Received January 5, 2022, accepted February 27, 2022, date of publication March 3, 2022, date of current version March 18, 2022.
Digital Object Identifier 10.1109/ACCESS.2022.3156477
Electromagnetic Characterization of UHF-RFID
Fixed Reader in Healthcare Centers Related
to the Personal and Labor Health
VICTORIA RAMOS 1, (Senior Member, IEEE), OSCAR JAVIER SUÁREZ2,
VÍCTOR M. FEBLES SANTANA3, DAVID SAMUEL SUÁREZ RODRÍGUEZ3, ERIK AGUIRRE4,
SILVIA DE MIGUEL-BILBAO 1, PABLO MARINA1, LUIS ENRIQUE RABASSA LÓPEZ-CALLEJA3,
MIKEL CELAYA-ECHARRI5, FRANCISCO FALCONE 4,6, (Senior Member, IEEE),
AND JOSE ÁNGEL HERNÁNDEZ-ARMAS 3
1Telemedicine and Digital Health Research Unit, Instituto de Salud Carlos III, 28029 Madrid, Spain
2Radiofrequency Laboratory, Dirección General de Telecomunicaciones y Ordenación de los Servicios de Comunicación Audiovisual, 28071 Madrid, Spain
3Engineering Department, Hospital Universitario de Canarias, La Laguna, 38320 Tenerife, Spain
4Electric, Electronic, and Communication Engineering Department, Universidad Pública de Navarra, 31006 Pamplona, Spain
5School of Engineering and Sciences, Tecnológico de Monterrey, Monterrey, NL 64849, Mexico
6Institute of Smart Cities, Universidad Pública de Navarra, 31006 Pamplona, Spain
Corresponding author: Victoria Ramos (vramos@isciii.es)
This work was supported in part by the Instituto de Salud Carlos III Project ‘‘Electromagnetic Characterization in Smart Environments of
Healthcare, and Their Involvement in Personal, Occupational, and Environmental Health’’ under Grant PI14CIII/00056, and in part by the
Sub-Directorate-General for Research Assessment and Promotion through the Project ‘‘Metrics Development for Electromagnetic Safety
Assessment in Healthcare Centers in the Context of 5G [(PI19CIII/00033) TMPY 508/19].’’
ABSTRACT Hospitals and healthcare centers are experiencing a remarkable implementation of new
systems based on wireless communications technologies. Many of these systems provide location services
and identification of materials, instrumentation and even patients, which promotes the increase of the
quality and the efficiency of healthcare. A tracking system based on short-range radio frequency, UHF-
RFID is evaluated. This system helps with location of orthopedic prosthesis according to the criteria and
requirements of a specific hospital environment. It is characterized the influence of UHF-RFID system in
the electromagnetic environment by measuring the parameters and characteristics of the emission levels. The
results of the assessment are represented through 2D contour maps and simulations have been performed by
means of an in-house 3D-RL algorithm. The proposed graph aims to provide a methodology of studying
the electromagnetic environments and the evaluation of the safety conditions of workers, patients, and
people in general. E field exposure levels due to the RFID localization system were analyzed in order to
verify regulations concerning the safety of patients and the general public in the labor and healthcare fields.
Localized electromagnetic field exposure at levels which may cause electromagnetic hazards in the specific
healthcare environment have been found and potentially excessive exposure to EMF emitted by UHF RFID
devices may apply to patients or bystanders. In all cases, insufficient electromagnetic immunity of electronic
devices (including AIMD and other medical devices) should be considered and the electromagnetic hazards
may be limited also by relevant preventive measures, as also shown in this paper, together with the principles
of an in-situ evaluation of electromagnetic hazards near the UHF-RFID devices.
INDEX TERMS UHF-RFID, E-field strength distribution, electromagnetic hazard, healthcare centers,
radiofrequency exposure, 2D contour maps, 3D ray launching (3D-RL), environmental assessment, radiation
protection.
I. INTRODUCTION
The implementation of new systems based on wireless com-
munications technologies in healthcare centers has increased
The associate editor coordinating the review of this manuscript and
approving it for publication was Su Yan .
in the last years. In the context of Smart Cities/Smart
Health, heterogeneous wireless network operation is piv-
otal in order to provide context-awareness, increasing the
use of wireless systems in these centers. The use and
presence of wireless technologies (employing non-ionizing
radiation, mostly from the radiofrequency (RF) range of
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V. Ramos et al.: Electromagnetic Characterization of UHF-RFID Fixed Reader in Healthcare Centers Related to Personal
electromagnetic field (EMF) have increased exponentially
at the same time, extending the technological advances and
developments to a large number of applications and services.
With more than half of the population living in cities [1] and
an average (constantly increasing) of more than 2.4 devices
per user connected to the internet in 2018 [2], billions of
devices and wireless technologies, interconnected by Het-
erogeneous Networks (HetNet), are and will be coexisting
as Complex Heterogeneous Environments. Information and
Communications Systems (ICS) are, unavoidably, sources
of electric and magnetic fields, to which a large proportion
of the population is exposed. We are immersed in a grow-
ing trend of implementation and adoption of new wireless
systems in various domains such as domestic, work envi-
ronments, and of course the healthcare environment with
dynamic condition changes and cumulative exposures in
terms of spatial and technical features as well as the dif-
ferent user densities, distributions and communication link
requirements. EMF exposure characterization, monitoring
and evaluation is particularly needed in indoor environ-
ments, [3], from domestic household to public environment
such as administrative, commercial centers and healthcare
environments [4]–[9]. Smart solutions for medical purposes
(e-Health) are one of the earliest and already the most
widely worldwide implemented smart solutions. Especially
the applications of information systems based on Short-range
technologies are experiencing a notable boom in the afore-
mentioned environments, especially the following technolo-
gies: Radio Frequency Identification (RFID), Bluetooth (BT),
ZigBee, ANT, Ultra Wide Band (UWB), Wi-Fi, and Near
Field Communication (NFC). Recently also new systems
such as fifth-generation (5G) networks, along with technical
improvements in miniaturization, the development of novel,
smart, small-sized wireless wearable sensors for biomoni-
toring and sensing applications, popularly known as Short-
RangeDevices (SRDs), has been enabled for general use [10].
Many of these systems provide location services and iden-
tification of materials, instrumentation and even patients.
In the healthcare field, these wireless systems are being used
to control, record, and transmit a variety of health related
data. In relation to the development of medical activity and
which constitutes an imminent need in any healthcare envi-
ronment, is monitoring the location of the material and the
location of people or patients. In this scope, they are usually
recognized as crucial Healthcare Treatment relying on remote
medicine safety, wellness or location control and the track-
ing of personnel, patients, biological materials and medical
devices [11]–[16].
It is projected and installed a tracking system based on
UHF-RFID, to locate orthopedic prosthesis according to the
criteria and requirements of a specific hospital environment.
Hence, it is compulsory to analyze the effects of exposure
of the general and occupational public to electromagnetic
fields in healthcare environment, because these scenarios
can be affected by UHF-RFID sources of EMF expo-
sure [17], [18]. There are multiple factors to consider with
respect to the biophysical effects of EMF influence and
their significance with respect to the safety and health of
the population: human body characterization is a complex
task, where the behavior of human tissues is based on the
frequency under analysis and, hence, there is a vast range of
frequencies to study; biological interactions may be thermal
from tissue being physically heating by absorbed electromag-
netic energy, or more complex non-thermal bioelectromag-
netic effects involving various biochemical or bioelectrical
processes [19]–[30].
