Please wait a minute...
Clinical and Experimental Obstetrics & Gynecology  2020, Vol. 47 Issue (4): 459-464    DOI: 10.31083/j.ceog.2020.04.5422
Review | Next articles
Current methods of non-invasive fetal heart rate surveillance
A. Theodoridou1, *(), A. Athanasiadis2, G. Tsakmakidis2, Ι. Tsakiridis2, A. Pilavidi2, C. Vosnakis2, T. Dagklis2, G. Mavromatidis2, A. Mamopoulos2
1School of Health Sciences, Midwifery Department, International Hellenic University, Thessaloniki, Greece
2Third Department of Obstetrics and Gynecology, Medical School, Aristotle University of Thessaloniki, Thessaloniki, Greece
Download:  PDF(182KB)  ( 312 ) Full text   ( 29 )
Export:  BibTeX | EndNote (RIS)      

Introduction: As accurate fetal evaluation during labor is essential, there is a continuous need for better noninvasive ways of monitoring. Electronic fetal monitoring (EFM) is an essential tool towards effective fetal assessment during labor, with the invasive Intrapartum ST Segment Analyses (STAN) system an early favorite. There are very few non-invasive EFM devices worldwide, with only two having Food and Drug Administration (FDA) approval. Methodology: This state of the science review focuses on the most recent available scientific data regarding the role of non-invasive EFM and its effect on perinatal outcomes. Results: The Monica AN24 system, FDA approved and comparable to an external Doppler CTG, is independent of maternal BMI. The Mind child Meridian monitor, the second EFM device with FDA approval, is comparable to STAN, but with up to 32 electrodes for improved accuracy it can be difficult for medical professionals to master. The Nemo System, new to the market, was found to be highly acceptable as a 24-hour monitoring device by pregnant women in a single inaugural pilot study. Discussion: Non-invasive monitoring technology is making progress but there are still issues with signal acquisition and quality that stem from the newfound mobility of the monitored pregnant women. The two FDA approved devices are promising with a few caveats and there are also new devices that aim to improve on the shortcomings of the leaders with promising advances in signal acquisition and processing via additional electrodes and setups.

Key words:  Electrocardiography      Electrocardiotocography      Peripartum care      Cardiotocography     
Submitted:  09 November 2019      Accepted:  10 February 2020      Published:  15 August 2020     
*Corresponding Author(s):  A. Theodoridou     E-mail:

Cite this article: 

A. Theodoridou, A. Athanasiadis, G. Tsakmakidis, Ι. Tsakiridis, A. Pilavidi, C. Vosnakis, T. Dagklis, G. Mavromatidis, A. Mamopoulos. Current methods of non-invasive fetal heart rate surveillance. Clinical and Experimental Obstetrics & Gynecology, 2020, 47(4): 459-464.

URL:     OR

Table 1  — Pros and Cons of current fetal heart rate surveillance devices.
Method Main device Type Pros Cons
Cardiotocography Doppler
Ultrasound/toco dynamometer
I Most commonly used, Contraction monitoring, HR time series, Reduces incidence of fetal hypoxia [13] Expert user required, No real-time beat to beat data, Signal loss, (MHR)/(FHR) discrimination issues [1, 13-15]. Restricts mobility [14, 16]. Higher incidence of operative delivery [17, 18]
Magnetocardiography [19] Superconducting Quantum
Device (SQUID) sensors
NI. Multichannel, Good SNR for fetal signals, Good results [20] Expert user required. Specialist set up required. Short term monitoring only. Expensive, lack of mobility [21]
STAN monitor [27] I Very good FHR, Reduces neonatal metabolic acidosis, [4, 18, 28-31]. Reduces the need for blood sampling [40] Expert user required. Use only after the membranes have ruptured and cervical dilation has exceeded 2-3 cm [14, 18]
Latest meta-analysis has concluded that STAN does not have a place in modern obstetrics [4, 18]
Monitor* [23]
NI FDA approved for Weeks of Gestation (WOG) ≥ 36, Comparable to STAN [43] No skin preparation, Number of electrodes
[32] can be inconvenient for both staff and patient [42]
NEMO System [41] NI Highly accepted by patients [41]. Minor skin preparation, New to the market, 2 studies only [41, 44]
Non-invasive fetal electrocardiography FDA approved for WOG ≥ 36 weeks, Europe, WOG (≥ 20 weeks), Real-time FH, MHR EHG capable, Equal or even superiority in signal quality to the external Doppler, CTG independent of maternal BMI [54, 55] evaluate precise fetal cardiac time intervals (fCTIs) [57] Skin preparation required, Success of beat-to-beat fHR detection, dependant strongly on location, timing, maternal activity levels, and maternal posture. Might have limited clinical utility if it is unsupervised with physical activity or posture shifts [58].

