46 research outputs found
A Knowledge Distillation Framework For Enhancing Ear-EEG Based Sleep Staging With Scalp-EEG Data
Sleep plays a crucial role in the well-being of human lives. Traditional
sleep studies using Polysomnography are associated with discomfort and often
lower sleep quality caused by the acquisition setup. Previous works have
focused on developing less obtrusive methods to conduct high-quality sleep
studies, and ear-EEG is among popular alternatives. However, the performance of
sleep staging based on ear-EEG is still inferior to scalp-EEG based sleep
staging. In order to address the performance gap between scalp-EEG and ear-EEG
based sleep staging, we propose a cross-modal knowledge distillation strategy,
which is a domain adaptation approach. Our experiments and analysis validate
the effectiveness of the proposed approach with existing architectures, where
it enhances the accuracy of the ear-EEG based sleep staging by 3.46% and
Cohen's kappa coefficient by a margin of 0.038.Comment: Code available at :
https://github.com/Mithunjha/EarEEG_KnowledgeDistillatio
Real-Time Hand Gesture Recognition Using Temporal Muscle Activation Maps of Multi-Channel sEMG Signals
Accurate and real-time hand gesture recognition is essential for controlling
advanced hand prostheses. Surface Electromyography (sEMG) signals obtained from
the forearm are widely used for this purpose. Here, we introduce a novel hand
gesture representation called Temporal Muscle Activation (TMA) maps which
captures information about the activation patterns of muscles in the forearm.
Based on these maps, we propose an algorithm that can recognize hand gestures
in real-time using a Convolution Neural Network. The algorithm was tested on 8
healthy subjects with sEMG signals acquired from 8 electrodes placed along the
circumference of the forearm. The average classification accuracy of the
proposed method was 94%, which is comparable to state-of-the-art methods. The
average computation time of a prediction was 5.5ms, making the algorithm ideal
for the real-time gesture recognition applications.Comment: Paper accepted to IEEE International Conference on Acoustics, Speech,
and Signal Processing (ICASSP) 202
Towards Interpretable Sleep Stage Classification Using Cross-Modal Transformers
Accurate sleep stage classification is significant for sleep health
assessment. In recent years, several machine-learning based sleep staging
algorithms have been developed, and in particular, deep-learning based
algorithms have achieved performance on par with human annotation. Despite the
improved performance, a limitation of most deep-learning based algorithms is
their black-box behavior, which has limited their use in clinical settings.
Here, we propose a cross-modal transformer, which is a transformer-based method
for sleep stage classification. The proposed cross-modal transformer consists
of a novel cross-modal transformer encoder architecture along with a
multi-scale one-dimensional convolutional neural network for automatic
representation learning. Our method outperforms the state-of-the-art methods
and eliminates the black-box behavior of deep-learning models by utilizing the
interpretability aspect of the attention modules. Furthermore, our method
provides considerable reductions in the number of parameters and training time
compared to the state-of-the-art methods. Our code is available at
https://github.com/Jathurshan0330/Cross-Modal-Transformer.Comment: 11 pages, 7 figures, 6 table
Dynamic navicular motion measured using a stretch sensor is different between walking and running, and between over-ground and treadmill conditions
Parental Height Differences Predict the Need for an Emergency Caesarean Section
More than 30% of all pregnancies in the UK require some form of assistance at delivery, with one of the more severe forms of assistance being an emergency Caesarean section (ECS). Previously it has been shown that the likelihood of a delivery via ECS is positively associated with the birth weight and size of the newborn and negatively with maternal height. Paternal height affects skeletal growth and mass of the fetus, and thus might also affect pregnancy outcomes. We hypothesized that the effect of newborn birth weight on the risk of ECS would decrease with increasing maternal height. Similarly, we predicted that there would be an increase in ECS risk as a function of paternal height, but that this effect would be relative to maternal height (i.e., parental height differences). We used data from the Millennium Cohort Study: a large-scale survey (N = 18,819 births) with data on babies born and their parents from the United Kingdom surveyed 9 to 12-months after birth. We found that in primiparous women, both maternal height and parental height differences interacted with birth weight and predicted the likelihood of an ECS. When carrying a heavy newborn, the risk of ECS was more than doubled for short women (46.3%) compared to tall women (21.7%), in agreement with earlier findings. For women of average height carrying a heavy newborn while having a relatively short compared to tall partner reduced the risk by 6.7%. In conclusion, the size of the baby, the height of the mother and parental height differences affect the likelihood of an ECS in primiparous women
Geographical limits to species-range shifts are suggested by climate velocity
The reorganization of patterns of species diversity driven by anthropogenic climate change, and the consequences for humans, are not yet fully understood or appreciated. Nevertheless, changes in climate conditions are useful for predicting shifts in species distributions at global and local scales. Here we use the velocity of climate change to derive spatial trajectories for climatic niches from 1960 to 2009 (ref. 7) and from 2006 to 2100, and use the properties of these trajectories to infer changes in species distributions. Coastlines act as barriers and locally cooler areas act as attractors for trajectories, creating source and sink areas for local climatic conditions. Climate source areas indicate where locally novel conditions are not connected to areas where similar climates previously occurred, and are thereby inaccessible to climate migrants tracking isotherms: 16% of global surface area for 1960 to 2009, and 34% of ocean for the \u27business as usual\u27 climate scenario (representative concentration pathway (RCP) 8.5)8 representing continued use of fossil fuels without mitigation. Climate sink areas are where climate conditions locally disappear, potentially blocking the movement of climate migrants. Sink areas comprise 1.0% of ocean area and 3.6% of land and are prevalent on coasts and high ground. Using this approach to infer shifts in species distributions gives global and regional maps of the expected direction and rate of shifts of climate migrants, and suggests areas of potential loss of species richness
