A COMPACT ULTRA-WIDE BAND PRINTED LOG-PERIODIC ANTENNA USING A BOW-TIE STRUCTURE

In this letter, an ultra-wideband compact printed log periodic dipole (LPD) array antenna is designed to operate between 500MHz and 6 GHz frequencies. The proposed LPD antenna structure consists of one bow-tie dipole and 15 regular dipole elements. The bow-tie element is introduced to improve the antenna's performance at the lowest frequencies below 1 GHz and at the same time to reduce the antenna size maintaining a good performance. An experimental antenna prototype has been designed, optimized, fabricated, numerically and experimentally assessed. The obtained results are very promising, and they demonstrated that the presented antenna prototype is able to operate in the range between 500MHz and 6 GHz with an average gain of 6 dBi and a very compact size

Towards multimodal brain monitoring in asphyxiated newborns with amplitude-integrated EEG and simultaneous somatosensory evoked potentials

Background: Somatosensory evoked potentials (SEPs) offer an additional bedside tool for outcome prediction after perinatal asphyxia. Aims: To assess the reliability of SEPs recorded with bifrontoparietal amplitude-integrated electroencephalography (aEEG) brain monitoring setup for outcome prediction in asphyxiated newborns undergoing therapeutic hypothermia. Study design: Retrospective observational single-center study. Subjects: 27 consecutive asphyxiated fullor near-term newborns (25 under hypothermia) that underwent median nerve aEEG-SEPs as part of their clinical evaluation at the neonatal intensive care unit of Helsinki University Hospital. Outcome measures: aEEG-SEP classification (present, absent or unreliable) was compared to classification of SEPs recorded with a full EEG montage (EEG-SEP), and outcome determined from medical records at approximately 12-months-age. Unfavorable outcome included death, cerebral palsy, or severe epilepsy. Results: The aEEG-SEP and EEG-SEP classifications were concordant in 21 of the 22 newborns with both recordings available. All five newborns with bilaterally absent aEEG-SEPs had absent EEG-SEPs and the four with outcome information available had an unfavorable outcome (one was lost to follow-up). Of the newborns with aEEG-SEPs present, all with follow-up exams available had bilaterally present EEG-SEPs and a favorable outcome (one was lost to follow-up). One newborn with unilaterally absent aEEG-SEP at 25 h of age had bilaterally present EEG-SEPs on the next day, and a favorable outcome. Conclusions: aEEG-SEPs recorded during therapeutic hypothermia on the first postnatal days are reliable for assessing brain injury severity. Adding SEP into routine aEEG brain monitoring offers an additional tool for very early outcome prediction after birth asphyxia.Peer reviewe

Sub-ppm NO2 Detection through Chipless RFID Sensor Functionalized with Reduced SnO2

NO2 is an important environmental pollutant and is harmful to human health even at very low concentrations. In this paper, we propose a novel chipless RFID sensor able to work at room temperature and to detect sub-ppm concentration of NO2 in the environment. The sensor is made of a metallic resonator covered with NO2-sensitive tin oxide and works by monitoring both the frequency and the intensity of the output signal. The experimental measurements show a fast response (a few minutes) but a very slow recovery. The sensor could therefore be used for non-continuous threshold monitoring. However, we also demonstrated that the recovery can be strongly accelerated upon exposure to a UV source. This opens the way to the reuse of the sensor, which can be easily regenerated after prolonged exposure and recycled several times

Automated pose estimation captures key aspects of General Movements at eight to 17 weeks from conventional videos

Aim: General movement assessment requires substantial expertise for accurate visual interpretation. Our aim was to evaluate an automated pose estimation method, using conventional video records, to see if it could capture infant movements using objective biomarkers. Methods: We selected archived videos from 21 infants aged eight to 17 weeks who had taken part in studies at the IRCCS Fondazione Stella Maris (Italy), from 2011 to 2017. Of these, 14 presented with typical low-risk movements, while seven presented with atypical movements and were later diagnosed with cerebral palsy. Skeleton videos were produced using a computational pose estimation model adapted for infants and these were blindly assessed to see whether they contained the information needed for classification by human experts. Movements of skeletal key points were analysed using kinematic metrics to provide a biomarker to distinguish between groups. Results: The visual assessments of the skeleton videos were very accurate, with Cohen's K of 0.90 when compared with the classification of conventional videos. Quantitative analysis showed that arm movements were more variable in infants with typical movements. Conclusion: It was possible to extract automated estimation of movement patterns from conventional video records and convert them to skeleton footage. This could allow quantitative analysis of existing footage.Peer reviewe

Neonatal neuroimaging and neurophysiology predict infantile onset epilepsy after perinatal hypoxic ischemic encephalopathy