KhAI-MEDICA [42] NI Only patent submitted N/A N/A
[1] Ayres-de-Campos D., Spong C.Y., Chandraharan E.: “FIGO consensus guidelines on intrapartum fetal monitoring, Cardiotocography”. International Journal of Gynecology & Obstetrics, 2015, 131, 13-24.
doi: 10.1016/j.ijgo.2015.06.020 pmid: 26433401
[2] Sletten J., Kiserud T., Kessler J.: “Effect of uterine contractions on fetal heart rate in pregnancy, a prospective observational study”. Acta obstetricia et gynecologica Scandinavica, 2016, 95, 1129-35.
doi: 10.1111/aogs.12949 pmid: 27460848
[3] Behar J.: “Extraction of clinical information from the non-invasive fetal electrocardiogram”. arXiv preprint arXiv, 2016, 160601093.
pmid: 32550251
[4] Neilson J.P.: “Fetal electrocardiogram (ECG) for fetal monitoring during labour”. Cochrane Database of Systematic Reviews, 2015, 12.
doi: 10.1002/14651858.CD013505 pmid: 31845767
[5] Khandoker A.H., Marzbanrad F., Kimura Y.: “Recent advances in doppler signal processing and modelling techniques for fetal monitoring”. Frontiers in Physiology, 2018, 9, 691.
doi: 10.3389/fphys.2018.00691 pmid: 29922181
[6] Clark S.L., Hamilton E.F., Garite T.J., Timmins A., Warrick P.A., Smith S.: “The limits of electronic fetal heart rate monitoring in the prevention of neonatal metabolic academia”. American Journal of Obstetrics & Gynecology, 2017, 216, 163, e1-e6.
doi: 10.1016/j.ajog.2016.10.009
[7] Ogunyemi D., Jovanovski A., Friedman P., Sweatman B., Madan I.: “Temporal and quantitative associations of electronic fetal heart rate monitoring patterns and neonatal outcomes”. The Journal of Maternal-Fetal & Neonatal Medicine, 2018, 1-10.
doi: 10.1097/00005792-198401000-00001 pmid: 6690883
[8] Eden R.D., Evans M.I., Britt D.W., Evans S.M., Schifrin B.S.: “Safely lowering the emergency Cesarean and operative vaginal delivery rates using the Fetal Reserve Index”. The Journal of Maternal-Fetal & Neonatal Medicine, 2018, 1-7.
doi: 10.1097/00005792-198401000-00001 pmid: 6690883
[9] Yli B., Kjellmer I.: “Pathophysiology of foetal oxygenation and cell damage during labour”. Best Practice & Research Clinical Obstetrics & Gynaecology, 2016, 30, 9-21.
doi: 10.1016/j.bpobgyn.2015.05.004 pmid: 26211833
[10] Alfirevic Z., Devane D., Gyte G.M., Cuthbert A.: “Continuous cardiotocography (CTG) as a form of electronic fetal monitoring (EFM) for fetal assessment during labour”. The Cochrane Library. 2017.
doi: 10.1002/14651858.CD010274 pmid: 23833567
[11] Hon E.H.: “The electronic evaluation of the fetal heart rate, Preliminary report”. American Journal of Obstetrics & Gynecology, 1958, 75, 1215-1230.
doi: 10.1016/0002-9378(58)90707-5 pmid: 13545252
[12] Schmidt J.V., McCartney P.R.: “History and development of fetal heart assessment, a composite”. Journal of Obstetric, Gynecologic, & Neonatal Nursing, 2000, 29, 295-305.