Moreover, exposure to EMF can also cause indirect effects
by the presence of an object in an EMF, which may become
the cause of a safety or health hazard, such as interference
with medical electronic equipment and devices (including
implants or medical devices worn on the body), which can
even lead to fatal consequences in critical health cases [31].
The pervasive use of wireless communication devices has
emphasized the need for assessing RF-EMF exposure, with
great interest in ensuring safe exposure conditions consid-
ering the health impact and/or potential malfunctions in
electronic devices caused by the RF-EMF emissions from
the combination of all the available wireless communica-
tion systems [32]–[43]. Fig. 1 presents a schematic view
of UHF-RFID system that can be involved in healthcare
environments [44].
FIGURE 1. RFID basic system components.
Preliminary experimental results were represented through
2D contour maps as conference article [45]. This work is
focused on exposure levels due to the UHF-RFID localization
system in order to verify regulations concerning the safety
of patients and the general public in the labor and health-
care fields. A complete E-field strength distribution study,
focusing on UHF-RFID frequency band, is carried out con-
sidering the usual E-Field exposure levels in realistic oper-
ational scenario to provide an intensive and comprehensive
in-depth a tracking system based on short-range radio fre-
quency, UHF-RFID E-field characterization study. An ane-
choic chamber evaluation of this technology has allowed to
assess the exposure conditions in the worst case. The experi-
mental and simulated results are represented through 2D con-
tour maps, and have been compared with the recommended
safety and exposure thresholds. Finally, simulations have
been performed by means of an in-house 3D-RL algorithm.
It must be pointed out that considering the low exposure levels
and research results collected to date, there is no convincing
scientific evidence that theweakRF signals can cause adverse
health effects. Nevertheless, research is still being promoted
by WHO [46] to determine whether there are any health
consequences from the lower RF exposures levels.
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A. UHF-RFID TECHNOLOGY
The bar codes are already fully integrated into the san-
itary operation and their utility was unquestionable to
avoid the incorrect interpretation of handwritten texts, both
when labeling devices, products and biological samples,
and when filling in medical records. RFID is the most
common and fastest-growing wireless technology of auto-
matic identification and data capture, which identifies and
tracks RFID sensors (tags) attached to objects. RFID tech-
nology dates back to the 1970s (some sources mention
even the 1950s). Over time, RFID technology has evolved,
introducing different frequencies, ranges, higher data rates
and upgraded characteristics and may be integrated with
various wireless communication networks such as WSNs
or WLANs.
The most commonly used RFID systems in the world are
low frequency (LF band: 30–300 kHz; operating typically
at 125 kHz), high frequency (HF band: 3–30 MHz; operat-
ing typically at 13.56 MHz frequency), ultra-high frequency
(UHF band: 300–1000MHz; operating in the frequency range
860–965 MHz (in Europe, 865–868 MHz) for passive tags
and 443MHz for active tags), and super-high frequency (SHF
bands: 2.400–2.4835 GHz and 5.725–5.875 GHz; operating
typically at 2.45 and 5.8 MHz frequency) [47].
Like bar code, RFID allows digital marking, but also con-
tains certain exclusive attributes that introduce promising new
use cases for telemedicine and telecare. Thus, while barcodes
contain fixed information and can only communicate data
when read, requiring visual alignment with the receiver, RFID
allows objects to identify themselves without requiring such
alignment. On the other hand, the information is not static,
but is stored in a rewritable memory contained in a tag which
can be attached or incorporated into products, animals and
people.
These tags embed antennas, which allow them to receive
and respond to requests for information via radio frequency.
The data exchanged will, in turn, be processed in a remote
computer system for a specific use, for example, for the
management of stocks in any warehouse, for the monitoring
of the drugs themselves from the laboratory to the point of
sale to avoid theft or adulterations, or, within the sanitary
precincts for the trace of the clinical or surgical material
(marking goods, wares, devices, and books, document track-
ing in offices, or even patients, biological material or pharma-
ceuticals). This software can be configured in order to provide
access of real-time data relevant to each tracked material for
different groups or specific personnel and provide informa-
tion of historical reporting functionality and to demonstrate
compliance with various regulations and provides a pow-
erful data collection tool for facilities seeking to improve
operational efficiency and reduce costs of various processes.
Applications based on the integration of radiofrequency iden-
tification with other ubiquitous computing technologies, such
as communications protocols and wireless sensor networks,
Internet of Things (IoT) and specially Internet of Medical
Things (IoMT) are also being introduced to support our daily
lives and address our health in so-called assisted environ-
ments with a minimum of human intervention.
One of the frequency bands in which they can operate is
that of UHF, in Spain 865-868 MHz, on which this work
focuses. An UHF-RFID reader reads and writes data on tags
and power up the passive tags that receive electromagnetic
energy by wireless interaction from a nearby UHF-RFID
reader interrogating tags. They may use fixed readers and
handheld readers equipped with antennas of various dimen-
sions. Handheld readers usually operate with antennas of
dimensions smaller than 20 centimeters, which are built into
small portable electronic intelligent devices or are a kind of
periphery accessory [48].
The advantages of this technology in healthcare centers
has promoted it’s use in a wide variety of rapidly developing
applications, such as monitoring, controlling or managing
objects in medical centers and the public environment. Tak-
ing into account the popularity and widespread use of this
technology, it is compulsory to analyze in-depth non-ionizing
radiation exposure in this type of environment and verify
compliance with legal exposure limits.
One of the most prominent applications of RFID within
health centers is the monitoring of clinical material and
other hospital goods. The utility for the monitoring and loca-
tion of patients, especially those most vulnerable by age
(elderly and children) or by the type of ailment (dementia,
Alzheimer’s . . . ) as well as in relation to the treatment of
blood, is becoming more important, either for diagnostic or
therapeutic purposes. As with barcodes, the environment of
hemotherapy and transfusion medicine pioneered the incor-
poration of RFID innovations that positively result in patient
safety.
For the author’s knowledge, there are a limited amount
of studies of EMF exposure about the human exposure to
RFID systems in these clinical applications, operating at a
frequency of the present work of 865-868 MHz. The evalu-
ation of the EMF exposure of an RFID reader with respect
to the limits established for the implant-bearing population
may be insufficient to protect the implant user. In these envi-
ronments, electromagnetic fields exposure presents particular
features, given by the fact that individual exposure levels can
be affected by the emission from personal communication
devices of nearby users.
Previously, the authors presented in [49] the study of EMF
emitted by RFID handheld readers (UHF-RFID guns) and
tags and were characterized and evaluated with respect to
humans exposure metrics – the strength of the electric field
affecting anyone present near UHF (ultra-high frequency)
RFID guns and the specific absorption rate (SAR) values in
their body.
1) SCENARIOS OF EXPOSURE TO EMF NEXT UHF-RFID
DEVICES
Reports in the literature on RFID technology mainly con-
cern the design of low cost, simplified antennas with cir-
cular polarization, allowing tag detection from the greatest
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V. Ramos et al.: Electromagnetic Characterization of UHF-RFID Fixed Reader in Healthcare Centers Related to Personal
possible range [49]. In this context, estimations of SAR
(6-minutes averaged) for various anatomical human body
models exposed to EMF emitted by a UHF RFID reader with
an antenna of circular polarization, in various locations and
distances (10, 20, 50 cm) against human body models have
been obtained. Within the vicinity of readers with higher
power ratings, SAR values may be exceeded in an exposure
time shorter than the 6 minutes interval considered above.
