A Non-invasive Methodology for Fetal Monitoring during Pregnancy

Summary

Objectives: This paper describes a methodology for the monitoring of the fetal cardiac health status during pregnancy, through the effective and non-invasive monitoring of the abdominal ECG signals (abdECG) of the mother.

Methods: For this purpose, a three-stage methodology has been developed. In the first stage, the fetal heart rate (fHR) is extracted from the abdECG signals, using nonlinear analysis. Also, the eliminated ECG (eECG) is calculated, which is the abdECG after the maternal QRSs elimination. In the second stage, a blind source separation technique is applied to the eECG signals and the fetal ECG (fECG) is obtained. Finally, monitoring of the fetus is implemented using features extracted from the fHR and f ECG, such as the T/QRS ratio and the characterization of the fetal ST waveforms.

Results: The methodology is evaluated using a dataset of simulated multichannel abdECG signals: 94.79% accuracy for fHR extraction, 92.49% accuracy in T/QRS ratio calculation and 79.87% in ST waveform classification.

Conclusions: The novel non-invasive proposed methodology is advantageous since it offers automated identification of fHR and fECG and automated ST waveform analysis, exhibiting a high diagnostic accuracy.

Keywords

Fetal ECG - heart rate - blind source separation - fetal monitoring - ST analysis