[13] Peters C.H., ten Broeke E.D., Andriessen P., Vermeulen B., Berendsen R.C., Wijn P.F., et al.: “Beat-to-beat detection of fetal heart rate, Doppler ultrasound cardiotocography compared to direct ECG cardiotocography in time and frequency domain”. Physiological measurement, 2004, 25, 585.
doi: 10.1088/0967-3334/25/2/015 pmid: 15132321
[14] Clifford G.D., Silva I., Behar J., Moody G.B.: “Non-invasive fetal ECG analysis”. Physiological measurement, 2014, 35, 1521.
doi: 10.1088/0967-3334/35/8/1521
[15] Bakker P., Colenbrander G., Verstraeten A., Van Geijn H.: “The quality of intrapartum fetal heart rate monitoring”. European Journal of Obstetrics & Gynecology and Reproductive Biology. 2004, 116, 22-27.
[16] Nguyen K., Bamgbose E., Cox B.P., Huang S.P., Mierzwa A., Hutchins S., et al.: “Wearable fetal monitoring solution for improved mobility during labor & delivery”. 2018 40th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC), 2018, IEEE.
[17] Rzepka R., Torbé A., Kwiatkowski S., Blogowski W., Czajka R.: “Clinical outcomes of high-risk labours monitored using fetal electrocardiography”. Annals Academy of Medicine Singapore, 2010, 39, 27.
[18] Blix E., Brurberg K.G., Reierth E., Reinar L.M., Øian P. S.T.: “waveform analysis versus cardiotocography alone for intrapartum fetal monitoring, a systematic review and meta- analysis of randomized trials”. Acta obstetricia et gynecologica Scandinavica, 2016, 95, 16-27.
doi: 10.1111/aogs.12828 pmid: 26610052
[19] Cuneo B.F., Strasburger J.F., Yu S., Horigome H., Hosono T., Kandori A., et al.: “In utero diagnosis of long qt syndrome by magnetocardiography clinical perspective”. Circulation, 2013, 128, 2183-2191.
doi: 10.1161/CIRCULATIONAHA.113.004840
[20] Donofrio M.T., Moon-Grady A.J., Hornberger L.K., Copel J.A., Sklansky M.S., Abuhamad A., et al.: “Diagnosis and treatment of fetal cardiac disease, a scientific statement from the American Heart Association”. Circulation, 2014, 129, 2183-242.
doi: 10.1161/01.cir.0000437597.44550.5d
[21] Lakhno I., Behar J.A., Oster J., Shulgin V., Ostras O., Andreotti F.: “The use of non-invasive fetal electrocardiography in diagnosing second-degree fetal atrioventricular block”. Maternal health, neonatology and perinatology, 2017, 3, 14.
[22] Amer-Wahlin I., Kwee A.: “Combined cardiotocographic and ST event analysis, a review”. Best Practice & Research Clinical Obstetrics & Gynaecology, 2016, 30, 48-61.
doi: 10.1016/j.bpobgyn.2015.05.007 pmid: 26206514
[23] Behar J., Zhu T., Oster J., Niksch A., Mah D.Y., Chun T., et al.: “Evaluation of the fetal QT interval using non-invasive fetal ECG technology”. Physiological measurement, 2016, 37, 1392.
doi: 10.1088/0967-3334/37/9/1392 pmid: 27480078
[24] Burton G.J., Jauniaux E.: “Pathophysiology of placental-derived fetal growth restriction”. American Journal of Obstetrics & Gynecology, 2018, 218, S745-S61.
doi: 10.1016/j.ajog.2017.11.577 pmid: 29422210
[25] Bhogal K., Reinhard J.: “Maternal and fetal heart rate confusion during labour”. British Journal of Midwifery, 2010, 18, 424-428.
doi: 10.12968/bjom.2010.18.7.48781
[26] Behar J., Andreotti F., Zaunseder S., Oster J., Clifford G.D.: “A practical guide to non-invasive foetal electrocardiogram extraction and analysis”. Physiological measurement, 2016, 37, R1.
doi: 10.1088/0967-3334/37/5/R1 pmid: 27067431
[27] Hayes-Gill B., Hassan S., Mirza F.G., Ommani S., Himsworth J., Solomon M., et al.: “Accuracy and reliability of uterine contraction identification using abdominal surface electrodes”. Clinical Medicine Insights, Women's Health, 2012, 5, CMWH. S10444.
doi: 10.2217/whe.09.19 pmid: 19392617
[28] 28. Westerhuis M.E., Moons K.G., van Beek E., Bijvoet S.M., Drogtrop A.P., van Geijn H.P., et al.: “A randomised clinical trial on cardiotocography plus fetal blood sampling versus cardiotocography plus ST- analysis of the fetal electrocardiogram (STAN®) for intrapartum monitoring”. BMC Pregnancy & Childbirth, 2007, 7, 13.
