2006 14th European Signal Processing Conference, 2006
Nowadays a lot of methods for the estimation of Hurst's coefficient (H) in time series are av... more Nowadays a lot of methods for the estimation of Hurst's coefficient (H) in time series are available. Most of them, even if very effective, need some a priori information to be applied (in particular about the stationarity of the series). We analyzed eight up-to-date methods (working both in time and in frequency domain) at work with four kinds of synthetic time series (fBm, fGn, 1/f, FARIMA) in the range 0.1≤H≤0.9. We built graphs for each method evaluating the quality of the estimation, in terms of accuracy (bias) and precision (STD) of the deviation from the expected estimation value. Beginning from that, we formulated a procedure useful for a reliable estimation of H, using these existing methods, without any assumption on the stationarity of the time series. This procedure suggests to estimate, at first, the coefficient “alpha”, spectral slope in a bi-logarithmic scale-estimator chart, next to the zero-frequency axis, of the unknown time series. Once estimated alpha, i.e. a...
In this paper, new parameters based on the Phase Rectified Signal Average (PRSA) of the Fetal Hea... more In this paper, new parameters based on the Phase Rectified Signal Average (PRSA) of the Fetal Heart Rate (FHR) signal are introduced to assess fetal wellbeing. They are defined as the positive and negative slopes of the PRSA curve, namely Acceleration Phase Rectified Slope (APRS) and Deceleration Phase Rectified Slope (DPRS), depending on the sign of the slope. The parameters were computed on FHR time series recorded from 59 healthy and 61 Intra Uterine Growth Restricted (IUGR) fetuses, during CTG non-stress tests. The performance of APRS and DPRS was compared with the performance of other parameters extracted from the PRSA curve already existing in literature, and with other clinical indices that are provided by computerized cardiotocographic systems. The APRS and DPRS performed better than any other parameter considered in this study to distinguish between healthy and IUGR fetuses. We believe that these new indices might provide useful improvements of the quality of fetus early di...
Proceedings of the Second Joint 24th Annual Conference and the Annual Fall Meeting of the Biomedical Engineering Society] [Engineering in Medicine and Biology
Summary Objectives : The intrauterine growth restriction (IUGR) is a pathological state: the fetu... more Summary Objectives : The intrauterine growth restriction (IUGR) is a pathological state: the fetus is at risk of hypoxia and this condition is associated with increased perinatal morbidity and mortality. However, evidence-based guidelines for clinical surveillance are poor and lack reliable indexes. This study introduces new procedures to extract parameters from the fetal heart rate signal in order to identify severe intrauterine growth restricted (IUGR) fetuses Methods : Standard parameters (time domain and frequency domain indexes) are compared to a new parameter, the Lempel Ziv complexity, and to two regularity estimators (approximate entropy and sample entropy). The paper analyzes the robustness of the indexes coming from the parameter extraction procedure. Results and Conclusions : The results show that the LZ complexity is a stable parameter and it is able to significantly discriminate the severe IUGR (preterm delivered) from moderate IUGR (at term delivered) and from healthy ...
Medical & biological engineering & computing, Jan 10, 2018
Infants born at 35-37 weeks' gestational age (GA) are at higher risk for a range of pathologi... more Infants born at 35-37 weeks' gestational age (GA) are at higher risk for a range of pathological conditions and poorer neurodevelopmental outcomes. However, mechanisms responsible are not fully understood. The purpose of this paper is to use traditional and novel techniques to assess newborn autonomic development as a function of GA at birth, focusing on cardiorespiratory regulation. ECG and respiration were acquired during sleep on 329 healthy newborns. Infants were divided into GA groups: 35-36 weeks (late preterm (LPT)), 37-38 weeks (early term (ET)), and 39-40 weeks (full term (FT)). Time domain, frequency domain, and non-linear measures were calculated. Increased heart rate short-term variability and complexity as a function of GA were observed in time domain and non-linear measures. Decreasing inter-breath interval variability was found as a function of GA, with increasing linear cardiorespiratory coupling. A complexity parameter (quadratic sample entropy) was less affecte...
