



@article {3312,
	title = {Development and evaluation of an algorithm for computer analysis of maternal heart rate during labor},
	journal = {Computers in Biology and Medicine},
	volume = {49},
	year = {2014},
	note = {Export Date: 21 November 2014},
	month = {2014},
	pages = {30 - 35},
	abstract = {Background: Maternal heart rate (MHR) recordings are morphologically similar and sometimes coincident with fetal heart rate (FHR) recordings and may be useful for maternal-fetal monitoring if appropriately interpreted. However, similarly to FHR, visual interpretation of MHR features may be poorly reproducible. Methods: A computer algorithm for on-line MHR analysis was developed based on a previously existing version for FHR analysis. Inter-observer and computer-observer agreement and reliability were assessed in 40 one-hour recordings obtained from 20 women during the last 2. h of labor. Agreement and reliability were evaluated for the detection of basal MHR, long-term variability (LTV), accelerations and decelerations, using proportions of agreement (PA) and Kappa statistic (K), with 95\% confidence intervals (95\% CI). Changes in MHR characteristics between the first and the second hour of the tracings were also evaluated. Results: There was a statistically significant inter-observer and computer-observer agreement and reliability in estimation of basal MHR, accelerations, decelerations and LTV, with PA values ranging from 0.72 (95\% CI: 0.62-0.79) to 1.00 (95\% CI: 0.99-1.00), and K values ranging from 0.44 (95\% CI: 0.28-0.60) to 0.89 (95\% CI: 0.82-0.96). Moreover, basal MHR, number of accelerations and LTV were significantly higher in the last hour of labor, when compared to the initial hour. Discussion: The developed algorithm for on-line computer analysis of MHR recordings provided good to excellent computer-observer agreement and reliability. Moreover, it allowed an objective detection of MHR changes associated with labor progression, providing more information about the interpretation of maternal-fetal monitoring during labor. {\textcopyright} 2014 Elsevier Ltd.},
	keywords = {Agreement, Cardiotocography, computer analysis, Fetal heart rate, Maternal heart rate, reliability},
	url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84897934596\&partnerID=40\&md5=95b314c6374a68fedb313594f59fdcce},
	author = {Pinto, P. and Bernardes, J. and Costa-Santos, C. and Amorim-Costa, C. and Silva, M. and Ayres-de-Campos, D.}
}
@article {3287,
	title = {External uterine contractions signal analysis in relation to labor progression and dystocia},
	journal = {IFMBE Proceedings},
	volume = {41},
	year = {2014},
	note = {Export Date: 21 November 2014},
	month = {2014},
	pages = {555 - 558},
	abstract = {Labor dystocia is a major cause of operative delivery, which is associated with increased risks for both mother and fetus. We assessed linear and non-linear dynamics of external uterine contraction signals, in relation to labor progression and dystocia. Linear time domain, spectral and entropy methods were used to analyze external uterine contraction recordings obtained during the last two hours of labor, in 28 cases with normal and 27 cases with operative deliveries (forceps, vacuum or caesarean). Progression of labor was associated with a statistically significant increase in most linear time domain and spectral indices, both in normal and operative deliveries, whereas most entropy indices increased in normal deliveries, but did not change in operative deliveries. On the other hand, when compared with normal births, operative deliveries were associated with significantly increased entropy indices before the last hour of labor and significantly decreased (a probably associated) sympatho-vagal balance in the last hour of labor. Linear and non-linear analysis of external uterine contraction recordings may provide useful physiopathological and clinical information on the progression of labor and the diagnosis of dystocia. {\textcopyright} Springer International Publishing Switzerland 2014.},
	keywords = {Cardiotocography, Dystocia, entropy, External uterine contractions, Spectral analysis},
	url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84891293956\&partnerID=40\&md5=2d53a97f6000b704bf67435b61662c09},
	author = {Gon{\c c}alves, H. and Pinto, P. and Ayres-de-Campos, D. and Bernardes, J.}
}
@article {3288,
	title = {Fetal behavioral dynamics in cephalic versus breech presentations},
	journal = {Developmental Psychobiology},
	volume = {56},
	year = {2014},
	note = {Export Date: 21 November 2014},
	pages = {1595 - 1600},
	abstract = {Differences in fetal neurodevelopment can have important implications on future perceptual and learning capabilities. The aim of this study was to assess autonomic nervous system and complexity dynamics in fetal heart rate (FHR) tracings from 27 singleton fetuses in cephalic or breech presentations, matched for gestational age (37+3-40+4 weeks), weight, gender and outcome. Breeches exhibited significantly higher mean FHR and LF/(MF+HF) ratio, as well as lower entropy, denoting increased sympatho-vagal balance and decreased complexity, consistent with the occurrence of more active fetal behavioral states. These findings suggest that there are neurodevelopment differences between fetuses in cephalic and breech presentation.},
	keywords = {Breech presentation, Development, entropy, Fetal behavior, Heart rate, Spectral analysis},
	url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84907881885\&partnerID=40\&md5=efdb9069ff9f41b3b0d0e85ee6b9abb1},
	author = {Gon{\c c}alves, H. and Ayres-de-Campos, D. and Bernardes, J.}
}
@article {3396,
	title = {Impact of the introduction of fetal central monitoring on hospital expenses with cardiotocographic paper},
	journal = {Journal of Obstetrics and Gynaecology},
	volume = {34},
	year = {2014},
	month = {2014},
	pages = {82-84},
	url = {<Go to ISI>://WOS:000328947300020},
	author = {Amorim-Costa, C. and Ayres-de-Campos, D. and Costa-Santos, C. and Bernardes, J.}
}
@article {2833,
	title = {Co-expression network analysis and genetic algorithms for gene prioritization in preeclampsia},
	journal = {BMC Medical Genomics},
	volume = {6},
	year = {2013},
	note = {Export Date: 12 December 2013Source: ScopusArt. No.: 51},
	month = {2013///},
	url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84887314151\&partnerID=40\&md5=3daae7034430deb7d1e057fa432b236d},
	author = {Tejera, E. and Bernardes, J. and Rebelo, I.}
}
@article {2868,
	title = {Comparison of different methods of heart rate entropy analysis during acute anoxia superimposed on a chronic rat model of pulmonary hypertension},
	journal = {Medical Engineering and Physics},
	volume = {35},
	year = {2013},
	note = {Cited By (since 1996):1Export Date: 12 December 2013Source: Scopus},
	month = {2013///},
	pages = {559 - 568},
	url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84877632838\&partnerID=40\&md5=05c9ef6d6fea4a96d6a63f1749251066},
	author = {Gon{\c c}alves, H. and Henriques-Coelho, T. and Rocha, A.P. and Louren{\c c}o, A.P. and Leite-Moreira, A. and Bernardes, J.}
}
@article {2860,
	title = {Comparison of real beat-to-beat signals with commercially available 4 Hz sampling on the evaluation of foetal heart rate variability},
	journal = {Medical and Biological Engineering and Computing},
	volume = {51},
	year = {2013},
	note = {Export Date: 12 December 2013Source: Scopus},
	month = {2013///},
	pages = {665 - 676},
	url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84877784836\&partnerID=40\&md5=cfdde94007fba73e03e51da6af74b995},
	author = {Gon{\c c}alves, H. and Costa, A. and Ayres-de-Campos, D. and Costa-Santos, C. and Rocha, A.P. and Bernardes, J.}
}
@article {2861,
	title = {Gender-specific heart rate dynamics in severe intrauterine growth-restricted fetuses},
	journal = {Early Human Development},
	volume = {89},
	year = {2013},
	note = {Export Date: 12 December 2013Source: Scopus},
	month = {2013///},
	pages = {431 - 437},
	url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84876735249\&partnerID=40\&md5=fb66d2a3f8a56a6f99cfe8008a3def01},
	author = {Gon{\c c}alves, H. and Bernardes, J. and Ayres-de-Campos, D.}
}
@article {2877,
	title = {Information-based measure of disagreement for more than two observers: A useful tool to compare the degree of observer disagreement},
	journal = {BMC Medical Research Methodology},
	volume = {13},
	year = {2013},
	note = {Export Date: 12 December 2013Source: ScopusArt. No.: 47},
	month = {2013///},
	url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84875159444\&partnerID=40\&md5=c62818fbdde48aa73825e4780acb6f70},
	author = {Henriques, T. and Antunes, L. and Bernardes, J. and Matias, M. and Sato, D. and Costa-Santos, C.}
}
@article {2887,
	title = {An overview of central fetal monitoring systems in labour},
	journal = {Journal of Perinatal Medicine},
	volume = {41},
	year = {2013},
	note = {Cited By (since 1996):1Export Date: 12 December 2013Source: Scopus},
	month = {2013///},
	pages = {93 - 99},
	url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84881633207\&partnerID=40\&md5=f9c824ddb554c46a92331e20852ef509},
	author = {Nunes, I. and Ayres-de-Campos, D. and Figueiredo, C. and Bernardes, J.}
}
@article {2852,
	title = {Should European perinatal indicators be revisited?},
	journal = {European Journal of Obstetrics Gynecology and Reproductive Biology},
	volume = {170},
	year = {2013},
	note = {Cited By (since 1996):2Export Date: 12 December 2013Source: Scopus},
	month = {2013///},
	pages = {85 - 89},
	url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84883051720\&partnerID=40\&md5=3a02193e168ada76c4ca21d9ea20785b},
	author = {Santos, J.V. and Correia, C. and Cabral, F. and Bernardes, J. and Costa-Pereira, A. and Freitas, A.}
}
@article {2208,
	title = {Poor reliability of visual analysis of fetal heart rate tracings: What should be done about it?},
	journal = {American Journal of Obstetrics and GynecologyAm. J. Obstet. Gynecol.},
	volume = {206},
	year = {2012},
	note = {Export Date: 21 November 2012Source: ScopusCODEN: AJOGAdoi: 10.1016/j.ajog.2012.02.027PubMed ID: 22425405Language of Original Document: EnglishCorrespondence Address: Bernardes, J.; Institute of Biomedical Engineering, University of Porto, S. Joao Hospital, Porto, Portugal; email: jbernardes59@gmail.comReferences: Blackwell, S.C., Grobman, W.A., Antoniewicz, L., Hutchinson, M., Gyamfi Bannerman, C., Interobserver and intraobserver reliability of the NICHD 3-Tier fetal heart rate interpretation system (2011) Am J Obstet Gynecol, 205, pp. 378e1-378e5;Bernardes, J., Ayres-De-Campos, D., The persistent challenge of foetal heart rate monitoring (2010) Curr Opin Obstet Gynecol, 22, pp. 104-109; 
Ayres-De-Campos, D., Bernardes, J., Twenty-five years after the FIGO guidelines for the use of fetal monitoring: Time for a simplified approach? (2010) Int J Gynaecol Obstet, 110, pp. 1-6. , FIGO Subcommittee; 
Pehrson, C., Sorensen, J.L., Amer-W{\r a}hlin, I., Evaluation and impact of cardiotocography training programmes: A systematic review (2011) BJOG, 118, pp. 926-935
},
	month = {2012///},
	pages = { - },
	keywords = {accuracy, Cardiotocography, clinical decision making, clinical practice, computer analysis, fetus blood sampling, fetus electrocardiography, fetus heart rate, Heart Rate, Fetal, human, Humans, letter, medical education, metabolic acidosis, newborn disease, priority journal, reliability, visual acuity},
	isbn = {00029378 (ISSN)},
	url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84861573254\&partnerID=40\&md5=2d68d4ec0e762adf745a8b7b433023bf},
	author = {Bernardes, J. and Ayres-de-Campos, D.}
}
@article {2230,
	title = {Complexity and categorical analysis may improve the interpretation of agreement studies using continuous variables},
	journal = {Journal of Evaluation in Clinical PracticeJ. Eval. Clin. Pract.},
	volume = {17},
	year = {2011},
	note = {Cited By (since 1996): 2Export Date: 21 November 2012Source: ScopusCODEN: JECPFdoi: 10.1111/j.1365-2753.2011.01668.xPubMed ID: 21489051Language of Original Document: EnglishCorrespondence Address: Costa-Santos, C.; Department of Biostatistics and Medical Informatics, Faculty of Medicine, University of Porto, Al. Prof. Hern{\^a}ni Monteiro, 4200-319 Porto, Portugal; email: csantos@med.up.ptReferences: Costa Santos, C., Costa Pereira, A., Bernardes, J., Agreement studies in obstetrics and gynaecology: Inappropriateness, controversies and consequences (2005) BJOG: An International Journal of Obstetrics and Gynaecology, 112 (5), pp. 667-669. , DOI 10.1111/j.1471-0528.2004.00505.x;Khan, K.S., Chien, P.F., Evaluation of a clinical test. I: Assessment of reliability (2001) BJOG, 108, pp. 562-567; 
Luiz, R.R., Szklo, M., More than one statistical strategy to assess agreement of quantitative measurements may usefully be reported (2005) Journal of Clinical Epidemiology, 58 (3), pp. 215-216. , DOI 10.1016/j.jclinepi.2004.07.007; 
Costa-Santos, C., Bernardes, J., Ayres-De-Campos, D., Costa, A., Costa, C., The limits of agreement and the intraclass correlation coefficient may be inconsistent in the interpretation of agreement (2011) Journal of Clinical Epidemiology, 64 (3), pp. 264-269; 
Costa-Santos, C., Antunes, L., Souto, A., Bernardes, J., Assessment of disagreement: A new information-based approach (2010) Annals of Epidemiology, 20, pp. 555-561; 
Luiz, R.R., Costa, A.J.L., Kale, P.L., Werneck, G.L., Assessment of agreement of a quantitative variable: A new graphical approach (2003) Journal of Clinical Epidemiology, 56 (10), pp. 963-967. , DOI 10.1016/S0895-4356(03)00164-1; 
Plsek, P.E., Greenhalgh, T., The challenge of complexity in health care (2001) British Medical Journal, 323 (7313), pp. 625-628; 
Shiell, A., Hawe, P., Gold, L., Complex interventions or complex systems? Implications for health economic evaluation (2008) BMJ, 336 (7656), pp. 1281-1283; 
Wilson, T., Holt, T., Complexity science: Complexity and clinical care (2001) British Medical Journal, 323 (7314), pp. 685-688; 
Miles, A., Complexity in medicine and healthcare: People and systems, theory and practice (2009) Journal of Evaluation in Clinical Practice, 15 (3), pp. 409-410; 
Shannon, {\^I}., A mathematical theory of communication (1948) Bell System Technical Journal, 27, pp. 379-423. , 623- 656; 
Bernardes, J., Costa-Pereira, A., Ayres-De-Campos, D., Van Geijn, H.P., Pereira-Leite, L., Evaluation of interobserver agreement of cardiotocograms (1997) International Journal of Gynecology and Obstetrics, 57 (1), pp. 33-37. , DOI 10.1016/S0020-7292(97)02846-4, PII S0020729297028464; 
Ayres-De-Campos, D., Bernardes, J., Costa-Pereira, A., Pereira-Leite, L., Inconsistencies in classification by experts of cardiotocograms and subsequent clinical decision (1999) British Journal of Obstetrics and Gynaecology, 106, pp. 1307-1310; 
Rooth, G., Guidelines for the use of fetal monitoring (1987) International Journal of Gynaecology and Obstetrics, 25, pp. 159-167; 
Grant, J.M., The fetal heart rate is normal, isn{\textquoteright}t it? Observer agreement of categorical assessments (1991) Lancet, 337, pp. 215-218; 
M{\"u}ller, R., B{\"u}ttner, P., A critical discussion of intraclass correlation coefficients (1994) Statistics in Medicine, 13, pp. 2465-2476; 
Byrt, T., Bishop, J., Carlin, J.B., Bias, prevalence and kappa (1993) Journal of Clinical Epidemiology, 46 (5), pp. 423-429. , DOI 10.1016/0895-4356(93)90018-V; 
West, B.J., Homeostasis and Gauss statistics: Barriers to understanding natural variability (2010) Journal of Evaluation in Clinical Practice, 16, pp. 403-408; 
Goncalves, H., Rocha, A.P., Ayres-de-Campos, D., Bernardes, J., Linear and nonlinear fetal heart rate analysis of normal and acidemic fetuses in the minutes preceding delivery (2006) Medical and Biological Engineering and Computing, 44 (10), pp. 847-855. , DOI 10.1007/s11517-006-0105-6; 
Costa Santos, C., Vitanyi, P.M.B., Bernardes, J., Antunes, L., Clustering fetal heart rate tracings by compression (2006) Proceedings - IEEE Symposium on Computer-Based Medical Systems, 2006, pp. 685-690. , DOI 10.1109/CBMS.2006.68, 1647650, Proceedings - 19th IEEE International Symposium on Computer-Based Medical Systems, CBMS 2006
},
	month = {2011///},
	pages = {511 - 514},
	abstract = {Rationale Complex clinical scenarios involving a high degree of uncertainty frequently lead to a poor agreement over diagnosis and management. However, inconsistent results can be found with the most widely used measures of agreement for continuous variables - the limits of agreement and the intraclass correlation coefficient. Aims and objectives We aim to improve the interpretation of agreement studies using continues variables. Methods and results Evaluation of agreement may be improved by complexity analysis and by categorization of variables, followed by the use of the proportions of agreement. Conclusions The average never characterizes a complex phenomenon and the methods used to access agreement in continuous variables are based on the mean. For future agreement studies, involving complex continuous variables, we recommend a complexity and categorical analysis. {\textcopyright} 2011 Blackwell Publishing Ltd.},
	keywords = {article, Biomedical research, Cardiotocography, clinical decision making, clinical practice, complexity, Data Interpretation, Statistical, Decision Making, entropy, Female, fetus heart rate, Heart Rate, Fetal, human, Humans, observer variation, Pregnancy, Pregnancy Outcome, priority journal, Reproducibility of Results, statistical data interpretation, Uncertainty},
	isbn = {13561294 (ISSN)},
	url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-79956081274\&partnerID=40\&md5=bd7376dca48228f4c4b1b21389689596},
	author = {Costa-Santos, C. and Bernardes, J. and Antunes, L. and Ayres-de-Campos, D.}
}
@article {2225,
	title = {Knowledge of adverse neonatal outcome alters clinicians{\textquoteright} interpretation of the intrapartum cardiotocograph},
	journal = {BJOG: An International Journal of Obstetrics and GynaecologyBJOG Int. J. Obstet. Gynaecol.},
	volume = {118},
	year = {2011},
	note = {Cited By (since 1996): 2Export Date: 21 November 2012Source: ScopusCODEN: BIOGFdoi: 10.1111/j.1471-0528.2011.03003.xPubMed ID: 21609381Language of Original Document: EnglishCorrespondence Address: Ayres-de-Campos, D.; Departmento de Ginecologia e Obstetr{\'\i}cia, Faculdade de Medicina do Porto, 4200-309 Porto, Portugal; email: dcampos@med.up.ptReferences: (2006) Perinatal Mortality Surveillance 2004: England, Wales and Northern Ireland, , CEMACH - Centre for Maternal and Child Enquiries (previously Confidential Enquiries into Maternal and Child Health). London: CEMACH;(1997) CESDI - Confidential Enquiry into Stillbirths and Deaths in Infancy, , 4th Annual Report. London: CESDI; 
Wood, C., Renou, P., Oats, J., A controlled trial of fetal heart rate monitoring in a low-risk obstetric population (1981) American Journal of Obstetrics and Gynecology, 141 (5), pp. 527-534; 
