Stress Wave Signal Denoising Using Ensemble Empirical Mode Decomposition and an Instantaneous Half Period Model

Stress-wave-based techniques have been proven to be an accurate nondestructive test means for determining the quality of wood based materials and they been widely used for this purpose. However, the results are usually inconsistent, partially due to the significant difficulties in processing the nonlinear, non-stationary stress wave signals which are often corrupted by noise. In this paper, an ensemble empirical mode decomposition (EEMD) based approach with the aim of signal denoising was proposed and applied to stress wave signals. The method defined the time interval between two adjacent zero-crossings within the intrinsic mode function (IMF) as the instantaneous half period (IHP) and used it as a criterion to detect and classify the noise oscillations. The waveform between the two adjacent zero-crossings was retained when the IHP was larger than the predefined threshold, whereas the waveforms with smaller IHP were set to zero. Finally the estimated signal was obtained by reconstructing the processed IMFs. The details of threshold choosing rules were also discussed in the paper. Additive Gaussian white noise was embedded into real stress wave signals to test the proposed method. Butterworth low pass filter, EEMD-based low pass filter and EEMD-based thresholding filter were used to compare filtering performance. Mean square error between clean and filtered stress waves was used as filtering performance indexes. The results demonstrated the excellent efficiency of the proposed method

Models and analysis of vocal emissions for biomedical applications: 5th International Workshop: December 13-15, 2007, Firenze, Italy

The MAVEBA Workshop proceedings, held on a biannual basis, collect the scientific papers presented both as oral and poster contributions, during the conference. The main subjects are: development of theoretical and mechanical models as an aid to the study of main phonatory dysfunctions, as well as the biomedical engineering methods for the analysis of voice signals and images, as a support to clinical diagnosis and classification of vocal pathologies. The Workshop has the sponsorship of: Ente Cassa Risparmio di Firenze, COST Action 2103, Biomedical Signal Processing and Control Journal (Elsevier Eds.), IEEE Biomedical Engineering Soc. Special Issues of International Journals have been, and will be, published, collecting selected papers from the conference

Towards respiratory muscle-protective mechanical ventilation in the critically ill: technology to monitor and assist physiology

Inadequate delivery of ventilatory assist and unphysiological respiratory drive may severely worsen respiratory muscle function in mechanically ventilated critically ill patients. Diaphragm weakness in these patients is exceedingly common (>60% of patients) and associated with poor clinical outcomes, including difficult ventilator liberation, increased risks of intensive care unit (ICU) and hospital readmission, and mortality. The underlying mechanisms of diaphragm dysfunction were extensively discussed in this thesis. Pathways primarily include the development of diaphragm disuse atrophy due to muscle inactivity or low respiratory drive (strong clinical evidence), and diaphragm injury as a result of excessive breathing effort due to insufficient ventilator assist or excessive respiratory drive (moderate evidence, mostly from experimental work). Excessive breathing effort may also worsen lung injury through pathways that include high lung stress and strain, pendelluft, increased lung perfusion, and patient-ventilator dyssynchrony. Relatively little attention has been paid to the effects of critical illness and mechanical ventilation on the expiratory muscles; however, dysfunction of these muscles has been linked to inadequate central airway clearance and extubation failure. The motivation for performing the work presented in this thesis was the hypothesis that maintaining physiological levels of respiratory muscle activity under mechanical ventilation could prevent or attenuate the development respiratory muscle weakness, and hence, improve patient outcomes. This strategy, integrated with lung-protective ventilation, was recently proposed by international experts from different professional societies (this thesis), and is referred to as a combined lung and diaphragm-protective ventilation approach. Today, an important barrier for implementing and evaluating such an approach is the lack of feasible, reliable and well-understood modalities to assess breathing effort at the bedside, as well as strategies for assisting and restoring respiratory muscle function during mechanical ventilation. Furthermore, monitoring breathing effort is crucial to identify potential relationships between patient management and detrimental respiratory (muscle) function that can be targeted to improve clinical outcomes. In this thesis we identified and improved monitoring modalities for the diaphragm (Part I), we investigated the impact of mechanical ventilation on the respiratory pump, especially the diaphragm (Part II), and we evaluated a novel strategy for maintaining expiratory muscle activity under mechanical ventilation (Part III)

Epidemiology of Injury in English Women's Super league Football: A Cohort Study

INTRODUCTION: The epidemiology of injury in male professional football has been well documented (Ekstrand, Hägglund, & Waldén, 2011) and used as a basis to understand injury trends for a number of years. The prevalence and incidence of injuries occurring in womens super league football is unknown. The aim of this study is to estimate the prevalence and incidence of injury in an English Super League Women’s Football squad. METHODS: Following ethical approval from Leeds Beckett University, players (n = 25) signed to a Women’s Super League Football club provided written informed consent to complete a self-administered injury survey. Measures of exposure, injury and performance over a 12-month period was gathered. Participants were classified as injured if they reported a football injury that required medical attention or withdrawal from participation for one day or more. Injuries were categorised as either traumatic or overuse and whether the injury was a new injury and/or re-injury of the same anatomical site RESULTS: 43 injuries, including re-injury were reported by the 25 participants providing a clinical incidence of 1.72 injuries per player. Total incidence of injury was 10.8/1000 h (95% CI: 7.5 to 14.03). Participants were at higher risk of injury during a match compared with training (32.4 (95% CI: 15.6 to 48.4) vs 8.0 (95% CI: 5.0 to 10.85)/1000 hours, p 28 days) of which there were three non-contact anterior cruciate ligament (ACL) injuries. The epidemiological incidence proportion was 0.80 (95% CI: 0.64 to 0.95) and the average probability that any player on this team will sustain at least one injury was 80.0% (95% CI: 64.3% to 95.6%) CONCLUSION: This is the first report capturing exposure and injury incidence by anatomical site from a cohort of English players and is comparable to that found in Europe (6.3/1000 h (95% CI 5.4 to 7.36) Larruskain et al 2017). The number of ACL injuries highlights a potential injury burden for a squad of this size. Multi-site prospective investigations into the incidence and prevalence of injury in women’s football are require