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Número de publicaciónCN103083011 A
Tipo de publicaciónSolicitud
Número de solicitudCN 201310023902
Fecha de publicación8 May 2013
Fecha de presentación22 Ene 2013
Fecha de prioridad22 Ene 2013
También publicado comoCN103083011B
Número de publicación201310023902.2, CN 103083011 A, CN 103083011A, CN 201310023902, CN-A-103083011, CN103083011 A, CN103083011A, CN201310023902, CN201310023902.2
Inventores张建保, 王欢, 孔庆水
Solicitante西安交通大学
Exportar citaBiBTeX, EndNote, RefMan
Enlaces externos:  SIPO, Espacenet
Electrocardio R wave crest real-time locating method assisted by chest impedance second order difference image
CN 103083011 A
Resumen
The invention provides an electrocardio R wave crest real-time locating method assisted by a chest impedance second order difference image. The method comprises that synchronous electrocardio signals and chest impedance signals are collected, the electrocardio signals are pre-processed, electrocardio signals with removed base lines are obtained, a second order difference operation is carried out to the chest impedance signals, the chest impedance second order difference image is obtained, according to locations of sampling points of main peak values in the chest impedance second order difference image, sampling points of corresponding locations of the electrocardio signals are regarded as an original point, a forward direction searching range is delimited, and an R wave crest is searched in the forward direction searching range. Compared with the prior art, the electrocardio R wave crest real-time locating method assisted by the chest impedance second order difference image has the advantages of being rapid, accurate, free of extra stimulus to human bodies and the like.
Reclamaciones(9)  traducido del chino
1.一种利用胸阻抗二阶差分图辅助实时定位心电R波峰的方法,其特征在于:包括以下步骤: 1)采集同步的心电信号和胸阻抗信号,对心电信号进行预处理得到去除基线的心电信号,对胸阻抗信号进行二阶差分运算获得胸阻抗二阶差分图; 2)经过步骤I)后,根据胸阻抗二阶差分图中主峰值的采样点位置,以心电信号对应位置的采样点为原点划定前向搜索范围,然后在前向搜索范围内搜索R波峰。 A second-order differential use of thoracic impedance diagram auxiliary RTLS ECG R peak method comprising: the steps of: 1) the acquisition synchronized ECG and transthoracic impedance signal, to pre-treatment ECG ECG baseline removal of the thoracic impedance signal to obtain second-order differential operator of second order differential FIG thoracic impedance; 2) after step I), the second-order differential according to thoracic impedance diagram of the main peak of the sampling point position to ECG sampling point signal corresponding to the position of origin for the former demarcation to search, then search within the search range R crest to the front.
2.根据权利要求1所述一种利用胸阻抗二阶差分图辅助实时定位心电R波峰的方法,其特征在于:所述前向搜索范围根据胸阻抗二阶差分图中主峰值距离对应的R波峰的间隔范围进行划定。 According to claim 1, a use of real-time location-assisted thoracic impedance Second Order ECG R peak difference image method, wherein: the former corresponds to the search range based on second-order differential thoracic impedance diagram of the main peak distance R interval range delineation peaks.
3.根据权利要求1所述一种利用胸阻抗二阶差分图辅助实时定位心电R波峰的方法,其特征在于:在采样频率为250Hz的条件下,前向搜索范围起点与原点的间隔为20个采样点,前向搜索范围终点与原点的间隔为70个采样点。 According to claim 1, a use of second-order differential FIG assisted thoracic impedance RTLS ECG R peak, characterized in that: the sampling frequency is 250Hz under the conditions, before starting to search for the origin of the interval 20 sampling points, before the end of the search and the origin of the sample interval of 70 points.
4.根据权利要求1所述一种利用胸阻抗二阶差分图辅助实时定位心电R波峰的方法,其特征在于:所述步骤2)的具体方法包括以下步骤:根据胸阻抗二阶差分幅度阈值对胸阻抗二阶差分图中主峰值进行搜索,在前向搜索范围内进行峰值搜索得最大峰值,将最大峰值与心电信号幅度阈值比较,若最大峰值大于心电信号幅度阈值,则判定该最大峰值为R波峰。 According to claim 1, a use of second-order differential FIG assisted thoracic impedance RTLS ECG R peak, characterized in that: the step 2) of the specific method comprising the steps of: thoracic impedance second-order differential amplitude thoracic impedance threshold for second-order differential figure main peak search, the forward peak search within the search range of the largest peak, maximum peak compared with the ECG signal amplitude threshold, if the maximum peak value is greater than the ECG signal amplitude threshold is determined The maximum peak R peak.
5.根据权利要求4所述一种利用胸阻抗二阶差分图辅助实时定位心电R波峰的方法,其特征在于:所述胸阻抗二阶差分幅度阈值以及心电信号幅度阈值为动态幅度阈值,Th=0.45XF,Th_R=0.65XR, Th表示胸阻抗二阶差分幅度阈值,F表示胸阻抗二阶差分图中的前一个主峰值,Th_R表示心电信号幅度阈值,R表示前一个R波峰的峰值。 5. An advantage of second-order differential FIG assisted thoracic impedance RTLS ECG R peak method according to claim 4, wherein: the thoracic impedance threshold and the second-order differential amplitude ECG signal amplitude threshold is dynamic amplitude threshold , Th = 0.45XF, Th_R = 0.65XR, Th represents thoracic impedance second-order differential amplitude threshold value, F represents thoracic impedance second-order differential figure before a main peak, Th_R represents ECG amplitude threshold, R represents a previous R peak peak.
6.根据权利要求4所述一种利用胸阻抗二阶差分图辅助实时定位心电R波峰的方法,其特征在于:当搜索到一个R波峰后,在胸阻抗二阶差分图上以当前主峰值为起点、向后一个时间段内继续搜索下一个主峰值,所述时间段为RR,RR表示最近三个连续RR间期的平均值。 A second-order differential use of thoracic impedance diagram auxiliary RTLS ECG R peak method according to claim 4, wherein: when R peak after a search in the thoracic impedance diagram of second order differential current master peak as a starting point, a period of time to continue to search back next main peak, the time period for the RR, RR indicates the most recent three successive RR interval average.
7.根据权利要求4所述一种利用胸阻抗二阶差分图辅助实时定位心电R波峰的方法,其特征在于:所述步骤2)的具体方法还包括以下步骤:将最大峰值与心电信号幅度阈值比较前,对最大峰值进行回溯重检判断:若Tl ( dF< T2,则将最大峰值与心电信号幅度阈值比较;若dF ^ T2,则降低心电信号幅度阈值和胸阻抗二阶差分幅度阈值,然后回溯到前一个检测到的R波峰之后重新获取最大峰值;若dF ( Tl,则提高心电信号幅度阈值和胸阻抗二阶差分幅度阈值,然后回溯到前一个检测到的R波峰之后重新获取最大峰值,dF表示最大峰值与胸阻抗二阶差分图中前一个主峰值之间的距离,Tl表示防多检距离阈值,T2表示防漏检距离阈值。 According to a use of second-order differential FIG assisted thoracic impedance RTLS ECG R peak method according to claim 4, wherein: the step 2) of the specific method further includes the steps of: the maximum peak and ECG before the signal amplitude threshold comparison, the maximum peak backtracking re-inspection to determine: if Tl (dF <T2, then the maximum peak amplitude threshold comparison ECG; if dF ^ T2, the lower amplitude threshold ECG and transthoracic impedance two order differential amplitude threshold, and then re-acquire the maximum peak after back to the previous detected R peaks; if dF (Tl, the increase ECG amplitude threshold and thoracic impedance second-order differential amplitude threshold, then go back to the previous one detected reacquire maximum peak after peak R, dF represents the distance between the maximum peak and thoracic impedance diagram in front of a second-order differential between the main peak, Tl represents more anti-seizure distance threshold, T2 represents leak detection distance threshold.
8.根据权利要求7所述一种利用胸阻抗二阶差分图辅助实时定位心电R波峰的方法,其特征在于:重新获取最大峰值后再次进行回溯重检判断,若最大峰值仍满足dF > T2或dF ( Tl,则将最大峰值判定为R波峰。 According to claim 7 of a second-order differential FIG assisted thoracic impedance RTLS ECG R peak Methods, wherein: retrieve backtracking retesting determine the maximum peak again, if the maximum peak still satisfies dF> T2 or dF (Tl, then the maximum peak is determined that the R peak.
9.根据权利要求7所述一种利用胸阻抗二阶差分图辅助实时定位心电R波峰的方法,其特征在于:所述Tl=0.45 X RR, T2=l.66 X RR, RR表示最近三个连续RR间期的平均值。 According to claim 7, wherein a use of second-order differential FIG assisted thoracic impedance RTLS ECG R peak, characterized in that: the Tl = 0.45 X RR, T2 = l.66 X RR, RR indicates the most recent the average period of between three consecutive RR.
Descripción  traducido del chino

