An experimental method for bio-signal denoising using unconventional sensors

In bio-signal denoising, current methods reported in literature consider purely simulated envi-ronments, requiring high computational powers and signal processing algorithms that may in-troduce signal distortion. To achieve an efficient noise reduction, such methods require previous knowledge of the noise signals or to have certain periodicity and stability, making the noise es-timation difficult to predict. In this paper, we solve these challenges through the development of an experimental method applied for bio-signal denoising using a combined approach. This is based on the implementation of unconventional electric field sensors used for creating a noise replica required to obtain the ideal Wiener filter transfer function and achieve further noise reduction. This work aims to investigate the suitability of the proposed approach for the real-time noise reduction affecting bio-signal recordings. The experimental evaluation presented considers two scenarios: a) human bio-signals trials including electrocardiogram, electromyogram and elec-trooculogram; and b) bio-signal recordings from the MIT-MIH arrhythmia database. The per-formance of the proposed method is evaluated using qualitative (i.e. power spectral density) and quantitative criteria (i.e. signal-to-noise ratio and mean square error) followed by a comparison between the proposed methodology and state of the art denoising methods. The results indicate that the combined approach proposed in this paper can be used for noise reduction in electro-cardiogram, electromyogram and electrooculogram signals achieving noise attenuation levels of 26.4 dB, 21.2 dB and 40.8 dB, respectively

Neo-SENSE: a non-invasive smart sensing mattress for cardiac monitoring of babies

Within the first minute of life a newborn must take its first breath to make the transition from life inside the womb to the outside world. If a baby does not start breathing, its heart rate will drop and the circulation of blood carrying oxygen to the organs will be seriously affected. The damage done to a newborn who is deprived of oxygen happens so quickly that rapid response is imperative. During birth, the attending neonatal staff manually listen to the baby´s heart and count the heart rate; however, this has proven inaccurate and inefficient. Nowadays, there is not a reliable method to monitor newborn heart rate promptly throughout birth. In this paper, we report the design and development of a novel smart mattress device to measure the babies’ electrocardiogram and respiration non-invasively. The device is based on electrometer-based amplifier sensors combined with novel screen-printing techniques. Proof of concept tests are carried out to demonstrate the suitability of the smart-mattress for new born ECG monitoring. We perform tests with a young infant and demonstrate the potential of this sensing technology to provide a quick and reliable application as ECG readings were displayed within a time < 30 seconds. This will aid the neonatal staff to assess the success of the resuscitation technology aiming to lower the incidence of long-term consequences of poor adaptation to life outside the womb

Characterisation of textile embedded electrodes for use in a neonatal smart mattress electrocardiography system

Heart rate monitoring is the predominant quantitative health indicator of a newborn in the delivery room. A rapid and accurate heart rate measurement is vital during the first minutes after birth. Clinical recommendations suggest that electrocardiogram (ECG) monitoring should be widely adopted in the neonatal intensive care unit to reduce infant mortality and improve long term health outcomes in births that require intervention. Novel non-contact electrocardiogram sensors can reduce the time from birth to heart rate reading as well as providing unobtrusive and continuous monitoring during intervention. In this work we report the design and development of a solution to provide high resolution, real time electrocardiogram data to the clinicians within the delivery room using non-contact electric potential sensors embedded in a neonatal intensive care unit mattress. A real-time high-resolution electrocardiogram acquisition solution based on a low power embedded system was developed and textile embedded electrodes were fabricated and characterised. Proof of concept tests were carried out on simulated and human cardiac signals, producing electrocardiograms suitable for the calculation of heart rate having an accuracy within ±1 beat per minute using a test ECG signal, ECG recordings from a human volunteer with a correlation coefficient of ~ 87% proved accurate beat to beat morphology reproduction of the waveform without morphological alterations and a time from application to heart rate display below 6 s. This provides evidence that flexible non-contact textile-based electrodes can be embedded in wearable devices for assisting births through heart rate monitoring and serves as a proof of concept for a complete neonate electrocardiogram monitoring system