Other applications of RFID are those based on the integra-
tion of radio frequency identification with other ubiquitous
computing technologies, such as communications protocols
and wireless sensor networks, to support assisted environ-
ments in the health context. However, it is not possible to
ignore that the immediate consequence of creating environ-
ments supported by wireless systems will be the notable
increase in electromagnetic emissions and EMF around peo-
ple, which makes it essential to analyze their risks and deter-
mine, if necessary, the most appropriate security measures.
The advantages of wireless technology in healthcare centers
is leading to awide variety of rapidly developing applications,
such as monitoring, controlling or managing objects. The
expected benefits of RF identification technologies for health
could be questioned if the acceptable thresholds for EMF
exposure of multiple field components and in many cases,
continuous, are not determined exactly. It is also essential that
the technical conditions that would avoid interference with
other devices or systems, mainly electromedical, be estab-
lished unequivocally. How these critical factors are addressed
may depend on their acceptance or rejection by health service
providers, sector professionals and patients.
The UHF-RFID platform under analysis is located within
different floor levels and locations of the Hospital Univer-
sitario de Canarias (HUC), where the different devices that
integrate the platform will be deployed, which influences the
areas that will be affected by radio emissions frequency from
UHF-RFID devices. The operation protocol was determined
and once the platform was installed, the requirements com-
pliance were checked. The UHF-RFID device evaluated are
presented in Fig. 2:
In general, UHF RFID systems have the limit of effective
radiated power (ERP) from the antenna fixed maximum 2 W
for devices where use does not require special permission in
accordance with ETSI/EN 302-208 V3.1.1:2016-12, being a
harmonized standard with Directive 2014/53/EU (recognized
as the RED directive). This is the case for the deployment
under analysis in this work.
2) GENERATION OF 2D CONTOUR MAPS
This paper analyzes the signals emitted by our RFID sys-
tem in a ward of the HUC, and presents a methodology
to generate a graphic and accurate 2D contour map of the
EM fields. After collecting all data, they were transferred
to the specific software (SURFER 8) to create 2D contour
maps according to the previouslymeasured levels of intensity.
Surfer is a contouring and surface mapping program that runs
under Microsoft Windows. It converts data into outstanding
FIGURE 2. Devices of location and identification of material,
instrumentation and even of patients frequently used UHF-RFID: fixed
reader RFID xArray Gateway R680 (ETSI).
contour, surface, wireframe, vector, image, shaded relief, and
post maps.
3) EMF EXPOSURE METRICS AND EVALUATION
In most countries, EMF regulations and legislation and thus,
RF-EMF radiation exposure limits, are based generally on the
two most international adopted guidelines and standards, the
International Commission onNon-Ionizing Radiation Protec-
tion (ICNIRP) guidelines (ICNIRP 2020) [19] or the Insti-
tute of Electrical and Electronics Engineers (IEEE) standard
C95.1-2019 by the IEEE International Committee on Elec-
tromagnetic Safety [50]. In general, EMF exposure limits are
adequately established in order to attend two main different
group of population: occupational and general public, with
independency of the selected EMF standard or guideline.
On March 2020, the International Commission on Non
Ionizing Radiation Protection (ICNIRP) announced that it
had released new guidelines on radiofrequency radiation (RF)
exposure levels. These will replace the current guidelines that
have been in place since 1998. The ICNIRP Guidelines are
promoted by the World Health Organization and form the
basis for radiation standards in many countries. The updated
Guidelines cover the frequencies that will be used for new 5G
technologies, as well as those currently used for wireless and
radio transmissions in the range 100 kHz to 300 GHz.
Limits for general public and worker exposure are dif-
ferent in the 2020 ICNIRP recommendation based on the
guidelines of the International Commission on Non-Ionizing
Radiation Protection (ICNIRP) [19] that updates the radiofre-
quency electromagnetic field (RF EMF) part of the ICNIRP
1998 guidelines and recognized by the World Health Orga-
nization (WHO) [46]. The body of scientific information
has not increased greatly higher than the ICNIRP (1998)
restrictions, particularly in terms of thermal effects. However,
there are two new restrictions in ICNIRP (2020) that have
the potential to further strengthen health protection. The first
relates to the development of technologies that utilize EMF
frequencies >6 GHz, such as 5G, with new restrictions to
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V. Ramos et al.: Electromagnetic Characterization of UHF-RFID Fixed Reader in Healthcare Centers Related to Personal
better protect against excessive temperature rise in the body.
The second relates to brief RF EMF exposures (<6 minutes),
to ensure that transient temperature rise is not sufficient to
cause pain or adversely affect tissue, although the present
guidelines do not provide protection for low intensity expo-
sure of long durations and over the whole body.
The averaging time for this restriction has also been
changed from 6 minutes in ICNIRP (1998) to 30 minutes
in ICNIRP (2020), to better match the time taken for body
core temperature to rise. Particularly relevant for ensuring
safety with future technologies, such as 5G, which beams
are not ‘sufficiently’ focused to cause harm. ICNIRP (2020)
provides additional restrictions to ensure that exposures over
brief intervals do not result in excessive temperature rises.
These restrictions are set as a function of exposure duration,
and are applicable to both continuous (e.g. sinusoidal) and
discontinuous (e.g. pulsed) RF EMF. ICNIRP (1998) pro-
vided reference levels for continuous whole-body exposures.
However, those reference levels did not cover all of the types
of basic restriction. ICNIRP (2020) provides reference levels
corresponding to all the basic restrictions.
Research has now better determined the relations between
basic restrictions and both the electric and magnetic field
reference levels, and ICNIRP (2020) has updated these ref-
erence levels to incorporate our improved knowledge and the
reference levels have been increased accordingly.
The experimental data have been compared with the rec-
ommended safety and exposure thresholds to provide relia-
bility of the prediction procedures of the exposure levels in
the indicated environments. Evaluation of exposure levels due
to the UHF-RFID localization system is provided in order to
verify regulations concerning the safety of workers, patients
and the general public in the healthcare environment and
should be considered to assure a proper, reliable and safe
usage of the RFID localization system.
Research has shown that to match the whole-body basic
restrictions, this increase should start at 30 MHz. ICNIRP
(2020) thus has a monotonous increase in both the E- and
H-field reference level values with decreasing frequency, that
begins at 30MHz. These differences can be seen in Fig. 3 and
Fig. 4. New scientific knowledge allowed rules to be set in
ICNIRP (2020) for the application of reference levels in the
near- and far-field separately. This will ensure that exposures
within the near-field zone will not result in over-exposure.
In addition, although ICNIRP (1998) allowed E-field and
H-field to be used for whole-body average reference levels
across the entire 100 kHz to 300 GHz frequency range, this
method can potentially result in inaccuracies for frequencies
above about 2 GHz within the near-field zone and so is
not permitted within the new guidelines; measures of power
density must be used instead.