MacDonald, D., Grant, A., Sheridan-Pereira, M., The Dublin randomized controlled trial of intrapartum fetal heart rate monitoring (1985) American Journal of Obstetrics and Gynecology, 152 (5), pp. 524-539; 
Shy, K.K., Luthy, D.A., Bennett, F.C., Whitfield, M., Larson, E.B., Van Belle, G., Hughes, J.P., Stenchever, M.A., Effects of electronic fetal-heart-rate monitoring, as compared with periodic auscultation, on the neurologic development of premature infants (1990) New England Journal of Medicine, 322 (9), pp. 588-593; 
Dillner, L., Babies{\textquoteright} deaths linked to suboptimal care (1995) Br Med J, 310, p. 757; 
Ayres-de-Campos, D., Bernardes, J., Costa-Pereira, A., Pereira-Leite, L., Inconsistencies in classification by experts of cardiotocograms and subsequent clinical decision (1999) Br J Obstet Gynaecol, 106, pp. 1307-1310; 
Palomaki, O., Luukkaala, T., Luoto, R., Tuimala, R., Intrapartum cardiotocography - The dilemma of interpretational variation (2006) Journal of Perinatal Medicine, 34 (4), pp. 298-302. , DOI 10.1515/JPM.2006.057, PII JPME344298; 
Westerhuis, M., Van Horen, E., Kwee, A., Van Der Tweel, I., Visser, G., Moons, K., Inter- and intra-observer agreement of intrapartum ST analysis of the fetal electrocardiogram in women monitored by STAN (2009) BJOG, 116, pp. 545-551; 
Caplan, R.A., Posner, K.L., Cheney, F.W., Effect of outcome on physician judgment of appropriateness of care (1991) J Am Med Assoc, 265, pp. 1957-1960; 
Rooth, G., Huch, A., Huch, R., Guidelines for the use of fetal monitoring (1987) Int J Gynecol Obstet, 25, pp. 159-167. , FIGO News; 
Amer-Wahlin, I., Hellsten, C., Noren, H., Hagberg, H., Herbst, A., Kjellmer, I., Lilja, H., Marsal, K., Cardiotocography only versus cardiotocography plus ST analysis of fetal electrocardiogram for intrapartum fetal monitoring: A Swedish randomised controlled trial (2001) Lancet, 358 (9281), pp. 534-538. , DOI 10.1016/S0140-6736(01)05703-8; 
Westgate, J., Garibaldi, J.M., Greene, K.R., Umbilical cord blood gas analysis at delivery: A time for quality data (1994) British Journal of Obstetrics and Gynaecology, 101 (12), pp. 1054-1063; 
Figueras, F., Albela, S., Bonino, S., Palacio, M., Barrau, E., Hernandez, S., Casellas, C., Cararach, V., Visual analysis of antepartum fetal heart rate tracings: Inter- and intra-observer agreement and impact of knowledge of neonatal outcome (2005) Journal of Perinatal Medicine, 33 (3), pp. 241-245. , http://www.extenza-eps.com/extenza/loadPDF?objectIDValue=64432, DOI 10.1515/JPM.2005.044; 
Zain, H.A., Wright, J.W., Parrish, G.E., Diehl, S.J., Interpreting the fetal heart rate tracing: Effect of knowledge of neonatal outcome (1998) Journal of Reproductive Medicine for the Obstetrician and Gynecologist, 43 (4), pp. 367-370; 
Almstr{\"o}m, H., Axelsson, O., Ekman, G., Ingemarsson, I., Maesel, A., Arstr{\"o}m, K., Umbilical artery velocimetry may influence clinical interpretation of intrapartum cardiotocograms (1995) Acta Obstet Gynecol Scand, 74, pp. 526-529; 
Spencer, J.A.D., Clinical overview of cardiotocography (1993) British Journal of Obstetrics and Gynaecology, Supplement, 100 (9), pp. 4-7; 
Ayres-de-Campos, D., Bernardes, J., Early, variable and late decelerations: Can a consensus be reached in their identification? (1999) Int J Gynecol Obstet, 65, pp. 305-306; 
Capstick, J.B., Edwards, P.J., Trends in obstetric malpractice claims (1990) Lancet, 336 (8720), pp. 931-932. , DOI 10.1016/0140-6736(90)92291-O; 
Symonds, E.M., Litigation and the cardiotocogram (1993) British Journal of Obstetrics and Gynaecology, Supplement, 100 (9), pp. 8-9; 
Williams, B., Arulkumaran, S., Cardiotocography and medicolegal issues (2004) Best Practice and Research: Clinical Obstetrics and Gynaecology, 18 (3), pp. 457-466. , DOI 10.1016/j.bpobgyn.2004.02.005, PII S1521693404000318
},
	month = {2011///},
	pages = {978 - 983},
	abstract = {Objective: To evaluate the impact of knowledge of neonatal outcome on clinicians{\textquoteright} interpretation of the intrapartum cardiotocograph (CTG). Design: Prospective evaluation of pre-recorded cases. Setting: Five maternity hospitals. Population: From a database of intrapartum CTGs acquired with a scalp electrode in singleton near-term fetuses, 20 tracings were sequentially selected from cases with newborn umbilical artery pH < 7.05 and 20 from cases with pH > 7.20. Methods: Five experienced obstetricians practising in different maternity hospitals were asked to analyse the 40 tracings individually, according to the International Federation of Gynaecology and Obstetrics guidelines. In a first round, clinicians were given no information on neonatal outcome. In a second round, carried out 2 months later, clinicians were asked to analyse the same tracings, but the order was randomly altered and information on the newborn{\textquoteright}s arterial pH was provided. Clinicians were not informed of the purpose of the study or whether the tracings were the same. Main outcome measures: The incidence of individual fetal heart rate feature identification and tracing classification, before and after neonatal outcome was made available. Results: In the group with pH < 7.05, repetitive decelerations and reduced variability were more common in the second round (P < 0.001 and P = 0.001, respectively), as was a pathological classification (P = 0.002); variable decelerations were less common (P = 0.008). In the group with normal pH, less tracings in the second round had prolonged decelerations (P = 0.013) and no accelerations (P = 0.013), but more had pronounced decelerations (P = 0.031) and reduced variability (P = 0.007); there was a reduction in pathological classifications, but this difference failed to reach statistical significance (P = 0.051). Conclusions: A knowledge of adverse neonatal outcome leads to a more severe classification of the intrapartum CTG, which derives mainly from the evaluation of decelerations and variability. {\textcopyright} 2011 The Authors BJOG An International Journal of Obstetrics and Gynaecology {\textcopyright} 2011 RCOG.},
	keywords = {adverse outcome, Agreement, article, bradycardia, Cardiotocography, clinical competence, Female, Fetal, Fetal hypoxia, Fetal monitoring, fetus heart rate, fetus outcome, health practitioner, Heart rate, Heart Rate, Fetal, human, Humans, Hydrogen-Ion Concentration, incidence, Infant, Newborn, intrapartum care, Labor, Obstetric, medical practice, pH, practice guideline, Practice Guidelines as Topic, Pregnancy, Pregnancy Outcome, priority journal, Prospective Studies, Questionnaires, Reference Standards, Reproducibility of Results, Research Design, Risk Factors, Sweden, tachycardia, umbilical artery},
	isbn = {14700328 (ISSN)},
	url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-79959836242\&partnerID=40\&md5=6b43f72dfcfa8829dfc5395ed140ab7b},
	author = {Ayres-de-Campos, D. and Arteiro, D. and Costa-Santos, C. and Bernardes, J.}
}
@article {2238,
	title = {The limits of agreement and the intraclass correlation coefficient may be inconsistent in the interpretation of agreement},
	journal = {Journal of Clinical EpidemiologyJ. Clin. Epidemiol.},
	volume = {64},
	year = {2011},
	note = {Cited By (since 1996): 13Export Date: 21 November 2012Source: ScopusCODEN: JCEPEdoi: 10.1016/j.jclinepi.2009.11.010PubMed ID: 20189765Language of Original Document: EnglishCorrespondence Address: Costa-Santos, C.; Biostatistics and Medical Informatics Department, Faculty of Medicine, University of Porto, Al. Prof. Hern{\^a}ni Monteiro, 4200-319 Porto, Portugal; email: csantos@med.up.ptReferences: De Vet, H., Observer reliability and agreement (1999) Encyclopedia of Biostatistics, pp. 3123-3127;Ayres-De-Campos, D., Bernardes, J., Costa-Pereira, A., Pereira-Leite, L., Inconsistencies in expert{\textquoteright}s classification of cardiotocograms and subsequent clinical decision (1999) Br J Obstet Gynaecol, 106, pp. 1307-1310; 
Santos, C.C., Pereira, C.A., Bernardes, J., Agreement studies in obstetrics and gynaecology: Inappropriateness, controversies and consequences (2005) Br J Obstet Gynaecol, 112, pp. 667-669; 
Luiz, R.R., Szklo, M., More than one statistical strategy to assess agreement of quantitative measurements may usefully be reported (2003) J Clin Epidemiol, 56, pp. 963-967; 
Bland, J.M., Altman, D.G., Statistical methods for assessing two methods of clinical measurement (1986) Lancet, 1, pp. 307-310; 
Bartko, J.J., The intraclass correlation coefficient as a measure of reliability (1966) Psychol Rep, 19, pp. 3-11; 
Muller, R., Buttner, P., A critical discussion of intraclass correlation coefficients (1994) Stat Med, 13, pp. 2465-2476; 
Burdock, E., Fleiss, J.L., Hardesty, A.S., A new view of interobserver agreement (1963) Person Psychol, 16, pp. 373-384; 
Casey, B.M., McLntire, D.D., Leveno, K.J., The continuing value of the Apgar score for the assessment of newborn infants (2001) N Engl J Med, 344, pp. 467-471; 
Van De Riet, J.E., Vandenbussche, F.P., Le Cessie, S., Keirse, M.J., Newborn assessment and long-term adverse outcome: A systematic review (1999) Am J Obstet Gynecol, 180, pp. 1024-1029; 
Shrout, P.E., Fleiss, J.L., Intraclass correlations: Uses in assessing rater reliability (1979) Psychol Bull, 86, pp. 420-427; 
Fleiss, J.U., Davies, M., Measuring nominal scale agreement among many raters (1971) Psychol Bull, 76, pp. 378-382; 
Carpenter, J., Bithell, J., Bootstrap confidence intervals: When, which, what? A practical guide for medical statisticians (2000) Stat Med, 19, pp. 1141-1164; 
Landis, J.R., Koch, G.G., The measurement of observer agreement for categorical data (1977) Biometrics, 33, pp. 159-174
},
	month = {2011///},
	pages = {264 - 269},
	abstract = {Objective: To compare the interpretation of agreement in the prediction of neonatal outcome variables, using the limits of agreement (LA) and the intraclass correlation coefficient (ICC). Study Design and Setting: Three obstetricians were asked to predict neonatal outcomes independently based on the evaluation of intrapartum cardiotocographic tracings. Interobserver agreement was assessed with the LA and the ICC, and the results obtained were interpreted by six clinicians and six statisticians on a scale that established agreement as very poor, poor, fair, good, or very good. Results: Interpretation of the LA results was less consensual than the ICC results, with proportions of agreement of 0.36 (95\% confidence interval [CI]: 0.28-0.44) vs. 0.63 (95\% CI: 0.54-0.73), respectively. LA results suggested a fair to good agreement among obstetricians, whereas interpretation of ICC results suggested a poor to fair agreement. LA results were more plausible with reality, suggesting that obstetricians predicted neonatal outcomes better than randomly generated values, whereas it was not always the case with the ICC. Conclusions: LA and ICC can provide inconsistent results in agreement studies. Accordingly, in the absence of better strategies to assess agreement, both should be used for this purpose, but their results need to be interpreted with caution keeping their respective limitations in mind. {\textcopyright} 2011 Elsevier Inc. All rights reserved.},
	keywords = {Agreement, Apgar score, Cardiotocography, correlation coefficient, Female, Fetal Blood, human, Humans, Hydrogen-Ion Concentration, Infant, Newborn, intrapartum care, limit of agreement, newborn assessment, normal human, observer variation, Obstetrics, outcome variable, Pregnancy, Pregnancy Outcome, priority journal, reproducibility, Reproducibility of Results, review, statistical data interpretation, statistical parameters, Umbilical Arteries, Umbilical artery blood pH, umbilical cord blood},
	isbn = {08954356 (ISSN)},
	url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-78751646336\&partnerID=40\&md5=a64bd277d4122b8ce3affa5f3d5d68a5},
	author = {Costa-Santos, C. and Bernardes, J. and Ayres-de-Campos, D. and Costa, A. and Costa, C.}
}
@article {2229,
	title = {Observer reliability and agreement: Differences, difficulties, and controversies},
	journal = {Journal of Clinical EpidemiologyJ. Clin. Epidemiol.},
	volume = {64},
	year = {2011},
	note = {Export Date: 21 November 2012Source: ScopusCODEN: JCEPEdoi: 10.1016/j.jclinepi.2010.12.002Language of Original Document: EnglishCorrespondence Address: Costa Santos, C.; Department of Biostatistics and Medical Informatics, Faculty of Medicine, University of Porto, Porto, Portugal; email: csantos.cristina@gmail.comReferences: Costa-Santos, C., Bernardes, J., Ayres-De-Campos, D., Costa, A., Costa, C., The limits of agreement and the intraclass correlation coefficient may be inconsistent in the interpretation of agreement (2010) J Clin Epidemiol;Streiner, D.L., Norman, G.R., (1996) PDQ Epidemiology, , 2nd edition Mosby St. Louis; 
Costa Santos, C., Costa Pereira, A., Bernardes, J., Agreement studies in obstetrics and gynaecology: Inappropriateness, controversies and consequences (2005) BJOG: An International Journal of Obstetrics and Gynaecology, 112 (5), pp. 667-669. , DOI 10.1111/j.1471-0528.2004.00505.x; 
Bland, M., How Do i Analyse Observer Variation Studies?, , http://www-users.york.ac.uk/~mb55/meas/observer.pdf
},
	month = {2011///},
	pages = {702},
	keywords = {consensus, correlation coefficient, letter, methodology, organization, priority journal, reliability, research, scientific literature, validity},
	isbn = {08954356 (ISSN)},
	url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-79955028603\&partnerID=40\&md5=be278b8ed9336b6268066fca66d45280},
	author = {Costa Santos, C. and Bernardes, J. and Ayres-de-Campos, D.}
}
@article {2257,
	title = {Access to computerised analysis of intrapartum cardiotocographs improves clinicians{\textquoteright} prediction of newborn umbilical artery blood pH},
	journal = {BJOG: An International Journal of Obstetrics and GynaecologyBJOG Int. J. Obstet. Gynaecol.},
	volume = {117},
	year = {2010},
	note = {Cited By (since 1996): 3Export Date: 21 November 2012Source: ScopusCODEN: BIOGFdoi: 10.1111/j.1471-0528.2010.02645.xPubMed ID: 20618316Language of Original Document: EnglishCorrespondence Address: Costa, A.; Departamento de Ginecologia e Obstetr{\'\i}cia, Faculdade de Medicina da Universidade Do Porto, Alameda Hernani Monteiro, 4200-319 Porto, Portugal; email: cosantonia@gmail.comReferences: Ayres-De-Campos, D., Bernardes, J., Costa-Pereira, A., Pereira-Leite, L., Inconsistencies in classification by experts of cardiotocograms and subsequent clinical decision (1999) Br J Obstet Gynaecol, 106, pp. 1307-10;Donker, D.K., Van Geijn, H.P., Hasman, A., Interobserver variation in the assessment of fetal heart rate recordings (1993) Eur J Obstet Gynecol Reprod Biol, 52, pp. 21-8; 
Paneth, N., Bommarito, M., Stricker, J., Electronic fetal monitoring and later outcome (1993) Clin Invest Med, 16, pp. 159-65; 
Bernardes, J., Moura, C., Marques-De-S{\'a}, J.P., Pereira-Leite, L., The Porto system for automated cardiotocographic signal analysis (1991) J Perinat Med, 19, pp. 61-5; 
Ayres-De-Campos, D., Sousa, P., Costa, A., Bernardes, J., Omniview-SisPorto {\textregistered} 3.5 - A central fetal monitoring station with online alerts based on computerized cardiotocogram+ST event analysis (2008) J Perinat Med, 36, pp. 260-4; 
Costa, A., Ayres-De-Campos, D., Costa, F., Santos, C., Bernardes, J., Prediction of neonatal acidemia by computer analysis of fetal heart rate and ST event signals (2009) Am J Obstet Gynecol, 201, pp. 464e1-6. , Jun 17. [Epub ahead of print]; 
Westerhuis, M., Van Horen, E., Kwee, A., Van Dertweel, I., Visser, G., Moons, K., Inter- and intra-observer agreement of intrapartum ST analysis of the fetal electrocardiogram in women monitored by STAN (2009) BJOG, 116, pp. 545-51; 
Ayres-De-Campos, D., Bernardes, J., Marsalb, K., Nickelsen, C., Makarainend, L., Banfield, P., Can the reproducibility of fetal heart rate baseline estimation be improved? (2004) Eur J Obstet Gynecol Reprod Biol, 112, pp. 49-54; 
Huch, A., Huch, C., Rooth, G., Guidelines for blood sampling and measurement of pH and blood gas values in Obstetrics (1994) Eur J Obstet Gynecol Reprod Biol, 54, pp. 165-75; 
Umbilical artery blood acid-base analysis (1996) Int J Gynecol Obstet, 52, pp. 305-10. , ACOG technical bulletin; 
Westgate, J., Garibaldi, J.M., Greene, K.R., Umbilical cord blood gas analysis at delivery: A time for quality data (1994) Br J Obstet Gynaecol, 101, pp. 1054-63; 
Costa-Santos, C., Costa Pereira, A., Bernardes, J., Agreement studies in obstetrics and gynaecology: Inappropriateness, controversies and consequences (2005) BJOG, 112, pp. 667-9; 
Bland, J.M., Altman, D.G., Agreement between methods of measurement with multiple observations per individual (2007) J Biopharm Stat, 17, pp. 571-82; 
Chauhan, S.P., Klauser, C.K., Woodring, T.C., Sanderson, M., Magann, E.F., Morrison, J.C., Intrapartum nonreassuring fetal heart rate tracing and prediction of adverse outcomes: Interobserver variability (2008) Am J Obstet Gynecol, 199, pp. 623e1-e5; 
Nielsen, P.V., Stigsby, B., Nickelsen, C., Nim, J., The value of computer assessment compared with visual assessment (1988) Acta Obstet Gynecol Scand, 67, pp. 461-464
},
	month = {2010///},
	pages = {1288 - 1293},
	abstract = {Objective To evaluate the impact of access to computerised cardiotocograph (CTG) analysis on reproducibility and accuracy of clinicians{\textquoteright} predictions of umbilical artery blood pH (UAB pH) and 5-minute Apgar score. Design Prospective evaluation of pre-recorded cases. Setting A tertiary-care university hospital. Population From databases of intrapartum CTGs acquired in singleton term pregnancies, 204 tracings with low signal loss and short time interval to delivery were consecutively selected. Methods Tracings were randomly assigned to computer analysis by the Omniview-SisPorto 3.5                        {\textregistered} system (study group n = 104) or to no analysis (control group n = 100). Three experienced clinicians evaluated all tracing printouts independently and were asked to predict the newborns{\textquoteright} UAB pH and 5-minute Apgar scores from them. Main outcome measures Interobserver agreement (measured by the intraclass correlation coefficient [ICC]) and accuracy in prediction of neonatal outcomes with 95\% CI. Results Agreement on prediction of UAB pH was significantly higher in the study group (ICC = 0.70; 95\% CI 0.61-0.77) than in the control group (ICC = 0.43; 95\% CI 0.21-0.60), and a trend towards better agreement was also seen in estimation of 5-minute Apgar scores (ICC = 0.55; 95\% CI 0.38-0.68 versus ICC = 0.43; 95\% CI 0.25-0.57). Observers predicted UAB pH values correctly within a 0.10 margin in 70\% of cases in the study group (95\% CI 0.61-0.79) versus 46\% in the control group (95\% CI 0.35-0.56). They predicted 5-minute Apgar scores within a margin of one in 81\% of cases in the study group (95\% CI 0.73-0.88) and in 70\% of cases in the control group (95\% CI 0.61-0.79). Conclusions Prediction of UAB pH is more reproducible and accurate when clinicians have access to computerised analysis of CTGs. {\textcopyright} RCOG 2010 BJOG An International Journal of Obstetrics and Gynaecology.