Temperature Anomalies and Mortality Events in Marine Communities: Insights on Factors behind Differential Mortality Impacts in the NW Mediterranean
Two large-scale mass mortality events (MMEs) of unprecedented extent and severity affecting rocky benthic communities occurred during the summers of 1999 and 2003 along the coasts of the NW Mediterranean Sea. These mortality outbreaks were associated with positive thermal anomalies. In this study, we performed an analysis of inter-regional and inter-annual differences in temperature (T) conditions associated with MMEs of the red gorgonian Paramuricea clavata by analyzing high resolution T time series (hourly records for 3 to 8 years) from four regions of the NW Mediterranean with differing hydrological conditions and biological impacts. High resolution records allowed a detailed analysis using classical and new descriptors to characterize T anomalies. We were able to determine that the MMEs were triggered by two main types of positive thermal anomalies, with the first type being characterized by short periods (2 to 5 days) with high Mean T reaching more than 27°C in some regions and being associated with high intra-day and intra-period variability, while the second type of anomaly presented long duration (near one month) at warm T (24°C) with low intra-period variability. Inter-regional patterns arose; some regions displayed both types of anomalies, while others exhibited only one type. The results showed that T conditions should be considered as the main factor that explains the observed inter-regional and inter-annual differences in mortality impacts. In explaining these differences, the late timing of T anomalies, in addition to their magnitude was found to be determinant. Finally, by combining thermotolerance experimental data with the maximal T stress conditions observed in the four regions, we were able to determine the differential risk of mass mortality across regions. We conclude that expanding high resolution T series is important for the development of sound management and conservation plans to protect Mediterranean marine biodiversity in the face of climate change
The handbook for standardized field and laboratory measurements in terrestrial climate change experiments and observational studies (ClimEx)
1. Climate change is a world‐wide threat to biodiversity and ecosystem structure, functioning and services. To understand the underlying drivers and mechanisms, and to predict the consequences for nature and people, we urgently need better understanding of the direction and magnitude of climate change impacts across the soil–plant–atmosphere continuum. An increasing number of climate change studies are creating new opportunities for meaningful and high‐quality generalizations and improved process understanding. However, significant challenges exist related to data availability and/or compatibility across studies, compromising opportunities for data re‐use, synthesis and upscaling. Many of these challenges relate to a lack of an established ‘best practice’ for measuring key impacts and responses. This restrains our current understanding of complex processes and mechanisms in terrestrial ecosystems related to climate change.
2. To overcome these challenges, we collected best‐practice methods emerging from major ecological research networks and experiments, as synthesized by 115 experts from across a wide range of scientific disciplines. Our handbook contains guidance on the selection of response variables for different purposes, protocols for standardized measurements of 66 such response variables and advice on data management. Specifically, we recommend a minimum subset of variables that should be collected in all climate change studies to allow data re‐use and synthesis, and give guidance on additional variables critical for different types of synthesis and upscaling. The goal of this community effort is to facilitate awareness of the importance and broader application of standardized methods to promote data re‐use, availability, compatibility and transparency. We envision improved research practices that will increase returns on investments in individual research projects, facilitate second‐order research outputs and create opportunities for collaboration across scientific communities. Ultimately, this should significantly improve the quality and impact of the science, which is required to fulfil society's needs in a changing world
A Novel Method for Measuring In-Shoe Navicular Drop during Gait
Analysis of foot movement is essential in the treatment and prevention of foot-related disorders. Measuring the in-shoe foot movement during everyday activities, such as sports, has the potential to become an important diagnostic tool in clinical practice. The current paper describes the development of a thin, flexible and robust capacitive strain sensor for the in-shoe measurement of the navicular drop. The navicular drop is a well-recognized measure of foot movement. The position of the strain sensor on the foot was analyzed to determine the optimal points of attachment. The sensor was evaluated against a state-of-the-art video-based system that tracks reflective markers on the bare foot. Preliminary experimental results show that the developed strain sensor is able to measure navicular drop on the bare foot with an accuracy on par with the video-based system and with a high reproducibility. Temporal comparison of video-based, barefoot and in-shoe measurements indicate that the developed sensor measures the navicular drop accurately in shoes and can be used without any discomfort for the user