Number of trials and data structure affect the number and components of muscle synergies in upper-limb reaching movements
This study recommends that at least five trials and four reaching directions and the concatenation method are considered in muscle synergies analysis during upper limb tasks. Significance. This study makes the researchers focus on the variability analysis induced by the diseases rather than the techniques applied for synergies analysis and promotes applications of muscle synergies in clinical scenarios. (Source: Physiological Measurement)
Source: Physiological Measurement - October 31, 2022 Category: Physiology Authors: Kunkun Zhao, Zhisheng Zhang, Haiying Wen and Alessandro Scano Source Type: research
Optimal bipolar system positioning to provide information about the trapezius activity associated with scapular retraction during shoulder exercises for resistance training
Objective. Recently, the use of EMG biofeedback to make subjects aware of the stabilizer activation associated with scapular retraction during exercise has been of interest, and challenges related to EMG detection have been addressed. Whether there is an optimal bipolar positioning that discriminates the stabilizer activation with retraction from a neutral scapular position during resistance exercises is an open issue that we address here by simultaneously mapping different positions using high-density surface electromyography (HD-sEMG). Approach. Sixteen resistance-trained males performed five pulling exercises with and w...
Source: Physiological Measurement - October 31, 2022 Category: Physiology Authors: F V Dos Anjos, G Boccia, P R Brustio, A Rainoldi and M Gazzoni Source Type: research
A comparative study of the performance of methods for f-wave extraction
This study proposes a novel technique for atrial fibrillatory waves (f-waves) extraction and investigates the performance of the proposed method comparing with different f-wave extraction methods. Approach. We propose a novel technique combining a periodic component analysis (PiCA) and echo state network (ESN) for f-waves extraction, denoted PiCA-ESN. PiCA-ESN benefits from the advantages of using both source separation and nonlinear adaptive filtering. PiCA-ESN is evaluated by comparing with other state-of-the-art approaches, which include template subtraction technique based on principal component analysis, spatiotempora...
Source: Physiological Measurement - October 25, 2022 Category: Physiology Authors: Sara Mihandoost, Leif S örnmo, Matthieu Doyen and Julien Oster Source Type: research
Seismocardiography as a tool for assessment of bi-ventricular pacing
In this study, we have investigated the pacing-induced changes in the seismocardiogram (SCG). Approach. 14 patients with heart failure, LBBB, and CRT were included. SCG was recorded with pacing turned on and off. Based on a mean SCG heartbeat from each patient, fiducial points were annotated, and cardiac timing intervals (CTI) and amplitudes were derived. These were compared between the CRT group and a group of healthy normal subjects (n = 14). Echocardiography was also used to derive CTI. Intervals derived from the SCG and echocardiogram were correlated. Main results. The isovolumetric contraction time (IVCT) derived from...
Source: Physiological Measurement - October 25, 2022 Category: Physiology Authors: Kasper S ørensen, Peter Søgaard, Kasper Emerek, Ask Schou Jensen, Johannes Jan Struijk and Samuel Emil Schmidt Source Type: research
A new database with annotations of P waves in ECGs with various types of arrhythmias
Objective. The aim of this study is to create a database for the development, evaluation and objective comparison of algorithms for P wave detection in ECG signals. Brno University of Technology ECG Signal Database with Annotations of P-Wave (BUT PDB) is an ECG signal database with marked peaks of P waves annotated by ECG experts. Currently, there are only a few databases of pathological ECG signals with P-wave annotations, and some are incorrect. Approach. The pathological ECG signals used in this work were selected from three existing databases of ECG signals: MIT-BIH Arrhythmia Database, MIT-BIH Supraventricular Arrhyth...
