Electromagnetic Fields In Human Body Research Articles

EVALUATION OF ELECTROMAGNETIC FIELDS IN HUMAN BODY EXPOSED TO INVERTER OF PURE ELECTRIC VEHICLE.

On the basis of the basic principle of electromagnetic dosimetry, the paper studies the electromagnetic exposure of a passenger's body to a compound electromagnetic field caused by the combined action of DC and AC bus currents of a pure electric vehicle inverter. By building an electromagnetic model of a pure electric vehicle body, adult human body and inverter, the finite element method is used to calculate the magnetic induction intensity(|B|), induced electric field intensity(|E|) and induced current density(|J|) of the compound electromagnetic field to the human trunk and central nervous system in the driver and front seat passenger. The numerical results are compared with the exposure limits defined by the International Commission on Non-Ionizing Radiation Protection (ICNIRP). The fields are well below the safe exposure limits defined by ICNIRP.

Radiation Characteristic Analysis of Antenna Deeply Implanted in Human Body and Localization Sensor Array

In-vivo antennas are increasingly used in human implant devices. However, the two most confusing issues, analytical solutions of radiation fields and communication frequency selection of antennas deeply implanted in human bodies, have not been studied and resolved, whereas they are both significant to antenna design, communication and localization system construction of human implant devices. Therefore, in this paper, the electromagnetic model of an antenna in a lossy multi-layered cylindrical media is established, which can more accurately simulate the human environment. The analytical solutions of electric intensity, magnetic intensity and Poynting vector are derived by solving the boundary value problem of electromagnetic fields, which have not been reported in the existing literatures. Through theoretical calculations at 433 MHz, 915 MHz and 2.45 GHz, the radiation characteristics of the antenna in the torso are analyzed, and the important results are achieved. (i)The electromagnetic fields in human body do not attenuate monotonously with the increasing of the field point distance, and multiple extreme points appear due to the influence of the reflected wave at the interface of different human tissues. (ii)The electromagnetic field intensity at the surface of human body is the largest at 915 MHz, while the induced voltage of receiving antenna outside the body is the largest at 2.45 GHz. Finally, by experiments and simulations, the analytical solutions are verified, which can provide theoretical guidance for the in-vivo antenna design, frequency selection, communication and electromagnetic localization. A localization system for human implant devices as an antenna application example is built, and it is proved that the theoretical model proposed in this paper can be used for human implant device localization.

Variable characteristics of viscosity and thermal conductivity in peristalsis of magneto-Carreau nanoliquid with heat transfer irreversibilities

Background: Peristaltic is a basic way of fluid transportation in physiology, engineering and nuclear industry. Importance of peristalsis is due to its contraction and compulsion property of symmetric and asymmetric type channel walls. Another beauty of this mechanism is that the channel walls propagates and push the material along the tube/conduit channel walls. This mechanism shows its presence in physiology while food particles are transferred through esophagus and stomach, urine through intestines, spermatoza transportation in reproductive tract. In industry it is found in roller and finger pumps, drug delivery and various nuclear materials e.g. toxic, corrosive, noxious etc. Magnetic field in peristalsis is found helpful in treatment of various treatments using magnets. Actually earth and human body as a whole comprises of magnetic and electric fields. The medical specialists found that unbalances of electromagnetic field in human body is the reason for emotional and physical disturbance. In addition it has significant and potential utilizations in modification of medical, industrial and chemical, procedures for example MRI, evaporation, convection, thermoregulation, MHD throttles, and in various types of tumor treatments. Entropy production work out irreversibility in complex systems which are frequently encountered in industrial mechanisms. In view of that, this methodology is effectually implemented in distinct technological applications covering porous media, propulsion ducts, electronic cooling, turbo-machinery and combustion. Method: Modelled flow mechanism is nonlinear and coupled due to considered assumptions (i.e. nanofluid, nonlinear porous channel, mixed convection, variable viscosity and thermal conductivity, activation energy and chemical reaction). Such nonlinear and coupled system is difficult to tackle analytically. Thus to obtain the solution we employed RK algorithm for numerical simulations. Results: Stronger magnetic parameter shows resistive characteristics to the flow field. Nonlinear Darcy medium assists the fluid motion at channel center and resits at walls vicinity. Variable characteristics of thermal conductivity moderate the soak or disperse up heat ability which corresponds to temperature reduction. Thermal slip quantity increase the temperature whereas concentration slip deduct the concentration of Carreau nanomaterial. Entropy and Bejan number shows maximum response for higher dissipation estimations. Brownian and thermopherotic motions aspects has reverse impact on nanomaterial concentration. Conclusion: Entropy and Bejan number deduces for higher variable thermal conductivity values. Carreau material variable enhance the entropy of the system as a whole.

Electromagnetic fields in body by wireless inductive system

Purpose– The purpose of this paper is to calculate the induced electromagnetic fields in human body exposed to the wireless inductive charging system of electric vehicles has been conducted based on the numerical simulation.Design/methodology/approach– A homogeneous human body model is built and a representative wireless inductive charging system is used for the exposure assessment. The numerical simulation relies on finite element method with formulations in terms of the magnetic vector potential. The electromagnetic fields in terms of magnetic flux density and electric field are computed in the human body and compared with the electromagnetic exposure limits.Findings– It has been found that the induced EMFs in the near-field exposure configuration greatly comply with the safety guidelines.Originality/value– This study could help the development of the wireless inductive charging system with meeting the safety standard of radiation protection.

Evaluation of Electromagnetic Fields in Human Body Exposed to Wireless Inductive Charging System

This paper presents an evaluation of the EMFs in the human body exposed to the wireless inductive charging system of electric vehicles such that the compliance of this charging system with respect to human EM exposure limits can be examined. A magnetic resonance imaging-derived and high-resolution model of the human body is used. An exposure assessment of a representative wireless inductive charging system, under a limited set of operating conditions, is provided to estimate the induced EMFs. The numerical analysis is performed with the finite element method. Numerical modeling of the system next to a standing human model shows that the EM exposure limits can be absolutely satisfied even when the transmitter coil is very close to the body. Furthermore, the worst configuration for the exposure evaluation of the wireless charging system is taken into consideration. This paper provides a useful guideline for the industry to develop inductive charging systems following the safety standards of radiation protection.