Conference proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual Conference, 2015
The paper presents results of a sleep study on 60 newborn infants and 22 one-month infants, in qu... more The paper presents results of a sleep study on 60 newborn infants and 22 one-month infants, in quiet and active sleep and in prone and supine position. During the study, HRV and respiration were acquired and then analyzed with a multi-parametric approach. Time, Frequency Domain and Non-Linear parameters were calculated, also encompassing indices from the adult and fetal field. The novelty of this study is the introduction of innovative measurements in a thorough investigation to characterize the effect of sleep state and position on the cardio-respiratory control in newborns. Results show that most parameters succeed in classifying different sleep states, while differences between positions were found in the one-month population only. This study comes as a continuation of previous analysis with the addition of respiratory signal. These results are encouraging for the aim of defining a set of parameters that could help characterizing the autonomic control of infants and early detect ...
Conference proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual Conference, 2014
Fetal Heart Rate (FHR) monitoring represents a powerful tool for checking the arousal of patholog... more Fetal Heart Rate (FHR) monitoring represents a powerful tool for checking the arousal of pathological fetal conditions during pregnancy. This paper proposes a multivariate approach for the discrimination of Normal and Intra Uterine Growth Restricted (IUGR) fetuses based on a small set of parameters computed on the FHR signal. We collected FHR recordings in a population of 120 fetuses (60 normals and 60 IUGRs) at approximately the same gestational week through a standard CTG non-stress test. A set of 8 linear and non-linear indices were selected and computed on each recording, on the basis of their "stand-alone" discriminative properties, demonstrated in previous studies. By using the Orange® data mining suite we checked various multivariate discrimination models. The results show that a Logistic Regression performed on a limited set of only 4 parameters can reach 92.5% accuracy in the correct identification of fetuses, with 93% sensitivity and 91.5% specificity.
Conference proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual Conference, 2014
Severe premature babies present a risk profile higher than the normal population. Reasons are rel... more Severe premature babies present a risk profile higher than the normal population. Reasons are related to the incomplete development of physiological systems that support baby's life. Heart Rate Variability (HRV) analysis can help the identification of distress conditions as it is sensitive to Autonomic Nervous System (ANS) behavior. This paper presents results obtained in 35 babies with severe prematurity, in quiet and active sleep and in prone and supine position. HRV was analyzed in time and frequency domain and with nonlinear parameters. The novelty of this approach lies in the combined use of parameters generally adopted in fetal monitoring and "adult" indices. Results show that most parameters succeed in classifying different experimental conditions. This is very promising as our final objective is to identify a set of parameters that could be the basis for a risk classifier to improve the care path of premature population.
... e di Tele-ecografia A. Di Lieto*, M. Campanile*, M. De Falco*, G. Magenes", MG Signorina... more ... e di Tele-ecografia A. Di Lieto*, M. Campanile*, M. De Falco*, G. Magenes", MG Signorina 'università degli Studi di Napoli Federico li ■ Dipartimento ... tnt J Gynecol Obstet 1997;57:33-7. 2. Anceschi MM, Piazze 11, Ruozi-Berretta A et a!. - Validity of short term variation (STV) in ...
Summary Objectives: The objective of this work was to contribute to the development, validation a... more Summary Objectives: The objective of this work was to contribute to the development, validation and application of data mining methods for prediction in decision support systems in medicine. The particular focus was on the prediction of cardiovascular risk factors in hemodialysis patients, specifically the interventricular septum (IVS) thickness of the heart of individual patients as an important quantitative indicator to diagnose left ventricular hypertrophy. The work was based on data from 63 long-term hemodialysis patients of the KfH Dialysis Centre in Jena, Germany. Methods: The approach applied is based on data mining methods and involves four major steps: data based clustering, cluster based rule extraction, rulebase construction and cluster and rule based prediction. The methods employed include crisp and fuzzy algorithms. At each step, logical and medical validation of results was carried out. Different sets of randomly selected patient data were used to train, test and opti...