},
	keywords = {access to information, Apgar score, arterial pH, article, Cardiotocography, clinical competence, computer analysis, computerised analysis, controlled study, delivery, Diagnosis, Computer-Assisted, diagnostic accuracy, Female, Fetal Blood, Fetal heart rate, Fetal monitoring, Gestational Age, human, Humans, Hydrogen-Ion Concentration, Infant, Newborn, male, neonatal acidaemia, Neonatology, newborn, observer variation, outcome assessment, prediction, Pregnancy, priority journal, Prospective Studies, prospective study, reproducibility, Umbilical Arteries, umbilical artery, university hospital},
	isbn = {14700328 (ISSN)},
	url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-77955794381\&partnerID=40\&md5=49e6cf80fa55cf7009fcb9ccec497ab2},
	author = {Costa, A. and Santos, C. and Ayres-de-Campos, D. and Costa, C. and Bernardes, J.}
}
@article {2260,
	title = {Analysis of heart rate variability in a rat model of induced pulmonary hypertension},
	journal = {Medical Engineering and PhysicsMed. Eng. Phys.},
	volume = {32},
	year = {2010},
	note = {Cited By (since 1996): 1Export Date: 21 November 2012Source: ScopusCODEN: MEPHEdoi: 10.1016/j.medengphy.2010.04.018PubMed ID: 20547091Language of Original Document: EnglishCorrespondence Address: Gon{\c c}alves, H.; Departamento de Geoci{\^e}ncias, Ambiente e Ordenamento do Territ{\'o}rio, Faculdade de Ci{\^e}ncias, Universidade do Porto, Rua do Campo Alegre 687, 4169-007 Porto, Portugal; email: hernani.goncalves@fc.up.ptChemicals/CAS: monocrotaline, 315-22-0, 8051-27-2; Ketamine, 6740-88-1; Monocrotaline, 315-22-0References: (2005), ACOG, American College of Obstetricians and Gynecologists. ACOG Practice Bulletin. Clinical Management Guidelines for Obstetrician-Gynecologists, Number 70, December 2005. Obstet Gynecol 106(6):1453-60Akhavein, F., St.-Michel, E.J., Seifert, E., Rohlicek, C.V., Decreased left ventricular function, myocarditis, and coronary arteriolar medial thickening following monocrotaline administration in adult rats (2007) J Appl Physiol, 103 (1), pp. 287-295;Beckers, F., Verheyden, B., Aubert, A.E., Aging and nonlinear heart rate control in a healthy population (2006) Am J Physiol Heart Circ Physiol, 290 (6), pp. H2560-H2570; 
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},
	month = {2010///},
	pages = {746 - 752},
	abstract = {Monocrotaline (MCT) is commonly used to experimentally induce pulmonary hypertension (PH), which might lead to chronic heart failure. In this study, linear and non-linear heart rate (HR) dynamics were weekly assessed in MCT-treated and non-treated Wistar rats.The HR of 10 adult Wistar rats injected with MCT (MCT group) and of 10 similar rats injected with vehicle (non-MCT group), anesthetized with Ketamine, was weekly recorded during 4 weeks. The first four segments of 1-min length of each HR recording were analysed using linear, time and frequency domains, and approximate (ApEn) and sample (SampEn) entropy indices, considering recently proposed values for the threshold parameter of ApEn and SampEn. Statistical analysis was performed using 95\% confidence intervals and statistical tests.Along the study period, an overall weekly maintenance of HR indices, or a decrease, namely in weeks 1-2, was manifest, in the MCT group, except for LF and LF/HF, in week 1, denoting a short-term increase in sympathetic activity without any other changes. On the other hand, a maintenance of HR indices, or an increase, namely on week 4, was observed in the non-MCT group, except for LF/HF, denoting a long-term increase of the overall activity of HR control systems, with a parasympathetic like dominance.Studies on long-term HR dynamics should be performed in very carefully controlled experimental settings, as significant weekly changes may occur, both among anesthetized MCT-treated and non-treated rats. {\textcopyright} 2010 IPEM.},
	keywords = {adrenergic activity, Amines, animal experiment, animal model, Animals, article, cholinergic activity, Chronic heart failures, Confidence interval, controlled study, Disease Models, Animal, Electrocardiography, entropy, Female, Frequency domain analysis, Frequency domains, Heart, heart electrophysiology, Heart rate, Heart rate variability, Heart rate variability (HRV), Heart rates, Hypertension, Pulmonary, Injections, Subcutaneous, Ketamine, Maintenance, Monocrotaline, Non-linear, nonhuman, priority journal, Pulmonary hypertension, rat, Rat model, Rats, Rats, Wistar, Statistical analysis, statistical parameters, Sympathetic activities, Threshold parameters, Time and frequency domain analysis, Time domain analysis, Time Factors, Wistar rat, Wistar rats},
	isbn = {13504533 (ISSN)},
	url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-77955279673\&partnerID=40\&md5=5fa2879d821f37e48f50a723fa1cb225},
	author = {Gon{\c c}alves, H. and Henriques-Coelho, T. and Bernardes, J. and Rocha, A.P. and Brand{\~a}o-Nogueira, A. and Leite-Moreira, A.}
}
@article {2271,
	title = {Assessment of Disagreement: A New Information-Based Approach},
	journal = {Annals of EpidemiologyAnn. Epidemiol.},
	volume = {20},
	year = {2010},
	note = {Cited By (since 1996): 2Export Date: 21 November 2012Source: ScopusCODEN: ANNPEdoi: 10.1016/j.annepidem.2010.02.011Language of Original Document: EnglishCorrespondence Address: Costa-Santos, C.; Biostatistics and Medical Informatics Department, Faculty of Medicine, University of Porto, Al. Prof. Hern{\^a}ni Monteiro, 4200-319 Porto, Portugal; email: csantos@med.up.ptReferences: Bland, M., (2000) An introduction to medical statistics, , Oxford University Press, Oxford;Costa Santos, C., Costa Pereira, A., Bernardes, J., Agreement studies in obstetrics and gynecology: inappropriateness, controversies and consequences (2005) Br J Obstet Gynaecol, 112, pp. 667-669; 
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de Vet, H., Observer reliability and agreement (1999) Encyclopedia of Biostatistics, pp. 3123-3127. , Wiley, Chichester, P. Armitage, T. Colton (Eds.); 
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Luiz, R.R., Costa, A.J., Kale, P.L., Werneck, G.L., Assessment of agreement of a quantitative variable: a new graphical approach (2003) J Clin Epidemiol, 56, pp. 963-967; 
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},
	month = {2010///},
	pages = {554 - 561},
	abstract = {Purpose: Disagreement on the interpretation of diagnostic tests and clinical decisions remains an important problem in medicine. As no strategy to assess agreement seems to be fail-safe to compare the degree of agreement, or disagreement, we propose a new information-based approach to assess disagreement. Methods: The sum over all logarithms of possible outcomes of a variable is a valid measure of the amount of information contained in the variable. The proposed measure is based on the amount of information contained in the differences between two observations. This measure is normalized and satisfies the flowing properties: it is a metric, scaled invariant and it has differential weighting. Results: Two real examples and a simulation were used to illustrate the usefulness of the proposed measure to compare the degree of disagreement. Conclusions: Used as complement to the existing methods, we believe our approach can be useful to compare the degree of disagreement among different populations. {\textcopyright} 2010 Elsevier Inc.},
	keywords = {analysis of variance, Apgar score, article, Blood Pressure Determination, blood pressure measurement, correlation coefficient, human, Humans, information science, Information Theory, intermethod comparison, mathematical computing, measurement error, medical research, metric system, Models, Statistical, observer variation, priority journal, probability, process model, reliability, Reproducibility of Results, scale up, standard, Statistical analysis, statistical model, statistics, Statistics as Topic, systolic blood pressure, validity, variance},
	isbn = {10472797 (ISSN)},
	url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-77953667921\&partnerID=40\&md5=2c69deee8cc7bb3a02019dfa464095a1},
	author = {Costa-Santos, C. and Antunes, L. and Souto, A. and Bernardes, J.}
}
@article {2283,
	title = {Comparison of a computer system evaluation of intrapartum cardiotocographic events and a consensus of clinicians.},
	journal = {Journal of perinatal medicineJ Perinat Med},
	volume = {38},
	year = {2010},
	note = {Cited By (since 1996): 2Export Date: 21 November 2012Source: Scopusdoi: 10.1515/JPM.2010.030PubMed ID: 20121542Language of Original Document: EnglishCorrespondence Address: Costa, M.A.email: cosantonia@gmail.com},
	month = {2010///},
	pages = {191 - 195},
	abstract = {AIMS: To compare between computer analysis of intrapartum cardiotocography (CTG) features by the Omniview-SisPorto 3.5 and a consensus of clinicians. METHODS: Agreement study using 50 consecutively acquired tracings (206 h of signals) with >60 min duration, <10\% signal loss and recorded in labor at term by internal fetal heart rate (FHR) monitoring. Tracings were divided into 10-min segments and independently analyzed by three experienced clinicians, in order to estimate the FHR baseline and identify periodic events. A consensus was reached using a three round Delphi procedure. Results were compared with the analysis provided by the Omniview-SisPorto 3.5 system. RESULTS: For baseline estimation, agreement between the computer and the consensus was high [intraclass correlation coefficient (ICC)=0.85; 95\% confidence interval (CI) 0.46-0.93], with a mean difference of 3.7 bpm (limits of agreement -4.4-11.9 bpm), and 99\% of differences under 15 bpm. A concordant identification was observed in 71\% of accelerations (95\% CI: 69\%-73\%), 68\% of decelerations (95\% CI: 66\%-70\%), and 87\% of uterine contractions (95\% CI: 85\%-89\%). CONCLUSIONS: A high agreement was observed between the Omniview-SisPorto 3.5 and a consensus of clinicians in evaluation of intrapartum CTG baseline, accelerations, decelerations and uterine contractions.},
	keywords = {algorithm, Algorithms, article, Cardiotocography, comparative study, computer assisted diagnosis, Diagnosis, Computer-Assisted, Female, Fetal Heart, Fetal monitoring, fetus heart, fetus monitoring, human, Humans, instrumentation, methodology, physician, Physicians, physiology, Pregnancy},
	isbn = {16193997 (ISSN)},
	url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-77953038696\&partnerID=40\&md5=bca187de4ffea0b2f2c4d2dcfb2140d9},
	author = {Costa, M.A. and Ayres-de-Campos, D. and Machado, A.P. and Santos, C.C. and Bernardes, J.}
}
@book {2249,
	title = {Monitoring incremental histogram distribution for change detection in data streams},
	series = {Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)Lect. Notes Comput. Sci.},
	volume = {5840 LNCS},
	year = {2010},
	note = {Conference code: 81882Cited By (since 1996): 1Export Date: 21 November 2012Source: Scopusdoi: 10.1007/978-3-642-12519-5_2Language of Original Document: EnglishCorrespondence Address: Sebasti{\~a}o, R.; LIAAD, INESC Porto, L.A. Rua de Ceuta, 118, 6, Porto 4050-190, Portugal; email: raquel@liaad.up.ptReferences: Ayres-De-Campos, D., Sousa, P., Costa, A., Bernardes, J., Omniview-SisPorto{\textregistered} 3.5 - A central fetal monitoring station with online alerts based on computerized cardiotocogram+ST event analysis (2008) J. Perinat. Med., 36, pp. 260-264;Ayres-De-Campos, D., Bernardes, J., Garrido, A., Marques-De-{\'S}a, J., Pereira-Leite, L., SisPorto 2.0: A program for automated analysis of cardiotocograms (2000) J. Matern Fetal Med., 9, pp. 311-318; 
Barba{\'r}a, D., Requirements for clustering data streams (2002) SIGKDD Explorations (Special Issue on Online, Interactive and Anytime Data Mining), 3 (2), pp. 23-27; 
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Cormode, G., Garofalakis, M., Sketching probabilistic data streams (2007) Proceedings of the 2007 ACM SIGMOD International Conference on Management of Data, pp. 281-292. , June 2007; 
Correa, M., De, J., Raḿirez, M., Bielza, C., Pamies, J., Alique, J.R., Prediction of surface quality using probabilistic models (2007) 7th Congress of the Colombian Association of Automatic, Cali, Colombia, , March 21-24 Spanish; 
Dasu, T., Krishnan, S., Venkatasubramanian, S., Yi, K., An information-theoretic approach to detecting changes in multi-dimensional data streams (2006) Interface 2006, , Pasadena, CA Report; 
Gama, J., Medas, P., Castillo, G., Rodrigues, P.P., Learning with drift detection (2004) LNCS (LNAI), 3171, pp. 286-295. , Bazzan, A.L.C., Labidi, S. (eds.) Springer, Heidelberg SBIA 2004; 
Gama, J., Pinto, C., Discretization from data streams: Applications to histograms and data mining (2006) Proceedings of the 2006 ACM Symposium on Applied Computing, pp. 662-667; 
Goncalves, H., Bernardes, J., Paula Rocha, J.A., Linear and nonlinear analysis of heart rate patterns associated with fetal behavioral states in the antepartum period (2007) Early Human Development, 83 (9), pp. 585-591; 
Guha, S., Koudas, N., Woo, J., (2004) REHIST: Relative Error Histogram Construction Algorithms, pp. 300-311. , Proceedings of the VLDB Conference; 
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Kifer, D., Ben-David, S., Gehrke, J., (2004) Detecting Change in Data Streams, pp. 180-191. , VLDB 2004: Proceedings of the 30th International Conference on Very Large Data Bases Morgan Kaufmann Publishers Inc., San Francisco; 
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Klinkenberg, R., Learning drifting concepts: Example selection vs. example weight-ing (2004) Intelligent Data Analysis, 8 (3), pp. 281-300; 
Maloof, M., Michalski, R., Selecting examples for partial memory learning (2000) Machine Learning, 41, pp. 27-52; 
Pestana, D.D., Velosa, S.F., Introdu̧c̃a{\`o}a Probabilidade{\`e}a Estat̀istica (2002) Funda̧c̃ao Calouste Gulbenkian; 
Pinto, C., Gama, J., Incremental discretization, application to data with concept drift (2007) Proceedings of the 2007 ACM Symposium on Applied Computing, pp. 467-468. , March 2007; 
Sebastiao, R., Gama, J., Change detection in learning histograms from data streams (2007) Proceedings of Portuguese Conference on Artificial Intelligence, Guimar̃aes, Portugal, , December; 
Spinosa, E.J., Carvalho, A., Gama, J., OLINDDA: A cluster-based approach for detecting novelty and concept drift in data streams (2007) Proceedings of the 2007 ACM Symposium on Applied Computing, March 2007, pp. 448-452; 
Widmer, G., Kubat, M., Learning in the presence of concept drift and hidden contexts (1996) Machine Learning, 23, pp. 69-101
},
	month = {2010///},
	pages = {25 - 42},
	address = {Las Vegas, NV},
	abstract = {Histograms are a common technique for density estimation and they have been widely used as a tool in exploratory data analysis. Learning histograms from static and stationary data is a well known topic. Nevertheless, very few works discuss this problem when we have a continuous flow of data generated from dynamic environments. The scope of this paper is to detect changes from high-speed time-changing data streams. To address this problem, we construct histograms able to process examples once at the rate they arrive. The main goal of this work is continuously maintain a histogram consistent with the current status of the nature. We study strategies to detect changes in the distribution generating examples, and adapt the histogram to the most recent data by forgetting outdated data. We use the Partition Incremental Discretization algorithm that was designed to learn histograms from high-speed data streams. We present a method to detect whenever a change in the distribution generating examples occurs. The base idea consists of monitoring distributions from two different time windows: the reference window, reflecting the distribution observed in the past; and the current window which receives the most recent data. The current window is cumulative and can have a fixed or an adaptive step depending on the distance between distributions. We compared both distributions using Kullback-Leibler divergence, defining a threshold for change detection decision based on the asymmetry of this measure. We evaluated our algorithm with controlled artificial data sets and compare the proposed approach with nonparametric tests. We also present results with real word data sets from industrial and medical domains. Those results suggest that an adaptive window{\textquoteright}s step exhibit high probability in change detection and faster detection rates, with few false positives alarms. {\textcopyright} 2010 Springer-Verlag Berlin Heidelberg.},
	keywords = {Adaptive Cumulative Windows, Change detection, Data communication systems, Data reduction, Data stream, Data streams, Graphic methods, Learning histograms, Learning systems, Machine learning, Machine-learning, Monitoring, Monitoring data distribution, Sensors, signal detection, Statistical methods},
	isbn = {03029743 (ISSN); 3642125182 (ISBN); 9783642125188 (ISBN)},
	url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-77957913416\&partnerID=40\&md5=ec0810650dda3c604d494473a9ffd649},
	author = {Sebasti{\~a}o, R. and Gama, J. and Rodrigues, P.P. and Bernardes, J.}
}
@article {2294,
	title = {Prediction of neonatal acidemia by computer analysis of fetal heart rate and ST event signals},
	journal = {American Journal of Obstetrics and GynecologyAm. J. Obstet. Gynecol.},
	volume = {201},
	year = {2009},