The evaluation has been carried out in accordance with the
regulations applicable in Spanish territory. With regard to the
protection of the general public, Royal Decree 1066/2001,
of September 28 [51], which approves the Regulation that
establishes conditions for the protection of the radioelectric
FIGURE 3. Whole body average reference levels for the general public for
the ICNIRP (1998), ICNIRP (2010) and ICNIRP (2020) guidelines, for the
100 kHz to 300 GHz frequency range [5]. Note that the units of the two
y-axes (i.e. electric field and power density) are independent of each
other.
FIGURE 4. Whole body average reference levels for workers for the
ICNIRP (1998), ICNIRP (2010) and ICNIRP (2020) guidelines, for the
100 kHz to 300 GHz frequency range. Note that the units of the two y-axes
(i.e. electric field and power density) are independent of each other [5].
public domain, restrictions on radioelectric emissions and
sanitary protection measures against radioelectric emis-
sions, the transposition of the European recommendation
1999/519/EC allowed a harmonized vision of the protection
of health against non-ionizing radiation in all the European
Union [52].
Regarding the protection of workers, the transposition of
the European Directive 2013/35/EU of the European Parlia-
ment and of the Council of 26 June 2013 [31] is reflected
in the Spanish Royal Decree 299/2016, of July 22 [53] on the
protection of the health and safety of workers against the risks
related to exposure to electromagnetic fields. ‘‘Occupational
exposure’’ is applied to those individuals who are exposed to
EMFs as a result of performing their regular job activities.
This legal text establishes exposure limits for the protection
of workers’ health from the immediate effects of short time
exposures to non-ionizing radiation, which in the case at
hand, of RF signals, would be potentially harmful thermal
effects.
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In real conditions, the exposure to the emissions of the
equipment studied will be considered occupational, with
the workers being exposed in a non-continuous and non-
homogeneous way. In Fig. 3 and Fig. 4 are showed the expo-
sure limits for electric and magnetic fields, for occupational
and general public exposure, published by ICNIRP 2020, the
most extended standard in Europe.
There are a range of improvements to the ICNIRP
(2020) restrictions, including the addition of new restric-
tions, amendments to old restrictions, and the removal of
some restrictions. Additional restrictions were introduced to
account for situations whereby the ICNIRP (1998) restric-
tions would not adequately account for new technological
developments, such as aspects of 5G technologies; amend-
ments to existing restrictions were made to improve preci-
sion based on scientific advances since 1998, such as more
accurate knowledge concerning the relation between spatial
averaging of exposure and temperature rise. There are a range
of improvements to the ICNIRP (2020) restrictions, including
the addition of new restrictions, amendments to old restric-
tions, and the removal of some restrictions.
A new restrictions in ICNIRP (2020) that have the potential
to further strengthen health protection. One of them relates to
the development of technologies that utilize EMF frequencies
>6 GHz, such as 5G, with new restrictions to better protect
against excessive temperature rise in the body. This allows
a simpler means of assessing compliance with all the basic
restrictions as is showed in Fig. 3 and Fig. 4. ‘Guidance’
has been provided to help inform those responsible for occu-
pational RF EMF exposures, to assist them in ensuring that
this hazard is understood, and accounted for in an appropriate
health and safety program.
This work is organized as follows: in Section II (MATE-
RIALS AND METHODS), the measurements campaign,
graphic presentation and simulation scenario are presented.
In Section III (RESULTS), the results obtained are explained,
the indoor geographical representation of the UHF-RFID
device where different transmission positions have been
showed as well as simulation parameters. Section IV
(DISCUSSION) presents discussion in relation with the sim-
ulation andmeasurements results and different exposure level
thresholds, showing that E-Field results are below the max-
imum reference levels of ICNIRP. In Section V (CONCLU-
SIONS) are presented. In consequence, a simulation-based
analysis methodology is provided, aiding in the assessment
of future wireless deployments.
II. MATERIALS AND METHODS
A. MEASUREMENTS CAMPAIGN
A campaign of measurements was designed and implemented
in two different locations in Spain, (Tenerife, Canary Islands
and Madrid) to analyze the UHF-RFID technology. The
corresponding received E-field distribution levels has been
obtained, thus, compliance with legal exposure thresholds
can be assessed. An UHF-RFID location system has been
designed and installed for the location of prostheses attend-
ing to HUC criteria. The implementation of the UHF-RFID
platform involves the choice of the location where the differ-
ent devices that make up the platform were located, which
influences the areas that will be affected by radio frequency
emissions from RFID devices. Once the platform is installed,
the fulfillment of requirements are analyzed. The evaluation
of electromagnetic emission levels were carried out in order
to guarantee the safety of patients, workers and the general
population. The characterization measures of the EIRP in the
worst case were carried out in the Radio Frequency Labora-
tory, DirecciónGeneral de Telecomunicaciones yOrdenación
de los Servicios de Comunicación Audiovisual (Madrid).
On the other hand, the generated electric field values,
both in far-field and near-field conditions, must be taken into
account to analyze the possible operating problems that may
affect the operation of other wireless networks operating in
the vicinity, including in addition the appliances that can emit
in the same frequency of operation. For each of the distances
from the antenna to the equipment, the measurements were
made by accumulating a maximum of three measurement
cycles to obtain the maximum emission measurement of the
equipment. Once the EIRP was characterized the adequacy of
the established European regulations was verified.
There are different strategies andmethodologies tomonitor
the EMF exposure. In this work, two types of evaluations
have been carried out: in the HUC the measurements have
done in the places where the UHF-RFID technology has been
installed for evaluation: an array on the roof of a wide room.
In Madrid, evaluation was carried out in anechoic chamber in
worse case situation. Both methods are experimental protocol
for measuring the spectral distribution of radio frequency
(RF) energy by means of frequency selective measurement
equipment (band 865 - 868 MHz) to determine the signal
strength of a specific frequency in positions and configura-
tions of maximum emission. The system under test is a Fixed
RFID reader xArray Gateway R680 (ETSI), connected to
Impinj’s ItemSense software, to enable asset or item identifi-
cation, location information and zone transition information,
among others.
1) HOSPITAL MEASUREMENTS
The spectral distribution of radio frequency (RF) energy has
been studied via selective frequency measurement tools in
the HUC at 865-868 MHz frequency range. The influence of
RFID on the environment is defined by the measurement of
the variables and features of the emission levels [45].
The monitoring has been performed by means of a Rhode
& Schwartz FSH6 spectrum analyzer and a receiving antenna
ETS-LINDGREN, Mod.3182 (500MHz-9GHz), shown in
Fig. 5. The spectrum analyzer performs measurements of
E, and the representation, identification and monitoring of
the signals within the environment under study. The broad-
band omni-directional antenna is designed for surveillance,
spectrum monitoring, and shielding studies. The polariza-
tion offering the highest field intensity was chosen. In the
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V. Ramos et al.: Electromagnetic Characterization of UHF-RFID Fixed Reader in Healthcare Centers Related to Personal
FIGURE 5. Equipment for spectrum evaluation: Rhode & Schwartz FSH6
spectrum analyzer and receiving antenna on tripod ETS-LINDGREN,
Mod. 3182.
TABLE 1. Fixed RFID reader xArray gateway R680 (ETSI).
rooms where it was installed, prior to installation, there was
no radiant technology at the operating frequencies that we
have evaluated. Impinj’s ItemSense software enables real-
time Item Intelligence, centralizes, and automates the man-
agement and monitoring infrastructure that offers item or
asset identification, location information, and zone transition.
