CN101554325B - Method for extracting fetal electrocardiograms (FECG) by separation - Google Patents
Method for extracting fetal electrocardiograms (FECG) by separation Download PDFInfo
- Publication number
- CN101554325B CN101554325B CN2009100279790A CN200910027979A CN101554325B CN 101554325 B CN101554325 B CN 101554325B CN 2009100279790 A CN2009100279790 A CN 2009100279790A CN 200910027979 A CN200910027979 A CN 200910027979A CN 101554325 B CN101554325 B CN 101554325B
- Authority
- CN
- China
- Prior art keywords
- extraction
- fetus
- waveform
- parent
- component
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
- 238000000034 method Methods 0.000 title claims abstract description 105
- 238000000926 separation method Methods 0.000 title claims abstract description 80
- 230000001605 fetal effect Effects 0.000 title claims abstract description 30
- 238000000605 extraction Methods 0.000 claims abstract description 84
- 238000005070 sampling Methods 0.000 claims abstract description 22
- 238000001514 detection method Methods 0.000 claims abstract description 14
- 238000012935 Averaging Methods 0.000 claims abstract description 11
- 210000003754 fetus Anatomy 0.000 claims description 69
- 238000000265 homogenisation Methods 0.000 claims description 33
- 238000012952 Resampling Methods 0.000 claims description 26
- 238000002156 mixing Methods 0.000 claims description 10
- 210000001015 abdomen Anatomy 0.000 claims description 9
- 230000008774 maternal effect Effects 0.000 abstract 1
- 238000007781 pre-processing Methods 0.000 abstract 1
- 238000011084 recovery Methods 0.000 abstract 1
- 239000000203 mixture Substances 0.000 description 13
- 238000001914 filtration Methods 0.000 description 8
- 230000033764 rhythmic process Effects 0.000 description 8
- 238000000354 decomposition reaction Methods 0.000 description 7
- 230000000747 cardiac effect Effects 0.000 description 5
- 230000005611 electricity Effects 0.000 description 4
- 238000012880 independent component analysis Methods 0.000 description 4
- 230000000737 periodic effect Effects 0.000 description 4
- 238000012545 processing Methods 0.000 description 4
- 230000003187 abdominal effect Effects 0.000 description 3
- 238000006243 chemical reaction Methods 0.000 description 3
- 241000132023 Bellis perennis Species 0.000 description 2
- 235000005633 Chrysanthemum balsamita Nutrition 0.000 description 2
- 210000000481 breast Anatomy 0.000 description 2
- 238000001228 spectrum Methods 0.000 description 2
- 206010002660 Anoxia Diseases 0.000 description 1
- 241000976983 Anoxia Species 0.000 description 1
- 208000002330 Congenital Heart Defects Diseases 0.000 description 1
- 208000001951 Fetal Death Diseases 0.000 description 1
- 208000032943 Fetal Distress Diseases 0.000 description 1
- 206010055690 Foetal death Diseases 0.000 description 1
- 206010016855 Foetal distress syndrome Diseases 0.000 description 1
- 206010021143 Hypoxia Diseases 0.000 description 1
- 208000000418 Premature Cardiac Complexes Diseases 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 230000000996 additive effect Effects 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 208000007502 anemia Diseases 0.000 description 1
- 230000007953 anoxia Effects 0.000 description 1
- 238000013459 approach Methods 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 238000004891 communication Methods 0.000 description 1
- 208000028831 congenital heart disease Diseases 0.000 description 1
- 230000000875 corresponding effect Effects 0.000 description 1
- 238000013480 data collection Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 231100000479 fetal death Toxicity 0.000 description 1
- 230000006870 function Effects 0.000 description 1
- 230000004927 fusion Effects 0.000 description 1
- 238000012806 monitoring device Methods 0.000 description 1
- 238000012544 monitoring process Methods 0.000 description 1
- 230000003387 muscular Effects 0.000 description 1
- 238000005192 partition Methods 0.000 description 1
- 230000001575 pathological effect Effects 0.000 description 1
- 238000002203 pretreatment Methods 0.000 description 1
- 238000003672 processing method Methods 0.000 description 1
- 238000005204 segregation Methods 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
- 210000004291 uterus Anatomy 0.000 description 1
Images
Landscapes
- Measurement And Recording Of Electrical Phenomena And Electrical Characteristics Of The Living Body (AREA)
Abstract
A method for extracting fetal electrocardiograms (FECG) by separation comprises the following major steps: 1, separating maternal electrocardiogram component from mixed maternal-fetal electrocardiogram signals to acquire the preliminary estimation of fetal electrocardiogram signals, herein referred to as the primary separating extraction; and 2, further separating disturbance and noise from the preliminary estimation of the fetal electrocardiogram signals acquired from the primary separating extraction to acquire the final estimation of the fetal electrocardiogram signals, herein referred to as the secondary separating extraction. The invention relates to a method for the primary separating extraction of FECG and a method for the secondary separating extraction of FECG respectively. The two methods comprise basically the same steps as follows: signal pre-processing; R-wave crest detection; re-sampling; time-domain averaging; recovery re-sampling and the like. Both the methods are methods of extraction by separating one-channel signals. The separating extractability of the two methods is higher than that of other existing methods of extraction by separating one-channel signals.
Description
Technical field
Present patent application relates to the separating and extracting process of fetal electrocardiogram (FECG).
So-called fetal electrocardiogram is meant the complete waveform of having eliminated the fetus electrocardiosignal behind the interference noise.Fetal electrocardiogram has been arranged, not only can know the fetal rhythm rate, also can know parameters such as its S-T section, PQRS time limit, and can in time find some pathologic conditions of fetus according to them: in utero anoxia, embryocardia is uneven, the fetal rhythm rate is not normal, fetal rhythm premature beat, fetal distress, the change of S-T section, PQRS time limit broadening, congenital heart disease etc.