	note = {Cited By (since 1996): 9Export Date: 21 November 2012Source: ScopusCODEN: AJOGAdoi: 10.1016/j.ajog.2009.04.033PubMed ID: 19539895Language of Original Document: EnglishCorrespondence Address: Costa, A.; Departamento de Ginecologia e Obstetr{\'\i}cia, Faculdade de Medicina, Hospital S. Jo{\~a}oPortugal; email: cosantonia@gmail.comReferences: (2006) Perinatal Mortality Surveillance 2004: England, Wales, and Northern Ireland, , CEMACH (Confidential Enquiry into Maternal and Child Health), Confidential Enquiry into Maternal and Child Health, London, UK;(1997) 4th annual report, , CESDI (Confidential Enquiry into Stillbirths and Deaths in Infancy), Maternal and Child Health Research Consortium, London, UK; 
Ayres-de-Campos, D., Bernardes, J., Costa-Pereira, A., Pereira-Leite, L., Inconsistencies in classification by experts of cardiotocograms and subsequent clinical decision (1999) Br J Obstet Gynaecol, 106, pp. 1307-1310; 
Paneth, N., Bommarito, M., Stricker, J., Electronic fetal monitoring and later outcome (1993) Clin Invest Med, 16, pp. 159-165; 
Bernardes, J., Costa-Pereira, A., Ayres-de-Campos, D., van Geijn, H.P., Pereira-Leite, L., Evaluation of interobserver agreement of cardiotocograms (1997) Int J Gynecol Obstet, 57, pp. 33-37; 
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Westerhuis, M., Kwee, A., van Ginkel, A., Drogtrop, A., Gyselaers, W., Visser, G., Limitations of ST analysis in clinical practice: three cases of intrapartum metabolic acidosis (2007) BJOG, 114, pp. 1194-1201; 
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Ayres-de-Campos, D., Bernardes, J., Garrido, A., Marques-de-S{\'a}, J.P., Pereira-Leite, L., SisPorto 2.0-a program for automated analysis of cardiotocograms (2000) J Matern Fetal Med, 9, pp. 311-318; 
Ayres-de-Campos, D., Sousa, P., Costa, A., Bernardes, J., Omniview-SisPorto{\textregistered} 3.5-a central fetal monitoring station with online alerts based on computerized cardiotocogram+S.T.event analysis (2008) J Perinat Med, 36, pp. 260-264; 
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Moster, D., Lie, R.T., Irgens, L.M., Bjerkedal, T., Markestad, The association of Apgar score with subsequent death and cerebral palsy: a population-based study in term infants (2001) J Pediatr, 138, pp. 798-803
},
	month = {2009///},
	pages = {464.e1 - 464.e6},
	abstract = {Objective: The objective of the study was to evaluate the accuracy of computer analysis of fetal heart rate (FHR) and ST event signals in prediction of neonatal acidemia. Study Design: One hundred forty-eight FHR tracings were evaluated to identify red alerts provided by the system, based on automated analysis of FHR and ST event signals, and compared with the occurrence of umbilical artery acidemia (pH <=7.05). Results: The presence of red alerts obtained sensitivity of 1.00 (95\% confidence interval [CI], 0.56-1.00), specificity of 0.94 (95\% CI, 0.89-0.97), positive predictive value (PPV) of 0.47 (95\% CI, 0.22-0.72), negative predictive value (NPV) of 1 (95\% CI, 0.96-1.00), positive likelihood ratio (PLR) of 17.6 (95\% CI, 9.0-34.5), and negative likelihood ratio (NLR) of 0. When limiting analysis to red alerts that did not include ST data, sensitivity was 0.57 (95\% CI, 0.20-0.88), specificity was 0.97 (95\% CI, 0.92-0.99), PPV was 0.50 (95\% CI, 0.17-0.82), NPV was 0.98 (95\% CI, 0.93-0.99), PLR was 20.14 (95\% CI, 6.3-64.2), and NLR was 0.44 (95\% CI, 0.19-1.04). Conclusion: Computer analysis of FHR and ST event signals provide higher accuracy in predicting neonatal academia. {\textcopyright} 2009 Mosby, Inc. All rights reserved.},
	keywords = {acidemia, Acidosis, article, autoanalysis, Cardiotocography, computer analysis, computer assisted, computer prediction, Diagnosis, Computer-Assisted, diagnostic value, Electrocardiography, Female, Fetal heart rate, Fetal hypoxia, Fetal monitoring, fetus electrocardiography, fetus heart rate, Heart Rate, Fetal, human, Humans, Infant, Newborn, major clinical study, male, newborn, newborn acidosis, observational study, pH, Predictive Value of Tests, priority journal, Prospective Studies, prospective study, Reproducibility of Results, sensitivity and specificity, signal transduction, ST segment, umbilical artery},
	isbn = {00029378 (ISSN)},
	url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-70350572323\&partnerID=40\&md5=6ffddbacf1381ab65c9bd35f8db108dd},
	author = {Costa, A. and Ayres-de-Campos, D. and Costa, F. and Santos, C. and Bernardes, J.}
}
@article {2314,
	title = {Sex differences in linear and complex fetal heart rate dynamics of normal and acidemic fetuses in the minutes preceding delivery},
	journal = {Journal of Perinatal MedicineJ. Perinat. Med.},
	volume = {37},
	year = {2009},
	note = {Cited By (since 1996): 4Export Date: 21 November 2012Source: ScopusCODEN: JPEMAdoi: 10.1515/JPM.2009.024PubMed ID: 19021459Language of Original Document: EnglishCorrespondence Address: Bernardes, J.; Faculdade de Medicina, Universidade Do Porto, Ginecologia e Obstetr{\'\i}cia, Al. Hernani Monteiro, Porto, 4200, Portugal; email: jbernardes59@gmail.comReferences: Ayres-de-Campos, D., Bernardes, J., Costa-Pereira, A., Pereira-Leite, L., Inconsistencies in classification by experts of cardiotocograms and subsequent clinical decision (1999) Br J Obstet Gynaecol, 106, pp. 1307-1310;Ayres-de-Campos, D., Bernardes, J., Garrido, A., Marques-de-S{\`a}, J.P., Pereira-Leite, L., SisPorto 2.0 - a program for automated analysis of cardiotocograms (2000) J Matern Fetal Med, 9, pp. 311-318; 
Ayres-de-Campos, D., Costa-Santos, C., Bernardes, J., SisPorto Multicentre Validation Study Group. Prediction of neonatal state by computer analysis of fetal heart rate tracings: The antepartum arm of the SisPorto multicentre validation study (2005) Eur J Obstet Gynecol Reprod Biol, 118, pp. 52-60; 
Ayres-de-Campos, D., Sousa, P., Costa, A., Bernardes, J., Omniview-SisPorto 3.5 - a central fetal monitoring station with online alerts based on computerized cardio-tocogram+ST event analysis (2008) J Perinat Med, 36, pp. 260-264; 
Beckers, F., Verheyden, B., Aubert, A.E., Aging and non-linear heart rate control in a healthy population (2006) Am J Physiol Heart Circ Physiol, 290, pp. H2560-H2570; 
Bekedam, D.J., Engelsbel, S., Mol, B.W., Buitendijk, S.E., van der Pal-de Bruin, K.M., Male predominance in fetal distress during labor (2002) Am J Obstet Gynecol, 187, pp. 1605-1607; 
Bennet, L., Booth, L.C., Ahmed-Nasef, N., Dean, J.M., Davidson, J., Quaedackers, J.S., Male disadvantage? Fetal sex and cardiovascular responses to asphyxia in preterm fetal sheep (2007) Am J Physiol Regul Integr Comp Physiol, 293, pp. R1280-R1286; 
Bernardes, J., Moura, C., Marques-de-S{\'a}, J.P., Pereira-Leite, L., The Porto system for automated cardiotocographic signal analysis (1991) J Perinat Med, 19, pp. 61-65; 
Bernardes, J., Costa-Pereira, A., Ayres-de-Campos, D., van Geijn, H.P., Pereira-Leite, L., Evaluation of interobserver agreement of cardiotocograms (1997) Int J Gynecol Obstet, 57, pp. 33-37; 
Bernardes, J., Ayres-de-Campos, D., Costa-Pereira, A., Pereira-Leite, L., Garrido, A., Objective computerized fetal heart rate analysis (1998) Int J Gynaecol Obstet, 62, pp. 141-147; 
Bernardes, J., Gon{\c c}alves, H., Ayres-de-Campos, D., Rocha, A.P., Linear and complex heart rate dynamics vary with sex in relation to fetal behavioural states (2008) Early Hum Dev, 84, pp. 433-439; 
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Gon{\c c}alves, H., Rocha, A.P., Ayres-de-Campos, D., Bernardes, J., Internal versus external intrapartum foetal heart rate monitoring: The effect on linear and nonlinear parameters (2006) Physiol Meas, 27, pp. 307-319; 
Goncalves, H., Rocha, A.P., Ayres-de-Campos, D., Bernardes, J., Linear and nonlinear fetal heart rate analysis of normal and acidemic fetuses in the minutes preceding delivery (2006) Med Biol Eng Comput, 44, pp. 847-855; 
Goncalves, H., Bernardes, J., Rocha, A.P., Ayres-de-Campos, D., Linear and nonlinear analysis of heart rate patterns associated with fetal behavioral states in the antepartum period (2007) Early Hum Dev, 83, pp. 585-591; 
Groome, L.J., Mooney, D.M., Holland, S.B., Smith, L.A., Atterbury, J.L., Dykman, R.A., Behavioral state affects heart rate response to low-intensity sound in human fetuses (1999) Early Hum Dev, 54, pp. 39-54; 
Ingemarsson, I., Herbst, A., Thorngren-Jerneck, K., Long-term outcome after umbilical artery acidemia at term birth: Influence of gender and duration of fetal heart rate abnormalities (1997) Br J Obstet Gynaecol, 104, pp. 1123-1127; 
Jensen-Urstad, K., Storck, N., Bouvier, F., Ericson, M., Lindblad, L.E., Jensen-Urstad, M., Heart rate variability in healthy subjects is related to age and gender (1997) Acta Physiol Scand, 160, pp. 235-241; 
King, T., Parer, J., The physiology of fetal heart rate patterns and perinatal asphyxia (2000) J Perinat Neonat Nurs, 14, pp. 19-39; 
Kuo, T.B., Yang, C.C., Sexual dimorphism in the complexity of cardiac pacemaker activity (2002) Am J Physiol Heart Circ Physiol, 283, pp. H1695-H1702; 
Li, X., Tang, D., Zhou, S., Zhou, G., Wang, C., Zhuang, Y., Redistribution of power spectrum of heart rate variability during acute umbilical artery embolism and hypoxemia in late-gestation fetal sheep (2004) J Obstet Gynecol Reprod Biol, 114, pp. 137-143; 
Magenes, G., Signorini, M.G., Arduini, D., Classification of cardiotocographic records by neural networks (2000) IJCNN 2000, Proceedings of the IEEE-INNS-ENNS International Joint Conference on Neural Networks, 3, pp. 637-641; 
Martinez, W.L., Martinez, A.R., (2002) Computational statistics handbook with MATLAB, , CRC Press;; 
Pincus, S., Approximate entropy as a measure of system complexity (1991) Proc Natl Acad Sci USA, 88, pp. 2297-2301; 
Pincus, S., Viscarello, R., Approximate Entropy: A regularity measure for fetal heart rate analysis (1992) Obstet Gynecol, 79, pp. 249-255; 
Richman, J.S., Moorman, J.R., Physiological time-series analysis using approximate entropy and sample entropy (2000) Am J Physiol Heart Circ Physiol, 278, pp. H2039-H2049; 
Ryan, S.M., Goldberger, A.L., Pincus, S.M., Mietus, J., Lipsitz, L.A., Gender- and age-related differences in heart rate dynamics: Are women more complex than men? (1994) J Am Coll Cardiol, 24, pp. 1700-1707; 
Sheiner, E., Hadar, A., Hallak, M., Katz, M., Mazor, M., Shoham-Vardi, I., Clinical significance of fetal heart rate tracings during the second stage of labor (2001) Obstet Gynecol, 97, pp. 747-752; 
Signorini, M.G., Magenes, G., Cerrutti, S., Arduini, D., Linear and nonlinear parameters for the analysis of fetal heart rate signal from cardiotacographic recordings (2003) IEEE Transactions on Biomedical Engineering, 50, pp. 365-373; 
Siira, S.M., Ojala, T.H., Vahlberg, T.J., Jalonen, J.O., V{\"a}lim{\"a}ki, I.A., Ros{\'e}n, K.G., Marked fetal acidosis and specific changes in power spectrum analysis of fetal heart rate variability recorded during the last hour of labor (2005) Br J Obstet Gynaecol, 112, pp. 418-423; 
Suzuki, T., Okamura, K., Kimura, Y., Watanabe, T., Yaegashi, N., Murotsuki, J., Power spectral analysis of R-R interval variability before and during the sinusoidal heart rate pattern in fetal lambs (2000) Am J Obstet Gynecol, 182, pp. 1227-1232; 
},
	month = {2009///},
	pages = {168 - 176},
	abstract = {Aim: To assess linear and complex heart rate dynamics in relation to fetal gender in normal and acidemic fetuses during the minutes preceding delivery. Methods: Linear and non-linear fetal heart rate indices, namely mean FHR, long-term irregularity index, short-term variability, low and high frequency spectral indices, approximate and sample entropy, were assessed in 36 female and 30 male fetuses, adjusted for gestational age and weight, during the minutes preceding delivery. Analysis was performed in the initial and final minutes of each tracing in fetuses with umbilical artery blood pH at delivery >=7.20, 7.11-7.19 and <=7.10. Results: Progression of labor was associated with a significant decrease in non-linear indices and an increase in almost all linear indices, both in female and male fetuses, but changes were more marked in female fetuses. Non-acidemic females showed higher mean FHR in the final minutes of labor, compared with males. Acidemic females had higher linear indices when compared to similar male fetuses. Conclusions: During the minutes preceding delivery, female fetuses express higher linear indices than male fetuses, suggesting greater activation of the autonomic nervous system, while maintaining similar complexity indices, which suggests different reaction and adaptation capabilities to stress and distress. {\textcopyright} 2009 by Walter de Gruyter.},
	keywords = {acidemia, Acidemic fetuses, article, autonomic nervous system, Birth Weight, blood pH, Cross-Sectional Studies, delivery, Delivery, Obstetric, entropy, Entropy and spectral analysis, Female, Fetal Heart, fetus, fetus heart rate, Gestational Age, Heart Rate, Fetal, human, Humans, Hydrogen-Ion Concentration, Intrapartum, labor, Labor, Obstetric, male, Pregnancy, priority journal, Retrospective Studies, Sex Characteristics, sex difference, Umbilical Arteries, umbilical artery},
	isbn = {03005577 (ISSN)},
	url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-59449089216\&partnerID=40\&md5=7a093bd5c056231b3f8150912abca652},
	author = {Bernardes, J. and Gon{\c c}alves, H. and Ayres-de-Campos, D. and Rocha, A.P.}
}
@article {2347,
	title = {Linear and complex heart rate dynamics vary with sex in relation to fetal behavioural states},
	journal = {Early Human DevelopmentEarly Hum. Dev.},
	volume = {84},
	year = {2008},
	note = {Cited By (since 1996): 16Export Date: 21 November 2012Source: ScopusCODEN: EHDEDdoi: 10.1016/j.earlhumdev.2007.12.001PubMed ID: 18248921Language of Original Document: EnglishCorrespondence Address: Bernardes, J.; Departamento de Ginecologia e Obstetr{\'\i}cia, Faculdade de Medicina, Universidade do Porto and INEB (Instituto Nacional de Engenharia Biom{\'e}dica), Porto, Portugal; email: jbernardes@mail.telepac.ptReferences: Ingemarsson, I., Herbst, A., Thorngren-Jerneck, K., Long term outcome after umbilical artery acidaemia at term birth: influence of gender and duration of fetal heart rate abnormalities (1997) Br J Obstet Gynaecol, 104 (10), pp. 1123-1127;Ingemarsson, I., Gender aspects of preterm birth (2003) BJOG, 110 (SUPPL. 20), pp. 34-38; 
DiPietro, J.A., Hodgson, D.M., Costigan, K.A., Hilton, S.C., Johnson, T.R., Development of fetal movement-fetal heart rate coupling from 20~weeks through term (1996) Early Hum Dev, 44 (2), pp. 139-151; 
DiPietro, J.A., Costigan, K.A., Shupe, A.K., Pressman, E.K., Johnson, T.R., Fetal neurobehavioral development: associations with socioeconomic class and fetal sex (1998) Dev Psychobiol, 33 (1), pp. 79-91; 
Ogueh, O., Steer, P., Gender does not affect fetal heart rate variation (1998) Br J Obstet Gynaecol, 105 (12), pp. 1312-1314; 
Dawes, N.W., Dawes, G.S., Moulden, M., Redman, C.W., Fetal heart rate patterns in term labor vary with sex, gestational age, epidural analgesia, and fetal weight (1999) Am J Obstet Gynecol, 180, pp. 181-187; 
Lange, S., Van Leeuwen, P., Geue, D., Hatzmann, W., Gronemeyer, D., Influence of gestational age, heart rate, gender and time of day on fetal heart rate variability (2005) Med Biol Eng Comput, 43 (4), pp. 481-486; 
Gon{\c c}alves, H., Bernardes, J., Rocha, A.P., Ayres-de-Campos, D., Linear and nonlinear analysis of heart rate patterns associated with fetal behavioral states in the antepartum period (2007) Early Hum Dev, 83 (9), pp. 585-591; 
Nijhuis, J.G., Prechtl, H.F., Martin Jr., C.B., Bots, R.S., Are there behavioural states in the human fetus? (1982) Early Hum Dev, 6 (2), pp. 177-195; 
Gon{\c c}alves, H., Rocha, A.P., Ayres-de-Campos, D., Bernardes, J., Internal versus external intrapartum foetal heart rate monitoring: the effect on linear and nonlinear parameters (2006) Physiol Meas, 27 (3), pp. 307-319; 
Goncalves, H., Rocha, A.P., Bernardes, J., Ayres-de-Campos, D., Linear and nonlinear fetal heart rate analysis of normal and acidemic fetuses in the minutes preceding delivery (2006) Med Biol Eng Comput, 44 (10), pp. 847-855; 
Ayres-de-Campos, D., Bernardes, J., Garrido, A., Marques-de-S{\'a}, Pereira-Leite, L., SisPorto 2.0 - a program for automated analysis of cardiotocograms (2000) J Matern Fetal Med, 9, pp. 311-318.; 
Magenes, G., Signorini, M.G., Arduini, D., Classification of cardiotocographic records by neural networks (2000) IJCNN 2000, Proceedings of the IEEE-INNS-ENNS International Joint Conference on Neural Networks, 3, pp. 637-641; 
Signorini, M.G., Magenes, G., Cerrutti, S., Arduini, D., Linear and nonlinear parameters for the analysis of fetal heart rate signal from cardiotacographic recordings (2003) IEEE Trans Biomed Eng, 50, pp. 365-373; 
Task force of the European Society of Cardiology and the North American Society of Pacing and Electrophysiology, Heart rate variability - standards of measurement, physiological interpretation and clinical use (1996) Circulation, 17, pp. 354-381; 
Boog, G., Analyse informatis{\'e}e du rythme cardiaque foetal au cours de la grosssesse et de l{\textquoteright}accouchement (2004) Encyclop{\'e}die M{\'e}dico-Chirurgicale, 148 (5-49 -D-23), pp. 1-10; 
Suzuki, T., Okamura, K., Kimura, Y., Watanabe, T., Yaegashi, N., Murotsuki, J., Power spectral analysis of R-R interval variability before and during the sinusoidal heart rate pattern in fetal lambs (2000) Am J Obstet Gynecol, 182, pp. 1227-1232; 
Pincus, S., Approximate entropy as a measure of system complexity (1991) Proc Natl Acad Sci U. S. A., 88, pp. 2297-2301; 
Richman, J.S., Moorman, J.R., Physiological time-series analysis using approximate entropy and sample entropy (2000) Am J Physiol Heart Circ Physiol, 278, pp. H2039-H2049; 