The xArray provides always-on, wide-area monitoring
for real-time identification, location, and direction of RFID
tagged items. The technical characteristics are presented in
Table 1. The xArray was positioned on center of the ceiling of
a room without windows and with a door, around 3.5 m high,
covering an estimated zone of 4 × 4 meters. Measurements
are carried out at 100 cm and 170 cm heights from floor level.
The solution offers automated control of stock in real time
in areas at room temperature. This is done automatically
thanks to the previous tagging with RFID TAGs of the stored
product, being able to manage the products individually or
through double compartment management in ISO baskets or
shelves. The monitoring, reporting and control of the system
is carried out by the management software, which is respon-
sible for device management and at the same time provides
access to parameter reports. With this procedure, we were
FIGURE 6. Floor plan of the scenario generated with AutoCAD in which
the fixed RFID reader xArray Gateway R680 is introduced.
FIGURE 7. Measurement setup for the radiation patterns measurements
inside the anechoic chamber.
able to analyze different areas, measuring E-field levels in
the closest area where devices are in use.
2) EVALUATION IN SEMI ANECHOIC CHAMBER
The radiated emission characteristics of the devices under
test have been obtained by performing measurements within
the RF Laboratory of the Dirección General de Telecomu-
nicaciones y Ordenación de los Servicios de Comunicación
Audiovisual (Ministerio de Asuntos Económicos y Transfor-
mación Digital), which includes among others equipment and
software relevant to the topic considered such as showed in
Table 2. Laboratory measurements have been carried out to
characterize and analyze the emissions of a XArray that oper-
ates at 865-868 MHz, in order to obtain the radiation pattern
of the XArray and identify maximum field orientation.
The measurements to obtain the radiation pattern in worst
case were performed in a semi anechoic chamber, shown in
Fig. 7 and Fig. 8. The room has dimensions of 9.76 m ×
6.71 m × 6.10 m, the walls are lined with a foam based
radiofrequency absorber material (RANTEC Ferrosorb300)
specified to have a re-flection/absorption coefficient of
−18 dB at the frequency of RFID center frequency 865.73±
0.05 MHz, at a distance of 3 meters and the distance to
the floor was 1.5 m.. The measurement antenna was placed
in the two polarizations and moved in height to find the
maximum signal level, at the 0◦ angle (measurement antenna
facing the emitting equipment). Once the maximum level of
field intensity had been recorded, the intensity values were
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FIGURE 8. Measuring antenna and positioners required for the radiation
patterns measurements inside the anechoic chamber.
TABLE 2. Laboratory equipments.
characterized by rotating the antenna in steps of 45 degrees.
Subsequently, the same was done, at distances of 1 and
0.5 meters, in these cases, the level of Effective Radiated
Power (ERP).was measured and with these data the level of
field intensity was calculated. Moreover, this location was
employed in order to measure the EMF exposure levels in
the most probable location for patients, workers or general
public. In addition, no other wireless devices, were used dur-
ing the data collection process, avoiding inaccurate or incor-
rect measurements. A positioner with an EMCO 1051 motor
allows the changes of the measuring antenna between the
horizontal and vertical position. The measurements were
carried out with an EMI Test Receiver ESIB26, Rhode &
Schwartz with a frequency range of 20 Hz - 26.5 GHz, and
the measuring antenna is an EMCO 3146 log-period antenna
with a frequency range of 200MHz - 1GHz and those showed
in Table 2.
After obtaining the radiation pattern, the position of each
tested device at which the electric field strength is maximum
was fixed. In that position the electric field strength was
measured as a function of the distance in near field conditions
to check the influence on other wearable electrical devices
3) 2D GRAPHIC REPRESENTATION
A methodology for the generation of 2D contour maps that
provide a graphic, immediate and accurate representation
FIGURE 9. Grid and measure points in a care room of the HUC for XArray
spectrum evaluation.
of the EM fields of RFID xArray has been developed. The
experimental data are represented by means of 2D con-
tour maps, and have been compared with the recommended
thresholds for both safety and exposure to provide reliabil-
ity of the prediction methods of the exposure levels in our
environments. Evaluation of our exposure levels results is
provided so as to verify regulations regarding the safety of
workforce, patients and the general public in the healthcare
environment and should be contemplated to guarantee an
appropriate, reliable and safe usage of the RFID localization
system. Data collected were transferred to the graphic soft-
ware SURFER 8 which draws lines and colors areas accord-
ing to the previously measured levels of E field intensity.
Radiation graph with the measurement points were located
and the measurement points selected are represented in
Fig. 9. An alphanumeric codification system was established,
in order to identify the location of any measurement point in
the database designed for the storage and management of the
measurements.
4) RAY LAUNCHING SIMULATION
With the aim of analyzing electromagnetic environment due
to UHF-RFID devices within hospital, it is highly impor-
tant to have the knowledge of the effects that exposure
to electromagnetic fields has in the human body. A priori,
the most precise way to estimate electromagnetic exposure
and perform dosimetric evaluation is obtained by in situ
measurements. However, to obtain insight on the potential
impact of different wireless devices and their integration as
complete systems requires the use of theoretical estimations.
On the other hand, these theoretical estimations exhibit some
problems, related to the accuracy of the radio propagation
parameters and to the human body characteristics. There is
a great assortment of techniques to estimate radio propaga-
tion and representing the human body. The most accurate
method to perform dosimetric estimation is directly solving
Maxwell’s equations, in which SAR calculations are achieved
using full wave techniques such as Finite Difference Time
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V. Ramos et al.: Electromagnetic Characterization of UHF-RFID Fixed Reader in Healthcare Centers Related to Personal
Domain [54]–[56], or equivalent methods, which enable near
field calculations. This leads to a commitment between the
computational complexity in terms of calculation time and the
final accuracy of the results. However, the large requirements
in terms of memory use and the high computational cost
make them inappropriate for large area calculations at high
frequency bands. The search for optimized evaluation of SAR
values has led to enhanced estimation procedures, including
modification of the measurement setup to maintain level of
exposure and field uniformity, such as described in [57]–[59].
In order to obtain E field estimations within the complete
volume of the indoor scenario under analysis, an in-house
implemented simulation algorithm has been employed, based
on deterministic 3DRay Launching technique inMatlab envi-
ronment. In this way, estimations based on reference level,
in far field conditions can be provided within the scenario,
considering all of the topological parameters, as well as
the frequency dispersive material parameters (i.e., dielectric
permittivity and conductivity) for each one of the elements
included. The simulation code is based in the application
of Geometric Optics combined with Uniform Theory of
Diffraction, in which rays are launched following a solid
angle distribution, for each one of the transmitting sources
considered within the scenario and computing transmitted,
refracted and reflected rays by application of frequency and
polarization depended Fresnel coefficients. Diffraction is also
taken into account by performing edge detection and comput-
ing losses based on diffraction coefficient estimation. In order
to decrease computational cost and hence enable charac-
terization of large, complex scenario, a hybrid simulation
approach has been implemented, based in the use of neural
network ray interpolators (to decrease launching resolution),
the combined use of 3D RL with electromagnetic diffusion
equation, based on transport theory in order to decrease com-
putational cost related with the consideration of diffraction in
2D planes and the use of deep learning techniques, based on
collaborative filtering, in order to reduce computational cost,
by taking advantage of pre-computed canonical scenarios.