利用胸阻抗二阶差分图辅助实时定位心电R波峰的方法 The use of second-order differential FIG assisted thoracic impedance RTLS ECG R peak method

技术领域 Technical Field

[0001] 本发明涉及心电R波峰定位的技术领域,具体涉及一种利用其他生理信号辅助快速准确定位R波峰的方法。 [0001] The technical field relates ECG R peak positioning of the present invention particularly relates to a use other physiological signals quickly and accurately locate R peaks assisted methods.

背景技术 Background

[0002] 在心电信号测量中,虽然有创方法的信噪比小,但其创伤大,所以一般研究的心电信号都是体表测得的。 [0002] measurement of ECG signal, although small invasive method of signal to noise ratio, but its trauma, so ECG general study of the surface are measured. 这种体表心电信号是一种心脏有规律的电传导活动,在波形上主要表现为P波、QRS复合波、T波以及U波等。 This is a surface ECG heart electrical conduction regular activities, mainly in the waveform of P-wave, QRS complexes, T wave and U wave. 相较于心房去极化的P波和心室复极化的T波,反映心室去极化的R波拥有更陡峭的斜率和更高的幅值,成为心电信号中各个波形的定位算法的基础和依据。 Depolarization compared to the P wave of atrial and ventricular repolarization of the T wave reflects ventricular depolarization R wave has a steeper slope and a higher amplitude, becoming the ECG waveform of each location algorithm the basis and foundation.