Correction: Volume88, Page158-158 DOI10.1016/j.seizure.2021.04.001 PublishedMAY 2021Purpose: To evaluate the accuracy of hypoxic ischemic encephalopathy (HIE) grade, and neonatal neurophysiological and neuroimaging measures for predicting development of infantile spasms syndrome (IS) or other postneonatal, infantile onset epilepsy after perinatal HIE. Methods: We examined a population-based cohort of 92 consequent infants with moderate-to-severe HIE. The HIE grade and neonatal neuroimaging (MRI) and neurophysiology (EEG and somatosensory evoked potentials, SEPs) findings were compared to the development of IS or other epilepsy within the first year of life. Results: Out of 74 surviving infants with follow-up information, five developed IS and one developed a focal onset epilepsy. They all had recovered from severe HIE. All survivors with inactive neonatal EEG (recorded within the first few postnatal days, n = 4) or the most severe type of brain injury in MRI (n = 3) developed epilepsy (positive predictive value, PPV 100 %). Bilaterally absent SEPs had 100 % sensitivity and 75 % PPV for epilepsy. A combination of absent SEPs and a poor MRI finding (combined deep and cortical gray matter injury) resulted in higher PPV (86 %) without lowering sensitivity (100 %). Follow-up EEGs showed recurrent epileptiform activity already between 1- and 2-months age in those that developed epilepsy, distinguishing them from those surviving without epilepsy. Conclusions: Poor neonatal neuroimaging and neurophysiological findings provide accurate prediction for development of infantile onset epilepsy after HIE. Of the neonates with severe HIE, the ones with severe neonatal MRI and neurophysiological abnormalities need frequent follow-up, including repeated EEGs, for early detection of IS.Peer reviewe

Asymmetry in sleep spindles and motor outcome in infants with unilateral brain injury

Aim To determine whether interhemispheric difference in sleep spindles in infants with perinatal unilateral brain injury could link to a pathological network reorganization that underpins the development of unilateral cerebral palsy (CP). Method This was a multicentre retrospective study of 40 infants (19 females, 21 males) with unilateral brain injury. Sleep spindles were detected and quantified with an automated algorithm from electroencephalograph records performed at 2 months to 5 months of age. The clinical outcomes after 18 months were compared to spindle power asymmetry (SPA) between hemispheres in different brain regions. Results We found a significantly increased SPA in infants who later developed unilateral CP (n=13, with the most robust interhemispheric difference seen in the central spindles. The best individual-level prediction of unilateral CP was seen in the centro-occipital spindles with an overall accuracy of 93%. An empiric cut-off level for SPA at 0.65 gave a positive predictive value of 100% and a negative predictive value of 93% for later development of unilateral CP. Interpretation Our data suggest that automated analysis of interhemispheric SPA provides a potential biomarker of unilateral CP at a very early age. This holds promise for guiding the early diagnostic process in infants with a perinatally identified brain injury.Peer reviewe

An automated bedside measure for monitoring neonatal cortical activity: a supervised deep learning-based electroencephalogram classifier with external cohort validation

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Measuring Cot-Side the Effects of Parenteral Nutrition on Preterm Cortical Function

Early nutritional compromise after preterm birth is shown to affect long-term neurodevelopment, however, there has been a lack of early functional measures of nutritional effects. Recent progress in computational electroencephalography (EEG) analysis has provided means to measure the early maturation of cortical activity. Our study aimed to explore whether computational metrics of early sequential EEG recordings could reflect early nutritional care measured by energy and macronutrient intake in the first week of life. A higher energy or macronutrient intake was assumed to associate with improved development of the cortical activity. We analyzed multichannel EEG recorded at 32 weeks (32.4 ± 0.7) and 36 weeks (36.6 ± 0.9) of postmenstrual age in a cohort of 28 preterm infants born before 32 weeks of postmenstrual age (range: 24.3–32 weeks). We computed several quantitative EEG measures from epochs of quiet sleep (QS): (i) spectral power; (ii) continuity; (iii) interhemispheric synchrony, as well as (iv) the recently developed estimate of maturational age. Parenteral nutritional intake from day 1 to day 7 was monitored and clinical factors collected. Lower calories and carbohydrates were found to correlate with a higher reduction of spectral amplitude in the delta band. Lower protein amount associated with higher discontinuity. Both higher proteins and lipids intake correlated with a more developmental increase in interhemispheric synchrony as well as with better progress in the estimate of EEG maturational age (EMA). Our study shows that early nutritional balance after preterm birth may influence subsequent maturation of brain activity in a way that can be observed with several intuitively reasoned and transparent computational EEG metrics. Such measures could become early functional biomarkers that hold promise for benchmarking in the future development of therapeutic interventions.Peer reviewe

Automatic Posture and Movement Tracking of Infants with Wearable Movement Sensors

Infants' spontaneous and voluntary movements mirror developmental integrity of brain networks since they require coordinated activation of multiple sites in the central nervous system. Accordingly, early detection of infants with atypical motor development holds promise for recognizing those infants who are at risk for a wide range of neurodevelopmental disorders (e.g., cerebral palsy, autism spectrum disorders). Previously, novel wearable technology has shown promise for offering efficient, scalable and automated methods for movement assessment in adults. Here, we describe the development of an infant wearable, a multi-sensor smart jumpsuit that allows mobile accelerometer and gyroscope data collection during movements. Using this suit, we first recorded play sessions of 22 typically developing infants of approximately 7 months of age. These data were manually annotated for infant posture and movement based on video recordings of the sessions, and using a novel annotation scheme specifically designed to assess the overall movement pattern of infants in the given age group. A machine learning algorithm, based on deep convolutional neural networks (CNNs) was then trained for automatic detection of posture and movement classes using the data and annotations. Our experiments show that the setup can be used for quantitative tracking of infant movement activities with a human equivalent accuracy, i.e., it meets the human inter-rater agreement levels in infant posture and movement classification. We also quantify the ambiguity of human observers in analyzing infant movements, and propose a method for utilizing this uncertainty for performance improvements in training of the automated classifier. Comparison of different sensor configurations also shows that four-limb recording leads to the best performance in posture and movement classification.Peer reviewe