Be used to obtain the fetal rhythm electricity custodial care facility of fetal electrocardiogram, mainly comprise ecg amplifier module, analog digital conversion (A/D) and memory module, data processing module.Ecg amplifier module and analog digital conversion and memory module, the data acquisition subsystem of formation fetal rhythm electricity custodial care facility.The data acquisition subsystem of fetal rhythm electricity custodial care facility and the principle and the method for ordinary individual's cardiac monitoring device data acquisition subsystem are basic identical.But because fetus in the parent body, as non-intrusion type fetus electrocardio-data collection subsystem, also shows some characteristics: the dynamic range of signals that (1) subsystem is supported wants big; (2) have at least one to lead from the body surface of parent abdominal part.
Electrocardiosignal from anemia of pregnant woman's abdomen body-surface is gathered has not only comprised fetus electrocardio composition, has also comprised parent electrocardio composition and other interference noises, and what account for main absolute status is parent component and interference noise, and the fetal rhythm electricity is submerged wherein; Fetus electrocardio composition in time domain, have approximately 10%～30% and mother's electrocardio composition overlap the most of especially overlapping of its frequency spectrum and mother's electrocardio frequency spectrum in frequency domain, electrocardiosignal non-stationary also very strong.Therefore, for fetus cardiac monitoring equipment, its data processing module is a difficult point, because there is a key issue that will solve---and separation and Extraction is come out the extremely low female tire mixing ecg signal data of the signal to noise ratio of how the fetus electrocardiosignal being picked up from the parent abdominal surface.
The separation and Extraction of fetus electrocardiosignal comprises two big steps: one, estimate parent electrocardio composition, the parent electrocardio composition of estimating is separated from female tire mixing electrocardiosignal that the parent abdominal part picks up, obtain the rough estimate in other words according to a preliminary estimate of fetus electrocardiosignal, might as well, such separation and Extraction process is called first order separation and Extraction; Two, the fetus electrocardiosignal that obtains from first order separation and Extraction according to a preliminary estimate, further divide some interference noises of leaving away, the final estimation that obtains the fetus electrocardiosignal is accurately estimated in other words, such process might as well be called second level separation and Extraction.The complete frame of fetus electrocardiosignal separation and Extraction is seen accompanying drawing 1.Certainly, sometimes, the signal to noise ratio of the fetus electrocardiosignal that first order separation and Extraction is estimated can be estimated it than higher, needn't carry out second level separation and Extraction as final.Separate (BSS) method based on the blind source of independent component analysis (ICA) and extract fetal electrocardiogram,, can be included into the first order separation and Extraction step here from essence.
Present patent application specifically, relates separately to a kind of method in the first order separation and Extraction of fetal electrocardiogram (FECG) and a kind of method in the separation and Extraction of the second level.Because the step of two kinds of methods is basic identical, so be placed in the same application.
Background technology
The first order separating and extracting process of fetal electrocardiogram can be divided at the separating and extracting process of one-channel signal with at separating and extracting process two classes of multiple signals.So-called separating and extracting process at one-channel signal, no matter it gathered several roads electrocardiosignal in the reality, all is to mix electrocardiosignal by one tunnel female tire to estimate one tunnel fetus electrocardiosignal, matched filtering method
[1] [31], singular value decomposition method (SVD)
[2], non-linear extracting method
[3]The method that comes to this; Certainly, the single channel separating and extracting process is respectively applied for the female tire mixed signal of multichannel also can estimate multichannel fetus electrocardiosignal, does not just exist the several abdomen to lead or breast is led the situation that signal fused goes out one tunnel fetus electrocardiosignal.So-called separating and extracting process at multiple signals then is to lead signal or breast is led signal by the multichannel abdomen of gathering, and estimates the method for one tunnel fetus electrocardiosignal by data fusion, as correlational analysis method
[4] [5], the adaptive-filtering method
[6] [7], spatial filtering method
[8] [9], also have independent component analysis (ICA) and other blind source partition methods (BSS)
[10] [11] [12]Deng.
Because the convenience of monitor signal thinks that at the separating and extracting process of one-channel signal application prospect is arranged most in the first order separation and Extraction, still, only to lead female tire mixing electrocardiosignal and isolate fetus electrocardio composition from one road abdomen, the difficulty of date processing is very big.Existing processing method, no matter be matched filtering method, singular value decomposition method (SVD) or non-linear extracting method, the fetus electrocardio of proposition according to a preliminary estimate waveform all distortion is bigger, increased the difficulty of second level separation and Extraction.
About the second level separating and extracting process of fetal electrocardiogram, can have equally at the separating and extracting process of one-channel signal with at the branch of the separating and extracting process of multiple signals.At the separating and extracting process of one-channel signal, be from the waveform according to a preliminary estimate of one tunnel fetus electrocardiosignal, further to propose the one road accurately to estimate waveform.The separating and extracting process of one-channel signal can comprise matched filtering method, singular value decomposition method (SVD), non-linear extracting method etc. equally, just no longer comprises main parent electrocardio component in the noise that will dispel and the interference.Existing as matched filtering method, singular value decomposition method (SVD) and non-linear extracting method etc., fetus electrocardiosignal is according to a preliminary estimate further extracted same big, the problem that can not fine proposition of the fetus ecg wave form distortion of extracting that exists as second level separating and extracting process.