[0003] 心率变异性(Heart Rate Variability, HRV)的时频域分析是探索自主神经功能系统对心脑血管系统调控的重要指标之一,对各种心律失常、分析睡眠呼吸暂停综合症等具有重要的研究价值。 [0003] The heart rate variability (Heart Rate Variability, HRV) frequency domain analysis is to explore the function of the autonomic nervous system, cardiovascular system, one of the important indicators of the regulation, for a variety of arrhythmias, analysis of sleep apnea syndrome have important research value. R波峰定位是从长期的ECG记录中提取RR间期及分析HRV的基础。 R peak position is extracted RR interval analysis of HRV and from long-term ECG recording. 在较大的数据量分析HRV时,R波峰的提取速度和精确度会直接影响HRV分析的可靠性和准确度。 When a large amount of data analysis HRV, R peak extraction speed and accuracy will directly affect the reliability and accuracy of HRV analysis.

[0004] R波峰定位可以分为两个环节:信号预处理和R波峰值检测。 [0004] R crest positioning can be divided into two areas: signal pre-processing and R wave peak detection. 预处理是为了去除信号中的噪声和干扰,主要有滤波器和差分法、小波变换法、数学形态、神经网络等方法。 Preprocessing is to remove signal noise and interference, the main filter and a differential method, wavelet transform, mathematical morphology, neural networks and other methods. R波峰值检测主要包括R波峰值搜索和决策两个部分,由于QRS复合波比较尖耸,峰值搜索的常用方法主要有幅度法、斜率法和面积法。 R-wave peak detector consists of two parts R-wave peak search and decision-making, due to the relatively sharp towering QRS complex, common methods are mainly the magnitude of the peak search method, the slope method and area method.

[0005] 近一个世纪以来R波峰定位一直都受到了广泛关注,定位方法层出不穷。 [0005] R crest nearly a century has been positioned by the attention, positioning method after another. 面对无创的心电信号噪声干扰大、信号微弱而变异性又强的特点,各方法都有其优劣点。 Faced with non-invasive ECG noise is large, weak signal variability and strong features, each method has its advantages and disadvantages. 差分滤波方法虽然实时性好,但是精确度有待提高;而小波分析精确度高,但实时性却不能满足动态QRS波检测的需求;神经网络方法计算量大,目前尚不能用于实际中;其他方法也都有需要继续改进的地方。 Differential filtering method, although real good, but the accuracy needs to be improved; and wavelet analysis accuracy, but it can not meet the needs of real-time dynamic QRS wave detection; neural network computing capacity, it is not yet used in practice; Other The method also has a need for continued improvement. 因此,实时性、稳定性、精确度兼顾的R波定位算法仍然需要进一步的研究。 Thus, real-time, stability, accuracy of both the R-wave localization algorithm still needs further study.

发明内容 DISCLOSURE

[0006] 本发明目的在于提供一种利用胸阻抗二阶差分图辅助实时定位心电R波峰的方法。 [0006] The object of the present invention is to provide a second-order differential FIG assisted thoracic impedance RTLS ECG R peak Methods.

[0007] 为达到上述目的,本发明采用了以下技术方案: [0007] To achieve the above object, the present invention employs the following technical solutions:

[0008] I)采集同步的心电信号和胸阻抗信号,对心电信号进行预处理得到去除基线的心电信号,对胸阻抗信号进行二阶差分运算获得胸阻抗二阶差分图; [0008] I) collection synchronized ECG and transthoracic impedance signal, to obtain the removal of pre-treatment ECG baseline ECG, thoracic impedance signal to obtain second-order differential operator of second order differential FIG thoracic impedance;

[0009] 2)经过步骤I)后,根据胸阻抗二阶差分图中主峰值的采样点位置,以心电信号对应位置的采样点为原点划定前向搜索范围,然后在前向搜索范围内搜索R波峰。 [0009] 2) After step I), the second-order differential according to thoracic impedance diagram of the main peak of the sampling point position to the ECG sampling points corresponding to the location for the first delineation of origin to search, then search forward R peaks in the search.

[0010] 所述前向搜索范围根据胸阻抗二阶差分图中主峰值距离对应的R波峰的间隔范围进行划定。 [0010] The delineation forward search range based on the interval of second order differential thoracic impedance diagram of the main peak corresponding to the distance R peaks. [0011] 在采样频率为250Hz的条件下,前向搜索范围起点与原点的间隔为20个采样点,前向搜索范围终点与原点的间隔为70个采样点。 [0011] In the sampling frequency of the condition of 250Hz, the former starting point to search the origin of the sample interval of 20 points, before the end of the search and the origin of the sample interval of 70 points.

[0012] 所述步骤2)的具体方法包括以下步骤:根据胸阻抗二阶差分幅度阈值对胸阻抗二阶差分图中主峰值进行搜索,在前向搜索范围内进行峰值搜索得最大峰值,将最大峰值与心电信号幅度阈值比较,若最大峰值大于心电信号幅度阈值,则判定该最大峰值为R波峰。 [0012] The step 2) of the specific method comprises the steps of: differential amplitude threshold for second-order differential thoracic impedance diagram main peak search by thoracic impedance of second order, the forward peak search within the search range of the largest peak, will Compared with the maximum peak amplitude threshold ECG, the ECG signal if the peak is greater than the maximum amplitude threshold, it is determined that the maximum peak R peak.