The application of the 3D RL simulation code is based
in the implementation of the scenario under test (i.e.
hospital ward previously described) at Departamento de
Ingeniería Eléctrica, Electrónica y de Comunicación, Univer-
sidad Pública de Navarra (UPNA). To this extent, the sizes,
shapes and specific materials have been considered, with
the parameters, obtained from consolidated characterization
found in the literature, given in Table 3. Once the scenario
has been implemented, the scenario is meshed employing
variable sized cuboids. The simulation parameters (angular
ray resolution, cuboid mesh size and maximum number of
rays until extinction) are given in Table 4 and have been
chosen based on previous convergence studies as well as
meshing effect studies performed on the specific 3D RL
code implemented. The same scenarios of Fig. 6 have been
implemented in the 3D-RL tool, considering in both cases
all furnishings and the dielectric properties of the materials
employed, considering not only the free space loses, but also
TABLE 3. Material properties for 3D ray launching simulations.
TABLE 4. Parameter configuration for 3D ray launching simulations.
other phenomena like reflection, diffraction or refraction.
Different simulations have been performed emulating UHF-
RFID device emitting at the same positions as they worked in
the measurement campaigns. These simulations give results
for E-field levels for the whole 3D scenario, which enable the
comparison of the received E-field levels at the same spatial
point as themeasurements. The frequency band simulated has
been 865-868 MHz. The considered transmitted power for
simulation follows the maximum and minimum transmitted
power permitted for the frequency band, shown in Table 4.
EU 2014/53/EU (RED) Commission Implementing Decision
of the operation of the Radio Equipment Directive on harmo-
nization of the radio spectrum for use by short-range devices.
In order to gain insight in relation with the E-field distribu-
tionwith the hospital ward, two different simulation scenarios
have been implemented. The first one emulates the hospital
ward, considering the real dimensions of the scenario, as well
as the topo-morphological characteristics. A second scenario
has also been implemented, corresponding to the previously
described test scenario (i.e., 8.2m∗8.2m room) in which mea-
surements have been performed. The characteristics of the
RFID transmitter antenna have been considered within the
3D RL algorithm, defining volumetric radiation diagram and
the corresponding transmitter output power. The results have
been obtained for the complete volume of the scenario under
analysis, with particular cut planes presented for the sake of
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FIGURE 10. E-field distribution within the hospital ward simulation
scenario.
FIGURE 11. E-field distribution within the hospital ward simulation
scenario particularized for a) cut plane XZ Y=4.6m, b) cut plane YZ
X=5.4m.
clarity. For the case of the ward scenario, E-field distribution
within cut plane heights at h=1m and h=1.7m are presented
in Fig. 10. As expected, higher values are observed inside the
room in which the RFID array is located, being detectable
along the complete surface of the scenario. As height is
increased, the average detected E-field values also increase,
as the observation points are closer the to the transmit array,
an effect that can be observed in more detail in the E-field
distributions within XZ planes locations, depicted in Fig. 11.
The simulation scenario for the specific room in which the
RFID equipment is located has also been implemented and
volumetric E-field estimations have also been obtained for
this case. The corresponding results for specific XY as well
XZ planes are shown in Fig. 12 and Fig. 13, respectively,
following a similar trend in relation with E-field amplitude
as a function of height and relative observation location.
In order to validate the E-field estimations obtained with
the 3D RL deterministic approach, measurement results have
been obtained for the ward scenario, considering different
angular radials (with orientations of 0◦, 45◦, 90◦ and 135◦)
FIGURE 12. E-field estimation detail within the 8m∗8m test scenario
a) cut plane height 1m, b) cut plane height 1.7m.
FIGURE 13. E-field estimation detail within the 8m∗8m test scenario
a) cut plane XZ, Y=4-1m, b) cut plane YZ, X=4.1m.
and different cut-plane heights (h=1m and h=1.7m) within
the room. The results are given in Figs. 14 to 17, for each
of the radial angles previously indicated, showing good
agreement between the simulation and measurement values,
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FIGURE 14. E-field estimation within a linear radial distribution,
0◦ orientation a) cut plane height 1m, b) cut plane height 1.7m.
FIGURE 15. E-field estimation within a linear radial distribution, 45◦
orientation a) cut plane height 1m, b) cut plane height 1.7m.
indicating the adequate estimation capability of the proposed
3D RL deterministic approach to perform volumetric E-field
estimation mapping.
III. RESULTS
A. MEASUREMENTS RESULTS
1) HOSPITAL MEASUREMENTS
Several graphs have been obtained with the measurements
corresponding to two height planes from the floor in case of
XArray antenna system. Level curves of the EMF observed
FIGURE 16. E-field estimation within a linear radial distribution,
90◦ orientation a) cut plane height 1m, b) cut plane height 1.7m.
FIGURE 17. E-field estimation within a linear radial distribution,
135◦ orientation a) cut plane height 1m, b) cut plane height 1.7m.
have been represented on them. The recording distances were
measured from the vertical on the floor of the center of
the transmitter (d = 0) to a distance d = 4 meters, taking
intensity values every 50 cm. For the measurement angles,
the xArray itself was taken as a reference, and records were
made between 0 and 315◦, with a 45◦ spacing. The electric
field measures were taken at 100 and 170 cm heights above
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TABLE 5. xArray maximum electric field values in dBµV / m at 100 cm.
TABLE 6. XArray maximum electric field values in dBµV / m at 170 cm.
the floor, resembling the position of the head of the seated or
standing workers respectively. Values obtained are presented
in Table 5, Table 6, Table 7 and Table 8.
At both heights, 100 and 170 cm, recorded E field intensity
values were generally in the range 92.04 and 99.08 dBµV/m.
However, at the angle 0◦, at the height of 100 cm and at
a distance of 150 cm in the vertical of the emitter a peak
of intensity of 106.44 dBµV/m was recorded. Somewhat
lower values of 102.92 dBµV/m and 101.58 dBµV/m were
recorded at the 180◦ angle, at distances of 150 and 200 cm,
respectively.
Also at the height of 170 cm, at the 0◦ angle and at a
distance of 100 cm, a peak of 105.58 dBµV/m intensity was
recorded, obtaining somewhat lower values, 104.08 dBµV/m
and 102.28 dBµV/m, at the 180◦ angle, at distances of
100 and 150 cm respectively.
2) EVALUATION IN SEMI ANECHOIC CHAMBER
The maximum values, 15.88 V / m and 10.68 V / m,
were recorded, as expected, at the shortest distance, 50 cm
from the transmitting antenna and at the 0◦ and 45◦ angles,
respectively. The values were drastically reduced (to approx-
imately 3.5 V / m) in the angles between 90◦-270◦, returning
TABLE 7. Summary xArray maximum electric field emitted (V/m).
FIGURE 18. Radiation pattern of the measured E-Field.
to recover a maximum value (12.16 V / m) at 315◦. As can
be seen, these values, transmitted by the XArray equip-
ment, decline significantly with distance, reaching values of
7.9 V / m and 5.3 V / m at the angles at a distance of 100 cm,
0◦ and 45◦, respectively, and 1.5 V / m at angles between
90◦-270◦. The lowest values were recorded at 3 meters from
the emitter, with levels of 1.49 V / m and 0.71 V / m in the
0◦ and 45◦ angles, respectively, and 0.25 V / m in the angles
between 90◦-270◦. Table 8 presents E-field strength in the
orientation of maximum radiation from the tested device in
function of the distance.