Fusheng, Y., Bo, H., Qingyu, T., Approximate entropy and its application in biosignal analysis (1998) Nonlinear biomedical signal processing - Volume II: Dynamical analysis and modelling, pp. 72-91. , Akay M. (Ed), IEEE Press; 
Pincus, S., Viscarello, R., Approximate entropy: a regularity measure for fetal heart rate analysis (1992) Obstet Gynecol, 79, pp. 249-255; 
Martinez, W.L., Martinez, A.R., (2002) Computational statistics handbook with MATLAB, , CRC Press; 
Dudewicz, E., Mishra, S., (1998) Modern Mathematical Statistics, , John Wiley and Sons, Inc; 
Robles de Medina, P.G., Visser, G.H., Huizink, A.C., Buitelaar, J.K., Mulder, E.J., Fetal behaviour does not differ between boys and girls (2003) Early Hum Dev, 73 (1-2), pp. 17-26; 
Ryan, S.M., Goldberger, A.L., Pincus, S.M., Mietus, J., Lipsitz, L.A., Gender- and age-related differences in heart rate dynamics: are women more complex than men? (1994) J Am Coll Cardiol, 24 (7), pp. 1700-1707; 
Jensen-Urstad, K., Storck, N., Bouvier, F., Ericson, M., Lindblad, L.E., Jensen-Urstad, M., Heart rate variability in healthy subjects is related to age and gender (1997) Acta Physiol Scand, 160 (3), pp. 235-241; 
Beckers, F., Verheyden, B., Aubert, A.E., Aging and nonlinear heart rate control in a healthy population (2006) Am J Physiol Heart Circ Physiol, 290 (6), pp. H2560-H2570; 
Kuo, T.B., Yang, C.C., Sexual dimorphism in the complexity of cardiac pacemaker activity (2002) Am J Physiol Heart Circ Physiol, 283 (4), pp. H1695-H1702; 
Groome, L.J., Mooney, D.M., Holland, S.B., Smith, L.A., Atterbury, J.L., Dykman, R.A., Behavioral state affects heart rate response to low-intensity sound in human fetuses (1999) Early Hum Dev, 54 (1), pp. 39-54; 
Fleisher, L.A., Dipietro, J.A., Johnson, T.R., Pincus, S., Complementary and non-coincident increases in heart rate variability and irregularity during fetal development (1997) Clin Sci (Lond), 92 (4), pp. 345-349; 
Bernardes, J., Costa-Pereira, A., Ayres-de-Campos, D., van Geijn, H.P., Pereira-Leite, L., Evaluation of interobserver agreement of cardiotocograms (1997) Int J Gynecol Obstet, Suppl, 57 (1), pp. 33-37; 
Ayres-de-Campos, D., Bernardes, J., Costa-Pereira, A., Pereira-Leite, L., Inconsistencies in expert{\textquoteright}s classification of cardiotocograms and subsequent clinical decision (1999) Br J Obstet Gynecol, 106, pp. 1307-1310; 
Bernardes, J., Moura, C., Marques-de-S{\'a}, J.P., Pereira-Leite, L., The Porto system for automated cardiotocographic signal analysis (1991) J Perinat Med, 19, pp. 61-65; 
Bernardes, J., Ayres-de-Campos, D., Costa-Pereira, A., Pereira-Leite, L., Garrido, A., Objective computerized fetal heart rate analysis (1998) Int J Gynaecol Obstet, 62 (2), pp. 141-147; 
Ayres-de-Campos, D., Costa-Santos, C., Bernardes, J., SisPorto Multicentre Validation Study Group. Prediction of neonatal state by computer analysis of fetal heart rate tracings: the antepartum arm of the SisPorto multicentre validation study (2005) Eur J Obstet Gynecol Reprod Biol, 118 (1), pp. 52-60; 
Dawes, G.S., Moulden, M., Redman, C.W., Improvements in computerized fetal heart rate analysis antepartum (1996) J Perinat Med, 24 (1), pp. 25-36
},
	month = {2008///},
	pages = {433 - 439},
	abstract = {Background: A better understanding of gender influences on fetal heart rate can help to improve analysis of the latter and perhaps elucidate the increased risk of perinatal death that occurs in males. Aim: To assess differences in linear and complex heart rate dynamics according to fetal sex, in the antepartum period of normal term pregnancies, for patterns associated with fetal behavioural states. Study design and subjects: One hundred and eighty seven fetal heart rate segments of 10-minute duration, acquired with a system for computerized analysis of cardiotocograms and classified into fetal behavioural patterns A, B, C or D were analysed. They had been acquired from 24 female and 23 male term fetuses, with uneventful perinatal outcomes. Four different comparative studies between female and male fetuses were conducted, considering different adjustments for gestational age, weight and FHR pattern. Outcome measures: Indices of linear and nonlinear fetal heart rate variability, namely, long-term irregularity index, very low, low and high frequency spectral indices, approximate entropy and sample entropy. Results: Pattern B was the most frequent, both in female and male fetuses. Pattern A was more likely to be associated to female than male fetuses, whereas the opposite occurred with patterns C and D. Linear indices were significantly higher in male than in female fetuses, whereas the opposite occurred with nonlinear indices. Conclusions: Male fetuses exhibited significantly more linear and significantly less complex fetal heart rate activity than female fetuses, expressing signs of a more active autonomous nervous system and of less active complexity control systems. These aspects may need to be considered when interpreting FHR tracings. {\textcopyright} 2007 Elsevier Ireland Ltd. All rights reserved.},
	keywords = {article, Behavior, Cardiotocography, comparative study, Computerized analysis, Entropy and spectral analysis, Female, Fetal behavioural states and sex, Fetal heart rate, Fetal monitoring, Fetal Movement, fetus, fetus heart rate, Gestational Age, heart hemodynamics, Heart Rate, Fetal, human, Humans, male, normal human, Pregnancy, Pregnancy Outcome, Sex Characteristics, sex difference, SisPorto},
	isbn = {03783782 (ISSN)},
	url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-44749091847\&partnerID=40\&md5=0a0fcbbe86dcad0bee063b6cc7687573},
	author = {Bernardes, J. and Gon{\c c}alves, H. and Ayres-de-Campos, D. and Rocha, A.P.}
}
@article {2339,
	title = {Linear and nonlinear heart-rate analysis in a rat model of acute anoxia},
	journal = {Physiological MeasurementPhysiol. Meas.},
	volume = {29},
	year = {2008},
	note = {Cited By (since 1996): 6Export Date: 21 November 2012Source: ScopusCODEN: PMEAEdoi: 10.1088/0967-3334/29/9/010PubMed ID: 18784391Language of Original Document: EnglishCorrespondence Address: Gon{\c c}alves, H.; Departamento de Matem{\'a}tica Aplicada, Faculdade de Ci{\^e}ncias, Universidade Do Porto, Rua do Campo Alegre 687, 4169-007 Porto, Portugal; email: hernani.goncalves@fc.up.ptReferences: American College of Obstetricians and Gynecologists. ACOG Practice Bulletin. Clinical Management Guidelines for Obstetrician-Gynecologists, Number 70, December 2005 (2005) Obstet. Gynecol., 106, pp. 1453-1460;Ayres-De-Campos, D., Bernardes, J., Garrido, A., Marques-De-S{\'a}, J., Pereira-Leite, L., SisPorto 2.0: A program for automated analysis of cardiotocograms (2000) J. Mat. Fet. Med., 9 (5), pp. 311-318; 
Ayres-De-Campos, D., Santos, C., Bernardes, J., Prediction of neonatal state by computer analysis of fetal heart rate tracings: The antepartum arm of the SisPorto{\textregistered} validation study (2005) Eur. J. Obstet. Gynecol. Reprod. Biol., 118 (1), pp. 52-60; 
Beckers, F., Verheyden, B., Aubert, A.E., Aging and nonlinear heart rate control in a healthy population (2006) Am. J. Physiol. Heart Circ. Physiol., 290 (6), pp. 2560-H2570; 
Beckers, F., Verheyden, B., Ramaekers, D., Swinghedauw, B., Aubert, A.E., Effects of autonomic blockade on non-linear cardiovascular variability indices in rats (2006) Clin. Exp. Pharmacol. Physiol., 33 (5-6), pp. 431-439; 
Bernardes, J., Ayres-De-Campos, D., Costa-Pereira, A., Pereira-Leite, L., Garrido, A., Objective computerized fetal heart rate analysis (1998) Int. J. Gynecol. Obstet., 62 (2), pp. 141-147; 
Bernardes, J., Moura, C., Marques-De-S{\'a}, J.P., Pereira-Leite, L., The Porto system for automated cardiotocographic signal analysis (1991) J. Perinat. Med., 19, pp. 61-65; 
Cerutti, C., Gustin, M.P., Paultre, C.Z., Lo, M., Julien, C., Vincent, M., Sassard, J., Autonomic nervous-system and cardiovascular variability in rats-a spectral-analysis approach (1991) Am. J. Physiol., 261, pp. 1292-H1299; 
Chaffin, D.G., Barnard, J.M., Phernetton, T., Reed, K.L., Decreased approximate entropy of heart rate variability in the hypoxic ovine fetus (1998) J. Matern. Fetal Invest., 8, pp. 23-26; 
Dudewicz, E., Mishra, S., (1988) Modern Mathematical Statistics; 
Felgueiras, C., Marques-De-S{\'a}, J.P., Bernardes, J., Gama, S., Fractal characterisation of fetal heart rate sequences (1998) Biomedical Eng., 36, pp. 197-201; 
Gon{\c c}alves, H., Bernardes, J., Rocha, A.P., Ayres-De-Campos, D., Linear and nonlinear analysis of heart rate patterns associated with fetal behavioral states in the antepartum period (2007) Early Human Develop., 83 (9), pp. 585-591; 
Gon{\c c}alves, H., Rocha, A.P., Ayres-De-Campos, D., Bernardes, J., Internal versus external intrapartum foetal heart rate monitoring: The effect on linear and nonlinear parameters (2006) Physiol. Meas., 27 (3), pp. 307-319; 
Gon{\c c}alves, H., Rocha, A.P., Ayres-De-Campos, D., Bernardes, J., Linear and nonlinear fetal heart rate analysis of normal and acidemic fetuses in the minutes preceding delivery (2006) Med. Biol. Eng. Comput., 44 (10), pp. 847-855; 
Hayes, M., (1996) Statistical Digital Signal Processing and Modelling; 
Henriques-Coelho, T., Correia-Pinto, J., Roncon-Albuquerque, R., Baptista, M.J., Lourenco, A.P., Oliveira, S.M., Brandao-Nogueira, A., Leite-Moreira, A.F., Endogenous production of ghrelin and beneficial effects of its exogenous administration in monocrotaline-induced pulmonary hypertension (2004) Am. J. Physiol. Heart Circ. Physiol., 287 (6), pp. 2885-H2890; 
Kuwahara, M., Yayou, K., Ishii, K., Hashimoto, S., Tsubone, H., Sugano, S., Power spectral analysis of heart rate variability as a new method for assessing autonomic activity in the rat (1994) J. Electrocardiology, 27 (4), pp. 333-337; 
Li, X., Tang, D., Zhou, S., Zhou, G., Wang, C., Zhuang, Y., Wu, G., Shen, L., Redistribution of power spectrum of heart rate variability during acute umbilical artery embolism and hypoxemia in late-gestation fetal sheep (2004) Eur. J. Obstet. Gynecol. Reprod. Biol., 114 (2), pp. 137-143; 
Louren{\c c}o, A.P., Roncon-Albuquerque, R., Bras-Silva, C., Faria, B., Wieland, J., Henriques-Coelho, T., Correia-Pinto, J., Leite-Moreira, A.F., Myocardial dysfunction and neurohumoral activation without remodeling in left ventricle of monocrotaline-induced pulmonary hypertensive rats (2006) Am. J. Physiol. Heart Circ. Physiol., 291 (4), pp. 1587-H1594; 
Magenes, G., Signorini, M.G., Arduini, D., Classification of cardiotocographic records by neural networks (2000) IJCNN 2000: Proc. IEEE-INNS-ENNS Int. Joint Conf. on Neural Network, 3, pp. 637-641; 
Martinez, W.L., Martinez, A.R., (2002) Computational Statistics Handbook with MATLAB; 
Moraru, L., Cimponeriu, L., Tong, S., Thakor, N., Bezerianos, A., Characterization of heart rate variability changes following asphyxia in rats (2004) Methods Inf. Med., 43 (1), pp. 118-121; 
Moraru, L., Tong, S., Malhotra, A., Geocadin, R., Thakor, N., Bezerianos, A., Investigation of the effects of ischemic preconditioning on the HRV response to transient global ischemia using linear and nonlinear methods (2005) Med. Eng. Phys., 27 (6), pp. 465-473; 
Murasato, Y., Hirakawa, H., Harada, Y., Nakamura, T., Hayashida, Y., Effects of systemic hypoxia on R-r interval and blood pressure variabilities in conscious rats (1998) Am. J. Physiol., 275, pp. 797-H804; 
Niklasson, U., Wiklund, U., Bjerle, P., Olofsson, B.O., Heart-rate variation-what are we measuring? (1993) Clin. Physiol., 13 (1), pp. 71-79; 
Pincus, S., Aproximate entropy (ApEn) as a complexity measure (1995) Chaos, 5 (1), pp. 110-117; 
Pincus, S.M., Gevers, E.F., Robinson, I.C.A.F., Vandenberg, G., Roelfsema, F., Hartman, M.L., Veldhuis, J.D., Females secrete growth hormone with more process irregularity than males in both humans and rats (1996) Am. J. Physiol., 270, pp. 107-E115; 
Pincus, S., Viscarello, R., Approximate Entropy: A regularity measure for fetal heart rate analysis (1992) Obstet. Gynecol., 79, pp. 249-255; 
Richman, J.S., Moorman, J.R., Physiological time-series analysis using approximate entropy and sample entropy (2000) Am. J. Physiol. Heart Circ. Physiol., 278, pp. 2039-H2049; 
Signorini, M.G., Magenes, G., Cerrutti, S., Arduini, D., Linear and nonlinear parameters for the analysis of fetal heart rate signal from cardiotacographic recordings (2003) IEEE Trans. Biomed. Eng., 50 (3), pp. 365-373; 
Siira, S.M., Ojala, T.H., Vahlberg, T.J., Jalonen, J.O., Valimaki, I.A., Rosen, K.G., Ekholm, E.M., Marked fetal acidosis and specific changes in power spectrum analysis of fetal heart rate variability recorded during the last hour of labour (2005) BJOG, 112 (4), pp. 418-423; 
Task force of the European Society of Cardiology and the North American Society of Pacing and Electrophysiology, Heart rate variability-standards of measurement, physiological interpretation and clinical use (1996) Circulation, 93, pp. 1043-1065; 
Vieira, P., Marques-De-S{\'a}, J.P., Bernardes, J., Fractal analysis of foetal heart rate (2004) Proc. Biosignal 2004, pp. 53-55
},
	month = {2008///},
	pages = {1133 - 1143},
	abstract = {The objective of this study was the assessment of heart-rate (HR) dynamics with linear and nonlinear methods during episodes of mechanical ventilation and acute anoxia in rats. Namely, to assess whether linear and nonlinear HR analysis was able to discriminate acute anoxia from baseline in rats and if this was consistent with human foetal and adult studies. Five HR segments of 1 min duration, during baseline recording, mechanical ventilation and first, second and third minutes of induced acute anoxia, were analysed in ten adult Wistar rats. Linear time and frequency domain and nonlinear methods were used, namely mean HR (mHR), long-term irregularity (LTI), interval index (II), low frequency (LF) and high frequency (HF), approximate entropy (ApEn) and sample entropy (SampEn). New parameters for the entropy indices are proposed for the analysis of rats{\textquoteright} HR. Bootstrap percentile confidence intervals and nonparametric statistical tests were used in the evaluation of the differences between segments. During mechanical ventilation a clear spectral band was detectable at the ventilation rate, but mHR, II and the {\textquoteright}new{\textquoteright} entropy indices were the only significantly changed indices. In the transition from baseline-mechanical- ventilation to mechanical-ventilation-induced anoxia, a statistically significant decrease of mHR, II and entropy indices was observed, clearly discriminating these two instances, whereas most linear indices increased. With continued anoxia, most linear indices decreased significantly, whereas entropy remained stably low. These results are consistent with other foetal human and non-human studies and evidence that the rat model may be used for further research on linear and nonlinear analysis of heart-rate dynamics. The transition from baseline to acute anoxia was encompassed by signs of increased activation of the autonomic nervous system sympathetic branch, and decreased or blunted activity of the HR complexity regulatory centres. {\textcopyright} 2008 Institute of Physics and Engineering in Medicine.},
	keywords = {acute disease, animal experiment, animal model, Animals, Anoxia, article, artificial ventilation, bootstrapping, controlled study, entropy, Female, Fetal monitoring, frequency analysis, Heart rate, Heart rate variability, Humans, Linear analysis, linear system, lung ventilation, Models, Cardiovascular, nonhuman, nonlinear system, priority journal, rat, Rats, Rats, Wistar, Rattus, Rattus norvegicus, Respiration, Artificial, Statistical analysis, Variability, Wistar rat, Wistar rats},
	isbn = {09673334 (ISSN)},
	url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-51849120545\&partnerID=40\&md5=56be327bb0d959060a2f4a0f080ae264},
	author = {Gon{\c c}alves, H. and Henriques-Coelho, T. and Bernardes, J. and Rocha, A.P. and Nogueira, A. and Leite-Moreira, A.}
}
@article {2353,
	title = {Omniview-SisPorto{\textregistered} 3.5 - A central fetal monitoring station with online alerts based on computerized cardiotocogram+ST event analysis},
	journal = {Journal of Perinatal MedicineJ. Perinat. Med.},
	volume = {36},
	year = {2008},
	note = {Cited By (since 1996): 13Export Date: 21 November 2012Source: ScopusCODEN: JPEMAdoi: 10.1515/JPM.2008.030Language of Original Document: EnglishCorrespondence Address: Ayres-De-Campos, D.; Departmento Ginecologia e Obstetricia, Faculdade de Medicina, Universidade Do Porto, Alameda Hernani Monteiro, 4200-319 Porto, Portugal; email: sisporto@med.up.ptTradenames: Omniview-SisPorto 3.5 system, SpeculumManufacturers: SpeculumReferences: Amer-Wahlin, I., Arulkumaran, S., Hagberg, H., Marsal, K., Visser, G., Fetal electrocardiogram: ST waveform analysis in intrapartum surveillance (2007) Br J Obstet Gynaecol, 114, pp. 1191-1193;Ayres-de-Campos, D., Bernardes, J., Garrido, A., Marquesde-S{\'a}, J., Pereira-Leite, L., SisPorto 2.0: A program for automated analysis of cardiotocograms (2000) J Matern Fetal Med, 9, pp. 311-318; 
Ayres-de-Campos, D., Bernardes, J., Comparison of fetal heart rate baseline estimation by SisPorto 2.01 and a consensus of clinicians (2004) Eur J Obstet Gynecol Reprod Biol, 117, pp. 174-178; 
Ayres-de-Campos, D., Costa-Santos, C., Bernardes, J., SisPorto Multicentre Validation Study Group. Prediction of neonatal state by computer analysis of fetal heart rate tracings: The antepartum arm of the SisPorto multicentre validation study (2005) Eur J Obstet Gynecol Reprod Biol, 118, pp. 52-60; 