• References

• 1 Sundström AK, Rosén D, Rosén KG. Fetal surveillance. Chicago:: Textbook, Neoventa Medical AB; 2006 http://www.fda.gov/ohrms/dockets/ AC/05/briefing/2005–4150b1_06_NEOVENTA% 20STAN%20S31%20TRAINING%20TEXT%20BOOK.PDF.
• 2 Smith JF. Fetal health assessment using prenatal diagnostic techniques. Curr Opin Obstet Gynecol 2008; 20: 152-156.
• 3 Tempfer C, Hefler L, Husslein P. Modern intrapartum fetal monitoring: room for improvement?. Arch Gynecol Obstet 2007; 276: 99-100.
• 4 Alfirevic Z, Devane D, Gyte GM. Continuous cardiotocography (CTG) as a form of electronic fetal monitoring (EFM) for fetal assessment during labour. Cochrane Database Syst Rev 2006; 3: CD006066.
• 5 Amer-Wåhlin I, Yli B, Arulkumaran S. Foetal ECG and STAN technology – A review. European Clinics in Obstetrics and Gynaecology 2005; 1: 61-73.
• 6 Rosn KG, Amer-Wahlin I, Luzietti R, Norn H. Fetal ECG waveform analysis. Best Practice and Research Clinical Obstetrics and Gynaecology 2004; 18: 485-514.
• 7 Su LL, Chong YS, Biswas A. Use of Fetal Electrocardiogram for Intrapartum Monitoring. Annals Academy of Medicine 2007; 36: 416-420.
• 8 Westgate J, Harris M, Curnow JS, Greene KR. Plymouth randomized trial of cardiotocography only versus ST waveform plus cardiotocogram for intrapartum monitoring in 2400 cases. Am J Obstet Gynecol 1993; 169: 1151-1160.
• 9 Neilson JP. Fetal electrocardiogram (ECG) for fetal monitoring during labour. Cochrane Database of Systematic Reviews 2006, Issue 2. (Art. No.: CD000116. DOI: 10.1002/14651858. CD000116. pub2).
• 10 Ferrario M, Signorini MG, Magenes G. Comparison between fetal heart rate standard parameters and complexity indexes for the identification of severe intrauterine growth restriction. Methods Inf Med 2007; 46 (02) 186-190.
• 11 Turan S, Turan OM, Berg C, Moyano D, Bhide A, Bower S, Thilaganathan B, Gembruch U, Nicolaides K, Harman C, Baschat AA. Computerized fetal heart rate analysis, Doppler ultrasound and biophysical profile score in the prediction of acid-base status of growth-restricted fetuses. Ultrasound Obstet Gynecol 2007; 30: 750-756.
• 12 Newnham JP, Doherty DA, Kendall GE, Zubrick SR, Landau LL, Stanley FJ. Effects of repeated prenatal ultrasound examinations on childhood outcome up to 8 years of age: follow-up of a randomised controlled trial. Lancet 2004; 364 9450 2038-2044.
• 13 Pieri JF, Crowe JA, Hayes-Gill BR, Spencer CJ, Bhogal K, James DK. Compact long-term recorder for the transabdominal foetal and maternal electrocardiogram. Med Biol Eng Comput 2001; 39: 118-125.
• 14 Zarzoso V, Nandi AK. Noninvasive Fetal Electrocardiogram Extraction: Blind Separation versus Adaptive Noise Cancellation. IEEE Trans Biomed Eng 2001; 48: 12-18.
• 15 Richter M, Schreiber T, Kaplan DT. Fetal ECG extraction with nonlinear state space projections. IEEE Trans Biomed Eng 1998; 45: 133-137.
• 16 Camps-Valls G, Martinez-Sober M, Soria-Olivas E, Guerrero-Martinez J, Calpe-Maravilla J. Foetal ECG recovery using dynamic neural networks. Artificial Intelligence in Medicine 2004; 31: 197-209.
• 17 Barros AK, Cichocki A. Extraction of Specific Signals with Temporal Structure. Neural Computation 2001; 13: 1995-2003.
• 18 Azad KAK. Fetal QRS Complex Detection from Abdominal ECG: A Fuzzy Approach. In: Nordic Signal Processing Symposium (NORSIG). Proceedings of the Annual International Conference of the IEEE; 2000, Sweden. September 22-24; 2000. pp 275-278.
• 19 Assaleh K, Al-Nashash H. A Novel Technique for the Extraction of Fetal ECG Using Polynomial Networks. IEEE Trans Biomed Eng 2005; 52: 1148-1152.
• 20 Karvounis EC, Tsipouras MG, Fotiadis DI, Naka KK. An Automated Methodology for Fetal Heart Rate Extraction from the Abdominal Electrocardiogram. IEEE Trans. on Information Technology in Biomedicine 2007; 11: 628-638.
• 21 Khamene A, Negahdaripour S. A New Method for the Extraction of Fetal ECG from the Composite Abdominal Signal. IEEE Trans Biomed Eng 2000; 47: 507-516.
• 22 Karvounis EC, Papaloukas C, Fotiadis DI, Michalis LK. Fetal Heart Rate Extraction from Composite Maternal ECG Using Complex Continuous Wavelet Transform. In: Computers in Cardiology, ICA 2004. Proceedings of the 5th Annual International Conference of the IEEE; 2004, Chicago (USA), September 22-24; 2004. pp 19-22.
• 23 Ibrahimy MI, Ahmed F, Mohd Ali MA, Zahedi E. Real-Time Signal Processing for Fetal Heart Rate Monitoring. IEEE Trans Biomed Eng 2003; 50: 258-262.