[0013] 所述胸阻抗二阶差分幅度阈值以及心电信号幅度阈值为动态幅度阈值,Th=0.45XF,Th_R=0.65XR, Th表示胸阻抗二阶差分幅度阈值,F表示胸阻抗二阶差分图中的前一个主峰值,Th_R表示心电信号幅度阈值,R表示前一个R波峰的峰值。 [0013] The thoracic impedance threshold and the second-order differential amplitude ECG signal amplitude threshold is dynamic amplitude threshold, Th = 0.45XF, Th_R = 0.65XR, Th represents thoracic impedance second-order differential amplitude threshold value, F represents second-order differential thoracic impedance Figure in front of a main peak, Th_R represents ECG amplitude threshold, R represents an R peak before the peak.

[0014] 当搜索到一个R波峰后,在胸阻抗二阶差分图上以当前主峰值为起点、向后一个时间段内继续搜索下一个主峰值,所述时间段为RR,RR表示最近三个连续RR间期的平均值。 [0014] When the search to an R peak after the thoracic impedance diagram of second order differential value starting at the current peak, a period of time back to continue the search for the next main peak, the time period for the RR, RR represents the last three mean successive RR interval.

[0015] 所述步骤2)的具体方法还包括以下步骤:将最大峰值与心电信号幅度阈值比较前,对最大峰值进行回溯重检判断:若Tl ( dF< T2,则将最大峰值与心电信号幅度阈值比较;若dF > T2,则降低心电信号幅度阈值和胸阻抗二阶差分幅度阈值,然后回溯到前一个检测到的R波峰之后重新获取最大峰值;若dF ( Tl,则提高心电信号幅度阈值和胸阻抗二阶差分幅度阈值,然后回溯到前一个检测到的R波峰之后重新获取最大峰值,dF表示最大峰值与胸阻抗二阶差分图中前一个主峰值之间的距离,Tl表示防多检距离阈值,T2表示防漏检距离阈值。 [0015] The step 2) of the specific method further includes the steps of: ECG before the maximum peak amplitude threshold comparison, the maximum peak backtracking re-inspection to determine: if Tl (dF <T2, then the maximum peak and heart electrical signal amplitude threshold comparison; if dF> T2, the lower amplitude threshold ECG and transthoracic impedance of second order differential amplitude threshold, and then re-acquire the maximum peak back to the front after a detected R peaks; if dF (Tl, then increase ECG amplitude threshold and thoracic impedance second-order differential amplitude threshold, then back to the front after a detected R peaks reacquire the maximum peak, dF represents the distance between the maximum peak and thoracic impedance diagram of second order differential between the front of a main peak , Tl represents more anti-seizure distance threshold, T2 represents leak detection distance threshold.

[0016] 重新获取最大峰值后再次进行回溯重检判断,若最大峰值仍满足dF > T2或dF ( Tl,则将最大峰值判定为R波峰。 Be [0016] to reacquire the maximum peak back again after re-examining the judgment, if the maximum peak still meet dF> T2 or dF (Tl, then the maximum peak is determined that the R peak.

[0017] 所述Tl=0.45 X RR, T2=l.66 X RR, RR表示最近三个连续RR间期的平均值。 [0017] The Tl = 0.45 X RR, T2 = l.66 X RR, RR indicates the most recent three successive RR interval average.

[0018] 胸阻抗将人体胸腔部分看成是一个均匀介质的椭圆柱形容积导体,通过该阻抗的变化反映胸部心血管活动的变化规律。 [0018] thoracic impedance as a human torso section elliptic cylindrical volume conductor of a homogeneous medium, reflecting the changes of chest cardiovascular activity through changes in the impedance. 胸阻抗一阶微分图反映了心血管容积的变化速度,即血液流速的速度;而其二阶微分图则是反映血液流速变化快慢的重要依据,其主峰值出现在血管扩张速率的变化最快的时刻。 Thoracic impedance first order differential chart reflects the rate of change in the volume of cardiovascular, or blood flow velocity; the second-order differential plan reflects changes in the speed of blood flow an important basis for the main peak in the blood vessels to dilate the fastest rate of change moment. 由于该主峰值距离R波峰之后不远处,且特征明显,因此可用于辅助搜索R波峰。 Since the main peak after peak not far from the R and distinctive characteristics, it can be used to assist in the search R peaks. 本发明在获取胸阻抗二阶差分图之后,通过在该图上设定动态幅度阈值寻找二阶差分图的主峰值。 After acquiring the present invention thoracic impedance differential second-order diagram, by setting the dynamic amplitude threshold on the graph to find the main peak of second order differential map. 当满足在其上所设置的幅度条件之后,依据主峰值的位置向前一定范围内搜索R波峰。 When the magnitude of the conditions on which meet the set, search R peaks within a certain range based on the main peak of the forward positions.