doi: 10.1186/1471-2393-7-13 pmid: 17655764
[29] Saccone G., Schuit E., Amer-Wåhlin I., Xodo S., Berghella V.: “Electrocardiogram ST analysis during labor, a systematic review and meta-analysis of randomized controlled trials”. Obstetrics & Gynecology, 2016, 127, 127-135.
doi: 10.1097/AOG.0000000000001198 pmid: 26646135
[30] Olofsson P., Ayres-de-Campos D., Kessler J., Tendal B., Yli B.M., Devoe L.: “A critical appraisal of the evidence for using cardiotocography plus ECG ST interval analysis for fetal surveillance in labor. Part II, the meta-analyses”. Acta obstetricia et gynecologica Scandinavica, 2014, 93, 571-586.
doi: 10.1111/aogs.12412
[31] Belfort M.A., Saade G.R., Thom E., Blackwell S.C., Reddy U.M., Thorp Jr J.M., et al.: “A randomized trial of intrapartum fetal ECG ST-segment analysis”. New England Journal of Medicine, 2015, 373, 632-641.
doi: 10.1056/NEJMoa1500600 pmid: 26267623
[32] Luzietti R., Erkkola R., Hasbargen U., Mattsson L.Å., Thoulon J.M., Rosén K.G.: “European community multi-center trial ‘fetal ECG analysis during labor’, ST plus CTG analysis”. Journal of perinatal medicine, 1999, 27, 431-440.
doi: 10.1515/JPM.1999.058 pmid: 10732301
[33] Amer-Wåhlin I., Bördahl P., Eikeland T., Hellsten C., Noren H., Sörnes T., et al.: “ST analysis of the fetal electrocardiogram during labor, Nordic observational multicenter study”. The Journal of Maternal-Fetal & Neonatal Medicine, 2002, 12, 260-266.
[34] Luttkus A.K., Norén H., Stupin J.H., Blad S., Arulkumaran S., Erkkola R.., et al.: “Fetal scalp pH and ST analysis of the fetal ECG as an adjunct to CTG. A multi-center, observational study”. Journal of perinatal medicine, 2004, 32, 486-494.
doi: 10.1515/JPM.2004.121 pmid: 15576269
[35] Kwee A., van der Hoorn-van den Beld C., Veerman J., Dekkers A., Visser G.: “STAN® S21 fetal heart monitor for fetal surveillance during labor, an observational study in 637 patients”.. The Journal of Maternal-Fetal & Neonatal Medicine, 2004, 15, 400-407.
[36] Amer-Wåhlin I., Hellsten C., Norén H., Hagberg H., Herbst A., Kjellmer I., et al.: “Cardiotocography only versus cardiotocography plus ST analysis of fetal electrocardiogram for intrapartum fetal monitoring, a Swedish randomised controlled trial”. The Lancet, 2001, 358, 534-538.
doi: 10.1016/S0140-6736(01)05703-8
[37] Ojala K., Vääräsmäki M., Mäkikallio K., Valkama M., Tekay A.: “A comparison of intrapartum automated fetal electrocardiography and conventional cardiotocography—a randomised controlled study”. BJOG, An International Journal of Obstetrics & Gynaecology, 2006, 113, 419-423.
[38] Brown R., Wijekoon J.H., Fernando A., Johnstone E.D., Heazell A.E.: “Continuous objective recording of fetal heart rate and fetal movements could reliably identify fetal compromise, which could reduce stillbirth rates by facilitating timely management”. Medical hypotheses, 2014, 83, 410-417.
doi: 10.1016/j.mehy.2014.07.009
[39] Rotariu C., Pasarica A., Andruseac G., Costin H., Nemescu D.: “Automatic analysis of the fetal heart rate variability and uterine contractions”. Electrical and Power Engineering (EPE),2014 International Conference and Exposition on, 2014, IEEE.
[40] Furdea A., Preissl H., Lowery C.L., Eswaran H., Govindan R.B.: “Conduction velocity of the uterine contraction in serial magnetomyogram (MMG) data, Event based simulation and validation”. Engineering in Medicine and Biology Society, EMBC, 2011 Annual International Conference of the IEEE, 2011, IEEE.