Evaluation of screen-printing techniques for embedding ECG sensors in medical devices

Heart rate monitoring is the most important indicator to evaluate the clinical status of a newborn during birth. Approximately 90% of newborn infants make the transition from the intrauterine to extra uterine environment without major complications; however, the remaining 10% of newborn infants require assistance during this transition. Heart rate monitoring is required for guiding further interventions in the event of complications such as the need for resuscitation. In this work we evaluate the suitability of embedding electrometer-based-amplifier sensors employing novel screen-printing techniques into medical devices. We compare our results with traditional copper based wired electrodes. Our implementation was able to acquire electrocardiogram with enough signal to noise ratio, suitable for heart rate detection with a 1% loss of heart rate accuracy, compared with the copper-based electrodes. Our device has the potential to be embedded in devices for assisting births though heart rate monitoring

Non-invasive sensor methods used in monitoring newborn babies after birth, a clinical perspective

Background Reducing the global new-born mortality is a paramount challenge for humanity. There are approximately 786,323 live births in the UK each year according to the office for National Statistics; around 10% of these newborn infants require assistance during this transition after birth. Each year around, globally around 2.5 million newborns die within their first month. The main causes are complications due to prematurity and during delivery. To act in a timely manner and prevent further damage, health professionals should rely on accurate monitoring of the main vital signs heart rate and respiratory rate. Aims To present a clinical perspective on innovative, non-invasive methods to monitor heart rate and respiratory rate in babies highlighting their advantages and limitations in comparison with well-established methods. Methods Using the data collected in our recently published systematic review we highlight the barriers and facilitators for the novel sensor devices in obtaining reliable heart rate measurements. Details about difficulties related to the application of sensors and interfaces, time to display, and user feedback are explored. We also provide a unique overview of using a non-invasive respiratory rate monitoring method by extracting RR from the pulse oximetry trace of newborn babies. Results Novel sensors to monitor heart rate offer the advantages of minimally obtrusive technologies but have limitations due to movement artefact, bad sensor coupling, intermittent measurement, and poor-quality recordings compared to gold standard well established methods. Respiratory rate can be derived accurately from pleth recordings in infants. Conclusion Some limitations have been identified in current methods to monitor heart rate and respiratory rate in newborn babies. Novel minimally invasive sensors have advantages that may help clinical practice. Further research studies are needed to assess whether they are sufficiently accurate, practical, and reliable to be suitable for clinical use

Palaeomagnetism of the Ordovician dolerites of the Crozon Peninsula (France)

In order to obtain a Lower Palaeozoic pole for the Armorican Massif and to test the origin of the Ibero-Armorican arc, the Ordovician dolerites of the Crozon peninsula have been palaeomagnetically studied. The samples show a multicomponent magnetization which has been revealed by AF and thermal demagnetization and thoroughly investigated with rock magnetic experiments, polished section examinations and K/Ar dating. Four groups of directions have been recognized, often superimposed on each other in an individual sample. One component (D) has always the lowest blocking temperatures and coercivities and is considered to be of viscous origin, acquired recently in situ or in the laboratory during storage. Two components (A and B) are interpreted to be of secondary origin and to correspond to the observed K/Ar age distribution between 300 and 190 Myr. These ages represent the time interval between two regional thermo-tectonic events, associated with the Hercynian orogeny and the intrusion of dykes related to the early opening of the Central Atlantic Ocean and the Bay of Biscay. A fourth component (C) could be of Ordovician or younger Palaeozoic age; it is not clear whether the age of the magnetization is pre- or post-folding, but a pre-folding age would yield a direction of magnetization similar to Ordovician results from the Iberian peninsula. The latter interpretation suggests a fairly high palaeolatitude, which is in agreement with a glacio-marine postulated for sediments overlying the dolerite sills.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73214/1/j.1365-246X.1983.tb03785.x.pd

