scholarly journals Simulation and Visualization of the electrical Activity of the Heart with focal ventricular tachycardia in a 3D Model

2021 ◽  
Vol 7 (2) ◽  
pp. 17-20
Author(s):  
Christian Quester ◽  
Matthias Heinke ◽  
Johannes Hörth
Keyword(s):  
Ventricular Tachycardia ◽  
Electric Field ◽  
Heart Rhythm ◽  
Frame Rate ◽  
Nerve Tissue ◽  
Medical Professionals ◽  
Simulation Results ◽  
Field Lines ◽  
Focal Excitation ◽  
Ventricular Tachycardias

Abstract Patients with focal ventricular tachycardia are at risk of hemodynamic failure and if no treatment is provided the mortality rate can exceed 30%. Therefore, medical professionals must be adequately trained in the management of these conditions. To achieve the best treatment, the origin of the abnormality should be known, as well as the course of the disease. This study provides an opportunity to visualize various focal ventricular tachycardias using the Offenburg heart rhythm model. Modeling and simulation of focal ventricular tachycardias in the Offenburg heart rhythm model was performed using CST (Computer Simulation Technology) software from Dessault Systèms. A bundle of nerve tissue in different regions in the left and right ventricle was defined as the focus in the already existing heart rhythm model. This ultimately served as the origin of the focal excitation sites. For the simulations, the heart rhythm model was divided into a mesh consisting of 5354516 tetrahedra, which is required to calculate the electric field lines. The simulations in the Offenburg heart rhythm model were able to successfully represent the progression of focal ventricular tachycardia in the heart using measured electrical field lines. The simulation results were realized as an animated sequence of images running in real time at a frame rate of 20 frames per second. By changing the frame rate, these simulations can additionally be produced at different speeds. The Offenburg heart rhythm model allows visualization of focal ventricular arrhythmias using computer simulations. By selecting the frame rate, the speed of the simulation results can be adjusted accordingly to visualize the electric field lines of focal ventricular tachycardias in more detail. The static and dynamic simulation results could be used in the future for teaching and research, including the training of medical professionals.

scholarly journals Global MHD Simulation of the Weak Southward IMF Condition for Different Time Resolutions

2021 ◽  
Vol 8 ◽  
Author(s):  
Kyung Sun Park
Keyword(s):  
Magnetic Field ◽  
Electric Field ◽  
Magnetic Reconnection ◽  
Three Dimensional ◽  
Slow Solar Wind ◽  
Polar Cap ◽  
Plasma Properties ◽  
Simulation Results ◽  
Field Lines ◽  
The Impact

We performed high-resolution three-dimensional global MHD simulations to determine the impact of weak southward interplanetary magnetic field (IMF) (Bz = −2 nT) and slow solar wind to the Earth’s magnetosphere and ionosphere. We considered two cases of differing, uniform time resolution with the same grid spacing simulation to find any possible differences in the simulation results. The simulation results show that dayside magnetic reconnection and tail reconnection continuously occur even during the weak and steady southward IMF conditions. A plasmoid is generated on closed plasma sheet field lines. Vortices are formed in the inner side of the magnetopause due to the viscous-like interaction, which is strengthened by dayside magnetic reconnection. We estimated the dayside magnetic reconnection which occurred in relation to the electric field at the magnetopause and confirmed that the enhanced electric field is caused by the reconnection and the twisted structure of the electric field is due to the vortex. The simulation results of the magnetic field and the plasma properties show quasi-periodic variations with a period of 9–11 min between the appearances of vortices. Also the peak values of the cross-polar cap potential are both approximately 50 kV, the occurrence time of dayside reconnections are the same, and the polar cap potential patterns are the same in both cases. Thus, there are no significant differences in outcome between the two cases.

scholarly journals RF-Carpets that Compress Ions to High Density Beams

2015 ◽  
Vol 21 (S4) ◽  
pp. 84-89
Author(s):  
H. Wollnik ◽  
F. Arai ◽  
Y. Ito ◽  
P. Schury ◽  
M. Wada
Keyword(s):  
Phase Space ◽  
Electric Field ◽  
Electric Fields ◽  
Ion Beams ◽  
High Density ◽  
Ion Density ◽  
Field Lines