List of references:
[1] Monica Healthcare Limited, Fetal Surveillance, European patent: EP1941832A1, application number: 07012903.6
[2]P.P.Kanjilal，S.Palit，and?G.Saha，“Fetal?ECG?extraction?from?single?channel?maternal?ECG?using?singular?valuedecomposition，”IEEE?Trans.Biomed.Eng.，vol.44，Jan.1997
[3]Marcus?Richter，Thomas?Schreiber，and?Daniel?T.Kaplan，“Fetal?ECG?extraction?with?nonlinear?state-space?projections，”IEEETrans.Biomed.Eng.，vol.45，no.1，pp.133-137，Jan.1998.
[4]S.Abound，A.Alaluf，S.Einav，and?D.Sadeh，“Real?time?abdominal?fetal?ECG?recording?using?hardware?correlator，”Comput.Biol?Med.，vol.22，pp.32-335，1992.
[5] Huanan Medical Electrical Tech Co., Ltd., Henan, fetal electrocardiograph, in May, 2006, Chinese utility model patent: Z1200520111843.5
[6]E.R.Ferrara?and?B.Widrow，“Fetal?electrocardiogram?enhancement?by?time?sequenced?adaptive?filtering，”IEEE?Trans.Biomed.Eng.，vol.BME-29，pp.458-460，1982.
[7]M.Martinez，E.Soria，J.Calpe，J.F.Guerrero，and?J.R.Magdalena，“Application?of?the?adaptive?impulse?correlated?filter?forrecovering?fetal?electrocardiogram，”in?Proc.Comput.Cardiol.，Lund，Sweden，1997，pp.9-12.
[8]P.Bergveld?and?W.J.H.Meijer，“A?new?technique?for?the?suppression?of?the?MECG，”IEEE?Trans.Biomed.Eng.，vol.BME-28，pp.384-354，1981.
[9]A.Van?Oosterom，“Spatial?filtering?of?the?fetal?electrocardiogram，”J.Perinatal?Med.，vol.14，pp.411-419，1986.
[10]V.Zarzoso?and?A.K.Nandi，“Noninvasive?fetal?electrocardiogram?extraction：blind?separation?versus?adaptive?noisecancellation，”IEEE?Trans.Biomed.Eng.，vol.48，no.1，pp.12-18，Jan.2001.
[11]L.De?Lathauwer，B.De?Moor，and?J.Vandewalle，“Fetal?electrocardiogram?extraction?by?blind?source?subspace?separation，”IEEE?Trans.Biomed.Eng.，vol.47，no.5，pp.567-572，May?2000.
[12]M.G.Jafari?and?J.A.Chambers，“Fetal?electrocardiogram?extraction?by?sequential?source?separation?in?the?wavelet?domain，”IEEE?Trans.Biomed.Eng，vol.52，no.3，pp.390-400，Mar.2005.
[13]A.Khamene?and?S.Negahdaripour，“A?new?method?for?the?extraction?of?fetal?ECG?from?the?composite?abdominal?signal，”IEEETrans.Biomed.Eng.，vol.47，no.4，pp.507-516，Apr.2000.
[14]E.C.Karvounis，C.Papaloukas，D.I.Fotiadis，and?L.K.Michalis，“Fetal?heart?rate?extraction?from?composite?maternal?ECGusing?complex?continuous?wavelet?transform，”in?Proc.Comput.Cardiol.2004，Chicago，IL，pp.19-22.
[15]G.Camps?Valls，M.Martinez?Sober，E.Soria?Olivas，R.Magdalena-Benedito，J.C?alpe-Maravilla，and?J.Guerrero-Martinez，“Foetal?ECG?recovery?using?dynamic?neural?networks，”Artif.Intell?Med.，vol.31，pp.197-209，2004.
[16]G.Camps，M.Martinez，and?E.Soria，“Fetal?ECG?extraction?using?an?FIR?neural?network，”in?Proc.Comput.Cardiol.2001，Rotterdam，The?Netherlands，pp.249-252.
[17]K.Assaleh?and?H.Al-Nashash，“A?novel?technique?for?the?extraction?of?fetal?ECG?using?polynomial?networks，”IEEE?Trans.Biomed.Eng.，vol.52，no.6，pp.1148-1152，Jun.2005.
[18]K.Assaleh，“Extraction?of?fetal?electrocardiogram?using?adaptive?neuro-fuzzy?inference?systems，”IEEE?Trans.Biomed.Eng.，vol.54，NO.1，pp.59-68，Jun.2007.
[19]M.I.Ibrahimy，F.Ahmed，M.A.Mohd?Ali，and?E.Zahedi，“Real-time?signal?processing?for?fetal?heart?rate?monitoring，”IEEETrans.Biomed.Eng.，vol.50，no.2，pp.258-262，Feb.2003.
[20]S.L.Horner，W.M.Holls，and?P.B.Crilly，“A?robust?real?time?algorithm?for?enhancing?non-invasive?foetal?electrocardiogram，”Digital?Signal?Process.，vol.5，pp.184-194，1995.
[21]Braun?S.“The?extraction?of?periodic?waveforms?by?the?time?domain?averaging，”Acustica，1975，32：69-77.
[22]P.D.McFadden，“A?revised?model?for?the?extraction?of?periodic?waveforms?by?time?domain?averaging，”Mechanical?Systems?andSignal?Processing?1(1)(1987)83-95.
[23]H.Liu，H.Zuo，C.Jiang，L.Qu，“An?improved?algorithm?for?direct?time-domain?averaging，”Mechanical?Systems?and?SignalProcessing，2000，vol.14，pp.279-285
[24]C.Li，C.Zheng，and?C.Tai，“Detection?of?ECG?characteristic?points?using?wavelet?transforms，”IEEE?Trans.on?Biomed.Eng.，vol.42，no.1，pp.21-28，Jan.1995.