[0019] 针对胸阻抗二阶微分图获取过程繁琐的问题,本发明设计了胸阻抗二阶差分图信号,用以代替胸阻抗二阶微分图;而后设计实验分析胸阻抗二阶差分图的主峰值与R波峰之间的距离变化范围的大小,确定辅助定位时的R波峰的前向搜索范围,验证该范围分布的稳定性;接着本发明完成了R波峰的搜索工作,在胸阻抗二阶差分图上设置第一重动态幅度阈值条件以寻找其主峰值,依据该主峰值向前一定范围内搜索R波峰;最后判断搜索到的潜在的R波峰位置是否会进入多检、漏检的异常处理,否则进入在心电信号上所设置的第二重幅度阈值条件判断,当满足该条件之后,潜在的R波峰被判定为R波峰。 [0019] For the second order differential thoracic impedance diagram acquisition process complicated problems, the present invention contemplates a second-order differential FIG thoracic impedance signal, to replace the second-order differential thoracic impedance map; then the main design experiments thoracic impedance analysis of second order differential map changes in the size of distance between the peak and R peak, before the search when determining assistance locating R peak, verify the stability of the distribution of the range; then completed the present invention R peaks of search efforts, in thoracic impedance Second Order Set on the first difference image heavy dynamic amplitude threshold condition to find its main peak, search R peaks within a certain range based on the main peak forward; whether the final judgment of the search to the potential of R peak position will enter the multi-examination, undetected anomalies treatment, or re-enter the second cardiac amplitude threshold condition set on the electrical signal is determined, when this condition is satisfied, a potential peak is determined to be R R peaks.

[0020] 本发明与现有技术相比, 具有以下优点: [0020] The present invention over the prior art, has the following advantages:

[0021] I)快速,因为本发明是在胸阻抗二阶差分主峰前一段时间内搜索R,搜索范围小,计算量小,速度快。 [0021] I) fast, since the present invention is to search for some time before the second-order differential peak transthoracic impedance R, small search range, a small amount of calculation speed. [0022] 2)准确,胸阻抗二阶差分主峰在R波和T波之间,可以抑制高T波干扰;另外本发明设置了二次阈值判断等一系列辅助条件,确保准确,提高了准确率。 [0022] 2) accurate, thoracic impedance peak in the second-order difference between R and T waves, can inhibit the high T-wave interference; In addition the present invention is provided a secondary threshold determination and a series of auxiliary conditions to ensure accurate, and improve accuracy rate.

[0023] 3)对人体无额外刺激,虽然本发明利用了辅助条件胸阻抗,但是,胸阻抗也是常规测量,应用广泛,不需要对人体施加额外的测量电极。 [0023] 3) the human body without additional stimulus, although the present invention utilizes assisted thoracic impedance condition, but also conventional thoracic impedance measurement, widely used, no additional measuring electrodes applied to the human body.

附图说明 Brief Description

[0024] 图1是本发明利用胸阻抗二阶差分图辅助定位R波峰方法的流程图; [0024] FIG. 1 is the use of the present invention thoracic impedance to the flow chart of second order differential method of assisted positioning R peaks;

[0025] 图2是I导联R波峰定位效果图;(a)为ECG,(b)为胸阻抗二阶差分图; [0025] FIG. 2 is a lead I locate R peaks renderings; (a) for the ECG, (b) second-order differential FIG thoracic impedance;

[0026] 图3是II导联R波峰定位效果图;(a)为ECG,(b)为胸阻抗二阶差分图; [0026] FIG. 3 is a joint R crest positioning effect II map; (a) for the ECG, (b) second-order differential FIG thoracic impedance;

[0027] 图4是III导联R波峰定位效果图;(a)为ECG,(b)为胸阻抗二阶差分图; [0027] FIG. 4 is a III leads R peaks positioned renderings; (a) for the ECG, (b) second-order differential FIG thoracic impedance;

[0028] 图5是高T波下R波峰定位效果图;(a)为ECG,(b)为胸阻抗二阶差分图; [0028] FIG. 5 is a high-T wave crest positioned at R renderings; (a) for the ECG, (b) second-order differential FIG thoracic impedance;

[0029] 图6是轻微活动下的R波峰定位效果;(a)为ECG,(b)为胸阻抗二阶差分图; [0029] FIG. 6 is R crest positioned under the effect of minor activities; (a) for the ECG, (b) second-order differential FIG thoracic impedance;

具体实施方式 DETAILED DESCRIPTION

[0030] 下面结合附图对本发明作进一步说明。 [0030] the following with reference to the present invention will be further described below.

[0031] 本发明在采集了同步的心电信号和胸阻抗信号之后,利用胸阻抗二阶差分图信号辅助搜索R波峰。 [0031] The present invention, after the acquisition of the ECG signal and synchronous chest impedance signal by thoracic impedance second-order difference image signal peaks R-assisted search. 如图1所示,具体的操作步骤有3步: Shown in Figure 1, the specific steps of three steps:

[0032] 1.心电去基线 [0032] 1. ECG to baseline

[0033] 采用中值滤波去除心电基线噪声,其主要思想是对信号中每个点前后长度分别为NI的序列进行排序,取中间值为该点处对应的基线信息。 [0033] The median filter ECG baseline noise, the main idea is to signal around each point in the sequence lengths of NI sort, take the middle value of baseline information of the corresponding point. 由于中值滤波无法提取数据头区和尾区的NI的长度基线,因此需要对序列进行延拓,头尾延拓的长度分别为NI。 Since the median filter can not extract data header area and the tail region of the length of the baseline NI, so the need for sequence extension, extension of the head and tail lengths is NI. 延拓后依照中值滤波的算法,对窗口内数据排序取中值,完成窗口中点处的基线提取。 After the extension in accordance with the median filtering algorithm to sort the data in the window to take in the value of the extraction window to complete the baseline at the midpoint. 原始ECG (心电图)信号与提取的基线信号相减,就获得了去除基线后的心电信号。 Original ECG (electrocardiogram) signal extracted baseline signal by subtracting the ECG is obtained after removal of the baseline.

