Nils Löfgren

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Fisher's linear discriminant (FLD), a feed-forward artificial neural network (ANN) and a support vector machine (SVM) were compared with respect to their ability to distinguish bursts from suppressions in electroencephalograms (EEG) displaying a burst-suppression pattern. Five features extracted from the EEG were used as inputs. The study was based on EEG(More)
This study examines a novel methodology for continuous fetal heart rate variability (FHRV) assessment in a non-stationary intrapartum fetal heart rate (FHR). The specific aim was to investigate simple statistics, dimension estimates and entropy estimates as methods to discriminate situations of low FHRV related to non-reassuring fetal status or as a(More)
The overall aim of our research is to develop methods for a monitoring system to be used at neonatal intensive care units. When monitoring a baby, a range of different types of background activity needs to be considered. In this work, we have developed a scheme for automatic classification of background EEG activity in newborn babies. EEG from six full-term(More)
CTG monitoring of the fetal heart rate and uterine contractions during pregnancy and delivery provide information on the physiological condition of the fetus needed to identify hypoxia. Interpretation, however, requires experience and important patterns might be missed or misinterpreted due to stress, exhaustion or distraction. Interpretation has also been(More)
OBJECTIVE To investigate whether very low EEG frequency activity can be recorded from post asphyctic full term neonates using EEG equipment where the high pass filter level was lowered to 0.05 Hz. METHODS The time constant of the amplifier hardware was set to 3.2 s in order to enable recordings that equal to a high pass filter cut off at 0.05 Hz. Burst(More)
Monitoring of the fetal heart rate during pregnancy and labor gives experienced clinicians information about the physiological condition of the fetus. The heart rate is calculated from the heartbeat interval and is updated for each heartbeat. Therefore, an accurate and reliable algorithm for R-wave detection is crucial. R-wave detection is constantly(More)
Cerebral cortical activity in healthy, full-term human neonates (10 boys and 10 girls) was evaluated using spectral estimation of electroencephalogram frequency content with new equipment and analysis technique allowing the assessment of the lowest frequencies (i.e. infraslow waves). The activity was analysed under quiet sleep and active wakefulness taking(More)
OBJECTIVE To study whether indomethacin used in conventional dose for closure of patent ductus arteriosus affects cerebral function measured by electroencephalograms (EEG) evaluated by quantitative measures. STUDY DESIGN Seven premature neonates with haemodynamically significant persistent ductus arteriosus were recruited. EEG were recorded before, during(More)
OBJECTIVE To investigate whether the periodic EEG patterns seen in healthy and sick full term neonates (trace alternant and burst suppression, respectively) have different frequency characteristics. METHODS Burst episodes were selected from the EEGs of 9 healthy and 9 post-asphyctic full-term neonates and subjected to power spectrum analysis. Powers in(More)
OBJECTIVE To evaluate the frequency content of the electroencephalogram (EEG) during recovery after a severe hypoxic insult in newborn piglets. METHODS EEG was continuously monitored in nine newborn piglets exposed to a severe hypoxic period. Power spectra in five frequency bands were calculated using Fourier transformation. Spectral edge frequency 90(More)