AbstractIons that are moved by electric fields in gases follow quite exactly the electric field lines since these ions have substantially lost their kinetic energies in collisions with gas atoms or molecules and so carry no momenta. Shaping the electric fields appropriately the phase space such ion beams occupy can be reduced and correspondingly the ion density of beams be increased.

scholarly journals Mapping of steady-state electric fields and convective drifts in geomagnetic fields – Part 1: Elementary models

2016 ◽  
Vol 34 (1) ◽  
pp. 55-65 ◽  
Author(s):  
A. D. M. Walker ◽  
G. J. Sofko
Keyword(s):  
Magnetic Field ◽  
Steady State ◽  
Electric Field ◽  
Electric Fields ◽  
Magnetic Field Line ◽  
Geomagnetic Field ◽  
Geomagnetic Field Models ◽  
Spatial Derivatives ◽  
Field Lines ◽  
The Magnetic Field

Abstract. When studying magnetospheric convection, it is often necessary to map the steady-state electric field, measured at some point on a magnetic field line, to a magnetically conjugate point in the other hemisphere, or the equatorial plane, or at the position of a satellite. Such mapping is relatively easy in a dipole field although the appropriate formulae are not easily accessible. They are derived and reviewed here with some examples. It is not possible to derive such formulae in more realistic geomagnetic field models. A new method is described in this paper for accurate mapping of electric fields along field lines, which can be used for any field model in which the magnetic field and its spatial derivatives can be computed. From the spatial derivatives of the magnetic field three first order differential equations are derived for the components of the normalized element of separation of two closely spaced field lines. These can be integrated along with the magnetic field tracing equations and Faraday's law used to obtain the electric field as a function of distance measured along the magnetic field line. The method is tested in a simple model consisting of a dipole field plus a magnetotail model. The method is shown to be accurate, convenient, and suitable for use with more realistic geomagnetic field models.

Electric Field Uniformity Characteristic of a Reverberation Chamber with a Composite QRD

2013 ◽  
Vol 684 ◽  
pp. 518-521
Author(s):  
Eugene Rhee ◽  
Ji Hoon Lee
Keyword(s):  
Electric Field ◽  
Electromagnetic Compatibility ◽  
Quadratic Residue ◽  
Test Facility ◽  
Uniform Electric Field ◽  
Reverberation Chamber ◽  
Standard Requirement ◽  
International Standard ◽  
Field Uniformity ◽  
Simulation Results

This paper presents the electric field characteristics in a reverberation chamber which is an electromagnetic compatibility test facility that uses a stirrer to generate a uniform electric field inside it. In this paper, a diffuser is introduced from acoustics and newly designed to overcome problems of a stirrer. To validate the effect of a diffuser, a composite quadratic residue diffuser and a reverberation chamber are modeled. Then, the field uniformity inside the reverberation chamber is simulated by XFDTD 6.2 simulation program. Simulation results show that the electric field uniformity in the reverberation chamber satisfies the international standard requirement. This shows that the composite quadratic residue diffuser can be substituted for a stirrer.

scholarly journals A Look into Students' Interpretation of Electric Field Lines

2017 ◽  
pp. 342-364
Author(s):  
Esmeralda Campos ◽  
Genaro Zavala
Keyword(s):  
Magnetic Field ◽  
Electric Field ◽  
Random Sample ◽  
Qualitative Approach ◽  
Undergraduate Level ◽  
Field Lines

On Electricity & Magnetism (EM) courses at undergraduate level, the concept of electric field poses one of the most relevant and basic topics, along with the concept of magnetic field. Professors and students may use different diagrams as a tool to visualize the electric field, such as vectors or electric field lines. The present study aims to identify how students interpret and use electric field lines as a tool or resource to describe the electric field. Two versions of a test with open-ended questions were administered in Spanish in a private Mexican university to a random sample of students taking the EM course, and were analyzed with a qualitative approach. It was found that students do not interpret electric field lines diagrams correctly, which may lead to misconceptions. Many students based their answers on the concepts of superposition, force and repulsion.