[41] Schramm K., Lapert F., Nees J., Lempersz C., Oei S.G., Haun M.W., et al.: “Acceptance of a new non- invasive fetal monitoring system and attitude for telemedicine approaches in obstetrics, a case-control study”. Archives of Gynecology & Obstetrics, 2018, 1-9.
doi: 10.1007/s00404-010-1521-2 pmid: 20505948
[42] Viunytskyi O., Shulgin V.: “Signal processing techniques for fetal electrocardiogram extraction and analysis”. Electronics and Nanotechnology (ELNANO), 2017 IEEE 37th International Conference on 2017, IEEE.
[43] Clifford G., Sameni R., Ward J., Robinson J., Wolfberg A.J.: “Clinically accurate fetal ECG parameters acquired from maternal abdominal sensors”. American Journal of Obstetrics & Gynecology, 2011, 205, 47.e1-e5.
doi: 10.1016/j.ajog.2011.02.066
[44] Vlemminx M.W., Thijssen K.M., Bajlekov G.I., Dieleman J.P., Van Der Hout-Van M.B., Jagt D., et al.: “Electrohysterography for uterine monitoring during term labour compared to external tocodynamometry and intra-uterine pressure catheter”. European Journal of Obstetrics & Gynecology and Reproductive Biology, 2017, 215, 197-205.
[45] Rauf Z., O'Brien E., Stampalija T., Ilioniu F.P, Lavender T., Alfirevic Z.: “Home labour induction with retrievable prostaglandin pessary and continuous telemetric trans-abdominal fetal ECG monitoring”. PLoS One, 2011, 6, e28129.
doi: 10.1371/journal.pone.0028129 pmid: 22140522
[46] Kapaya H., Dimelow E.R., Anumba D.: “Women’s experience of wearing a portable fetal- electrocardiogram device to monitor small-for-gestational age fetus in their home environment”. Women's Health, 2018, 14, 1745506518785620.
doi: 10.1177/1363459309358596 pmid: 20427636
[47] Vasak B., Graatsma E.M., Hekman-Drost E., Eijkemans M.J., van Leeuwen J.H.S., Visser G.H., et al.: “Uterine electromyography for identification of first-stage labor arrest in term nulliparous women with spontaneous onset of labor”. American Journal of Obstetrics & Gynecology, 2013, 209, 232, e1-e8.
doi: 10.1016/j.ajog.2013.05.056
[48] Reinhard J., Hayes-Gill B.R., Schiermeier S., Hatzmann H., Heinrich T.M., Louwen F.: “Intrapartum heart rate ambiguity, a comparison of cardiotocogram and abdominal fetal electrocardiogram with maternal electrocardiogram”. Gynecologic & Obstetric Investigation, 2013, 75, 101-108.
doi: 10.1159/000345059 pmid: 23328351
[49] Odendaal H., Groenewald C., Myers M.M., Fifer W.P.: “Maternal heart rate patterns under resting conditions in late pregnancy”. Trends in research, 2018, 1.
doi: 10.15761/TR.1000120 pmid: 30775690
[50] Hofmeyr F., Groenewald C., Nel D., Myers M., Fifer W., Signore C., et al.: “Fetal heart rate patterns at 20 to 24 weeks gestation as recorded by fetal electrocardiography”. The Journal of Maternal-Fetal & Neonatal Medicine, 2014, 27, 714-718.
[51] Ibrahim S., Jarefors E., Nel D.G., Vollmer L., Groenewald C.A., Odendaal H.J.: “Effect of maternal position and uterine activity on periodic maternal heart rate changes before elective cesarean section at term”. Acta obstetricia et gynecologica Scandinavica, 2015, 94, 1359-1366.
doi: 10.1111/aogs.12763 pmid: 26335140
[52] Odendaal H., Kieser E., Nel D., Brink L., du Plessis C., Groenewald C., et al.: “Effects of low maternal heart rate on fetal growth and birthweight”. International Journal of Gynecology & Obstetrics, 2019, 146, 250-256.
doi: 10.1002/ijgo.12873 pmid: 31131885
[53] Reinhard J., Hayes-Gill B., Yi Q., Hatzmann H., Schiermeier S.: “Signal quality of non-invasive foetal electrocardiogram (ECG) during labour”. Geburtshilfe und Frauenheilkunde, 2009, 69, 703-706.
doi: 10.1055/s-0029-1185936
[54] Stampalija T., Signaroldi M., Mastroianni C., Rosti E., Signorelli V., Casati D., et al.: “Fetal and maternal heart rate confusion during intra-partum monitoring, comparison of trans-abdominal fetal electrocardiogram and Doppler telemetry”. The Journal of Maternal-Fetal & Neonatal Medicine, 2012, 25, 1517-1520.