[25]S.Kadambe，R.Murray，and?G.Faye?Boudreaux-Bartels，“Wavelet?Transform-Based?QRS?Complex?Detector，”IEEE?Trans.onBiomed.Eng.，vol.46，no.7，pp.838-848，July.1999.
[26]V.Johneff，“Complex?valued?wavelet?analysis?for?QRS?detection?in?ECG?signals，”in?Proc.23rd?Leeds?Annu.Statistical?Res.Workshop，Leeds，U.K.，2004，pp.134-36.
[27]P.McSharry，G.Clifford，L.Tarassenko，and?L.Smith，“A?dynamical?model?for?gener?ating?synthetic?electrocardiogram?signals，”IEEE?Trans?Biomed.Eng.，vol.50，no.3，pp.289-294，Mar?2003.
[28]De?Moor?B.L.R.(ed.)，DaISy：Database?for?the?Identification?of?Systems，Department?of?Electrical?Engineering，ESAT/SISTA，K.U.Leuven，Belgium，URL：http://homes.esat.kuleuven.be/~smc/daisy/，2008，Jun.
[29]The?MIT-BIH?Non-Invasive?Fetal?Electrocardiogram?Database[Online].Available：http://www.physionet.org/pn3/nifecgdb
[30]Grandke?T.“Interpolating?algorithms?for?discrete?Fourier?transforms?of?weighted?signals，”IEEE?Trans.IM，1983，13(2)：350-355
[31] Lu Yaosheng, Liang Yuhou: be used to monitor the method and apparatus of parent uterine contraction activity and control labor, Chinese invention patent, application number: 03113712.1
Summary of the invention
The technical problem that solves.
In the existing fetal electrocardiogram first order or the second level separation and Extraction at the separating and extracting process of one-channel signal, as matched filtering method, singular value decomposition method (SVD), non-linear extracting method etc., the fetus ecg wave form distortion of extracting is bigger, many times can not extract at all.
Technical scheme.
A kind of separating and extracting process at one-channel signal that is used for fetal electrocardiogram first order separation and Extraction has been proposed.This method comprises these steps: (1) is read the one road female tire that picks up from the parent abdomen body-surface and is mixed electrocardiosignal; (2) Signal Pretreatment is dispeled baseline drift, 50Hz or the 60Hz power frequency of mixing in the electrocardiosignal and is disturbed and high-frequency noise; (3) detection mixes the position at each R wave-wave peak of the parent component that shows on the ecg wave form, calculates the head and the tail limit section time span of each R-R interval and whole waveform; (4) each R-R segment signal and two head and the tail limit segment signals are resampled respectively, obtain the waveform of cycle homogenization, allow each R-R segment signal have identical sampling number; (5) carry out Time domain averaging by the homogenization cycle, obtain estimation parent component cycle homogenization form; (6) the cycle homogenization parent component waveform that obtains is carried out restorative resampling, recover the heart rate variability (HRV) of parent electrocardio component, thereby obtain the final estimation of parent component; (7) deduct the parent component of final estimation the waveform that (2) step pretreatment obtains more than this method, obtain to fetus electrocardio component according to a preliminary estimate, so far, first order separation and Extraction finishes.The flow chart of this programme first order separating and extracting process is seen accompanying drawing 2.
A kind of separating and extracting process at one-channel signal that is used for second level separation and Extraction has been proposed.This method comprises these steps: (1) reads the waveform one tunnel according to a preliminary estimate of the fetus electrocardiosignal of first order separation and Extraction generation; (2) Signal Pretreatment is dispeled the baseline drift, 50Hz or the 60Hz power frequency that remain in the waveform according to a preliminary estimate and is disturbed and high-frequency noise; (3) the head and the tail limit section time span of each R-R interval and whole waveform is calculated in the position at each R wave-wave peak of fetus component in the detection waveform; (4) each R-R segment signal and two head and the tail limit segment signals are resampled respectively, obtain the waveform of cycle homogenization, allow each R-R segment signal have identical sampling number; (5) carry out Time domain averaging by the homogenization cycle, obtain estimation fetus electrocardio component cycle homogenization form; (6) the cycle homogenization fetus ecg wave form that obtains is carried out restorative resampling, recover the heart rate variability (HRV) of fetus electrocardio component, thereby obtain the final estimation of fetus electrocardio component, so far, second level separation and Extraction finishes.The flow chart of this programme second level separating and extracting process is seen accompanying drawing 3.
In a kind of method of first order separation and Extraction set forth above or second level separation and Extraction, (2) step all was a Signal Pretreatment, and effect is to dispel baseline drift, 50Hz or 60Hz power frequency to disturb and high-frequency noise.Baseline drift is a low frequency, is caused by breathe and other muscular movements etc.; It is a possible main interference that 50Hz or 60Hz power frequency are disturbed; High-frequency noise refers to the radio-frequency component beyond the signal frequency range interested.Dispel baseline drift and high-frequency noise, can adopt the method for method of wavelet, 0 Phase FIR bandpass filtering or the method for HHT conversion etc.; Dispel 50Hz or 60Hz power frequency and disturb, can adopt the method for comb filtering or notch filter, also have the accurate mutually estimation approach of power frequency composition amplitude-frequency
[30]Deng.These methods have the lot of documents introduction, and method is ripe.Certainly, for the situation that does not have baseline drift, 50Hz or interference of 60Hz power frequency and high-frequency noise, this pre-treatment step can not carried out.
In a kind of method of first order separation and Extraction set forth above or second level separation and Extraction, (3) step all was the position of detecting R wave-wave peak, calculated the head and the tail limit section time span of each R-R interval and whole waveform.The method that detects at present R wave-wave peak position is also a lot, as based on the both sides rise and fall of R wave-wave peak along the method for slope maximum, based on the wavelet singular detection
[24-26]Method etc., these methods have the lot of documents introduction, method is ripe.In the first order separation and Extraction, because fetus electrocardio composition is very weak, the crest of shown R ripple can think to be exactly the R wave-wave peak of parent electrocardio component in female tire mixing ecg wave form.
