRST amplitudes are referred to QRS onset as are P wave measurements, which represents a departure from
an early approach where a straight line was fitted between P onset and P termination.
嘗試了不同的方法尋找基準點，包括簡單形式的閾值法到更爲複雜的模板匹配技術。最終，將這些方法結合起來使用，例如，在一個噪聲很大的測試集上閾值技術定位QRS起點效果最好。另一方面，使用模板匹配方法定位T波終點效果最好。所有QRST幅度都是參考QRS起點，P波幅度測量也是一樣，一個早期使用的方法是在P起點和P末尾之間用直線擬合，P波幅度測量值表示偏移距離。（--------英文理解上有疑問，P波幅度可能不參考QRS起點，而是用後面描述的直線擬合求偏移的方法來計算）
Individual QRS and T fiducial points are derived for all leads and a method of selecting the earliest QRS onset for example is utilised in order to determine a global QRS onset. A similar approach is adopted for QRS termination and the difference between the two global measurements is taken as the overall QRS duration. It was found optimum to utilise a common P onset and P termination in view of the unreliability of P wave detection in many ECGs.
對所有導聯單獨的QRS和T波推斷出基準點，使用一種方法，例如選取最早的QRS起點確定整體的QRS起點。類似的方法應用到QRS終點，兩個整體測量點之間的距離認爲是總體QRS時限。考慮到在很多ECG上P波檢測的不可靠性，發現使用公共的P起點和P終點是最佳的。
The wave measurement section of the program meets all the requirements of the relevant IEC test procedures as shown in Table 1.
程序波形測量部分滿足全部有關IEC 測試要求，結果見表1。
Table 1. This table shows the mean and standard deviation of the difference between the measurements made by the Glasgow program and by 5 referees in the 100 ECGs in the CSE measurement set. The values in [ ]are the IEC acceptable differences and standard
deviations for global durations and intervals for biological ECGS. It can be seen that the program results are well
within the recommended tolerances. Difference Mean Standard Deviation
這個表格顯示了 在CSE測量數據集100個ECG病例上 Glasgow程序和5個專家測量結果之間的差別 的均值和標準差。方括號中的值是 對生理ECG整體時限和間期測量 IEC可以接受的偏差和標準差。可見程序結果在建議的容許限度內。偏差的均值和標準差是
___________________________________________
P Duration 1.348 [10] 8.501 [15]
QRS Duration 1.609 [10] 6.354 [10]
PR Interval 1.043 [10] 6.747 [10]
QT Interval 0.602 [25] 9.669 [30]
____________________________________________
（-------CSE 測量數據集100個測試ECG指的是MA1_系列數據，每個記錄都包含專家的測量參考值麼？NO。
M--------may indicate "Measurement"
A --------indicate "Artifical",
MA_是從原始MO1_每個記錄中選取一個心拍後重復此心拍的人造品。
）
2.2. Rhythm analysis ----------------節律分析
The approach to rhythm analysis remains as before (8) in that three leads are used. These are II, V1 and a third lead selected from limb leads, usually the one with the largest P wave amplitude in the case of sinus rhythm.The basic rhythm strategy is to determine a dominant rhythm such as sinus rhythm or atrial fibrillation and thereafter determine any supplementary abnormalities such as first degree AV block or ventricular extrasystoles.
節律分析方法依然像以前一樣（參考文獻8），使用三個導聯進行分析。它們是II，V1 導聯和從肢體導聯選出的第三個導聯，通常是竇性節律情況下具有最大P波幅度的導聯。基本的節律分析策略是確定主導節律，例如竇性節律或房顫，然後確定更細緻的異常作爲補充，例如一度房室阻滯或室性期前收縮。
A significant amount of work was done on the use of neural networks to attempt to improve the accuracy of determining atrial fibrillation (9) but ultimately it was found that deterministic methods were equally acceptable.Differentiation of atrial fibrillation with rapid ventricular
response from sinus tachycardia with frequent supra VES still remains a difficult problem for automated techniques.