Ayres-de-Campos, D., Bernardes, J., Kwee, A., Westehuis, M., Visser, G.H.A., Computer quantification of short-term variability as an adjunct to fetal electrocardiographic monitoring (2007) Br J Obstet Gynaecol, 114, pp. 1446-1447; 
Bernardes, J., Moura, C., Marques de, S.J., Pereira Leite, L., The Porto system for automated cardiotocographic signal analysis (1991) J Perinat Med, 19, pp. 61-65; 
Electronic fetal heart rate monitoring: Research guidelines for interpretation (1997) Am J Obstet Gynecol, 177, pp. 1385-1390. , National Institute of Child Health and Human Development Research Planning Workshop; 
Neilson, J.P., Fetal electrocardiogram (ECG) for fetal monitoring during labor (2006) Cochrane Database of Systematic Reviews, (3); 
Paneth, N., Bommarito, M., Stricker, J., Electronic fetal monitoring and later outcome (1993) Clin Invest Med, 16, pp. 159-165; 
(2001) Evidence-based clinical guideline: The use of electronic fetal monitoring, , RCOG, Royal College of Obstetricians and Gynaecologists, London, RCOG Press; 
Rooth, G., Huch, A., Huch, R., Guidelines for the use of fetal monitoring (1987) Int J Gynecol Obstet, 25, pp. 159-167
},
	month = {2008///},
	pages = {260 - 264},
	abstract = {Visual analysis of cardiotocograms is poorly reproducible and is currently recognized as the main weakness of the STAN{\textregistered} methodology. The Omniview-SisPorto{\textregistered} 3.5 program is the most recent version of a central monitoring system that provides visual and sound alerts, based on computer analysis of cardiotocographic and ST event features. This paper describes the program{\textquoteright}s main characteristics and provides an overview of the system{\textquoteright}s online alerts. Omniview-SisPorto{\textregistered} 3.5 is the first central monitoring system to incorporate computerized analysis of cardiotocographic and ST event features, providing health professionals with online alerts for minor and major changes in monitored signals. The system is currently undergoing extensive clinical evaluation. {\textcopyright} 2008 by Walter de Gruyter.},
	keywords = {article, Cardiotocography, computer program, Computer-assisted, Electrocardiography, Female, Fetal, Fetal hypoxia, Fetal monitoring, fetus hypoxia, fetus monitoring, Heart rate, human, Humans, instrumentation, online system, Pregnancy, priority journal, Signal processing, ST segment},
	isbn = {03005577 (ISSN)},
	url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-44949183434\&partnerID=40\&md5=8a8b193ca1077d049f7333b4f6595962},
	author = {Ayres-de-Campos, D. and Sousa, P. and Costa, A. and Bernardes, J.}
}
@article {2375,
	title = {Linear and nonlinear analysis of heart rate patterns associated with fetal behavioral states in the antepartum period},
	journal = {Early Human DevelopmentEarly Hum. Dev.},
	volume = {83},
	year = {2007},
	note = {Cited By (since 1996): 17Export Date: 21 November 2012Source: ScopusCODEN: EHDEDdoi: 10.1016/j.earlhumdev.2006.12.006PubMed ID: 17261357Language of Original Document: EnglishCorrespondence Address: Gon{\c c}alves, H.; Universidade do Porto, Faculdade de Ci{\^e}ncias, Departamento de Matem{\'a}tica Aplicada, Porto, Portugal; email: hernani.goncalves@fc.up.ptReferences: Nijhuis, J.G., Prechtl, H.F., Martin, C.B.J., Bots, R.S., Are there behavioural states in the human fetus? (1982) Early Hum Dev, 6, pp. 177-195;Nijhuis, I., ten Hof, J., Development of fetal heart rate and behavior: indirect measures to assess the fetal nervous system (1999) Eur J Obstet Gynaecol Reprod Biol, 87, pp. 1-2; 
Vindla, S., James, D., Fetal behaviour as a test of fetal wellbeing (1995) Br J Obstet Gynaecol, 102, pp. 597-600; 
Swartjes, J.M., van Geijn, H.P., Mantel, R., van Woerden, E.E., Schoemaker, H.C., Coincidence of behavioural state parameters in the human fetus at three gestational ages (1990) Early Hum Dev, 23, pp. 75-83; 
Ayres-de-Campos, D., Santos, C., Bernardes, J., Prediction of neonatal state by computer analysis of fetal heart rate tracings: the antepartum arm of the SisPorto{\textregistered} multicentre validation study (2005) Eur J Obstet Gynaecol Reprod Biol, 118, pp. 52-60; 
Ayres-de-Campos, D., Bernardes, J., Garrido, A., de S{\'a}, J.M., Pereira-Leite, L., SisPorto 2.0: a program for automated analysis of cardiotocograms (2000) J Matern Fetal Med, 9, pp. 311-318; 
Rooth, G., Huch, A., Huch, R., FIGO news. Guidelines for the use of fetal monitoring (1987) Int J Gynaecol Obstet, 25, p. 159; 
Bernardes, J., Moura, C., de S{\'a}, J.P.M., Pereira-Leite, L., The Porto system for automated cardiotocographic signal analysis (1991) J Perinat Med, 19, pp. 61-65; 
Gon{\c c}alves, H., Rocha, A.P., Ayres-de-Campos, D., Bernardes, J., Internal versus external intrapartum foetal heart rate monitoring: the effect on linear and nonlinear parameters (2006) Physiol Meas, 27, pp. 307-319; 
Signorini, M.G., Magenes, G., Cerrutti, S., Arduini, D., Linear and nonlinear parameters for the analysis of fetal heart rate signal from cardiotacographic recordings (2003) IEEE Trans Biomed Eng, 50 (3), pp. 365-373; 
Pincus, S., Viscarello, R., Approximate Entropy: a regularity measure for fetal heart rate analysis (1992) Obstet Gynaecol, 79 (2), pp. 249-255; 
Richman, J.S., Moorman, J.R., Physiological time-series analysis using approximate entropy and sample entropy (2000) Am J Physiol Heart Circ Physiol, 278, pp. H2039-H2049; 
Pincus, S., Approximate entropy (ApEn) as a complexity measure (1995) Chaos, 5 (1), pp. 110-117; 
Grant, J.M., The fetal heart rate trace is normal, isn{\textquoteright}t it? Observer agreement of categorical assessments (1991) Lancet, 337, pp. 215-218; 
Martinez, W.L., Martinez, A.R., (2002) Computational statistics handbook with MATLAB, , CRC Press; 
van Woerden, E.E., Geijn, H.P., Caron, F.J., Swartjes, J.M., Mantel, R., Arts, N.F., Automated assignment of behavioural states in the human near term fetus (1989) Early Hum Dev, 19, pp. 137-146; 
Ten Hof, J., Nijhuis, I.J., Mulder, E.J., Nijhuis, J.G., Narayan, H., Taylor, D.J., Longitudinal study of fetal body movements: nomograms, intrafetal consistency, and relationship with episodes of heart rate patterns A and B (2002) Pediatr Res, 52 (4), pp. 568-575; 
Bernardes, J., Costa-Pereira, A., de Campos, D.A., van Geijn, H.P., Pereira-Leite, L., Evaluation of interobserver agreement of cardiotocograms (1997) Int J Gynaecol Obstet, 57 (1), pp. 33-37; 
Bernardes, J., Costa-Pereira, A., van Geijn, H.P., Pereira-Leite, L., A more objective fetal heart rate baseline estimation (1996) Br J Obstet Gynaecol, 103, pp. 714-715; 
Mantel, R., van Geijn, H.P., Ververs, I.A., Copray, F.J., Automated analysis of near-term antepartum fetal heart rate in relation to fetal behavioral states: the Sonicaid System 8000 (1992) Am J Obstet Gynaecol, 167 (6), pp. 1912-1914; 
Court, D.J., Parer, J.T., Experimental studies of fetal asphyxia and fetal heart rate interpretation (1984) Research in perinatal medicine, pp. 113-169. , Nathanielsz P.W., and Parer J.T. (Eds), Perinatology Press, New York; 
Oppenheimer, L.W., Lewinsky, R.M., Power spectral analysis of fetal heart rate (1994) Bailliere{\textquoteright}s Clin Obstet Gynaecol, 8 (3), pp. 643-661; 
van Woerden, E.E., Geijn, H.P., Caron, F.J., Mantel, R., Spectral analysis of fetal heart rhythm in relation to fetal regular mouthing (1990) Int J Biomed Comput, 25 (4), pp. 253-260; 
Boog, G., Analyse informatis{\'e}e du rythme cardiaque foetal au cours de la grossesse et de l{\textquoteright}accouchement (2004) Encycl M{\'e}d-Chir, 148 (5-49 -D-23), pp. 1-10; 
Suzuki, T., Okamura, K., Kimura, Y., Watanabe, T., Murotsuki, N.Y.J., Uehara, S., Power spectral analysis of R-R interval variability before and during the sinusoidal heart rate pattern in fetal lambs (2000) Am J Obstet Gynaecol, 182, pp. 1227-1232; 
Dawes, G.S., Moulden, M., Sheil, O., Redman, C.W.G., Approximate entropy, a statistic of regularity, applied to fetal heart rate data before and during labour (1992) Obstet Gynaecol, 80 (5), pp. 763-768; 
Magenes, G., Signorini, M.G., Arduini, D., Cerutti, S., Fetal heart rate variability due to vibroacoustic stimulation: linear and nonlinear contribution (2004) Methods Inf Med, 43 (1), pp. 47-51; 
Felgueiras, C., de S{\'a}, J.P.M., Bernardes, J., Gama, S., Fractal characterisation of fetal heart rate sequences (1998) Biomed Eng, 36 (2), pp. 197-201; 
Vieira, P., Marques-de-S{\'a}, J.P., Bernardes, J., Fractal analysis of foetal heart rate (2004) Proceedings of biosignal 2004, pp. 53-55. , Jan J., Kozumpl{\'\i}k J., and Provazn{\'\i}k I. (Eds), Vutium Press, Brno University of Technology; 
di Renzo, G.C., Montani, M., Fioriti, V., Clerici, G., Branconi, F., Pardini, A., Fractal analysis: a new method for evaluating fetal heart rate variability (1996) J Perinat Med, 24 (3), pp. 261-269
},
	month = {2007///},
	pages = {585 - 591},
	abstract = {Background: Fetal behavioral states are important indicators of fetal physiology and pathology associated to typical fetal heart rate (FHR) patterns. Aim: To provide linear and nonlinear analysis of FHR patterns associated with fetal behavioral states regarding a better understanding of these states and patterns. Study design and subjects: Fifty FHR tracings from normal term pregnancies with a median duration of 40.3~min were acquired with the SisPorto{\textregistered} 2.01 system for computerized analysis of cardiotocograms. Each tracing was divided into consecutive 10-minute segments and each segment was classified by two experts as pattern A, B, C or D. Outcome measures: Linear and nonlinear indices were computed in each segment, namely mean FHR, long-term irregularity index (LTI), very low (VLF), low (LF) and high (HF) frequency spectral indices, approximate entropy (ApEn) and sample entropy (SampEn). Kappa statistic (κ) and proportions of agreement (Pa) were used for assessment of inter-observer agreement. Bootstrap percentile confidence intervals and nonparametric statistical tests were calculated for statistical inference. Results: Overall agreement between experts in pattern classification was good to excellent with values for κ and Pa of 0.74 (95\% CI: 0.64-0.94) and 0.94 (95\% CI: 0.92-0.96), respectively. Most linear domain indices increased significantly with rising fetal activity whereas the opposite occurred with nonlinear indices, except for SampEn(2, 0.1). LF/(MF + HF) ratio also significantly increased with fetal activity, denoting an increased sympatho-vagal balance. Conclusions: Results support the hypothesis that entropy and linear variability indices measure different FHR features. FHR patterns associated with active sleep (B) and active wakefulness (D) evidenced more signs of autonomous nervous system activity, with sympatho-vagal imbalance, and less signs related to complexity or irregularity control systems than patterns associated with calm sleep (A) and calm wakefulness (C). {\textcopyright} 2006 Elsevier Ireland Ltd. All rights reserved.},
	keywords = {adult, article, behavior change, Cardiotocography, Computerized analysis, controlled study, entropy, Female, Fetal behavioral states, Fetal heart rate, Fetal monitoring, fetus, fetus heart rate, fetus monitoring, Heart Rate, Fetal, human, Humans, Image Interpretation, Computer-Assisted, Linear Models, Nonlinear Dynamics, Pregnancy, SisPorto, Spectral analysis, vagus nerve stimulation},
	isbn = {03783782 (ISSN)},
	url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-34249751815\&partnerID=40\&md5=3a787d5accf317ad2b020e59ddb6a465},
	author = {Gon{\c c}alves, H. and Bernardes, J. and Paula Rocha, A. and Ayres-de-Campos, D.}
}
@conference {2388,
	title = {Characterization of fetal heart rate irregularity using approximate entropy and wavelet filtering},
	booktitle = {Computers in CardiologyComput Cardiol},
	series = {2006 Computers in Cardiology, CIC},
	volume = {33},
	year = {2006},
	note = {Conference code: 73228Cited By (since 1996): 3Export Date: 21 November 2012Source: ScopusArt. No.: 4512006CODEN: COCADLanguage of Original Document: EnglishCorrespondence Address: Marques De S{\'a}, J. P.; Faculdade de Engenharia, DEEC, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal; email: jmsa@fe.up.ptReferences: Pincus, S., Approximate entropy as a measure of system complexity (1991) Proc. Natl. Acad. Sci. U.S.A, 88, pp. 2297-2301;Pincus, S., Randomness and degrees of irregularity (1996) Proc. Natl. Acad. Sci. U.S.A, 93, pp. 2083-2088; 
Pincus, S.M., Viscarello, R.R., Approximate entropy: A regularity measure for fetal heart rate (1992) Obstet. Gynecol, 2, pp. 249-255; 
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Ayres-de-Campos, D., Bernardes, J., Garrido, A., Marques-de-S{\'a}, J., Pereira-Leite, L., SisPorto 2.0 - A Program for Automated Analysis of Cardiotocograms (2000) J Matern Fetal Med, 9, pp. 311-318; 
S{\'a} Couto, P.M., van Meurs, W.L., Bernardes, J.F., Marques de, S.J., Goodwin, J.A., Combined Model-Driven and Rule-Based Approach for Educational Simulation of Fetal Heart Rate (2002) Proc. 16th Biennial Int. Conf. Europ. Assoc. for Speech, Signal and Image Processing, pp. 400-402. , EURASIP, Brno, Czech Rep, pp; 
Marques de S{\'a}, J.P., Characterization of fetal heart rate using approximate entropy (2005) Proc. IEEE Comp. in Cardiology 2005, 32, pp. 671-673
},
	month = {2006///},
	pages = {933 - 936},
	address = {Valencia},
	abstract = {Approximate Entropy (ApEn) has been used by several researchers as a means to characterize the irregularity of fetal heart rate (FHR), a major contributor to fetal risk assessment. The present work starts by analyzing the influence of accelerative and decelerative (AD) components of the FHR signal in the computation of ApEn. Having shown that the AD components may completely distort the ApEn evaluation we proceed to present two methods of eliminating the influence of the AD components: wavelet filtering; AD detection using specific algorithms based on well-established physiological criteria. We obtained good results with the first method when applied to simulated signals; however it proved unreliable in the practical application of discriminating normal from pathological fetal FHR. With the second method we were able to achieve this discrimination with high statistical significance.},
	keywords = {Approximate entropy, Cardiology, Fetal heart rate, Neonatal monitoring, Occupational risks, Physiological models, risk assessment, Risk management, Safety engineering, Simulated signals, Statistical significance, Wavelet filtering},
	isbn = {02766574 (ISSN); 1424425328 (ISBN); 9781424425327 (ISBN)},
	url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-50149100681\&partnerID=40\&md5=51e2dd8109d66e30498d7c2f8689c820},
	author = {Magalh{\~a}es, F. and Marques De S{\'a}, J.P. and Bernardes, J. and Ayres-de-Campos, D.}
}
@article {2419,
	title = {Internal versus external intrapartum foetal heart rate monitoring: The effect on linear and nonlinear parameters},
	journal = {Physiological MeasurementPhysiol. Meas.},
	volume = {27},
	year = {2006},
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Ayres-De-Campos, D., Santos, C., Bernardes, J., Prediction of neonatal state by computer analysis of fetal heart rate tracings: The antepartum arm of the SisPorto {\textregistered}multicentre validation study (2005) Eur. J. Obstet. Gynecol. Reprod. Biol., 118 (1), pp. 52-60; 
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Dawes, G.S., Moulden, M., Sheil, O., Redman, C.W.G., Approximate entropy, a statistic of regularity, applied to fetal heart rate data before and during labour (1992) Obstet. Gynecol., 80, pp. 763-768; 
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Pincus, S., Approximate entropy (ApEn) as a complexity measure (1995) Chaos, 5 (1), pp. 110-117; 
Pincus, S., Viscarello, R., Approximate entropy: A regularity measure for fetal heart rate analysis (1992) Obstet. Gynecol., 79, pp. 249-255; 
Richman, J.S., Moorman, J.R., Physiological time-series analysis using approximate entropy and sample entropy (2000) Am. J. Physiol. Heart Circ. Physiol., 278, pp. 2039-H2049; 
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Suzuki, T., Okamura, K., Kimura, Y., Watanabe, T., Yaegashi, N., Murotsuki, J., Uehara, S., Yajima, A., Power spectral analysis of R-R interval variability before and during the sinusoidal heart rate pattern in fetal lambs (2000) Am. J. Obstet. Gynecol., 182 (5), pp. 1227-1232; 
Heart rate variability. Standards of measurement, physiological interpretation, and clinical use (1996) Eur. Heart J., 17, pp. 354-381; 
Wilcox, M.A., Wang, W., Sahota, D.S., Dawkins, R.R., Chung, T.K., Chang, A.M., The effect of different sampling intervals on the measurement of intrapartum fetal heart rate variability (1997) Obstet. Gynecol., 89 (4), pp. 577-580; 
Yum, M.K., Kim, K., Kim, J.H., Park, E.Y., A consistent abnormality in the average local smoothness of fetal heart rate in growth-restricted fetuses affected by severe pre-eclampsia (2004) Hypertens. Res., 27 (12), pp. 911-918
},
	month = {2006///},
	pages = {307 - 319},