Source: Physiological Measurement - October 25, 2022 Category: Physiology Authors: Lucie Saclova, Andrea Nemcova, Radovan Smisek, Lukas Smital, Martin Vitek and Marina Ronzhina Source Type: research
Bronchodilator effect on regional lung function in pediatric viral lower respiratory tract infections
Objective. Viral lower respiratory tract infections (LRTI) are the leading cause for acute admission to the intensive care unit in infants and young children. Nebulized bronchodilators are often used when treating the most severe cases. The aim of this study was to investigate the bronchodilator effect on respiratory mechanics during intensive care with electrical impedance tomography (EIT) and to assess the feasibility of EIT in this context. Approach. We continuously monitored the children with chest EIT for up to 72 h in an observational study design. The treatment decisions were done by clinical assessment, as the clin...
Source: Physiological Measurement - October 17, 2022 Category: Physiology Authors: Claas Strodthoff, Toni K ähkönen, Richard H Bayford, Tobias Becher, Inéz Frerichs and Merja Kallio Source Type: research
Reference values for triceps surae tissue oxygen saturation by near-infrared spectroscopy
Objective. To establish the reference values for peripheral tissue perfusion of the triceps surae muscle assessed by Near-infrared spectroscopy (NIRS) at rest and in progressive effort. Approach. A total of 288 apparently healthy individuals of both sexes were included; between 30 and 79 years of age; nonsmokers; without diagnosis of diabetes mellitus, systemic arterial hypertension, kidney disease, symptoms of angina and intermittent claudication, or any musculoskeletal alteration that would prevent physical exertion; and without diagnosis of Peripheral arterial disease (PAD) or other associated symptoms. All individuals ...
Source: Physiological Measurement - October 11, 2022 Category: Physiology Authors: Val éria C Faria, Luciano Fonseca Lemos de Oliveira, Ana Paula Ferreira, Tulio E O Cunha, Juliana S A Fernandes, Guilherme A Pussieldi and Danielle A G Pereira Source Type: research
Impact of ActiGraph sampling rate on free-living physical activity measurement in youth
ActiGraph sampling frequencies of more than 30 Hz may result in overestimation of activity counts in both children and adults, but research on free-living individuals has not included the range of sampling frequencies used by researchers. Objective. We compared count- and raw-acceleration-based metrics from free-living children and adolescents across a range of sampling frequencies. Approach. Participants (n = 445; 10–15 years of age) wore an ActiGraph accelerometer for at least one 10 h day. Vector magnitude counts, mean amplitude deviation, monitor-independent movement summary units, and activity intensity classifie...
Source: Physiological Measurement - October 9, 2022 Category: Physiology Authors: Kimberly A Clevenger, Jan C Br ønd, Kelly A Mackintosh, Karin A Pfeiffer, Alexander H K Montoye and Melitta A McNarry Source Type: research
Comparison of single-lead and multi-lead ECG for QT variability assessment using autoregressive modelling
This study aims to compare the utility of single and multi-lead ECG to disentangle the mechanisms contributing to QTV. Approach. Twelve-lead ECG was analysed in 57 coronary artery disease patients before and after an elective percutaneous transluminal coronary angiography (PTCA) procedure. QT, RR and respiration time series were extracted. QTV was decomposed into contributions by heart rate, respiration and QTV independent of heart rate and respiration using parametric autoregressive modelling. Signal-to-noise r atio, model goodness-of-fit, mean QT, corrected QT, QT variability and RR variability were also computed. Result...
Source: Physiological Measurement - October 5, 2022 Category: Physiology Authors: Fatima El-Hamad and Mathias Baumert Source Type: research
Hidden Markov model in nonnegative matrix factorization for fetal heart rate estimation using physiological priors
Objective. Fetal heart rate (fHR) analysis remains the most common technique for detecting fetal distress when monitoring the fetal well-being during labor. If cardiotocography (CTG) is nowadays the non-invasive clinical reference technique for fHR measurement, it suffers from several drawbacks, hence an increasing interest towards alternative technologies, especially around abdominal ECG (aECG). Approach. An original solution, using a single abdominal lead, was recently proposed to address both the feasibility in clinical routine and the challenging detection of temporal events when facing interfered signals from real lif...