In Fig. 18 and Fig. 19 are presented two graphs of the
E-field strength in the orientation of maximum radiation from
the tested device in function of the distance. Fig 18 shows the
radiation pattern of the XArray evaluated. Fig.19 presents E
field calculated at different distances.
3) 2D GRAPHIC REPRESENTATION
Fig. 9 presents points of measurement marked. In each mea-
surement point the antenna has been oriented to detect the
maximum value of the E-field at 100 cm and 170 cm heights
above the ground as was presented in [45]. In these locations,
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FIGURE 19. Radiation pattern of the XArray spectrum evaluation and
calculated E-field.
TABLE 8. XArray maximum electric field values in different units at
300 cm.
the values of the E-field were collected and registered. The
2D contour maps of the data set, and the location of the
radiation source are presented graphically in Fig. 20 and
Fig. 21. Analyzing the graphs, characteristic features of the
experimental results are remarkable. This specific rise of the
electric field intensity matches the position where there is a
greater exposure to the EM radiation than the other points of
the scenario under test.
Another aspect that has been studied is the variation in
results between 100 cm and 170 cm heights above the floor,
as the higher are more exposed and closer to the radiation
sources. After measuring and calculating the EM conditions,
it is crucial to carry out a study of the results and to check
whether the obtained values are under the thresholds of the
recommended exposure levels [19].
IV. DISCUSSION
A. ICNIRP COMPARISON WITH MAXIMUM TRANSMITTED
POWER AND LIMITATIONS
European regulations regarding human exposure to EMF
include requirements on safety of workers, general public and
vulnerable populations, focused significantly on the safety
of users of AIMD, including those exposed in assisted in
the context of health environments. The exposure limits set
by the Recommendation 1999/519/EC (general public) and
FIGURE 20. 2D Contour maps of the experimental values of the E-field
in dBµV/m in 100 cm high on XArray.
FIGURE 21. 2D Contour maps of the experimental values of the E-field
in dBµV/m in 170 cm high, on XArray.
Directive 2013/35/EU (workers) are based on the electric and
magnetic field reference levels provided for an evaluation
of the whole body EM exposure by the International Com-
mission of Non-ionizing Radiation Protection (in considered
case of exposure to EMF at 865-868 MHz frequency, E and
H of approximately 90 V/m and 0.24 A/m or 40 V/m and
0.11 A/m, for workers or general public exposure, respec-
tively) [31]. The ICNIRP published new guidelines in 2020
(including additional provisions on the evaluation of the
localised EM exposure); these have not been included in
any directive yet [19]. The use of UHF-RFID readers can
also alter EM conditions affecting the safety of vulnera-
ble population. Article 15 of the Occupational Health and
Safety Framework Directive 89/391/EEC [60], requires that
‘‘Particularly sensitive risk groups must be protected against
the dangers that specifically affect them’’. Factors of AIMD
use that influence the probability of EM interferences in
its functioning and related to health and safety hazards to
its users include: EMF frequency and exposure level and
duration, the EM performance of the AIMD, its settings and
the method of implantation, as well as the health status of a
particular user of AIMD. In this sense, some limitations about
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updated guidelines are observed. They have been developed
keeping the view that it’s only necessary to protect against
the thermal (heating) effects of exposure and not that harmful
effects occur at much lower levels. Secondly, ICNIRP has
assumed that exposure measurements can be averaged over a
period of time. This is not necessarily the case, and the impact
of short, intense exposure needs to be considered. So, too,
do the characteristics of the signal (polarization, pulsing and
modulation, for example) that affect how the body responds
to exposure. By taking into account only the mean values of
an exposure, the Guidelines underestimate its risk.
B. MEASUREMENTS RESULTS
As previously explained in detail in Section II, an EMF cam-
paign of measurements was designed and performed within
different types over fixed RFID readers. In Fig. 18 and
Fig. 19, the E-field measurement results for two different
protocols are depicted. The obtained EM levels are also under
the security threshold stated by ICNIRP-20 [19]. This means
that E-field levels in healthcare are apparently safe according
to the health and safety requirements concerning the exposure
of patients, workers and the general public to the risks derived
from electromagnetic fields.
Some concern involves the possibility of interference with
medical devices. The International Electrotechnical Commis-
sion (IEC) Standard IEC 60601-1-2 [61] sets a minimum
immunity level of 129.54 dBµV/m. Examining experimental
results, the maximum value of the E-field is much lower than
the 129.54 dBµV/m. The emissions of this equipment under
study are not continuous, but operate with a signal pattern
in the form of very short duration pulses and the field levels
decline significantly with distance.
In real conditions, the exposure to the emissions of the
studied equipment will be considered occupational, with the
user workers being exposed in a non-continuous and non-
homogeneous way. In case of occupational safety assessment
of exposures in the frequency range of interest in the present
case, the criteria is established in Directive 2013/35/EU of
the European Parliament and of the Council on the minimum
health and safety requirements concerning the exposure of
workers to the risks derived from physical agents (electro-
magnetic fields) [31]. This legal text establishes exposure
limits for the protection of staff health from the immediate
effects of short exposures to non-ionizing radiation. The
analysis of the data obtained reveals that of the maximum
levels of E-field emitted by the equipment under test, the
highest would be far from the Action Level established by
the standard (AL = 158.92 dBuV/m).
In the vicinity of these equipment, general public can
be present and in this case, their exposure levels would be
regulated by [51] which establishes a Reference Level RL =
152.15 dBµV/m. In this case, the highest maximum levels
are also under the RL, and also correspond to the RFID
transmitter (approx. 1/3 RL) and in-situ experimental EMF
evaluation needs to be performed using professional mea-
surement devices and ensuring immunity of the measurement
device to EM influence from other frequency bands. As in the
real measurements, the same transmitter locations have been
considered in the simulations to compare the obtained results
with the measured ones. Therefore, the comparison with cur-
rent legal exposure limits has been presented, verifying that,
for all cases, E-field levels were below the aforementioned
limits. These results and the proposed simulation method-
ology, can aid in an adequate assessment of EMF exposure
recommendations and limits, for this fixed readers.
V. CONCLUSION
A holistic, immediate and accurate vision that can help to
avoid EM interferences on electro medical equipment, and
supervise the exposure to EM fields of the workers, the
patients and the general public may be obtained by the com-
putation of 2D contour maps of EMF presented, in this case
in a healthcare center. The analysis and study of the EM
conditions in a healthcare environment using 2D contour
maps could be helpful for the following purposes:
- Detection of over-exposed points to electromagnetic
radiation and areas with greater absorption levels
- To be avoided potential harm to patients due to the inter-
ference on electromedical equipment and on implantable
personal devices.
- To monitor appropriately the exposure to electromag-
netic fields of healthcare workers, patients and the gen-
eral public.
- To achieve emission levels under the recommended
thresholds, but enough levels to guarantee a high quality
service of wireless communication systems.
- To plan and design new high-tech healthcare centers.
In accordance with all of the above, and considering the
mean value of instantaneous emissions, the actual operating
distance and the fact that the exposures would be infrequent,
it can be concluded that there is no risk that the staff using
the equipment evaluated or the public that may be found
nearby suffers thermal damage owing to exposure to the sort
of emissions recorded in this study.