做了大量的工作嘗試用神經網絡來提高確定房顫的準確度，但是最終發現確定性的方法同樣可接受。區分房顫伴快速心室率 和 竇性心動過速帶有頻發室上性期前收縮 仍然是自動技術的一個難題。
（---------房顫時節律不規整，心率快，容易看成是竇性過速加室上性早搏。更直觀地，可以看一個例子：http://www.ecglibrary.com/af_fast.html
）
Relatively recently, newer methods for enhancement of reporting atrial flutter were reported by the group (10).While logic for detection of saw tooth waves has always been present, the more recent logic adopted a threshold crossing technique combined with regularity of intervals between peaks resulting in an improvement in the sensitivity of reporting atrial flutter from 27% to 79%,with a specificity exceeding 98% in both cases.
最近，研究組（10）報告了更新的改進的房撲檢測方法。檢測鋸齒波的邏輯層出不窮，最近的檢測邏輯採用閾值技術結合波峯之間間期的規整性，改進後報告房撲的敏感度從27%提高到79%，特異性兩種情況下都是超過98%。
2.3. Diagnostic interpretation ------------診斷解釋
The diagnostic component of the software is capable of using age, sex, race, clinical classification and drug therapy within its logic. Experience has shown,however, that many staff, particularly nursing staff, will simply not take the time to input the appropriate measures
to the software, even the age and sex of a patient which it is known are fundamental to accurate interpretation.
軟件的診斷組件在它的邏輯中能利用年齡、性別、種族、臨牀分類和治療用藥信息。經驗顯示，很多工作人員，特別是護理人員，不會花時間輸入這些信息，包括病人年齡和性別這些用來準確解釋的基本信息。
The basic approach to interpretation is through the use of rule based criteria, but relatively recently this approach has been enhanced in several ways. First of all,smoothing techniques were introduced (11) to try to minimise repeat variation in interpretations by avoiding
the use of strict thresholds between abnormal and normal. In short, instead of a step function separating normal from abnormal an exponential or even a linear function between the normal and abnormal threshold value can be used as illustrated. This is usually associated with a scoring technique whereby it can be seen that a small change in voltage for example results in a small change in
score. In the case of multiple parameters, more complex combination rules apply as discussed elsewhere (12).
基本的解釋方法是使用以規則爲基礎的標準，但最近將這個方法用好幾種方式進行了改進。首先，引入平滑技術（11） 通過避免使用異常和正常之間的嚴格的閾值 儘量減少重複解釋差異。簡言之，像示範的那樣用正常和異常閾值之間的指數或線性函數替換區分正常和異常的階梯函數。這通常關係到評分技術，例如電壓上小的變化導致分數上小的變化。在多個參數的情形下，像其他地方討論的那樣（文獻12）應用更爲複雜的組合規則。
Neural networks have also been introduced for detection of abnormal Q waves. However, it was found in practice that these perform best in combination with deterministic criteria (13).
神經網絡也引入過用來檢測異常Q波。然而，在實踐中發現這些方法結合確定性的準則後表現最好。
Electrocardiography has not stood still in recent years and new terminology such as ST elevation myocardial infarction (STEMI) has been introduced. The software acknowledges the newer diagnoses and a significant amount of work has been done to adapt the output appropriately (14). Another example of newer terminology is that of the Brugada pattern of which account has to be taken (Figure 1).
近些年心電圖並沒有停滯不前，新的術語例如ST擡高心肌梗塞（STEMI）被引入。軟件增加了新的診斷結論，做了大量的工作來 適當地調整輸出結果。新術語的另外一個例子是Brugada模式，已經在分析中考慮進來。
The software makes extensive use of age and sex of patients in reaching an interpretation. Continuous limits of normality have been introduced particularly for children and younger males while different equations for normal limits of amplitudes are used for males and females especially in the younger adult age ranges. To a certain extent, the race of a patient is acknowledged through lower limits of normal voltage for Chinese individuals, for example.