Antioxidant effects of astaxanthin on electric field stimulated skin and sciatic nerve tissue

2021 ◽  
Vol 28 (5) ◽  
pp. 1003
Author(s):  
Fuat Uslusoy ◽  
Goktug Aslankoc ◽  
Arzu Yalcin ◽  
Selman Altuntas ◽  
Dudu Yavuz ◽  
...  
Keyword(s):  
Sciatic Nerve ◽  
Electric Field ◽  
Nerve Tissue ◽  
Antioxidant Effects

Rare presentation of antisynthetase syndrome complicated by myocarditis resulting in sustained ventricular tachycardia

2021 ◽  
Vol 14 (5) ◽  
pp. e234396
Author(s):  
Mehak Asad ◽  
Rajavarma Viswesvaraiah
Keyword(s):  
Differential Diagnosis ◽  
Ventricular Tachycardia ◽  
Sustained Ventricular Tachycardia ◽  
Complex Case ◽  
Medical Professionals ◽  
Antisynthetase Syndrome ◽  
Rare Presentation ◽  
Mortality And Morbidity ◽  
Autoimmune Condition ◽  
Guidelines And Recommendations

We report a complex case of a 66-year-old female patient with a diagnosis of interstitial lung disease (ILD) that was later correctly identified as an antisynthetase syndrome. This was only diagnosed after an episode of sustained ventricular tachycardia secondary to myocarditis. In this case report, we focus on the clinical features of this rare autoimmune condition and aim to provide useful tips to both general medical professionals and cardiologists to achieve correct differential diagnosis according to the updated international guidelines and recommendations. Early diagnosis is especially important due to the possible arrhythmogenic complications and the high mortality and morbidity associated with ILD and cardiac abnormalities.

An Embedded Vision System for RoboCup

2013 ◽  
pp. 333-351
Author(s):  
P. Cavestany Olivares ◽  
D. Herrero-Pérez ◽  
J. J. Alcaraz Jiménez ◽  
H. Martínez Barberá
Keyword(s):  
Vision System ◽  
Frame Rate ◽  
Image Process ◽  
Embedded Vision ◽  
Embedded Vision System ◽  
Robust Filters ◽  
Field Lines

In this chapter, the authors describe their vision system used in the Standard Platform League (SPL), one of the official leagues in RoboCup competition. The characteristics of SPL are very demanding, as all the processing must be done on board, and the changeable environment requires powerful methods for extracting information and robust filters. The purpose is to show a vision system that meets these goals. The chapter describes the architecture of the authors’ system as well as the flowchart of the image process, which is designed in such a manner that allows a rapid and reliable calibration. The authors deal with field features detection by finding intersections between field lines at frame rate, using a fuzzy-Markov localisation technique. Also, the methods implemented to recognise the ball and goals are explained.

General Relations between Fields and Sources

2019 ◽  
pp. 63-84
Author(s):  
Richard Freeman ◽  
James King ◽  
Gregory Lafyatis
Keyword(s):  
Electric Field ◽  
Spatial Variations ◽  
Rate Of Change ◽  
Retarded Time ◽  
Finite Speed ◽  
Radiation Fields ◽  
Source Current ◽  
Field Lines ◽  
General Relations ◽  
Relationship Of

The general relationship of changes in source current, charge and/or position and the fields that they produce are examined in the context of the development of equations that are known as “Jefimenko’s Equations.” These expressions give the fields at a point removed from the source in terms of the charge and current distributions evaluated at the “retarded time.” In this development, the finite speed of light is shown to connect the time rate of change in source conditions to the spatial variations of the potential at the field point. Using a graphical argument, the transverse nature of radiation fields is demonstrated based on electric field lines as envisioned by Faraday.

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