	abstract = {The effect of foetal heart rate (FHR) acquisition mode on linear and nonlinear parameters is still largely unknown. In 33 normal labouring women, FHR signals were acquired simultaneously by an external ultrasound sensor applied to the maternal abdomen and an internal scalp electrode, in the minutes preceding delivery. For each case, the initial and final 5, 10 and 20 min segments were analysed, considering FHR signals at a frequency of 4 Hz (the frequency at which they are transmitted by the majority of commercialized foetal monitors). Several time and frequency domain linear and nonlinear FHR indices were computed in these segments, namely mean FHR, very low frequency (VLF), low frequency (LF), high frequency (HF), approximate entropy (ApEn) and sample entropy (SampEn). Parametric confidence intervals, statistical tests and correlation coefficients were calculated in order to evaluate the effect of internal versus external FHR monitoring modes on the considered indices. The whole evaluation was repeated using FHR signals at a frequency of 2 Hz. Most time domain linear indices were similar with external and internal monitoring in the initial and final segments of the tracings. However, linear frequency domain indices were poorly correlated in the final segments and had significantly different mean values in the initial segments. Nonlinear indices were significantly different in both initial and final segments. The correlation between 4 and 2 Hz sampled parameters was high for both linear and nonlinear indices (most correlation coefficient values ranging between 0.95 and 1) but nonlinear index values were significantly higher at 2 Hz. In conclusion, the mode used to acquire FHR signals and the sampling rate employed can significantly affect most FHR indices. {\textcopyright} 2006 IOP Publishing Ltd.},
	keywords = {abdomen, Algorithms, article, Cardiotocography, commercial phenomena, Confidence interval, controlled study, correlation coefficient, delivery, Diagnosis, Computer-Assisted, Electrocardiography, electrode, entropy, External and internal monitoring, Female, fetus electrocardiography, fetus monitoring, Foetal heart rate (FHR), Frequency domain analysis, Heart, Heart rate, human, intermethod comparison, intrapartum care, Linear and nonlinear analysis, Linear Models, mathematical computing, Nonlinear Dynamics, normal human, priority journal, Reproducibility of Results, sensitivity and specificity, sensor, Signal Processing, Computer-Assisted, Statistical significance, ultrasound, Variability},
	isbn = {09673334 (ISSN)},
	url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-32144438860\&partnerID=40\&md5=dd6dbb9f364b7f974c7048c4cf08d53f},
	author = {Gon{\c c}alves, H. and Rocha, A.P. and Ayres-de-Campos, D. and Bernardes, J.}
}
@article {2400,
	title = {Linear and nonlinear fetal heart rate analysis of normal and acidemic fetuses in the minutes preceding delivery},
	journal = {Medical and Biological Engineering and ComputingMed. Biol. Eng. Comput.},
	volume = {44},
	year = {2006},
	note = {Cited By (since 1996): 20Export Date: 21 November 2012Source: ScopusCODEN: MBECDdoi: 10.1007/s11517-006-0105-6PubMed ID: 16988896Language of Original Document: EnglishCorrespondence Address: Gon{\c c}alves, H.; Departamento de Matem{\'a}tica Aplicada, Faculdade de Ci{\^e}ncias, Universidade do Porto, Rua do Campo Alegre - 687, 4169-007 Porto, Portugal; email: hernani.goncalves@fc.up.ptChemicals/CAS: AcidsReferences: ACOG technical bulletin. Fetal heart rate patterns: Monitoring, interpretation, and management (1995) Int J Gynecol Obstet, 51, pp. 65-74. , ACOG;Ayres-de-Campos, D., Bernardes, J., Costa-Pereira, A., Pereira-Leite, L., Inconsistencies in expert{\textquoteright}s classification of cardiotocograms and subsequent clinical decision (1999) Br J Obstet Gynecol, 106, pp. 1307-1310; 
Ayres-de-Campos, D., Bernardes, J., Garrido, A., de S{\'a}, J.M., Pereira-Leite, L., Sisporto 2.0: A program for automated analysis of cardiotocograms (2000) J Mat Fet Med, 9, pp. 311-318; 
Bernardes, J., de Campos, D.A., Costa-Pereira, A., Pereira-Leite, L., Garrido, A., Objective computerized fetal heart rate analysis (1998) Int J Gynecol Obstet, 62, pp. 141-147; 
Bernardes, J., Costa-Pereira, A., de Campos, D.A., van Geijn, H.P., Pereira-Leite, L., Evaluation of interobserver agreement of cardiotocograms (1997) Int J Gynecol Obstet, 57 (1), pp. 33-37; 
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Chaffin, D.G., Barnard, J.M., Phernetton, T., Reed, K.L., Decreased approximate entropy of heart rate variability in the hypoxic ovine fetus (1998) J Matern Fetal Invest, 8, pp. 23-26; 
Chung, D.Y., Sim, Y.B., Park, K.T., Yi, S.H., Shin, J.C., Kim, S.P., Spectral analysis of fetal heart rate variability as a predictor of intrapartum fetal distress (2001) Int J Gynecol Obstet, 73, pp. 109-116; 
Colenbrander, G.J., van Geijn, H.P., Goovaerts, H.G., Acquisition of fetal heart rate signals (1994) A Critical Appraisal of Fetal Surveillance, pp. 203-210. , In: Geijn HPV, Copray FJA (eds) Elsevier Science, Amsterdam; 
Dawes, G.S., Moulden, M., Sheil, O., Redman, C.W.G., Approximate entropy, a statistic of regularity, applied to fetal heart rate data before and during labour (1992) Obstet Gynecol, 80 (5), pp. 763-768; 
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Echeverrfa, J.C., Hayes-Gill, B.R., Crowe, J.A., Woolfson, M.S., Croaker, G.D.H., Detrended fluctuation analysis: A suitable method for studying fetal heart rate variability? (1990) Int J Biomed Comput, 25, pp. 287-294; 
Felgueiras, C., de S{\'a}, J.P.M., Bernardes, J., Gama, S., Fractal characterisation of fetal heart rate sequences (1998) Biomed Eng, 36 (2), pp. 197-201; 
Fusheng, Y., Bo, H., Qingyu, T., Approximate entropy and its application in biosignal analysis (1998) Nonlinear Biomedical Signal Processing. Dynamical Analysis and Modelling, 2, pp. 72-91. , In: Akay M (ed) IEEE Press, New York; 
Gon{\c c}alves, H., Rocha, A.P., de Campos, D.A., Bernardes, J., Internal versus external intrapartum foetal heart rate monitoring: The effect on linear and nonlinear parameters (2006) Physiol Meas, 27, pp. 307-319; 
Gough, N.A., Fractal analysis of foetal heart rate variability (1993) Physiol Meas, 14 (3), pp. 309-315; 
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Hewlett-Packard, (1993) Hewlett-Packard Series 50 Service Manual, , M1351A and 1353A. Germany; 
King, T., Parer, J., The physiology of fetal heart rate patterns and perinatal asphyxia (2000) J Perinat Neonat Nurs, 14 (3), pp. 19-39; 
Li, X., Tang, D., Zhou, S., Zhou, G., Wang, C., Zhuang, Y., Wu, G., Shen, L., Redistribution of power spectrum of heart rate variability during acute umbilical artery embolism and hypoxemia in late-gestation fetal sheep (2004) Eur J Obstet Gynecol Reprod Biol, 114, pp. 137-143; 
Magenes, G., Signorini, M.G., Arduini, D., Classification of cardiotocographic records by neural networks (2000) Proceedings of the IEEE-INNS-ENNS International Joint Conference on Neural Networks,, 3, pp. 637-641. , In: IJCNN 2000; 
Martin, J.C.B., Electronic fetal monitoring: A brief summary of its development, problems and prospects (1998) Eur J Obstet Gynecol Reprod Biol, 78, pp. 133-140; 
Martinez, W.L., Martinez, A.R., (2002) Computational Statistics Handbook With MATLAB, , CRC Press, Boca Raton; 
Oppenheimer, L.W., Lewinsky, R.M., Power spectral analysis of fetal heart rate (1994) Baillieres Clin Obstet Gynaecol, 8 (3), pp. 643-661; 
Pincus, S., Approximate entropy as a measure of system complexity (1991) Proc Natl Acad Sci USA, 88, pp. 2297-2301; 
Pincus, S., Approximate entropy (apen) as a complexity measure (1995) Chaos, 5 (1), pp. 110-117; 
Pincus, S., Viscarello, R., Approximate entropy: A regularity measure for fetal heart rate analysis (1992) Obstet Gynecol, 79 (2), pp. 249-255; 
di Renzo, G.C., Montani, M., Fioriti, V., Clerici, G., Branconi, F., Pardini, A., Indraccolo, R., Cosmi, E.V., Fractal analysis: A new method for evaluating fetal heart rate variability (1996) J Perinat Med, 24 (3), pp. 261-269; 
Richman, J.S., Moorman, J.R., Physiological time-series analysis using approximate entropy and sample entropy (2000) Am J Physiol Heart Circ Physiol, 278, pp. H2039-H2049; 
Ripley, B.D., (1996) Pattern Recognition and Neural Networks, , Cambridge University Press, London; 
Rooth, G., Huch, A., Huch, R., FIGO news. Guidelines for the use of fetal monitoring (1987) Int J Gynecol Obstet, 25, p. 159; 
(2001) Evidence-Based Clinical Guideline Number 8. The Use of Electronic Fetal Monitoring, , Royal College of Obstetricians and Gynaecologists Royal College of Obstetricians and Gynaecologists, London; 
Salamalekis, E., Thomopoulos, P., Giannaris, D., Salloum, I., Vasios, G., Prentza, A., Koutsouris, D., Computerised intrapartum diagnosis of fetal hypoxia based on fetal heart rate monitoring and fetal pulse oximetry recordings utilising wavelet analysis and neural networks (2002) BJOG, 109 (10), pp. 1137-1142; 
Signorini, M.G., Cerutti, S., Nonlinear properties of cardiovascular time series (1999) Methodology and Clinical Applications of Blood Pressure and Heart Rate Analysis, pp. 73-89. , In: Di Rienzo M, Mancia G, Parati G, Pedotti A, Zanchetti A (eds) IOS Press, Amsterdam; 
Signorini, M.G., Magenes, G., Cerrutti, S., Arduini, D., Linear and nonlinear parameters for the analysis of fetal heart rate signal from cardiotacographic recordings (2003) IEEE Trans Biomed Eng, 50 (3), pp. 365-373; 
Siira, S.M., Ojala, T.H., Vahlberg, T.J., Jalonen, J.O., Valimaki, I.A., Rosen, K.G., Ekholm, E.M., Marked fetal acidosis and specific changes in power spectrum analysis of fetal heart rate variability recorded during the last hour of labour (2005) Br J Obstet Gynaecol, 112, pp. 418-423; 
Suzuki, T., Okamura, K., Kimura, Y., Watanabe, T., Murotsuki, N.Y.J., Uehara, S., Yajima, A., Power spectral analysis of R-R interval variability before and during the sinusoidal heart rate pattern in fetal lambs (2000) Am J Obstet Gynecol, 182, pp. 1227-1232; 
Heart rate variability. Standards of measurement, physiological interpretation, and clinical use. Task force of the european society of cardiology and the north american society of pacing and electrophysiology (1996) Eur Heart J, 17, pp. 354-381. , Task-Force; 
Teich, M.C., Lowen, S.B., Jost, B.M., Vibe-Rheymer, K., Heneghan, C., Heart rate variability: Measures and models (1998) Nonlinear Biomedical Signal Processing. Dynamic Analysis and Modeling, 2, pp. 159-213. , In: Akay M (ed) IEEE Press, New York; 
Yum, M.K., Kim, K., Kim, J.H., Park, E.Y., A consistent abnormality in the average local smoothness of fetal heart rate in growth-restricted fetuses affected by severe pre-eclampsia (2004) Hypertens Res, 27 (12), pp. 911-918
},
	month = {2006///},
	pages = {847 - 855},
	abstract = {Linear and nonlinear fetal heart rate (FHR) indices, namely mean FHR, interval index (II), very low, low and high frequencies, approximate (ApEn) and sample entropy (SampEn), were computed, immediately before delivery, in the initial and final FHR tracing segments, from 48 normal, 10 mildly acidemic and 10 moderate-to-severely acidemic fetuses. Progression of labor was associated with a significant increase in linear frequency domain indices whereas nonlinear indices were significantly decreased. Moderate-to-severe fetal acidemia was associated with a significant decrease in nonlinear indices. The best discrimination between moderate-to-severe acidemic fetuses and the remaining cases was obtained combining II and ApEn(2,0.15), with a specificity of 71\% and a sensitivity of 80\%. These findings support the hypothesis of increased autonomic nervous system activity in the final minutes of labor and of decreased central nervous system activity, both in the final minutes of labor and in moderate-to-severe acidemic fetuses. {\textcopyright} International Federation for Medical and Biological Engineering 2006.},
	keywords = {acidemia, Acidosis, Acids, article, autonomic nervous system, Biological materials, Cardiology, Central nervous system, clinical article, controlled study, delivery, Delivery, Obstetric, Discriminant Analysis, disease severity, entropy, Fetal Diseases, Fetal heart rate, Fetal heart rate (FHR), Fetal monitoring, fetus, fetus heart rate, Frequency domain analysis, Heart Rate, Fetal, human, Humans, hypothesis, labor, Linear and nonlinear indices, linear system, Neurology, newborn, nonlinear system, Prenatal Care, Second stage of labor, sensitivity and specificity, Severity of Illness Index},
	isbn = {01400118 (ISSN)},
	url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-33749566759\&partnerID=40\&md5=88f9959edd8363f90b13742d0ce5221b},
	author = {Gon{\c c}alves, H. and Rocha, A.P. and Ayres-de-Campos, D. and Bernardes, J.}
}
@article {2564,
	title = {Fetal heart rate baselines in twins: Interobserver agreement in antepartum estimation},
	journal = {Journal of Reproductive Medicine for the Obstetrician and GynecologistJ. Reprod. Med. Obstet. Gynecol.},
	volume = {45},
	year = {2000},
	note = {Cited By (since 1996): 2Export Date: 21 November 2012Source: ScopusCODEN: JRPMAPubMed ID: 10710739Language of Original Document: EnglishCorrespondence Address: Bernardes, J.; Depto. de Ginecologia e Obstetricia, Faculdade de Medicina do Porto, Al. Prof. Hernani Monteiro, 4200 Porto, Portugal; email: Jbernardes@mail.telepac.ptReferences: Sherman, S.J., Kovacs, B.W., Medearis, A.L., Nonstress test assessment of twins (1992) J Reprod Med, 37, pp. 804-808;Grant, J.M., The fetal heart rate is normal, isn{\textquoteright}t it?: Observer agreement of categorical assessments (1991) Lancet, 337, pp. 215-218; 
Cibils, L.A., On intrapartum fetal monitoring (1996) Am J Obstet Gynecol, 174, pp. 1382-1389; 
Bernardes, J., Costa-Pereira, A., Ayres-De-Campos, D., Evaluation of interobserver agreement of cardiotocograms (1997) Int J Gynecol Obstet, 57, pp. 33-37; 
Bernardes, J., Costa-Pereira, A., Van Geijn, H.P., A more objective fetal heart rate baseline estimation (1996) Br J Obstet Gynaecol, 103, pp. 714-715; 
Bernardes, J., Ayres-De-Campos, D., Costa-Pereira, A., Objective computerized fetal heart rate analysis (1998) Int J Gynecol Obstet, 62, pp. 141-147; 
Bland, J.M., Altman, D.G., Statistical methods for assessing two methods of clinical measurement (1986) Lancet, 11, pp. 307-310; 
Armitage, P., Berry, G., (1994) Statistical Methods in Medical Research, pp. 273-276. , Oxford, Blackwell Science Ltd; 
Khan, K.S., Chien, P.F.W., Honest, M.R., Evaluating measurement variability of clinical investigations: The case of ultrasonic estimation of urinary bladder volume (1997) Br J Obstet Gynaecol, 104, pp. 1036-1043; 
Devoe, L.D., Carlton, E., Prescott, P., Neural network prediction of nonstress test results: How often should we perform nonstress tests? (1995) Am J Obstet Gynecol, 173, pp. 1128-1131; 
Bernardes, J., Ayres De Campos, D., Costa-Pereira, A., Baseline estimation in typical fetal heart rate patterns using different computerized methods (1997) Acta Obstet Gynecol Scand (Suppl), 76, p. 56; 
},
	month = {2000///},
	pages = {105 - 108},
	abstract = {OBJECTIVE: To assess interobserver agreement in antepartum estimation of fetal heart rate (FHR) baselines in twins. STUDY DESIGN: Two residents and one specialist in obstetrics and gynecology, all with special interest in FHR monitoring, independently estimated baselines in 162 consecutive antepartum FHR tracings recorded in 24 twins. Tracings were obtained with a dual-channel fetal monitor for the simultaneous recording of both twins{\textquoteright} heart rates. Baselines were estimated, as single values corresponding to the mean of the lowest stable FHR segment, in the absence of fetal movements and uterine contractions, within physiologic limits (110-150 beats per minute [bpm]). If these criteria were not met, the possibility of persistent bradycardia or tachycardia was considered, and if this was confirmed in a tracing with at least 40 minutes, a baseline < 110 or > 150 bpm was chosen. Interobserver agreement was assessed by the proportions of agreement (PA), kappa statistic (K) and intraclass correlation coefficient (ICCC), with 95\% confidence intervals (CIs). RESULTS: Interobserver agreement was excellent, with a PA of 0.90 (95\% CI: 0.89-0.91), K of 0.88 (95\% CI: 0.84-0.92) and ICCC of 0.91 (95\% CI: 0.88-0.94). CONCLUSION: Interobserver agreement in antepartum estimation of fetal heart rate baselines in twins was excellent with the baseline concept used in this study.},
	keywords = {adult, article, clinical article, Electrocardiography, Female, Fetal heart rate, Fetal monitoring, fetus, fetus heart rate, fetus monitoring, Heart rate variability, Heart Rate, Fetal, human, Humans, Internship and Residency, observer variation, Obstetrics, Pregnancy, Prenatal Care, priority journal, Professional Competence, Twins},
	isbn = {00247758 (ISSN)},
	url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0034002107\&partnerID=40\&md5=82b6075749b0531b00b1195b539b4bb3},
	author = {Bernardes, J. and Costa-Pereira, A. and Calejo, L. and Ayres-de-Campos, D. and Patr{\'\i}cio, B. and Pereira-Leite, L.}
}
@conference {2554,
	title = {Remote foetal heart rate acquisition and analysis},
	booktitle = {Computers in CardiologyComput Cardiol},
	series = {Computers in Cardiology 2000},
	year = {2000},
	note = {Conference code: 45063Cited By (since 1996): 1Export Date: 21 November 2012Source: ScopusCODEN: COCADLanguage of Original Document: EnglishCorrespondence Address: Marques, P.; INEB - Instituto de Engenharia, Biomedica, Porto, Portugal},
	month = {2000///},
	pages = {573 - 574},
	publisher = {IEEE},
	organization = {IEEE},
	address = {Cambridge, MA, USA},