• 24 Cichocki A, Amari S. Adaptive Blind Signal and Image Processing. England: John Wiley & Sons; 2002
• 25 Zarzoso V, Nandi AK, Bacharakis E. Maternal and Foetal ECG Separation using Blind Source Separation Methods. IMA J Math Appl Med and Biol 1997; 14: 207-225.
• 26 Lathauwer LD, Moor BD, Vandewalle J. Fetal Electrocardiogram Extraction by Blind Source Subspace Separation. IEEE Trans Biomed Eng 2000; 47: 567-572.
• 27 Jafari MG, Chambers JA. Fetal Electrocardiogram Extraction by Sequential Source Separation in the Wavelet Domain. IEEE Trans Biomed Eng 2005; 52: 390-400.
• 28 Lu W, Rajapakse JC. ICA with reference. Neurocomput 2006; 69: 2244-2257.
• 29 Karvounis EC, Tsipouras M, Fotiadis DI. Detection of Fetal Heart Rate through 3D Phase-Space Analysis from Multivariate Abdominal Recordings. IEEE Trans Biomed Eng 2009; 56 (05) 1394-406.
• 30 Jezewski J, Matonia A, Kupka T, Wrobel J. Fetal monitoring with online processing of electrocardiographic signals. In: EMBEC; Prague, November 20-25; 2005. pp 523-526.
• 31 Taylor MJO, Smith MJ, Thomas M, Green AR, Cheng F, Oseku-Afful S, Wee LY, Fisk NM, Gardiner HM. Non-invasive fetal electrocardiography in singleton and multiple pregnancies. British J Obstet Gynecol 2003; 110: 668-678.
• 32 Qinetiq non-invasive fetal ECG technology.. London. Available from: http://www.qinetiq.com/home/newsroom/news_releases_homepage/2003/3rd_quarter/scientists.html.
• 33 Monica AN24 Fetal Holter (Monica Healthcare Ltd).. Nottingham, UK. Available from: http://www.monicahealthcare.com.
• 34 Sameni R, Clifford GD, Jutten C, Shamsollahi MB. Multichannel ECG and Noise Modeling: Application to Maternal and Fetal ECG Signals. EURASIP Journal on Advances in Signal Processing, vol. 2007. (Research Article ID 43407, pp 1-14, , doi: 10.1155/2007/43407).
• 35 Zhang Q. Matlab Package for Robust and Efficient Location of T-Wave Ends in ECG and Its Evaluation with PhysioNet Data 2005. Available from: http://www.irisa.fr/sosso/zhang/biomedical.
• 36 Goring DG, Nikora VI. Despiking Acoustic Doppler Velocimeter Data. J Hydr Engrg 2002; 128: 117-126.
• 37 Mori N, Suzuki T, Kakuno S. Noise of acoustic Doppler velocimeter data in bubbly flow. Journal of Eng Mech 2007; 133: 122-125.
• 38 Abboud S, Sadeh D. Spectral analysis of the fetal electrocardiogram. Comput Biol Med 1989; 19: 409-415.
• 39 Aminghafari M, Cheze N, Poggi JM. Multivariate de-noising using wavelets and principal component analysis. Computational Statistics & Data Analysis 2006; 50: 2381-2398.
• 40 Koldovský Z, Tichavský P, Oja E. Efficient Variant of Algorithm FastICA for Independent Component Analysis Attaining the Cramér-Rao Lower Bound. IEEE Trans. on Neural Networks 2006; 17: 1265-1277.
• 41 Cichocki A, Amari S, Siwek K, Tanaka T, Anh Huy Phan AH, Zdunek R. ICALAB – MATLAB Toolbox Ver. 3 for signal processing. Available from: http://www.bsp.brain.riken.jp/ICALAB/ICALAB/SignalProc/.
• 42 Golbach EGM, Stinstra JG, Grot P, Peters MJ. Reference values for fetal MCG/ECG recordings in uncomplicated pregnancies. In: Biomagnetism, 2000. Proceedings of the 12th Annual International Conference; 2000, Espoo, Finland; 2000. pp 595-598.
• 43 Sato M, Kimura Y, Chida S, Ito T, Katayama N, Okamura K, Nakao M. A Novel Extraction Method of Fetal Electrocardiogram from the Composite Abdominal Signal. IEEE Trans Biomed Eng 2007; 54: 49-58.
• 44 Vrins V, Jutten C, Verleysen M. Sensor Array and Electrode Selection for Non-invasive Fetal Electrocardiogram Extraction by Independent Component Analysis. In: Computers in Cardiology, ICA 2004. Proceedings of the 5th Annual International Conference of the IEEE; 2004, Chicago (USA), September 22-24; 2004. pp 1017-1024.
• 45 Martens SMM, Rabotti C, Mischi M, Sluijter RJ. A robust fetal ECG detection method for abdominal recordings. Physiol Meas 2007; 28: 373-388.
• 46 Al-Zaden A, Al-Smadi A. Extraction of foetal ECG by combination of singular value decomposition and neuro-fuzzy inference system. Phys Med Biol 2006; 51: 137-143.
• 47 Tsipouras MG, Voglis C, Fotiadis DI. A Framework for Fuzzy Expert System Creation-Application to Cardiovascular Diseases. IEEE Trans Biomed Eng 2007; 54: 2089-2105.
• 48 Papaloukas C, Fotiadis DI, Likas A, Michalis LK. Automated methods for ischemia detection in long-duration ECGs. Cardiovascular Reviews and Reports 2003; 24: 313-320.