[0034] 获取胸阻抗二阶差分 [0034] The second-order differential Get thoracic impedance

[0035] 计算方法如下: [0035] is calculated as follows:

[0036][式 I] [0036] [Formula I]

[0037] f' (i)=I(i)-1(1-120) [0037] f '(i) = I (i) -1 (1-120)

[0038][式 2] [0038] [Formula 2]

[0039] f(i)=f'(i)-f' (1-20) [0039] f (i) = f '(i) -f' (1-20)

[0040] 亦即[式3] [0040] That [formula 3]

[0041 ] f (i) =I (i) -1 (1-20) -1 (1-120) +I (i_140) [0041] f (i) = I (i) -1 (1-20) -1 (1-120) + I (i_140)

[0042] 相较于微分计算两两时刻点间的差异,差分算法是选取合适的时间步长计算两两时间步长之间检测值的差异性,其是胸阻抗一阶和二阶微分算法的变形。 [0042] Compared to calculate the difference between any two points in time differential, differential algorithm is to select the appropriate time step detection value calculated between any two time step difference, which is the thoracic impedance first and second order differential algorithm The deformation. 在获取胸阻抗二阶差分图的过程中,由于心电信号和胸阻抗的采样频率是1000Hz,可以对胸阻抗每4点进行一次这种一阶差分的变换,以将胸阻抗的采样率降低到250Hz。 Second-order difference in access to thoracic impedance diagram of the process, since the ECG and transthoracic impedance of the sampling frequency is 1000Hz, thoracic impedance can be carried out once every 4 o'clock this first difference transformation, to reduce the sampling rate of thoracic impedance to 250Hz. 该方法中的一阶差分选用的是前向相隔120个点的差值,二阶差分是前向相隔80个点的差值。 The method of choice is the first-order differential separated by 120 points before the difference between the second-order differential is separated by a forward difference of 80 points. 经过三次加减运算直接从原始胸阻抗信号中获得胸阻抗二阶差分图,不需要对胸阻抗信号进行预处理去噪操作。 Obtained after three subtraction thoracic impedance signal directly from the original second-order differential FIG thoracic impedance, no need to de-noising thoracic impedance signal preprocessing operation.

[0043] 2.峰值检测[0044] I)参数初始化和自启动回溯 [0043] 2. Peak Detection [0044] I) parameter initialization and self-starting back

[0045] 参数初始化设置如下: [0045] initialization parameters are set as follows:

[0046] 胸阻抗二阶差分幅度阈值(Th),Th=0.8 ; [0046] thoracic impedance second-order differential amplitude threshold value (Th), Th = 0.8;

[0047] 心电信号幅度阈值(Th_R),Th_R=0.05 ; [0047] ECG signal amplitude threshold (Th_R), Th_R = 0.05;

[0048] 成功检测到得R波数目(numR), numR=0 ; [0048] The number of successful R wave was detected (numR), numR = 0;

[0049] RR 间期参数(RR),RR=250。 [0049] RR interval parameter (RR), RR = 250.

[0050] 程序自启动回溯的原理:峰值检测开始时RestartNum (重启次数)设置为0,由numR个数为O判断进入检测启动程序。 [0050] program since the start of the principles of backtracking: peak detection start RestartNum (restarts) is set to 0, the number of O numR judge enters the detection start the program. 在启动程序里,由于Th的初始值较高,程序难以进入R波峰值搜索环节,因此在最初的RR间期长度内检测不到R波峰。 In the startup program, because of the higher initial value Th, the program is difficult to enter the R-wave peak search links, and therefore can not be detected R peaks during the first RR interval length. 程序不断进入自启动回溯重检该RR间期段,Th逐渐降低。 Programs continue to enter from the start back in re-examining the period between the RR section, Th decreased. 一旦Th降低到胸阻抗二阶差分主峰值之下,即满足了第一次幅度阈值判断条件,由于Th_R的初始值较低,第二次幅度阈值条件极易满足,则检测到R波峰,更新参数numR、Th、Th_R。 Once Th thoracic impedance drops below the main peak of second-order difference is met by the first amplitude threshold determination conditions, due to the low initial value Th_R, second amplitude threshold conditions are easily satisfied, R peak is detected, the update parameters numR, Th, Th_R. 当检测到第二个R波峰时,开始更新RR。 When detecting the second R peak, start updating RR. 3个R波峰检测成功后,程序进入到正常的R波峰值搜索,阈值参数等自动更新到正常合理的水平,启动工作完成。 After three R peak detection is successful, the program proceeds to the normal R wave peak search, the threshold parameters automatically updated to normal and reasonable level, start the job done.