	abstract = {The remote foetal monitoring and analysis is part of INTERCARE project - an integrated healthcare system applied to Electrocardiography and Cardiotocography. Its aim is to provide low cost and wide spread technological infrastructure that supports an integrated healthcare system to users and healthcare providers. This paper illustrates the work done in the cardiotocography area. We have developed a system for remote acquisition and analysis of FHR. The system uses a portable {\textquoteright}foetal detector{\textquoteright} which can be used by the pregnant woman to acquire the heart beats. This detector sends a modulated audio signal via the telephone line or a computer connected to Internet. At the processing end the signal received by the telephone can be switched to the computer sound acquisition board. The signal is then processed by an application that reads from the soundcard. Due to the noise added by devices and telephone lines, the signal is filtered using optimal FIR filters and is decimated until its band of interest covers the peaks of the heart sounds. Next the signal is processed by a specially developed adaptive correlation algorithm in order to obtain the heart beat instants. The whole process operates in real time. The adaptive correlation algorithm performs a continuous adjustment of the heart beat template and threshold detection levels.},
	keywords = {Adaptive algorithms, Adaptive correlation algorithm, Cardiology, Cardiotocography, Client server computer systems, Data acquisition, Data warehouse, Database systems, Electrocardiography, FIR filters, Foetal heart rate, Internet, Patient monitoring, Remote foetal monitoring, Signal filtering and prediction, Sonoscope, Spurious signal noise, Telephone},
	isbn = {02766574 (ISSN)},
	url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0034474836\&partnerID=40\&md5=c85d04aba26fdb2f92645c8b762f8c40},
	author = {Marques, P. and Marques de Sa, J.P. and Bernardes, J. and Sousa, P.}
}
@article {2590,
	title = {Classification of foetal heart rate sequences based on fractal features},
	journal = {Medical and Biological Engineering and ComputingMed. Biol. Eng. Comput.},
	volume = {36},
	year = {1998},
	note = {Cited By (since 1996): 13Export Date: 21 November 2012Source: ScopusCODEN: MBECDdoi: 10.1007/BF02510743PubMed ID: 9684460Language of Original Document: EnglishCorrespondence Address: Felguiras, C.S.; Instituto de Engenharia Biomedica, Praca Coronel Pacheco 1, 4050 Porto, PortugalReferences: Bernardes, J., (1993) Leitura Automatizada Do Cardiotocograma. Desenvolvimento e Availia{\c c}{\`a}o, , Ph.D. thesis, Faculdade de Medicina da Universidade do Porto, Portugal;Bernardes, J., Moura, C., Marques De S{\'a}, J.P., Pereira Leite, L., Van Geijn, H.P., The Porto system (1994) A Critical Appraisal of Foetal Surveillance, pp. 315-324. , VAN GEIJN H. P. and COPRAY, F. J. A. (Eds.) Elsevier Science, Amsterdam; 
Chaffin, D.G., Goldberg, C.C., Reed, K.L., The dimension of chaos in foetal heart rate (1991) Am. J. Obstet. Gynecol., 165 (5), pp. 1425-1429; 
Dawes, G.S., Visser, G.H.A., Goodman, J.D.S., Redman, C.W.G., Numerical analysis of human foetal heart rate: The quality of ultrasound records (1981) Am. J. Obstet, Gynecol., 141 (1), pp. 43-52; 
Felgueiras, C.S., Marques De S{\'a}, J.P., Bernardes, J., Gama, S., On the reconstruction of foetal heart rate sequences (1996) Actas de Bieng {\textquoteright}96, Sociedade Portuguesa de Engenharia Biom{\'e}dica, Aveiro, Mar{\c c}o, 1996, pp. VII61-VII65; 
Goldberger, A.L., Fractal mechanisms in the electrophysiology of the heart (1992) IEEE Eng. Med. Biol., pp. 47-52. , June; 
Grant, A., Principles for clinical evaluation of methods of perinatal monitoring (1984) J. Perinat. Med., 12, pp. 227-231; 
Grassberger, P., Procaccia, I., Measuring the strangeness of strange attractors (1983) Physica D, 9, pp. 189-208; 
Higushi, T., Approach to an irregular time series on the basis of the fractal theory (1988) Physica D, 31, pp. 277-283; 
Hoyer, D., Liebovitch, L.S., Schmidt, K., Luethke, B., Zwiener, U., Practical problems of determining the dimensions of heart rate data (1997) Med. Biol. Eng. Comput., 35, pp. 27-32; 
Maldelbrot, B.B., Van Ness, J.W., Fractional Brownian motions, fractional noises and applications (1968) SIAM Rev., 10 (4), pp. 422-437; 
Marques De Sa, J.P., Moura, A.C., Bernardes, J., Pereira Leite, L., An{\'a}lise autom{\'a}tica de sinais cardiotocogr{\'a}ficos (1992) Acta M{\'e}dica Portuguesa 11 S{\'e}rie, 5 (1), pp. 28-30; 
Parker, T.S., Chua, L.O., (1989) Practical Numerical Algorithms for Chaotic Systems, , Springer-Verlag; 
Schulman, H., Schulman, S., Lai, P., Schneider, E., Farmakides, G., Dawes, G., Antepartum computerized foetal heart rate, chaos analysis, blood gases and perinatal outcome (1994) J. Maternal-Fetal Invest., 4, pp. 59-63
},
	month = {1998///},
	pages = {197 - 201},
	publisher = {Peter Peregrinus Ltd},
	abstract = {Visual inspection of foetal heart rate (FHR) sequences is an important means of foetal well-being evaluation. The application of fractal features for classifying physiologically relevant FHR sequence patterns is reported. The use of fractal features is motivated by the difficulties exhibited by traditional classification schemes to discriminate some classes of FHR sequence and by the recognition that this type of signal exhibits features on different scales of observation, just as fractal signals do. To characterise the signals by fractal features, two approaches are taken. The first models the FHR sequences as temporal fractals. The second uses techniques from the chaos-theory field and aims to model the attractor based on FHR sequences. The fractal features determined by both approaches are used to design a Bayesian classification scheme. Classification results for three classes are presented; they are quite satisfactory and illustrate the importance of this type of methodology.Visual inspection of foetal heart rate (FHR) sequences is an important means of foetal well-being evaluation. The application of fractal features for classifying physiologically relevant FHR sequence patterns is reported. The use of fractal features is motivated by the difficulties exhibited by traditional classification schemes to discriminate some classes of FHR sequence and by the recognition that this type of signal exhibits features on different scales of observation, just as fractal signals do. To characterise the signals by fractal features, two approaches are taken. The first models the FHR sequences as temporal fractals. The second uses techniques from the chaos-theory field and aims to model the attractor based on FHR sequences. The fractal features determined by both approaches are used to design a Bayesian classification scheme. Classification results for three classes are presented; they are quite satisfactory and illustrate the importance of this type of methodology.
},
	keywords = {article, Bayes Theorem, Cardiology, Chaos techniques, Chaos theory, Classification, Computer aided analysis, Computer simulation, Electrocardiography, Female, Fetal monitoring, fetus, fetus heart rate, FHR classification, FHR sequence, Foetal heart rate sequences, fractal analysis, Fractal features, Fractals, Heart Rate, Fetal, human, Humans, Pattern recognition, Pregnancy, Signal Processing, Computer-Assisted, technique},
	isbn = {01400118 (ISSN)},
	url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0032033010\&partnerID=40\&md5=563144fcdb064dd777002155aaa62f73},
	author = {Felgueiras, C.S. and De Marques S{\'a}, J.P. and Bernardes, J. and Gama, S.}
}
@article {2583,
	title = {Objective computerized fetal heart rate analysis},
	journal = {International Journal of Gynecology and ObstetricsInt. J. Gynecol. Obstet.},
	volume = {62},
	year = {1998},
	note = {Cited By (since 1996): 23Export Date: 21 November 2012Source: ScopusCODEN: IJGOAdoi: 10.1016/S0020-7292(98)00079-4PubMed ID: 9749885Language of Original Document: EnglishCorrespondence Address: Bernardes, J.; Departmento Ginecologia Obstetricia, Faculdade Medicina-Hospital S. Joao, Porto, Portugal; email: sisporto@mail.telepac.ptReferences: Bernardes, J., Costa-Pereira, A., Ayres-De-Campos, D., Van Geijn, H.P., Pereira-Leite, L., Evaluation of interobserver agreement of cardiotocograms (1997) Int J Gynecol Obstet, 57 (1), pp. 33-37;Bernardes, J., Costa-Pereira, A., Van Geijn, H.P., Pereira-Leite, L., A more objective fetal heart rate baseline estimation (1996) Br J Obstet Gynaecol, 103, pp. 714-715; 
Grant, A., Principles for clinical evaluation of methods of perinatal monitoring (1984) J Perinat Med, 12, pp. 227-231; 
Bernardes, J., Moura, C., Marques-De-S{\'a}, J.P., Pereira-Leite, L., Van Geijn, H.P., The Porto System (1994) A Critical Appraisal of Fetal Surveillance, pp. 315-324. , In: van Geijn HP, Copray FJA, editors. Amsterdam: Elsevier Science; 
Rooth, G., Huch, A., Huch, R., Guidelines for the use of fetal monitoring. FIGO news (1987) Int J Gynaecol Obstet, 25, pp. 159-167; 
Mohide, P., Grant, A., Evaluating diagnosis and screening during pregnancy and childbirth (1989) Effective Care in Pregnancy and Childbirth, pp. 66-80. , In: Chalmers I, Enkin M, Keirse M JNC, editors. Oxford University Press; 
Garcia-Romero, H., Garcia-Barrios, C., Ramos-Gutierrez, F.R., Effects of uncertain results on sensitivity and specificity of diagnostic tests (1996) Lancet, 348, pp. 1745-1746; 
Grant, J.M., The fetal heart rate is normal, isn{\textquoteright}t it?. Observer agreement of categorical assessments (1991) Lancet, 337, pp. 215-218; 
Guzman, E., Vintzileos, A., Martins, M., Benito, C., Houlihan, C., The efficacy of individual computer heart rate indices in detecting acidemia at birth in growth-restricted fetuses (1996) Obstet Gynecol, 87, pp. 969-974; 
Nielsen, P.V., Stigsby, B., Nickelsen, C., Nim, J., Computer assessment of the intrapartum cardiotocogram. II. The value of compared with visual assessment (1988) Acta Obstet Gynecol Scand, 67, pp. 461-464; 
Chung, T.K.H., Mohajer, M.P., Yang, Z.J., Chang, A.M.Z., Sahota, D.S., The prediction of fetal acidosis at birth by computerized analysis of intrapartum cardiotocography (1995) Br J Obstet Gynaecol, 102, pp. 454-460; 
Stigsby, B., Nielson, P.V., Nickelsen, C., Nim, J., Computer assessment of the intrapartum cardiotocogram. I. Methods of data reduction and diagnostic procedure (1988) Acta Obstet Gynecol Scand, 67, pp. 455-460
},
	month = {1998///},
	pages = {141 - 147},
	abstract = {Objective: To assess the validity of a computerized methodology for cardiotocogram analysis based on a recently described reproducible visual estimation of the baseline. Methods: Forty-two antepartum and 43 intrapartum cardiotocograms (CTGs) acquired by a personal computer were selected. Antepartum tracings were performed in the 48 h that preceded an elective cesarean section, and intrapartum tracings were performed until delivery. FHR baselines were estimated by an expert, according to an objective and reproducible methodology. Using these baselines, automated detection of accelerations and decelerations and estimation of variability was performed by the personal computer. A quantitative adaptation of the FIGO guidelines for fetal monitoring was used to classify tracings. Perinatal outcome was classified according to the Apgar score and umbilical arterial pH. Validity was then assessed by the proportions of agreement (PA), kappa statistic (κ), sensitivity and specificity, with 95\% confidence intervals (95\% CI). Cases showing a disagreement between CTG and perinatal classification were reviewed and an adjustment in baseline definition was tested. Results: The initial overall PA and κ between CTG and perinatal classification were, respectively, 0.79 (95\% CI: 0.69-0.87) and 0.62 (95\% CI: 0.41-0.83). The overall PA and κ, after baseline adjustment were, respectively, 0.89 (95\% CI: 0.81-0.95) and 0.78 (95\% CI: 0.58-0.98). Sensitivities and specificities ranged between 79\% (95\% CI: 60-92\%) and 100\% (95\% CI: 95-100\%). Conclusions: Good clinical prediction may be possible with an objective methodology for cardiotocogram analysis based on a recently described reproducible baseline estimation.},
	keywords = {Apgar score, arterial pH, article, Cardiotocography, cesarean section, computer analysis, Computerized analysis, Female, Fetal heart rate, fetus, fetus heart rate, fetus monitoring, Heart Rate, Fetal, human, Humans, Image Processing, Computer-Assisted, practice guideline, Predictive Value of Tests, Pregnancy, priority journal, umbilical artery, validity},
	isbn = {00207292 (ISSN)},
	url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0031873609\&partnerID=40\&md5=2b885fbc95cba06c5f31f417216ebba2},
	author = {Bernardes, J. and Ayres-de-Campos, D. and Costa-Pereira, A. and Pereira-Leite, L. and Garrido, A.}
}
@article {2592,
	title = {Semiautomated ultrasonographic measurement of fetal nuchal translucency using a computer software tool},
	journal = {Ultrasound in Medicine and BiologyUltrasound Med. Biol.},
	volume = {24},
	year = {1998},
	note = {Cited By (since 1996): 9Export Date: 21 November 2012Source: ScopusCODEN: USMBAdoi: 10.1016/S0301-5629(97)00235-4PubMed ID: 9483771Language of Original Document: EnglishCorrespondence Address: Marques De Sa, J.; Instituto de Engenharia Biomedica, Pt. Coronel Pacheco 1, P-4050 Porto, Portugal; email: jmsa@garfield.fe.up.ptTradenames: Microsoft Visual C++, microsoft, United StatesManufacturers: microsoft, United StatesReferences: Jain, A.K., (1982) Fundamentals of Digital Image Processing, , New York: Prentice Hall International Editions;Neilson, J., Grant, A., Ultrasound in pregnancy (1989) A Guide to Effective Care in Pregnancy and Childbirth., pp. 48-56. , Enkin M, Keirse MJN, Chalmers I. eds. New York, London: Oxford University Press; 
Nicolaides, K.H., Azar, G., Byrne, D., Mansur, C., Marks, K., Fetal nuchal translucency: Ultrasound screening for chromosomal detects in first trimester of pregnancy (1992) BMJ, 304, pp. 867-869; 
Pandya, P.P., Brizot, M.L., Kuhn, P., Snijders, R.J.M., Nicolaides, K.H., First trimester fetal nuchal translucency thickness and risk for trisomies (1994) Obstet Gynecol, 84, pp. 420-423; 
Pandya, P.P., Kondylios, A., Hilbert, L., Snijders, R.J.M., Nicolaides, K.H., Chromosomal defects and outcome in 1015 fetuses with increased nuchal translucency (1995) Ultrasound Obstet Gynecol, 5, pp. 15-19; 
Pandya, P.P., Altman, D.G., Brizot, M.L., Pettersen, H., Nicolaides, K.H., Repeatability of measurement of fetal nuchal translucency thickness (1995) Ultrasound Obstet Gynecol, 5, pp. 334-337; 
Roberts, L.J., Bewley, S., Mackinson, A.M., Rodeck, C.H., First trimester fetal nuchal translucency: Problems of screening the general population (1995) Br J Obstet Gynaecol, 102, pp. 381-385; 
Zador, I.E., Salari, V., Sokol, R.J., Computer applications in fetal medicine (1994) The Fetus As A Patient, pp. 117-124. , Kurjak A, Chervenak FA, eds. London/ New York: Parthenon Publ
},
	month = {1998///},
	pages = {51 - 54},
	publisher = {Elsevier Sci Ltd},
	abstract = {Nuchal translucency (NT) thickness measurement has been recently proposed as a part of routine ultrasound scanning during the late first trimester of pregnancy, for the early screening of chromosomal abnormalities. Manual determination of NT is currently performed using electronic callipers placed by the operator in the middle of two echogenic fines displayed on the screen. Therefore, intraobserver and interobserver repeatability can be questioned. This paper presents a software tool that has been developed for achieving this goal in a semiautomatic way, improving the reproducibility of the method.Nuchal translucency (NT) thickness measurement has been recently proposed as a part of routine ultrasound scanning during the late first trimester of pregnancy, for the early screening of chromosomal abnormalities. Manual determination of NT is currently performed using electronic callipers placed by the operator in the middle of two echogenic lines displayed on the screen. Therefore, intraobserver and interobserver repeatability can be questioned. This paper presents a software tool that has been developed for achieving this goal in a semiautomatic way, improving the reproducibility of the method.
},
	keywords = {article, cervical spine, chromosome aberration, Chromosome Aberrations, Chromosome Disorders, Computer aided diagnosis, computer program, Computer software, computer system, Female, Fetal monitoring, Fetal nuchal translucency, fetus echography, first trimester pregnancy, Humans, Image analysis, Image Processing, Computer-Assisted, Image thresholding, Medical imaging, Neck, observer variation, Pregnancy, Pregnancy Trimester, First, priority journal, reproducibility, Reproducibility of Results, Software, Software package NUCA, Thickness measurement, Ultrasonic imaging, Ultrasonography, Prenatal, ultrasound},
	isbn = {03015629 (ISSN)},
	url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0031974123\&partnerID=40\&md5=632da5e0661d27d445b101e03057ad56},
	author = {Bernardino, F. and Cardoso, R. and Montenegro, N. and Bernardes, J. and Marques de S{\'a}, J.}
}
@article {2637,
	title = {Computerized fetal heart rate analysis in labour based on 2-s sampling. Can it proceed with confidence? [1]},
	journal = {European Journal of Obstetrics Gynecology and Reproductive BiologyEUR. J. OBSTET. GYNECOL. REPROD. BIOL.},
	volume = {63},
	year = {1995},
	note = {Cited By (since 1996): 2Export Date: 21 November 2012Source: ScopusCODEN: EOGRAdoi: 10.1016/0301-2115(95)02215-SPubMed ID: 8674558Language of Original Document: EnglishCorrespondence Address: Bernardes, J.; Instituto Engenharia Biomedica, Praca Coronel Pacheco 1, 4000 Porto, Portugal},
	month = {1995///},
	pages = {105 - 107},
	keywords = {computer analysis, Computers, Female, Fetal monitoring, fetus, fetus heart rate, Heart Rate, Fetal, human, labor, Labor, Obstetric, letter, measurement, Pregnancy, priority journal, sampling, Time Factors},
	isbn = {03012115 (ISSN)},
	url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0028856781\&partnerID=40\&md5=d0c302fff078192103c46bde7d37746f},
	author = {Bernardes, J. and Garrido, A. and Chang, A. and Sahota, D.S. and Reed, N.N. and James, D.K. and Mohajer, M.P.}
}