Source: Physiological Measurement - October 5, 2022 Category: Physiology Authors: Mariel Res éndiz Rojas, Julie Fontecave-Jallon and Bertrand Rivet Source Type: research
A deep learning approach to real-time volumetric measurements without image reconstruction for cardiovascular magnetic resonance
Objective. Cardiovascular magnetic resonance (CMR) can measure ventricular volumes for the quantitative assessment of cardiac function in clinical cardiology. Conventionally, CMR volumetric measurements require image reconstruction and segmentation. There are limited clinical applications of real-time CMR for volumetric measurements because real-time images cannot provide sufficient quality for accurate segmentation. The presented work aims to develop a new deep learning approach to measuring ventricular volumes without image reconstruction and demonstrate that this 'imageless' approach would improve volumetric measurement...
Source: Physiological Measurement - October 5, 2022 Category: Physiology Authors: Yifan Qi, Fusheng Wang, Jane J Cao and Yu Yulee Li Source Type: research
Non-negative constrained dictionary learning for compressed sensing of ECG signals
Objective. Overcomplete dictionaries are widely used in compressed sensing (CS) to improve the quality of signal reconstruction. However, dictionary learning under the -norm or -norm constraint inevitably produces dictionary atoms that are negatively correlated with the original signal; meanwhile, when we use a sparse linear combination of dictionary atoms to represent a signal, it is suboptimal for the dictionary atoms to “cancel each other out” by addition and subtraction to approximate the sample. In this paper, we propose a non-negative constrained dictionary learning (NCDL) algorithm to improve the reconstruction ...
Source: Physiological Measurement - September 29, 2022 Category: Physiology Authors: Bing Zhang, Pengwen Xiong, Jizhong Liu and Jianhua Wu Source Type: research
Ensemble classification combining ResNet and handcrafted features with three-steps training
Objective. This work presents an ECG classifier for variable leads as a contribution to the Computing in Cardiology Challenge/CinC Challenge 2021. It aims to integrate deep and classic machine learning features into a single model, exploring the proper structure and training procedure. Approach. From the initial 88 253 signals, only 84 210 were included. Low quality and unscored recordings were excluded. Three different database subsets of 40 365 recording each were created by dividing in three normal sinus rhythm and sinus bradycardia recordings. Each subset was used to train a different model with shared architecture int...
Source: Physiological Measurement - September 29, 2022 Category: Physiology Authors: Guadalupe Garcia-Isla, Federico M. Muscato, Andrea Sansonetti, Stefano Magni, Valentina D. A. Corino and Luca T. Mainardi Source Type: research
Intratidal compliance of the lung and the total respiratory system
Objective. The worldwide rising quantity of surgeries and the corresponding need of mechanical ventilation means a rising number of patients are at risk of suffering from post-operative pulmonary complications. To prevent this risk, individual mechanics of the lung should be considered when setting the parameters of mechanical ventilation. Intratidal compliance analysis based on transpulmonal pressure would provide an estimate for individual lung mechanics. The downside of such measure, however, is its invasiveness. Accurate measurement requires recording of the esophageal pressure as surrogate for the actual pleural press...
Source: Physiological Measurement - September 25, 2022 Category: Physiology Authors: Patryk Dzierzawski, Jakob Oswalt, Steffen Wirth and Stefan Schumann Source Type: research
Temporal complexity of EEG encodes human alertness
In this study, we propose that balanced dynamics of Electroencephalography (EEG) (so called EEG temporal complexity) is a potentially usef ul feature for identifying human alertness states. Recently, a new signal entropy measure, called range entropy (RangeEn), was proposed to overcome some limitations of two of the most widely used entropy measures, namely approximate entropy (ApEn) and Sample Entropy (SampEn), and showed its relevanc e for the study of time domain EEG complexity. In this paper, we investigated whether the RangeEn holds discriminating information associated with human alertness states, namely awake, drows...
Source: Physiological Measurement - September 20, 2022 Category: Physiology Authors: Mohammad Hadra, Amir Omidvarnia and Mostefa Mesbah Source Type: research