In a kind of method of first order separation and Extraction set forth above or second level separation and Extraction, (4) step all was that each R-R segment signal and head and the tail limit segment signal are resampled respectively.Resampling will be satisfied sampling thheorem, and the different R-R segment signals in back that resample have identical sample points, and the sample points of head and the tail limit segment signal is also done respective change after resampling, the waveform of the promptly so-called cycle homogenization of data after so resampling.This resampling process sees that (a) in the accompanying drawing 4 schemes shown in the Resampling A l among the figure
1, l
2..., l
i(T) ..., l
nBe respectively the sample points of n R-R in interval that detects previously, l
a, l
bSample points about being respectively in the section of head and the tail limit; If l
1, l
2..., l
i(T) ..., l
nIn l
i(T) be maximum sample points, then in order to satisfy sampling thheorem, the sampling number T that each the R-R section after the resampling is unified is greater than or equals former l
i(T) maximum sampling numbers.The resampling of head and the tail limit section is counted and is calculated as follows:
In the formula (1), T
a, T
bRefer to the sample points after limit, left and right sides section resamples respectively, l
a, l
bRepresent the original sample points of limit, left and right sides section respectively, l
1, l
nRepresent the 1st R-R section and the original sample points of last R-R section respectively, round is a bracket function.
In a kind of method of first order separation and Extraction set forth above or second level separation and Extraction, (5) step all was to carry out Time domain averaging (TDA) by the homogenization cycle, and logical communication link is seen accompanying drawing 4 about it; To first order separation and Extraction, what this step obtained is the estimation of parent electrocardio component cycle homogenization form, and to this step acquisition of second level separation and Extraction is the estimation of fetus electrocardio component cycle homogenization form.The Time domain averaging method can be described as: any point in the list entries (input sequence) obtains the estimated value of this point at output sequence (output sequence) with its contiguous different R-R several corresponding point weighted average of interval (perhaps waiting weight average) that are arranged in; Its sketch map is seen accompanying drawing 5, among the figure be come with the correspondence position point (totally 5 points) in a point and near 4 the R-R sections average, obtain the A point in the output sequence, come average totally with the correspondence position point (5 points) in b point and near 4 the R-R sections, obtain the B point in the output sequence, N refers on average count, and is 5 here.The time domain average method
[21-23]At frequency domain is a dressing wave filter; Specifically average when handling, can carry out in time domain fully, also can realize by the frequency domain computing.
In a kind of method of first order separation and Extraction set forth above or second level separation and Extraction, (6) step all was that the cycle homogenization ecg wave form that obtains is carried out restorative resampling, recover the heart rate variability of former electrocardio component, thereby obtain the final estimation of electrocardio component.For first order separation and Extraction, what restorative resampling obtained is the final estimation of parent electrocardio component; For second level separation and Extraction, what restorative resampling obtained is the final estimation of fetus electrocardio component.Restorative resampling sees shown in (b) figure Resampling B in the accompanying drawing 4, recovered original each R-R aroused in interest sampling number and the sampling number of head and the tail limit section, the i.e. l of interval
a, l
1, l
2..., l
i(T) ..., l
n, l
bThe resampling (Resampling A) of this resampling and front all is the basic skills in the Digital Signal Processing, need not be described in detail.
In the method for first order separation and Extraction set forth above, (7) step was the parent component that deducts final estimation from its pretreated waveform of (2) step, obtained to fetus electrocardio component according to a preliminary estimate.
The above two kinds of methods that propose---a kind of method in the first order separation and Extraction and a kind of method in the separation and Extraction of the second level, with regard to the method for their each steps, it all is sophisticated method, but, the method of one step does not constitute the determine solution of technical problem of front quasi-solution, and this programme is that the combination of each step method just constitutes the determine solution of technical problem of front quasi-solution.The novelty of this programme, creativeness and practicality are embodied in the combination of each step method.
Time domain average is named relevant the detection again, is the effective ways that extract periodic component interested from be mixed with noise and other interferential sophisticated signals.The component that the time domain average method requires to extract is the cycle, and will know its cycle in advance.Suppose that the parent electrocardio composition that female tire mixes in the electrocardiosignal is strict periodic signal, then at definite its all after date, can separation and Extraction go out parent electrocardio component by time domain average, separating with regard to incoherent fetus electrocardio composition and other interference noises originally with it, thereby obtain fetus electrocardio component according to a preliminary estimate; Equally, if supposition fetus electrocardio component is strict periodic signal, then fetus electrocardio component according to a preliminary estimate can come out accurate fetus electrocardio component separation and Extraction by time domain average.But in the reality, parent electrocardio component and fetus electrocardio component are not strict periodic signals, all there is heart rate variability (HRV), for this reason, before using time domain average, component cycle homogenization by resampling and will extract by section is wanted the cardiac cycle homogenization of elder generation with parent electrocardio component to first order separation and Extraction earlier, and second level separation and Extraction is wanted the cardiac cycle homogenization of elder generation with fetus electrocardio component.The homogenization of cardiac cycle relies on the resampling based on sampling thheorem again.Resample again based on the detection of R wave-wave peak position.The detection of R wave-wave peak position is carried out according to the intrinsic propesties at electrocardiosignal R wave-wave peak and the rule of Singularity Detection aspect again.Therefore, being not difficult to find out that each step of two methods of this programme is an organic assembling, is not the embodiment of a subjective will, but having reflected the objective requirement of separation and Extraction fetal electrocardiogram, is the utilization of the natural law.The rule of this programme comprehensive utilization comprises: the principle of Time domain averaging, sampling and the rule that resamples, the intrinsic propesties at electrocardiosignal R wave-wave peak and the rule of Singularity Detection aspect.
