English
Related papers

Related papers: Electron-conformational transformations in nanosco…

200 papers

A parasystole from a heart-transplant patient is analysed using a beat-to-beat RR interval time series obtained from an electrocardiogram (ECG). The dysrhythmia, resulting from the co-existence of two pacemakers, the sinus node and an…

Medical Physics · Physics 2007-05-23 M. Costa , I. R. Pimentel , T. Santiago , M. J. Rebocho , J. Melo , E. Ducla-Soares

We propose and analyse the properties of a new class of models for the electromechanics of cardiac tissue. The set of governing equations consists of nonlinear elasticity using a viscoelastic and orthotropic exponential constitutive law…

Numerical Analysis · Mathematics 2022-04-08 Adrienne Propp , Alessio Gizzi , Francesc Levrero-Florencio , Ricardo Ruiz-Baier

While ventricular electromechanics is extensively studied, four-chamber heart models have only been addressed recently; most of these works however neglect atrial contraction. Indeed, as atria are characterized by a complex physiology…

A two-component model is developed that consists of a discrete loop of cardiac cells that circulates action potentials together with a cardiac pacing mechanism. Physiological properties of cells such as restitutions of refractoriness and of…

Adaptation and Self-Organizing Systems · Physics 2014-01-16 H. Sedaghat , M. A. Wood , J. W. Cain , C-K. Cheng , C. M. Baumgarten , D. M. Chan

The left ventricular end-systolic pressure-volume relationship (ESPVr) is a key indicator of cardiac contractility. Despite its established importance, several studies suggested that the mechanical mode of contraction, such as isovolumetric…

Medical Physics · Physics 2024-11-12 Francesco Regazzoni , Corrado Poggesi , Cecilia Ferrantini

A techniques, describing electron dynamics for magnetic models closed to cyclical accelerators, is developed and applied to the analysis of electromagnetic radiation emitted by charged particles. Formulas for the angular characteristics of…

Accelerator Physics · Physics 2018-11-27 Oleg Shishanin

We use the qualitative insight of a planar neuronal phase portrait to detect an excitability switch in arbitrary conductance-based models from a simple mathematical condition. The condition expresses a balance between ion channels that…

Neurons and Cognition · Quantitative Biology 2015-06-11 Alessio Franci , Guillaume Drion , Vincent Seutin , Rodolphe Sepulchre

Cardiac growth and remodeling (G&R) patterns change ventricular size, shape, and function both globally and locally. Biomechanical, neurohormonal, and genetic stimuli drive these patterns through changes in myocyte dimension and fibrosis.…

Tissues and Organs · Quantitative Biology 2023-05-04 Amadeus M. Gebauer , Martin R. Pfaller , Fabian A. Braeu , Christian J. Cyron , Wolfgang A. Wall

We present here a simple analytical model for self-oscillations in nano-electro-mechanical systems. We show that a field emission self-oscillator can be described by a lumped electrical circuit and that this approach is generalizable to…

Mesoscale and Nanoscale Physics · Physics 2015-05-18 A. Lazarus , T. Barois , S. Perisanu , P. Poncharal , P. Manneville , E. de Langre , S. T. Purcell , P. Vincent , A. Ayari

An arrhythmia, also known as a dysrhythmia, refers to an irregular heartbeat. There are various types of arrhythmias that can originate from different areas of the heart, resulting in either a rapid, slow, or irregular heartbeat. An…

Signal Processing · Electrical Eng. & Systems 2024-01-12 Taymaz Akan , Sait Alp , Mohammad Alfrad Nobel Bhuiyan

The heart is a vital organ that relies on the orchestrated propagation of electrical stimuli to coordinate each heart beat. Abnormalities in the heart's electrical behaviour can be managed with a cardiac pacemaker. Recently, the closed-loop…

Systems and Control · Computer Science 2016-03-21 Eugene Yip , Sidharta Andalam , Partha S. Roop , Avinash Malik , Mark Trew , Weiwei Ai , Nitish Patel

The low-frequency vibrational spectrum of an isolated nanometer-scale solid differs dramatically from that of a bulk crystal, causing the decay of a localized electronic state by phonon emission to be inhibited. We show, however, that an…

Materials Science · Physics 2009-10-31 Ho-Soon Yang , Michael R. Geller , W. M. Dennis

Non-invasive assessment of the electrical activation pattern can significantly contribute to the diagnosis and treatment of cardiac arrhythmias, due to faster and safer diagnosis, improved surgical planning and easier follow-up. One…

Medical Physics · Physics 2024-01-09 Nathan Dermul , Hans Dierckx

We report on the generic classical electric circuit modeling that describes standard single-tone microwave optomechanics. Based on a parallel RLC circuit in which a mechanical oscillator acts as a movable capacitor, derivations of…

Quantum Physics · Physics 2021-03-19 Xin Zhou , Dylan Cattiaux , Didier Theron , Eddy Collin

Calcium (Ca2+) plays a central role in mediating both contractile function and hypertrophic signalling in ventricular cardiomyocytes. L-type Ca2+ channels trigger release of Ca2+ from ryanodine receptors (RyRs) for cellular contraction,…

Subcellular Processes · Quantitative Biology 2020-08-18 Hilary Hunt , Agne Tilunaite , Greg Bass , Christian Soeller , H. Llewelyn Roderick , Vijay Rajagopal , Edmund J. Crampin

This work is dedicated to the simulation of full cycles of the electrical activity of the heart and the corresponding body surface potential. The model is based on a realistic torso and heart anatomy, including ventricles and atria. One of…

Medical Physics · Physics 2015-09-04 Elisa Schenone , Annabelle Collin , Jean-Frédéric Gerbeau

Background-The electric field applied to the heart during defibrillation causes mechanical forces (electrostriction), and as a result the heart deforms. This paper analyses the physical origin of the deformation, and how significant it is.…

Medical Physics · Physics 2011-02-22 Michelle M. Fritz , Phil W. Prior , Bradley J. Roth

The physics of vibrational kinetics in nitrogen-containing plasma produced by collisions with electrons is studied on the basis of recently derived cross sections and rate coefficients for the resonant vibrational-excitation by…

Chemical Physics · Physics 2013-04-17 V. Laporta , D. Bruno

When generating in-silico clinical electrophysiological outputs, such as electrocardiograms (ECGs) and body surface potential maps (BSPMs), mathematical models have relied on single physics, i.e. of the cardiac electrophysiology (EP),…

Numerical Analysis · Mathematics 2024-02-12 Elena Zappon , Matteo Salvador , Roberto Piersanti , Francesco Regazzoni , Luca Dede' , Alfio Quarteroni

The formation of the electron energy distribution function in nanosecond atmospheric nitrogen discharges is investigated by means of self-consistent solution of the chemical kinetics and the Boltzmann equation for free electrons. The…

‹ Prev 1 2 3 10 Next ›