2006 14th European Signal Processing Conference, 2006
Nowadays a lot of methods for the estimation of Hurst's coefficient (H) in time series are av... more Nowadays a lot of methods for the estimation of Hurst's coefficient (H) in time series are available. Most of them, even if very effective, need some a priori information to be applied (in particular about the stationarity of the series). We analyzed eight up-to-date methods (working both in time and in frequency domain) at work with four kinds of synthetic time series (fBm, fGn, 1/f, FARIMA) in the range 0.1≤H≤0.9. We built graphs for each method evaluating the quality of the estimation, in terms of accuracy (bias) and precision (STD) of the deviation from the expected estimation value. Beginning from that, we formulated a procedure useful for a reliable estimation of H, using these existing methods, without any assumption on the stationarity of the time series. This procedure suggests to estimate, at first, the coefficient “alpha”, spectral slope in a bi-logarithmic scale-estimator chart, next to the zero-frequency axis, of the unknown time series. Once estimated alpha, i.e. a...
In this paper, new parameters based on the Phase Rectified Signal Average (PRSA) of the Fetal Hea... more In this paper, new parameters based on the Phase Rectified Signal Average (PRSA) of the Fetal Heart Rate (FHR) signal are introduced to assess fetal wellbeing. They are defined as the positive and negative slopes of the PRSA curve, namely Acceleration Phase Rectified Slope (APRS) and Deceleration Phase Rectified Slope (DPRS), depending on the sign of the slope. The parameters were computed on FHR time series recorded from 59 healthy and 61 Intra Uterine Growth Restricted (IUGR) fetuses, during CTG non-stress tests. The performance of APRS and DPRS was compared with the performance of other parameters extracted from the PRSA curve already existing in literature, and with other clinical indices that are provided by computerized cardiotocographic systems. The APRS and DPRS performed better than any other parameter considered in this study to distinguish between healthy and IUGR fetuses. We believe that these new indices might provide useful improvements of the quality of fetus early di...
Proceedings of the Second Joint 24th Annual Conference and the Annual Fall Meeting of the Biomedical Engineering Society] [Engineering in Medicine and Biology
Summary Objectives : The intrauterine growth restriction (IUGR) is a pathological state: the fetu... more Summary Objectives : The intrauterine growth restriction (IUGR) is a pathological state: the fetus is at risk of hypoxia and this condition is associated with increased perinatal morbidity and mortality. However, evidence-based guidelines for clinical surveillance are poor and lack reliable indexes. This study introduces new procedures to extract parameters from the fetal heart rate signal in order to identify severe intrauterine growth restricted (IUGR) fetuses Methods : Standard parameters (time domain and frequency domain indexes) are compared to a new parameter, the Lempel Ziv complexity, and to two regularity estimators (approximate entropy and sample entropy). The paper analyzes the robustness of the indexes coming from the parameter extraction procedure. Results and Conclusions : The results show that the LZ complexity is a stable parameter and it is able to significantly discriminate the severe IUGR (preterm delivered) from moderate IUGR (at term delivered) and from healthy ...
Medical & biological engineering & computing, Jan 10, 2018
Infants born at 35-37 weeks' gestational age (GA) are at higher risk for a range of pathologi... more Infants born at 35-37 weeks' gestational age (GA) are at higher risk for a range of pathological conditions and poorer neurodevelopmental outcomes. However, mechanisms responsible are not fully understood. The purpose of this paper is to use traditional and novel techniques to assess newborn autonomic development as a function of GA at birth, focusing on cardiorespiratory regulation. ECG and respiration were acquired during sleep on 329 healthy newborns. Infants were divided into GA groups: 35-36 weeks (late preterm (LPT)), 37-38 weeks (early term (ET)), and 39-40 weeks (full term (FT)). Time domain, frequency domain, and non-linear measures were calculated. Increased heart rate short-term variability and complexity as a function of GA were observed in time domain and non-linear measures. Decreasing inter-breath interval variability was found as a function of GA, with increasing linear cardiorespiratory coupling. A complexity parameter (quadratic sample entropy) was less affecte...