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VICTORIA RAMOS (Senior Member, IEEE)
received the Ph.D. degree in biomedical engi-
neering and telemedicine from the University
of Alcalá, Madrid, Spain, in 2005. She was a
Telecommunications Engineer with the Polytech-
nic University of Madrid, Spain. From 1985 to
1996, she worked as a Radio Communications
Research and Development Engineer in the private
industry. Since 1996, she has been a Research
Scientist and is currently a Tenure Scientist with
the Research Area of Telemedicine and Digital Health, Instituto de Salud
Carlos III,Ministry of Science and Innovation,Madrid. Her research interests
include the area of wireless communications applications for home care and
the next generations of communications technologies for telemedicine appli-
cations. It involves standards related to human exposure, medical devices
immunity, and radio communication EMC.
OSCAR JAVIER SUÁREZ was a Telecommuni-
cations Engineer at the Polytechnic University of
Madrid, Spain. From 1988 to 1989, he worked as a
Technical Electronic Engineer at Spain television
TVE. In 1989, he worked as a Telecommunica-
tion’s Inspector. From 1990 to 1991, he worked
as a Radiodetermination Associate Professor with
the ETSIS Telecommunication, Polytechnic Uni-
versity of Madrid. Since 1991, he has been work-
ing with the RF Laboratory for the Surveillance
market of the telecommunications equipment of the Spanish Administration,
Ministry of Economy and Digital Transformation. He is currently the Head
of the RF Laboratory where radio, electromagnetic compatibility, safety, and
health protection tests are carried out according to European regulations to
verify the CE marking.
VÍCTOR M. FEBLES SANTANA received the
Master of Electronic Engineering degree from the
University of La Laguna, in 2012, the Master of
Telecommunication Engineering degree from the
Open University of Catalonia, in 2015, and the
Master of Industrial Engineering degree from the
University of La Laguna, in 2018. He is currently
pursuing the Master of Biomedical Engineering
degree with the International University of Valen-
cia. From 1999 to 2004, he worked as a Field
Engineer in local telecommunications services company concessionaire in
the Canary Islands. Since 2005, he has been working with the Biomedical
Engineering Section, Canary University Hospital, where he has also been
working with the Energy Engineering Section, since 2017. His research
interest includes electromagnetic radiation.
ERIK AGUIRRE received the M.Sc. degree in
telecommunications engineering from the Public
University of Navarre, in 2012, and the Ph.D.
degree, in 2014. After his M.S. degree, he has
been working in a research project with the Uni-
versity of Vigo related to dispersive propagation.
His research interests include radio propagation in
dispersive media, body centric communications,
and wireless sensor networks.
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V. Ramos et al.: Electromagnetic Characterization of UHF-RFID Fixed Reader in Healthcare Centers Related to Personal
SILVIA DE MIGUEL-BILBAO received the
Telecommunication Engineering and Ph.D.
degrees from the University of Valladolid (UVA),
Spain, in 2001 and 2015, respectively. From
2000 to 2009, she worked as a Research and
Development Engineer in the private industry,
and from 2005 to 2009, she was an Associate
Lecturer at UVA. Since 2010, shewas a Researcher
with the Research Area of Telemedicine and e-
Health, Instituto de Salud Carlos III, Madrid. Her
main research interests include experimental and numerical dosimetry in
bio-electromagnetics, electromagnetic compatibility, smart health, radio-
frequency electromagnetic fields, and assessment of exposure to no-ionizing
radiations. She was a recipient of the Doctorate Award 2016 in the engineer-
ing and architecture area awarded by UVA.
PABLO MARINA received the Telecommu-
nication Engineering, with a specialization in
telematics, and Master of Telecommunications
Engineering degrees from the University of
Valladolid (UVA), Spain, in 2018 and 2020,
respectively. Since 2020, he has been a Researcher
with the Research Area of Telemedicine and e-
Health, Instituto de Salud Carlos III. His main
research interests include dosimetry, smart health
and radiofrequency exposure, and its effects on
human body.
LUIS ENRIQUE RABASSA LÓPEZ-CALLEJA
received the Mechanical Engineering degree from
the University of León, Spain, in 2013.
In 2003, he was the Technical Industrial Engi-
neer and a Collegiate Member n◦ 899 of the Tech-
nical Industrial Engineers Official College, Santa
Cruz de Tenerife. He was a Mechanical Engineer
with the Zaporizhzhia State Medical University,
Ukraine, in coordinationwith theUniversity of Las
Villas, Cuba, from 1988 to 1994. From 2002 to
2004, he was a Researcher at the Photovoltaic Solar Energy Department,
Renewable Energies Technological Institute (ITER). Since 2007, he has
been working as an Engineer with the Engineering Subdirection, Hospital
Universitario de Canarias (HUC).
DAVID SAMUEL SUÁREZ RODRÍGUEZ
received the Telecommunication Engineering
degree, with a specialization in telecommunication
systems, from the Universidad de Las Palmas de
Gran Canaria, in 2005. From 2005 to 2008, he
worked as a Design Engineer in the private indus-
try. From 2008 to 2010, he was a Field Engineer
in radar systems. Since 2010, he has been working
with the Hospital Universitario de Canarias as an
Engineering Technical Coordinator.
MIKEL CELAYA-ECHARRI (Graduate Student
Member, IEEE) received the Computer Science
Engineering and M.Sc. degrees in project man-
agement from the Public University of Navarre
(UPNA), in 2011 and 2015, respectively, and the
Ph.D. degree in engineering and sciences from the
Tecnológico de Monterrey, Mexico, in 2022. From
2011 to 2014, he worked as a Research and Devel-
opment Engineer at Tafco Metawireless, Spain.
From 2015 to 2017, he was a Visiting Assistant
with the Networks and Telecommunications Research Group, Tecnológico
de Monterrey, where he is currently working as a Postdoctoral Researcher.
His research interests include radio frequency electromagnetic dosimetry,
radio propagation, wireless sensor networks, project management, and com-
puter science.
FRANCISCO FALCONE (Senior Member, IEEE)
received the Telecommunication Engineering and
Ph.D. degrees in communication engineering from
the Public University of Navarre, Spain, in 1999
and 2005, respectively. From 1999 to 2000, he
worked as a Microwave Commissioning Engi-
neer at Siemens-Italtel. From 2000 to 2008, he
worked as a Radio Network Engineer at Telefónica
Móviles. In 2009, he co-founded Tafco Metawire-
less. From 2003 to 2009, he was an Assistant
Lecturer at UPNA and became an Associate Professor, in 2009. His research
interests include artificial EM media, complex EM scenarios, and wireless
systems analysis.
JOSE ÁNGEL HERNÁNDEZ-ARMAS received
the Telecommunication Engineering degree from
the European University of Madrid (UEM), in
2013, and the Master of Information System
Direction degree from University CEU Cardenal
Herrera, in 2015. He has been a Telecommuni-
cations Technical Engineer with the University
of Las Palmas de Gran Canaria (ULPGC), since
1995. He became an Universitarian Expert both
in telecommunication systems (2005) and project
management (2006) at Remote Education University (UNED). Since 2000,
he has occupied several jobs related to engineering subdirection after work-
ing at several private technological companies associated with health ser-
vices. Since 2014, he manages the implementation and maintenance of
ICT technologies at the Hospital Universitario de Canarias (HUC) as a
Telecommunications and Telematics Chief Engineer.
28630 VOLUME 10, 2022