軟件在解釋心電圖時大量使用病人年齡和性別信息。引入特別針對兒童和青年的連續的正常界限，尤其是 在成人年齡範圍內的年輕男性和女性 使用不同的幅度正常界限方程（------成年年輕男女的界限不同）。 在一定程度上，承認病人種族的差異，例如對中國人用低一些的正常電壓界限。
Finally, the software contains methods for comparison of serial tracings. Two approaches are utilised the first of which involves integrating criteria within the main logic leading to statements such as “serial changes of myocardial infarction” (15). A newer approach has been to add on separate logic for serial comparison, which then functions as a secondary program that is run following the
main diagnostic logic. In this case, there are advantages of having almost all serial comparison logic in the same section of code although it is perhaps an approach more favoured in North America than elsewhere. This,therefore, highlights the question of user choice which also applies to the style of output presentation. Two different styles are offered, one whereby explanatory reasons are printed along with a diagnostic statement and the other where a much more brief diagnostic comment is produced. The different styles can be compared in Figure 2 where a research style output is produced to illustrate the different approaches.
最後，軟件包含比較一系列描記圖的方法。有兩個方法可以使用，第一個方法在主要邏輯中使用積分標準得出形如“連續的心肌梗塞改變”的表述。一個新方法添加到另外的一個連續比較邏輯中，然後作爲輔助功能程序在主診斷邏輯之後運行。這種情況下，這麼做的好處是幾乎全部的序列比較邏輯放在代碼的同一個部分，儘管它可能是一個在北美更受青睞的方法。因此，這就凸現了用戶選擇的問題，在輸出表現風格上又有此問題。提供了兩種不同的風格，一種伴隨診斷表述解釋原因也被打印出來，另一種產生更加簡潔的診斷評價。不同的風格在圖2中可進行比較，圖中產生的是研究性的風格輸出來演示兩種不同的方法。
Finally, it should be remarked that the program has a capability of handling 15 leads and the user is at liberty to select for example V3R, V4R and V7 even although the diagnostic logic at present does not incorporate criteria from these leads. If the additional leads happen to be X, Y, Z leads computed from the 12-lead ECG using an inverse Dower transformation for example (16), then additional vectorcardiographic measurements can be made and vectorcardiographic loops output.
最後，需要指出程序有處理15導的能力，用戶可自由選擇例如V3R，V4R，V7，儘管目前診斷邏輯中沒加入這些導聯的判斷標準。如果額外的導聯恰好是X,Y，Z，它們從12導聯ECG利用逆Dower變換計算出來，那麼可進行額外的心電向量圖測量，心電向量環輸出。
3. Discussion and conclusions --------討論和總結
The Uni-G program has continued to evolve over a long period of time and could still be said to be under development, given the changing fashions in medicine and the underlying fact that the 12-lead ECG still remains the most commonly used diagnostic test in clinical medicine despite the availability of much more complex procedures. The ECG still provides unique information which, in many ways is complementary to the newer techniques but is obtained in a much more simple and rapid fashion as demanded in many clinical situations.
Uni-G 程序已經連續發展很長時間並且仍在繼續開發，這是考慮到醫學上潮流的改變，在臨牀醫學上儘管有更爲複雜的方法可以使用 但12導聯ECG仍然是最常用的診斷測試。ECG仍然提供獨有的信息，在很多方面是新技術的補充，但是獲取ECG非常的簡單快捷，符合很多臨牀條件的需要。
Figure 1: Example showing Brugada pattern ---------Brugada 心電圖
Figure 2: Example showing two styles of report presentation for illustrative purposes only.
The brief format is on the right while the long format with reasons is shown on the left.
--------對比兩種報告風格。
----------注意：本文檢測QRS複合波時，用的是多個導聯聯合使用的方法。
收藏於 2011-05-18
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