Conference proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual Conference, 2015
The paper presents results of a sleep study on 60 newborn infants and 22 one-month infants, in qu... more The paper presents results of a sleep study on 60 newborn infants and 22 one-month infants, in quiet and active sleep and in prone and supine position. During the study, HRV and respiration were acquired and then analyzed with a multi-parametric approach. Time, Frequency Domain and Non-Linear parameters were calculated, also encompassing indices from the adult and fetal field. The novelty of this study is the introduction of innovative measurements in a thorough investigation to characterize the effect of sleep state and position on the cardio-respiratory control in newborns. Results show that most parameters succeed in classifying different sleep states, while differences between positions were found in the one-month population only. This study comes as a continuation of previous analysis with the addition of respiratory signal. These results are encouraging for the aim of defining a set of parameters that could help characterizing the autonomic control of infants and early detect ...
Conference proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual Conference, 2014
Fetal Heart Rate (FHR) monitoring represents a powerful tool for checking the arousal of patholog... more Fetal Heart Rate (FHR) monitoring represents a powerful tool for checking the arousal of pathological fetal conditions during pregnancy. This paper proposes a multivariate approach for the discrimination of Normal and Intra Uterine Growth Restricted (IUGR) fetuses based on a small set of parameters computed on the FHR signal. We collected FHR recordings in a population of 120 fetuses (60 normals and 60 IUGRs) at approximately the same gestational week through a standard CTG non-stress test. A set of 8 linear and non-linear indices were selected and computed on each recording, on the basis of their "stand-alone" discriminative properties, demonstrated in previous studies. By using the Orange® data mining suite we checked various multivariate discrimination models. The results show that a Logistic Regression performed on a limited set of only 4 parameters can reach 92.5% accuracy in the correct identification of fetuses, with 93% sensitivity and 91.5% specificity.
Conference proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual Conference, 2014
Severe premature babies present a risk profile higher than the normal population. Reasons are rel... more Severe premature babies present a risk profile higher than the normal population. Reasons are related to the incomplete development of physiological systems that support baby's life. Heart Rate Variability (HRV) analysis can help the identification of distress conditions as it is sensitive to Autonomic Nervous System (ANS) behavior. This paper presents results obtained in 35 babies with severe prematurity, in quiet and active sleep and in prone and supine position. HRV was analyzed in time and frequency domain and with nonlinear parameters. The novelty of this approach lies in the combined use of parameters generally adopted in fetal monitoring and "adult" indices. Results show that most parameters succeed in classifying different experimental conditions. This is very promising as our final objective is to identify a set of parameters that could be the basis for a risk classifier to improve the care path of premature population.
... e di Tele-ecografia A. Di Lieto*, M. Campanile*, M. De Falco*, G. Magenes", MG Signorina... more ... e di Tele-ecografia A. Di Lieto*, M. Campanile*, M. De Falco*, G. Magenes", MG Signorina 'università degli Studi di Napoli Federico li ■ Dipartimento ... tnt J Gynecol Obstet 1997;57:33-7. 2. Anceschi MM, Piazze 11, Ruozi-Berretta A et a!. - Validity of short term variation (STV) in ...
Summary Objectives: The objective of this work was to contribute to the development, validation a... more Summary Objectives: The objective of this work was to contribute to the development, validation and application of data mining methods for prediction in decision support systems in medicine. The particular focus was on the prediction of cardiovascular risk factors in hemodialysis patients, specifically the interventricular septum (IVS) thickness of the heart of individual patients as an important quantitative indicator to diagnose left ventricular hypertrophy. The work was based on data from 63 long-term hemodialysis patients of the KfH Dialysis Centre in Jena, Germany. Methods: The approach applied is based on data mining methods and involves four major steps: data based clustering, cluster based rule extraction, rulebase construction and cluster and rule based prediction. The methods employed include crisp and fuzzy algorithms. At each step, logical and medical validation of results was carried out. Different sets of randomly selected patient data were used to train, test and opti...
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