What in addition, this programme related to is two independently inventions.Take this programme additive method in addition for first order separation and Extraction, and second level separation and Extraction is taked the situation of this programme method, also belongs to the scope of present patent application protection; First order separation and Extraction is taked this programme method, and second level separation and Extraction is taked this case situation of method in addition, also belong to the scope of present patent application protection.
Beneficial effect.
Through using the Daisy data
[28]With U.S. MIT-BIH fetus ecg database
[29]In data---totally 28 routine data, two kinds of methods of test this programme are found can successful separation and Extraction go out fetal electrocardiogram to 20 routine data wherein, account for 71.4%; To 8 remaining routine data, with this programme method to the separation of can both succeeding of parent component, but to the fetus electrocardiosignal according to a preliminary estimate and final estimate, can't see the fetus ecg wave form, do not know reason, the detecting electrode placement location of fetal death reason, still be the reason that some month of fetus is difficult for measuring fetal electrocardiogram, or the like.From present appreciable data, the successful segregation ratio of this programme is the highest both at home and abroad.
Accompanying drawing 6 is the separation and Extraction of Daisy data 1 passage being carried out with this programme method.In the accompanying drawing 6, (a) figure is that the female tire that reads mixes electrocardiosignal, and (b) figure is the parent electrocardio component of estimating in the first order separation and Extraction, (c) figure for the fetus electrocardio component of first order separation and Extraction acquisition according to a preliminary estimate; (d) figure is the result of second level separation and Extraction, promptly the waveform according to a preliminary estimate of fetus electrocardio component is carried out the final estimation of the fetus ecg wave form that obtains after the further separation and Extraction.
Accompanying drawing 7 is the separation and Extraction of Data848 data 1 passage in the MIT fetus ecg database being carried out with this programme method.In the accompanying drawing 7, (a) figure is that the female tire that reads mixes electrocardiosignal, and (b) figure is the parent electrocardio component of estimating in the first order separation and Extraction, (c) figure for the fetus electrocardio component of first order separation and Extraction acquisition according to a preliminary estimate; (d) figure is the result of second level separation and Extraction, promptly the waveform according to a preliminary estimate of fetus electrocardio component is carried out the final estimation of the fetus ecg wave form that obtains after the further separation and Extraction.
Accompanying drawing 8 is to use singular value decomposition method
[2]To the separation and Extraction that Data848 data 1 passage in the MIT fetus ecg database carries out, initial data is with accompanying drawing 7.In the accompanying drawing 8, (a) figure is that the female tire that reads mixes electrocardiosignal, and (b) figure is the parent electrocardio component of estimating in the first order separation and Extraction, (c) figure be the fetus electrocardio component that obtains of first order separation and Extraction according to a preliminary estimate; (d) figure is the result of second level separation and Extraction, obviously, among the result of first order separation and Extraction, plays the initial line segment signal and loses; In the separation and Extraction of the second level, the serious distortion of the waveform of extraction, even can think and do not put forward.In a word, as can be seen, singular value decomposition method is good not as good as this programme method.
Description of drawings
Accompanying drawing 1, the complete frame figure of fetal electrocardiogram separation and Extraction
Accompanying drawing 2, the flow chart of this programme first order separating and extracting process
Accompanying drawing 3, the flow chart of this programme second level separating and extracting process
Accompanying drawing 4, the contact sketch map of pressing the section resampling and handling with time domain average (TDA)
Accompanying drawing 5, Time domain averaging method sketch map
Accompanying drawing 6, this programme mixes the separation and Extraction result of electrocardiosignal to a female tire
Accompanying drawing 7, this programme mixes the separation and Extraction result of electrocardiosignal to a female tire
Accompanying drawing 8, singular value decomposition method mixes the separation and Extraction result of electrocardiosignal to a female tire
The specific embodiment (embodiment)
The embodiment of first order separating and extracting process in the scheme.
(1) reads the one road female tire that picks up from the parent abdomen body-surface and mix electrocardiosignal.Data are from the fetus ecg database of MIT
[29], data name Data848, this data abdomen lead female tire and mix electrocardiosignal totally 4 passages (4 lead), and what read is the data of its 1st passage, 36500 samples of data length, sample rate 1000Hz.(a) figure in the accompanying drawing 7 is the oscillogram (part) of this list derivative certificate.
(2) Signal Pretreatment is dispeled baseline drift, 50Hz or the 60Hz power frequency of mixing in the electrocardiosignal and is disturbed and high-frequency noise.In this example, choose 0 Phase FIR band filter and go baseline drift and high-frequency noise to disturb, band passband scope is got 0.5-100Hz, and filter order is got 1001 rank; Accurately estimate by power frequency interference components amplitude-frequency phase parameter, remove power frequency and disturb
[30](power frequency is disturbed and is 50Hz in this example).
(3) detect the position of mixing each the R wave-wave peak of parent component that shows in the electrocardiosignal, calculate the head and the tail limit section time span of each R-R interval and whole waveform.When this example detects the position at pretreated female tire mixed signal R wave-wave peak, selected the method for wavelet singular detection, choosing of basic small echo and parameter thereof sees document [26] for details, and wavelet coefficient peak value searching logic sees document [25] for details.
(4) each R-R segment signal and head and the tail limit segment signal are resampled respectively, obtain the waveform of cycle homogenization, promptly allow each R-R segment signal have identical sampling number.In this example, the sampling number of each R-R section of the stylish sequence that resamples has just in time been got the sampling number of the longest R-R section of former sequence, has satisfied sampling thheorem.