[0051] 2)防空检回溯 [0051] 2) air defense seized back

[0052] 为防止胸阻抗二阶差分主峰值陡然增高时第一次幅度阈值难以通过造成大面积空检,设置防空检程序。 [0052] In order to prevent the first amplitude threshold difficult by causing a large area of empty detection, setting anti-aircraft inspection program thoracic impedance sharply higher second-order differential main peak. 当2.55个RR间期后仍未检测到R波峰时,自动进入重启动。 When after 2.55 RR interval is not detected R peaks automatically restart. 过高的阈值Th和Th_R被降低,待重启检测到R波峰之后,RestartNum恢复到0,阈值参数重新更新到正常水平。 High threshold Th and Th_R be reduced, to be restarted after the R peak is detected, RestartNum restored to 0, the threshold parameters are updated again to normal levels.

[0053] 3) R波峰值搜索 [0053] 3) R-wave peak search

[0054] R波峰值搜索主要包括三个环节,最大峰值搜索、二次幅度阈值判断、回溯重检判断。 [0054] R-wave peak search mainly includes three aspects, the maximum peak search, the second amplitude threshold determination, backtracking re-examining judge. 每检测到一个R波峰时,依据心电绝对不应期的原理,检测段跳过200ms不进行R波峰搜索; Every time an R peak is detected, according to the principles of ECG absolute refractory period, testing block skip R 200ms not peak search;

[0055] 此外还需更新各个参数以及清零各个标志 [0055] Also need to update the parameters of various flags and cleared

[0056] RR间期参数(RR),RR= (RR(1-1) +RR(1-2) +RR(I))/3 ;程序启动阶段,当检测到第二个R波峰时,取一个RR间期实际值,当检测到第三个R波峰时,取两个RR间期实际值的平均。 [0056] RR interval parameter (RR), RR = (RR (1-1) + RR (1-2) + RR (I)) / 3; program start-up phase, when the second R peak is detected, Take an actual value of the RR interval, when the third R peak is detected, averaging two RR interval of the actual value.

[0057]防多检距离阈值(Tl),Tl=0.45*RR ; [0057] the use of multiple detection distance threshold (Tl), Tl = 0.45 * RR;

[0058]防漏检距离阈值(T2),T2=l.66*RR ; [0058] The leak check distance threshold (T2), T2 = l.66 * RR;

[0059] 胸阻抗二阶差分幅度阈值,Th=0.45*F (F为上次检测到的胸阻抗二阶差分图的主峰值); [0059] thoracic impedance second-order differential amplitude threshold, Th = 0.45 * F (F for the last detected chest impedance diagram of the main peak of second-order differential);

[0060] 心电信号幅度阈值,Th_R=0.65*R (R表示前一个R波峰的峰值)。 [0060] ECG signal amplitude threshold, Th_R = 0.65 * R (R represents an R peak before the peak).

[0061] (I)最大峰值搜索 [0061] (I) Maximum peak search

[0062] 当前胸阻抗二阶差分幅值满足第一个幅度阈值条件时,程序需要在心电信号中当前点之前的一定范围内搜索最大峰值Rmax,即潜在的R波峰。 [0062] All thoracic impedance magnitude of second order differential amplitude threshold to meet the first condition, the program needs to search in ECG signal within a certain range before the current point of maximum peak Rmax, namely potential R peaks.

[0063] 经过统计,发现胸阻抗二阶差分图的主峰值距离R波峰之间的间隔RF大概分布在25-60左右,且大部分集中在35-55之间。 [0063] After the statistics, discovery interval RF thoracic impedance second-order differential map R main peak distance between the peaks is probably distributed about 25-60, and most concentrated in the 35-55. 根据采样频率为250Hz,RF大部分分布在140-220ms左右。 According to the sampling frequency is 250Hz, RF mostly distributed around 140-220ms. 由于统计的是平均值,为了防止少量的RF超出该统计范围,程序中设置的最大搜索范围是[20 70],相较于RF的范围略有扩张。 Since the statistics are averages, in order to prevent a small amount of RF exceeds the scope of statistics, the maximum search range set in the program is [2070], the scope Compared to RF slight expansion. [0064] 最大峰值搜索方法:一是初始化Rmax及其位置信息S_max ;二是排序,比较当前点的心电信号的绝对值与Rmax的绝对值,若大于Rmax,则将该点处的横纵坐标分别赋值给S_max、Rmax ;重复第二步,直至搜索范围内的数据都被遍历完,完成峰值搜索。 [0064] The maximum peak search method: First Initialization Rmax and location information S_max; the second is to sort, compare the current absolute value point of ECG and Rmax, if greater than the value Rmax, the horizontal and vertical point Coordinates were assigned to S_max, Rmax; repeat the second, until the data within the search range are traversed, complete peak search.