[55] Sänger N., Hayes-Gill B., Schiermeier S., Hatzmann W., Yuan J., Herrmann E., et al.: “Prenatal Foetal Noninvasive ECG instead of Doppler CTG-A Better Alternative”? Geburtshilfe und Frauenheilkunde, 2012, 72, 630.
doi: 10.1055/s-0032-1315012
[56] Narayan H.K., Vignola E.F., Fifer W.P., Williams I.A.: “Assessment of cardiac rate and rhythm in fetuses with arrhythmia via maternal abdominal fetal electrocardiography”. AJP reports, 2015, 5, e176.
doi: 10.1055/s-0035-1558401 pmid: 26495180
[57] Wacker-Gussmann A., Plankl C., Sewald M., Schneider K.T.M., Oberhoffer R., Lobmaier S.M.: “Fetal cardiac time intervals in healthy pregnancies-an observational study by fetal ECG (Monica Healthcare System)”. Journal of Perinatal Medicine, 2018, 46, 587-592.
doi: 10.1515/jpm-2017-0003 pmid: 28453441
[58] Huhn E.A., Müller M.I., Meyer A.H., Manegold-Brauer G., Holzgreve W., Hoesli I., et al.: “Quality predictors of abdominal fetal electrocardiography recording in antenatal ambulatory and bedside settings”. Fetal Diagnosis & Therapy, 2017, 41, 283-292.
doi: 10.1159/000448946 pmid: 27811482
[59] Hayes- Gill B.R., Martin T.R., Liu C., Cohen W.R.: “Relative accuracy of computerized intrapartum fetal heart rate pattern recognition by ultrasound and abdominal ECG detection”. Acta Obstetricia et Gynecologica Scandinavica, 2020.
doi: 10.1111/aogs.13965 pmid: 32726457
[60] Zhivolupova Y.A.: “Analysis of the fetal heart rate variability by means of the abdominal electrocardiogram monitoring system”. 2018 third international conference on human factors in complex technical systems and environments (ERGO) s and environments (ERGO), 2018, IEEE.
[61] Macones G.: “Intrapartum fetal heart rate monitoring, nomenclature, interpretation, and general management principles”. Obstetrics & Gynecology, 2009, 114, 192-202.
doi: 10.1097/AOG.0b013e3181aef106 pmid: 19546798
[62] Roham M., Saldivar E., Raghavan S., Mehregany M., Shah M.: “Wireless fetal monitoring system”. Google Patents, 2017.
[63] Gaster R.S.: “Wireless pregnancy monitor”. Google Patents, 2019.
[64] Lahiji R.R., Roham M.: “Integrated wearable device for detection of fetal heart rate and material uterine contractions with wireless communication capability”. Google Patents, 2019.
[65] Mugyenyi G.R., Atukunda E.C., Ngonzi J., Boatin A., Wylie B.J., Haberer J.E.: “Functionality and acceptability of a wireless fetal heart rate monitoring device in term pregnant women in rural southwestern Uganda”. BMC Pregnancy & Childbirth, 2017, 17, 178.
doi: 10.1186/s12884-017-1361-1 pmid: 28595604
[66] Ginting C.N., Lister I.N.E., Silaen M., Girsang E., Laila Y., Turnip M., et al.: “Fetal heart detection based wide area network technology with wireless sensor transmission”. Journal of Physics, Conference Series, 2019, 1230 012037.
[67] Schwartz N., Mhajna M., Jakobs M., Aviraham K.B., Reches A., Eswaran H., et al.: “Towards a solution for remote pregnancy monitoring, a novel non-invasive method for uterine activity monitoring”. American Journal of Obstetrics & Gynecology, 2020, 222, S241.
[68] Kahankova R., Martinek R., Jaros R., Behbehani K., Matonia A., Jezewski M., et al.: “A review of signal processing techniques for non-invasive fetal electrocardiography”. IEEE Reviews in Biomedical Engineering, 2019.
doi: 10.1109/RBME.2020.2969915 pmid: 32011262
No related articles found!
No Suggested Reading articles found!