(5) carry out Time domain averaging by the homogenization cycle, obtain estimation parent component cycle homogenization form.
(6) the cycle homogenization parent component waveform that obtains is carried out restorative resampling, recover the heart rate variability of parent electrocardio component, thereby obtain the final estimation of parent component.(b) figure of accompanying drawing 7 is seen in the final estimation of the parent component that this example is extracted.
(7) from pretreated waveform, deduct the parent component of final estimation, obtain according to a preliminary estimate, see (c) figure of accompanying drawing 7 fetus electrocardio component.So far, this routine first order separation and Extraction finishes.
The embodiment of second level separating and extracting process in the scheme.
(1) reads the waveform one tunnel according to a preliminary estimate of the fetus electrocardiosignal that first order separation and Extraction produces.The object that this example reads is exactly the result of this routine first order separation and Extraction---the data shown in (c) figure of accompanying drawing 7.
(2) Signal Pretreatment is dispeled baseline drift, 50Hz or the 60Hz power frequency of mixing in the electrocardiosignal and is disturbed and high-frequency noise.Equally, this example is chosen 0 Phase FIR band filter and is removed residual baseline drift and high-frequency noise interference, and band passband scope is got 0.5-100Hz, and filter order is got 1001 rank, accurately estimates by power frequency interference components amplitude-frequency phase parameter, removes residual power frequency and disturbs
[30](power frequency is disturbed and is 50Hz in this example).
(3) the head and the tail limit section time span of each R-R interval and whole waveform is calculated in the position at each the R wave-wave peak in the detection signal.This place is detected when the position at the pretreated signal of telecommunication of fetal rhythm according to a preliminary estimate R wave-wave peak, has selected the method for wavelet singular detection equally, and choosing of basic small echo and parameter thereof sees document [26] for details, and wavelet coefficient peak value searching logic sees document [25] for details.
(4) each R-R segment signal and head and the tail limit segment signal are resampled respectively, obtain the waveform of cycle homogenization, promptly allow each R-R segment signal have identical sampling number.In this example, when resampling, the sampling number that newly produces each R-R section of sequence is just in time got the sampling number of the longest R-R section in the resampling presequence, has satisfied sampling thheorem equally.
(5) carry out Time domain averaging by the homogenization cycle, obtain estimation fetus electrocardio component cycle homogenization form.
(6) the cycle homogenization fetus ecg wave form that obtains is carried out restorative resampling, recover the heart rate variability of fetus electrocardio component, thereby obtain the final estimation of fetus electrocardio component, see shown in (d) figure of accompanying drawing 7.So far, this routine second level separation and Extraction finishes.
Claims (2)
1. the separating and extracting process at one-channel signal that is used for fetal electrocardiogram first order separation and Extraction is characterized in that, comprises the steps: that (1) read the one road female tire that picks up from the parent abdomen body-surface and mix electrocardiosignal; (2) Signal Pretreatment is dispeled baseline drift, 50Hz or the 60Hz power frequency of mixing in the electrocardiosignal and is disturbed and high-frequency noise; (3) detection mixes the position at each R wave-wave peak of the parent electrocardio component that shows on the ecg wave form, calculates the head and the tail limit section time span of each R-R interval and whole waveform; (4) each R-R segment signal and head and the tail limit segment signal are resampled respectively, obtain the waveform of cycle homogenization, allow each R-R segment signal have identical sampling number; (5) carry out Time domain averaging by the homogenization cycle, obtain estimation parent electrocardio component cycle homogenization form; (6) the cycle homogenization parent electrocardio component waveform that obtains is carried out restorative resampling, recover the heart rate variability of parent electrocardio component, thereby obtain the final estimation of parent electrocardio component; (7) deduct the parent electrocardio component of final estimation from the waveform that above (2) step Signal Pretreatment obtains, obtain to fetus electrocardio component according to a preliminary estimate, so far, first order separation and Extraction finishes.
2. separating and extracting process that is used for fetal electrocardiogram second level separation and Extraction at one-channel signal, it is characterized in that, comprise the steps: that (1) read the waveform one tunnel according to a preliminary estimate of the fetus electrocardio component that first order separation and Extraction produces, this first order separation and Extraction is meant---estimates parent electrocardio component, the parent electrocardio component of estimating separated from female tire mixing electrocardiosignal that the parent abdomen body-surface picks up, thereby obtain fetus electrocardio component according to a preliminary estimate; (2) Signal Pretreatment is dispeled the baseline drift, 50Hz or the 60Hz power frequency that remain in the waveform according to a preliminary estimate and is disturbed and high-frequency noise; (3) the head and the tail limit section time span of each R-R interval and whole waveform is calculated in the position at each R wave-wave peak of fetus electrocardio component in the detection waveform; (4) each R-R segment signal and head and the tail limit segment signal are resampled respectively, obtain the waveform of cycle homogenization, allow each R-R segment signal have identical sampling number; (5) carry out Time domain averaging by the homogenization cycle, obtain estimation fetus electrocardio component cycle homogenization form; (6) the cycle homogenization fetus electrocardio component waveform that obtains is carried out restorative resampling, recover the heart rate variability of fetus electrocardio component, thereby obtain the final estimation of fetus electrocardio component, so far, second level separation and Extraction finishes.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2009100279790A CN101554325B (en) | 2009-05-15 | 2009-05-15 | Method for extracting fetal electrocardiograms (FECG) by separation |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2009100279790A CN101554325B (en) | 2009-05-15 | 2009-05-15 | Method for extracting fetal electrocardiograms (FECG) by separation |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN101554325A CN101554325A (en) | 2009-10-14 |
