Biomedical subjects

L Anglesio

Publications and source records attributed to L Anglesio.

9 recordsLinked to original sources

PubMed2004

Ray-tracing techniques to assess the electromagnetic field radiated by radio base stations: application and experimental validation in an urban environment.

This paper aims to validate a ray-tracing model for electromagnetic field calculation, which is used in urban environments to predict irradiation from radio base stations for population exposure evaluation. Validation was carried out through a measurement campaign by choosing measurement points in order to test different propagation environments and analysing broadcast control channels through narrow band measurements. Comparison of the calculated and measured fields indicates that the ray-tracing model used calculates electric field with good accuracy, in spite of the fact that the propagation environment is not described in detail, because of difficulties in modelling the geometrical and electrical characteristics of urban areas. Differences between the calculated and measured results remain below 1.5 dB, with a mean value of 1 dB.

Algorithms↗

PubMed2004

Hearing aids' electromagnetic immunity to environmental RF fields.

In this work, the electromagnetic interference on hearing aids was evaluated. Electromagnetic (EM) immunity tests on different types of hearing aids were carried out, using signals of intensity and modulation comparable to those present in the environment. The purpose of this work is to characterise the interference, establishing the immunity threshold for different frequencies and finding out which types of hearing aids are more susceptible, and in which frequency range. The tests were carried out in a GTEM cell on seven hearing aids, using AM and GSM signals in the radiofrequency (RF) range.

Cell Phone↗

PubMed2004

Experimental procedures and statistical results for evaluation of exposure to a radiofrequency electromagnetic field with complex analogue modulation.

The paper illustrates an experimental set-up used to monitor over long periods the peak and average power associated with a complex analogue modulated signal. The procedure was applied to a standard PAL television transmission. The measurement was carried out from a remote location, and a complete tele-measuring system was designed, configured and tested. Following the application of the measuring system to some real cases, interesting statistical results illustrating long-period exposure values were reported.

Algorithms↗

PubMed2004

Exposure measuring techniques for wide band mobile radiocommunications.

The paper illustrates the limits and performances of different experimental monitoring techniques, which are applied to digitally modulated radiofrequency electromagnetic fields used for mobile telecommunications. Different experimental set-ups have been developed, verified and applied for the analysis and characterisation of wide band probes and narrow band measuring procedures.

Algorithms↗

PubMed2001

Outdoor background ELF magnetic fields in an urban environment.

Classification of 'exposed/non-exposed' subjects in epidemiological studies concerning the possible cancer risk associated with ELF magnetic field exposure is based on the a priori assumption of magnetic field value cut-off points that, often, are defined equal to minimum exposure levels typical of a population residing near high voltage facilities (0.1-4.2 microT), but in some cases an environmental magnetic field level not associated with transmission lines can exist. The results of an ELF magnetic field survey in an Italian urban area (about 1 million inhabitants) are presented: average field levels are correlated with population density of different districts. Exposure indexes are obtained, which are compared with those evaluated in studies regarding domestic exposure: background average levels result in comparable to cut-off points in epidemiological studies, but in some districts with high population density, they are much higher. This shows that knowledge of background magnetic field level in urban areas can assume a significant role in exposure assessment.

Background Radiation↗

PubMed2001

Population exposure to electromagnetic fields generated by radio base stations: evaluation of the urban background by using provisional model and instrumental measurements.

Electromagnetic radiation, which is used by broadcasting and mobile telephone systems to transmit information, permeates the city environment. In order to properly evaluate population exposure to electromagnetic fields, knowledge of their intensity and spectral components is necessary. In this study the results of radiofrequency field monitoring carried out in Torino, a large town located in the north-west of Italy are shown: the variation of the electromagnetic field strength is evaluated as a function of the height from the ground, the location in the urban area and the frequency. separating the contributions of the different sources (broadcasting antennas and radio base stations for mobile phones). Furthermore, the contribution of the radio base stations is theoretically evaluated, adding the emissions off all installations situated in Torino and examining the field strength maps calculated, considering the orography, for different heights. The theoretical values are also compared with those measured in the frequency range of mobile telephony emissions.

Background Radiation↗

PubMed2001

Calibration and evaluation of uncertainty in the measurement of environmental electromagnetic fields.

After a brief description of the reference systems for the calibration of the electromagnetic field meters set up at IEN and the Ivrea Department of ARPA, the procedures for the evaluation of the measurement uncertainty are discussed, with reference to the problem of identifying and quantifying the different uncertainty components. which are due both to the field meter characteristics and to the measurement procedure and conditions. The problem of how to compare a measurement result, which consists of the measurement value and its associated uncertainty, with a limit fixed by the standards is also faced.

Calibration↗

PubMed2001

Numerical and experimental analysis of e-field scattering from the ground for base station antennae.

Based on the numerical determination of the complete irradiation volume of a commercial RBS antenna--performed using the FDTD method and the Kirchhoff integral formula for near to far field transformation--open site estimations of the electric field are made and compared with experimentally measured values. To describe the actual behaviour of the radiation field, the inherently complex phasic nature of plane waves is taken into account, together with their two independent states of polarisation. This information is contained in the radiation pattern previously deduced. Moreover, a reflected contribution from flat ground is introduced, along with the line-of-sight ray. Amplitude and phase of the reflected wave are calculated using Fresnel formulae for stratified ground and two polarisation states, i.e. normal and parallel to the plane of incidence. Good agreement with measured values is achieved only by using such assumptions.

Electromagnetic Fields↗

PubMed1995

Spectral analysis of magnetic fields from domestic appliances and corresponding induced current densities in an anatomically based model of the human head.

Magnetic fields emitted by electric appliances such as razors, hair dryers, and drills were measured in the frequency domain. Results show the presence of high-frequency components (up to 96 kHz for razors, up to 3.4 kHz for hair dryers, and up to 8.6 kHz for drills) in the harmonic content of the fields. The measured fields were used to calculate the induced current densities in an anatomically based model of the human head (resolution 1.31 cm) by using the impedance method. The harmonic field contribution to the current density was higher than that from the carrier frequency for all the tested appliances.

Electronics↗