Search results for "beat"
showing 10 items of 229 documents
Reliability of Short-Term Heart Rate Variability Indexes Assessed through Photoplethysmography
2018
The gold standard method to monitor heart rate variability (HRV) comprises measuring the time series of interbeat interval durations from electrocardiographic (ECG) recordings. However, due to the widespread use, simplicity and usability of photoplethysmographic (PPG) techniques, monitoring pulse rate variability (PRV) from pulse wave recordings has become a viable alternative to standard HRV analysis. The present study investigates the accuracy of PRV, measured as a surrogate of HRV, for the quantification of descriptive indexes computed in the time domain (mean, variance), frequency domain (low-to-high frequency power ratio LF/HF, HF band central frequency) and information domain (entropy…
A Review of Kernel Methods in ECG Signal Classification
2011
Kernel methods have been shown to be effective in the analysis of electrocardiogram (ECG) signals. These techniques provide a consistent and well-founded theoretical framework for developing nonlinear algorithms. Kernel methods exhibit useful properties when applied to challenging design scenarios, such as: (1) when dealing with low number of (potentially high dimensional) training samples; (2) in the presence of heterogenous multimodalities; and (3) with different noise sources in the data. These characteristics are particularly appropriate for biomedical signal processing and analysis, and hence, the widespread of these techniques in biomedical signal processing in general, and in ECG dat…
Non-invasive localization of atrial ectopic beats by using simulated body surface P-wave integral maps
2017
Non-invasive localization of continuous atrial ectopic beats remains a cornerstone for the treatment of atrial arrhythmias. The lack of accurate tools to guide electrophysiologists leads to an increase in the recurrence rate of ablation procedures. Existing approaches are based on the analysis of the P-waves main characteristics and the forward body surface potential maps (BSPMs) or on the inverse estimation of the electric activity of the heart from those BSPMs. These methods have not provided an efficient and systematic tool to localize ectopic triggers. In this work, we propose the use of machine learning techniques to spatially cluster and classify ectopic atrial foci into clearly diffe…
The supraventricular tachycardias: Proposal of a diagnostic algorithm for the narrow complex tachycardias
2013
AbstractThe narrow complex tachycardias (NCTs) are defined by the presence in a 12-lead electrocardiogram (ECG) of a QRS complex duration less than 120ms and a heart rate greater than 100 beats per minute; those are typically of supraventricular origin, although rarely narrow complex ventricular tachycardias have been reported in the literature.As some studies document, to diagnose correctly the NCTs is an arduous exercise because sometimes those have similar presentation on the ECG. In this paper, we have reviewed the physiopathological, clinical, and ECG findings of all known supraventricular tachycardias and, in order to reduce the possible diagnostic errors on the ECG, we have proposed …
Patient-Specific Analysis of Ascending Thoracic Aortic Aneurysm with the Living Heart Human Model
2021
In ascending thoracic aortic aneurysms (ATAAs), aneurysm kinematics are driven by ventricular traction occurring every heartbeat, increasing the stress level of dilated aortic wall. Aortic elongation due to heart motion and aortic length are emerging as potential indicators of adverse events in ATAAs
Evaluation of different mechanical fruit harvesting systems and oil quality in very large size olive trees
2014
In 2006 and 2009, trials were carried out in the Apulia region in Southern Italy to evalu-ate the possibility of mechanizing olive harvesting in groves of old and very large trees. The trees belonged to the cultivars ‘Cellina di Nardò’ and ‘Ogliarola Salentina’. They were 60-100 years old and 7-9 m tall with a canopy volume of 140-360 m3. In the first half of November 2006, with a mechanical beater mounted on a tractor plus hand-held pneumatic combs, the harvesting yield was close to 90% of the total olives present in the canopy, and the harvesting working productivity was around 60 kg of harvested olives h-1 worker-1. With a self-propelled shaker attached to the main branches the harvestin…
The interplay of interoceptive accuracy, facets of interoceptive sensibility, and trait anxiety: A network analysis
2021
Abstract Interoception is the sense of the body's physiological state. Both the ability to accurately perceive bodily signals, and the self-reported sensibility for the body were assumed to be reciprocally associated with negative affect. Up to now, the specific interplay between dimensions of interoception and negative affect remains largely unknown. We investigated the interplay of cardioceptive accuracy assessed by a heartbeat tracking task, facets of interoceptive sensibility as measured by the Multidimensional Assessment of Interoceptive Awareness, and trait anxiety as measured by the trait version of the State-Trait-Anxiety inventory across two studies (n = 243) using a network analyt…
The soundscape of the ceremonies for the beatification of St Teresa of Ávila in the Crown of Aragon, 1614
2015
[EN] The beatification of Saint Teresa of Ávila in October 1614 gave rise to widespread celebrations in many of the cities and towns of the Iberian Peninsula. Printed relaciones describing these celebrations, despite their limitations —in terms of political agenda, propaganda, rivalry and literary style— can nevertheless provide information about musical experience and can help to recreate the ephemeral soundscapes of these events. This article will focus on the ceremonies held in the Crown of Aragon, especially Saragossa and Barcelona, taking into consideration the typology of different musics —heraldic, divine and festive— and factors such as the moment in time, function, dynamic, urban s…
La imagen de Beatrice Portinari en la obra de Dante y su reflejo en el arte
2017
La tesis titulada La imagen de Beatrice Portinari en la obra de Dante y su reflejo en el arte, trata de realizar un estado de la cuestión de las representaciones artísticas sobre la figura de la musa de. Pero para poder centrarme en el periodo comprendido entre 1800 y 1921 ha sido necesario realizar un estado de la cuestión hasta alcanzar el siglo XIX para poder situar al lector de la importancia de resaltar este siglo en la representación artística de Beatrice Portinari. Fue precisamente en este periodo cuando nació una verdadera tradición representativa de la musa de Dante que se mantiene hasta nuestros días. La tesis está planteada en cinco grandes bloques que configuran el eje principal…