| CN101554325B true CN101554325B (en) | 2011-04-13 |
Family
ID=41172713
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2009100279790A Expired - Fee Related CN101554325B (en) | 2009-05-15 | 2009-05-15 | Method for extracting fetal electrocardiograms (FECG) by separation |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN101554325B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103610460A (en) * | 2013-12-11 | 2014-03-05 | 哈尔滨工业大学 | Fetus electrocardiosignal extracting method based on self-adaptation FLANN filter |
Families Citing this family (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101972145B (en) * | 2010-10-12 | 2012-05-09 | 华南理工大学 | Fetus electrocardio blind separation method based on relative sparsity of time domain of source signal |
| CN102670196A (en) * | 2011-01-18 | 2012-09-19 | 王卫东 | R-wave singularity analyzing method |
| CN102178522B (en) * | 2011-04-29 | 2013-03-06 | 华南理工大学 | Method for detecting and locating R wave in QRS (Quantum Resonance Spectrometer) waves of electrocardiographic signals of mother and fetus |
| CN102512153B (en) * | 2011-10-25 | 2014-04-09 | 电信科学技术研究院 | Non-contact electrocardio monitoring mobile terminal and electrocardio monitoring method |
| CN102715897B (en) * | 2012-07-17 | 2014-06-25 | 南京大学 | Method for determining average heart rates of fetuses on basis of fetal electrocardio spectrograms |
| CN104027105B (en) * | 2014-04-23 | 2016-08-24 | 河南科技大学 | A kind of novel female fetal electrocardiogram separation method |
| CN104382589B (en) * | 2014-12-09 | 2017-02-22 | 南京大学 | Fetal electrocardiogram separation extraction method based on partial resampling by segments |
| CN109009083A (en) * | 2018-07-19 | 2018-12-18 | 电子科技大学 | A kind of Fetal ECG extracting method and device merging small echo and fastICA |
| CN109567866B (en) * | 2018-10-15 | 2021-12-28 | 广东宝莱特医用科技股份有限公司 | Method for processing fetal heart rate cycle variation |
| CN109758143B (en) * | 2019-02-22 | 2021-07-27 | 南京大学 | Method for enhancing multichannel electrocardiosignal recorded synchronously |
| CN109645985B (en) * | 2019-02-22 | 2021-09-17 | 南京大学 | Method for detecting single-channel electrocardiogram R peak of abdominal wall electrogynae body of pregnant woman |
-
2009
- 2009-05-15 CN CN2009100279790A patent/CN101554325B/en not_active Expired - Fee Related
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103610460A (en) * | 2013-12-11 | 2014-03-05 | 哈尔滨工业大学 | Fetus electrocardiosignal extracting method based on self-adaptation FLANN filter |
| CN103610460B (en) * | 2013-12-11 | 2015-10-28 | 哈尔滨工业大学 | A kind of Fetal ECG method for extracting signal based on self adaptation FLANN wave filter |
Also Published As
| Publication number | Publication date |
|---|---|
| CN101554325A (en) | 2009-10-14 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN101554325B (en) | Method for extracting fetal electrocardiograms (FECG) by separation | |
| CN101596108B (en) | Nonlinear separation and extract methods of fetal electrocardiography | |
| CN101972145B (en) | Fetus electrocardio blind separation method based on relative sparsity of time domain of source signal | |
| CN103610460B (en) | A kind of Fetal ECG method for extracting signal based on self adaptation FLANN wave filter | |
| CN102178522B (en) | Method for detecting and locating R wave in QRS (Quantum Resonance Spectrometer) waves of electrocardiographic signals of mother and fetus | |
| CN103110418B (en) | Electroencephalogram signal characteristic extracting method | |
| JPWO2007029485A1 (en) | Nonlinear Signal Separation Method by Nonlinear State Space Projection Method | |
| CN107693004A (en) | Fetal ECG extraction and fetal heart frequency recognition methods based on hilbert conversion | |
| CN109567792A (en) | A kind of single channel abdomen record fetal electrocardiogram extracting method | |
| CN101627907A (en) | Device and method for analyzing and processing electrocardiograph signal | |
| CN104382589B (en) | Fetal electrocardiogram separation extraction method based on partial resampling by segments | |
| CN102783945A (en) | Fetal electrocardiogram signal extracting method based on wavelet threshold denoising | |
| Di Marco et al. | Multichannel foetal heartbeat detection by combining source cancellation with expectation-weighted estimation of fiducial points | |
| Algunaidi et al. | Evaluation of an improved algorithm for fetal QRS detection | |
| CN103637796B (en) | Fetal electrocardiosignal self-adaptive blind extraction method based on generalized eigenvalue maximization | |
| Hatai et al. | FPGA implementation of a fetal heart rate measuring system | |
| CN116269422A (en) | Fetal electrocardio separation acquisition method and device with high signal-to-noise ratio | |
| CN102058407A (en) | Method and apparatus for predicting ventricular fibrillation | |
| CN102940489B (en) | Filter designing method of weak electrophysiology signal and filtering method | |
| CN102090888B (en) | Method for separating and extracting fetal electrocardiogram by adopting multi-lead signal fusion mode | |
| CN103876730B (en) | Blind extraction method for electrocatdiogram of mother and electrocardiogram of fetus based on second-order statistical properties | |
| CN104935292A (en) | Source number estimation-based surface electromyogram signal adaptive filtering method | |
| Cho et al. | Adaptive noise canceling of electrocardiogram artifacts in single channel electroencephalogram | |
| Mou et al. | Noise removal and QRS detection of ECG signal | |
| Algunaidi et al. | Comparative analysis of fetal electrocardiogram (ECG) extraction techniques using system simulation |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20110413 Termination date: 20210515 |