[0065] (2) 二次幅度阈值判断 [0065] (2) Secondary amplitude threshold judgment

[0066] Rmax与前一个胸阻抗二阶差分峰值的距离为dF,当dF在Tl、T2之间时,进行二次幅度阈值判断,若Rmax又大于所设置的心电信号幅度阈值,Rmax则被判定为R波峰。 [0066] Rmax chest before a second-order differential impedance peak distance is dF, when dF is between Tl, T2, a second amplitude threshold determination, if Rmax is greater than the ECG signal amplitude threshold set, Rmax is R is determined as the peak. 否贝U,Rmax被判定为非R波峰。 No shellfish U, Rmax is determined non-R peaks. R波峰检测成功后,需要实时更新各个幅度阈值参数、距离阈值参数、标志参数等,为下一次的搜索工作做准备。 R peaks detected successfully, we need real-time updates each amplitude threshold parameter, the distance threshold parameter, mark parameters, to prepare for the next search for work.

[0067] (3)回溯重检 [0067] (3) back retesting

[0068] 防多检回溯:当dF小于Tl时,进入防多检回溯程序。 [0068] the use of multiple check back: When dF less than Tl, back into the anti-seizure program more. 为防止同一检测段多次进入防多检回溯程序,对进入过防多检回溯程序的检测数据段做了标记,UpError赋值为2。 In order to prevent the same test section repeatedly back into the anti-seizure program more on the subject back into the program through the use of multiple detection data segment made markers, UpError assigned to 2. 若UpError不等于2,则提高幅度阈值Th_R和Th。 If UpError not equal to 2, then increase the amplitude threshold Th_R and Th. 由于胸阻抗二阶差分幅值的波动范围相较于心电信号要更大,因此Th提高的幅度要略大于Th_R。 Since the thoracic impedance fluctuation range compared to the second-order differential amplitude ECG signal to greater and therefore the level of increase to be slightly larger than Th Th_R. 若UpError等于2,则该段连续两次多检,判断该段检测到的Rmax为R波峰,更新各个阈值参数,标志UpError清O。 If UpError equal to 2, the segment more than two consecutive inspection to determine if the section detected Rmax of R crest, update each threshold parameter flag UpError clear O.

[0069] 防漏检回溯:同样,当dF大于T2时,进入防漏检回溯程序。 [0069] leak check back: Again, when dF is greater than T2, into the leak check back program. 为防止同一检测段多次进入防漏检回溯程序,对进入过防漏检回溯程序的检测数据段做了标记,UpError赋值为 In order to prevent the same test section repeatedly back into the leak check procedures for detecting data segment entered leak check back program made a mark, UpError assigned

I。 I. 若UpError不等于1,降低幅度阈值Th_R和Th,回溯到前一个检测到的R波峰之后,继续重检。 If after UpError not equal to 1, a reduction in the threshold Th_R and Th, back to the previous detected R peaks, to continue re-examining. 若UpError等于1,则该段连续两次漏检,判断该段检测到的Rmax为R波峰,更新各个阈值参数,标志UpError清O。 If UpError equal to 1, the segment missed twice in a row, it is determined that the segment detected Rmax of R crest, update each threshold parameter flag UpError clear O.

`[0070] 参见图2-6,*号表示实际检测到的R波峰位置。 `[0070] Referring to Figure 2-6, an asterisk indicates the actual position of the detected R peaks. 从图中可以看出,胸阻抗二阶差分图的主峰随着R波峰的周期分布呈周期性分布且主峰值较明显。 As can be seen from the figure, thoracic impedance peak with the second-order differential map R cycle distribution cyclical peak and the main peak of the distribution is obvious.

[0071] 不同形态的心电R波峰定位效果良好,R波峰值的极性没有对定位结果产生太大的困扰(图2、图3),且在第三导联定位效果中,R波峰的幅度发生了较大的变化,但是对应的胸阻抗二阶差分图的主峰值却并没有受到影响,依赖胸阻抗二阶差分峰值辅助完成R波峰的搜索,方法效果好,具有一定的稳定性(图4)。 [0071] ECG R peak effects of different forms of good positioning, R-wave peak polar did not have much trouble (Figs. 2 and 3) positioning results, and in the third leads localized effects, R peaks margin undergone great changes, but second-order differential thoracic impedance main peak corresponding figure has not been affected, dependent on second-order differential peak-assisted thoracic impedance to complete the R peak search method works well, it has a certain stability ( Figure 4). 高T波,T波甚至比R波峰还要高大,斜率也较尖耸,但是本发明R波峰定位效果依然很好(图5)。 High T wave, T-wave even taller than R peaks towering slopes are more pointed, but the effects of the present invention R crest positioning is still very good (Figure 5). 在轻微活动时,高T波异常尖耸,且与R波峰非常临近,且在整个心电信号中都伴随着轻微的毛刺噪声,此外由于轻微的活动对心血管系统的或动有相应的增强,因此,胸阻抗二阶差分幅值相较于静态情况下大幅增高,尤其是大于Ov的幅值,R波峰定位效果并未因此受到太大的影响(图6)。 When minor activities, towering high T wave abnormalities tip, and with the R peak is very close to, and in the entire ECG are accompanied by a slight glitch noise, in addition due to the slight activity on the cardiovascular system or move a corresponding enhancement Therefore, chest impedance of second-order differential compared to the static case amplitude increased sharply, especially greater than Ov amplitude, R peak positioning performance has not been greatly affected (Fig. 6).

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Citada por
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