In situ CO2 and O2 measurements on a profiling float

In recent years, profiling floats, which form the basis of the successful international Argo observatory, are also being considered as platforms for marine biogeochemical research. This study showcases the utility of floats as a novel tool for combined gas measurements of CO2 partial pressure (pCO2) and O2. These float prototypes were equipped with a small-sized and submersible pCO2 sensor and an optode O2 sensor for high resolution measurements in the surface ocean layer. Four consecutive deployments were carried out during Nov. 2010 and June 2011 near the Cape Verde Ocean Observatory (CVOO) in the eastern tropical North Atlantic. The profiling float performed upcasts every 31 h while measuring pCO2, O2, salinity, temperature and hydrostatic pressure in the upper 200 m of the water column. In order to maintain accuracy, regular pCO2 sensor zeroings at depth and surface, as well as optode measurements in air, were performed for each profile. Through the application of data processing procedures (e.g., time-lag correction) accuracies of float-borne pCO2 measurements were greatly improved (10 – 15 μatm for water column and 5 μatm for surface measurements). O2 measurements yielded an accuracy of 2 μmol kg−1. First results of this pilot study show the possibility of using profiling floats as a platform for detailed and unattended observations of the marine carbon and oxygen cycle dynamics

Incretin-based therapies and risk of pancreatic cancer in patients with type 2 diabetes : A meta-analysis of randomized controlled trials

Aims: To perform a meta-analysis of randomized controlled trials (RCTs), including 6 recently published large-scale cardiovascular outcome trials (CVOTs), to evaluate the risk of pancreatic cancer with incretin-based therapies in patients with type 2 diabetes (T2DM). Materials and Methods: For the period January 1, 2007 to May 1, 2017, the PubMed, Embase, Cochrane Central Register and databases were searched for RCTs in people with T2DM that compared incretin drugs with placebo or other antidiabetic drugs, with treatment and follow-up durations of >= 52 weeks. Two reviewers screened the studies, extracted the data and assessed the risk of bias independently and in duplicate. Results: A total of 33 studies (n = 79971), including the 6 CVOTs, with 87 pancreatic cancer events were identified. Overall, the pancreatic cancer risk was not increased in patients administered incretin drugs compared with controls (Peto odds ratio [OR] 0.67, 95% confidence interval [CI] 0.44-1.02). In the 6 CVOTs, 79 pancreatic cancer events were identified in 55248 participants. Pooled estimates of the 6 CVOTs showed an identical tendency (Peto OR 0.65, 95% CI 0.42-1.01). Notably, in the subgroup of participants who received treatment and follow-up for >= 104 weeks, 84 pancreatic cancer events were identified in 59919 participants, and a lower risk of pancreatic cancer was associated with incretin-based therapies (Peto OR 0.62, 95% CI 0.41-0.95). Conclusions: Treatment with incretin drugs was not associated with an increased risk of pancreatic cancer in people with T2DM. Instead, it might protect against pancreatic malignancy in patients treated for 104 weeks.Peer reviewe

Quantifying diet-induced metabolic changes of the human gut microbiome

The human gut microbiome is known to be associated with various human disorders, but a major challenge is to go beyond association studies and elucidate causalities. Mathematical modeling of the human gut microbiome at a genome-scale is a useful tool to decipher microbe-microbe, diet-microbe and microbe-host interactions. Here, we describe the CASINO (Community and Systems-level Interactive Optimization) toolbox, a comprehensive computational platform for analysis of microbial communities through metabolic modeling. We first validated the toolbox by simulating and testing the performance of single bacteria and whole communities in in vitro. Focusing on metabolic interactions between the diet, gut microbiota and host metabolism, we demonstrated the predictive power of the toolbox in a diet-intervention study of 45 obese and overweight individuals, and validated our predictions by fecal and blood metabolomics data. Thus, modeling could quantitatively describe altered fecal and serum amino acid levels in response to diet intervention