Elektromagnetische velden in arbeidssituaties

NB Nederlandstalige versie verschenen onder nummer 610015001N De EU heeft richtlijn 2004/40/EG uitgevaardigd om de werknemer te beschermen tegen gezondheidsrisico's door blootstelling aan elektromagnetische velden op het werk. Deze richtlijn moet uiterlijk 30 april 2008 zijn omgezet in nationale wetgeving. Ter voorbereiding hiervan heeft het RIVM in opdracht van het Ministerie van SZW de blootstelling in Nederlandse arbeidssituaties geinventariseerd en geanalyseerd. Het doel van dit rapport is de werkgevers een handreiking te geven om vast te stellen of aan de eisen uit de richtlijn wordt voldaan en om de risico-inventarisatie en -evaluatie (RI&E) voor elektromagnetische velden op te stellen. Totdat er geharmoniseerde Europese normen van het Europees Comiti voor elektrotechnische normalisatie (CENELEC) beschikbaar zijn voor alle situaties die moeten worden beoordeeld, gemeten en berekend, mag dit rapport als richtsnoer gebruikt worden. Gebruik van dit rapport is dus geen verplichting. Voor de meeste werkgevers is het voldoende om de eerste twee hoofdstukken door te nemen. De volgende drie hoofdstukken bevatten voor een aantal arbeidssituaties informatie over de blootstelling, de rekenregels waarmee de situatie kan worden ingeschat en de mogelijke beheersmaatregelen. Het laatste hoofdstuk geeft een overzicht van de kosten die met invoering van de richtlijn samenhangen. Om te kunnen toetsen of de blootstelling onder de limieten van de richtlijn blijft, moeten CENELEC-normen worden gebruikt, voor zover ze bestaan. Deze normen zijn zonder specialistische kennis niet eenvoudig toe te passen. Ook hoeft niet alle apparatuur even uitgebreid beoordeeld te worden of zijn even zware maatregelen nodig. Om de beoordeling te vergemakkelijken geeft dit rapport een beoordelingsschema en tabellen met een indeling van alle relevante werkomgevingen in drie categorieen. Voor iedere categorie geldt een ander beoordelingstraject.The EU has issued Directive 2004/40/EC on the protection of workers from health and safety risks arising from exposure to electromagnetic fields in the workplace. This directive must be implemented in national legislation no later than 30 April 2008. To prepare for implementation, RIVM has, on commission of the Ministry of Social Affairs and Employment, investigated and analysed the exposure in Dutch working environments. The purpose of this report is to provide assistance to employers to assess whether compliance is met and to carry out the inventory and evaluation of risks (RI&E) due to electromagnetic fields. Until harmonised European standards from CENELEC cover all relevant assessment, measurement and calculation situations, this report may serve as a guide. It is not mandatory to use this report. It will be sufficient for most of the employers to confine themselves to the first two chapters. Subsequent chapters deal with the exposure found in several working environments and provide guidelines for assessing risks and possible measures in these working environments. Costs for implementing the directive are discussed in the last chapter. CENELEC standards, if available, are mandatory for assessing whether exposure occurs below the limits in the directive. However, these standards are not easy to use without specialist knowledge. Furthermore, not all equipment needs to be assessed to the same extent nor are the same measures needed. A flow chart and tables of relevant working environments, classified into three categories, are provided to facilitate the assessment. Each category has its own assessment path.SZ

Assessment of Electromagnetic Absorption towards Human Head Using Specific Absorption Rate

This paper presents a compact square slot patch antenna characterstics for wireless body area network (WBANs) applications.The assessment of the effects of electromagnetic energy (EM) on the human head is necessary because the sensitivity of human head to high radiation level. Although, structuring of low EM antennas is a major problem in the improvement of portable device and reducing the size of of the antenna is a major concern. However, performance of antenna reduces when antenna operates near human body which is lossy and complex in nature. The proposed antenna operates at 5.8GHz of the ISM Band for WBAN applications. The antenna has been designed and simulated with two different types of multilayer human head phantoms to characterize the antenna near the human head.The multilayer head phantom is constructed by five layers tissues head model using CST Microwave studio. Therefore, antenna with spherical phantom has the highest SAR value 0.206 W/Kg, while antenna with cubical phantom contributed the lowest SAR value of 0.166 for 10 g tissue at 5.8 GHz frequency exposed, whereas, the antenna with cubical phantom and spherical phantom have gain of 6.46 dBi and 6.2 dBi GHz respectively. It was observed that antenna performance significantly increased. The presented prototype has a potential to work for ISM applications

Safety and reliability of Radio Frequency Identification Devices in Magnetic Resonance Imaging and Computed Tomography

BACKGROUND: Radio Frequency Identification (RFID) devices are becoming more and more essential for patient safety in hospitals. The purpose of this study was to determine patient safety, data reliability and signal loss wearing on skin RFID devices during magnetic resonance imaging (MRI) and computed tomography (CT) scanning. METHODS: Sixty RFID tags of the type I-Code SLI, 13.56 MHz, ISO 18000-3.1 were tested: Thirty type 1, an RFID tag with a 76 x 45 mm aluminum-etched antenna and 30 type 2, a tag with a 31 x 14 mm copper-etched antenna. The signal loss, material movement and heat tests were performed in a 1.5 T and a 3 T MR system. For data integrity, the tags were tested additionally during CT scanning. Standardized function tests were performed with all transponders before and after all imaging studies. RESULTS: There was no memory loss or data alteration in the RFID tags after MRI and CT scanning. Concerning heating (a maximum of 3.6 degrees C) and device movement (below 1 N/kg) no relevant influence was found. Concerning signal loss (artifacts 2 - 4 mm), interpretability of MR images was impaired when superficial structures such as skin, subcutaneous tissues or tendons were assessed. CONCLUSIONS: Patients wearing RFID wristbands are safe in 1.5 T and 3 T MR scanners using normal operation mode for RF-field. The findings are specific to the RFID tags that underwent testing

Dosimetric study of the radiolectric influence of humans into complex environments through determistic simulations and the implementation of a simplified model

The research presented in this thesis falls under the framework of dosimetry and deterministic estimations. A dosimetric study is carried out with the aid of a 3D Ray Launching simulation technique, by means of an in-house developed code at UPNA. Dosimetry is defined as the calculation of the absorbed dose when a tissue is exposed to electromagnetic radiation, in this case, non-ionizing radiation. It has reached a great importance since a part of the society starts to show concern about the exposure of people to artificial exposures caused by mobile phones or Wi-Fi networks. In fact, some entities (administrations and health bodies) are involved in the regulation and the release of guidelines about this subject. The objective of this thesis is to study dosimetry through 3D Ray Launching simulation technique, calibrating it by the implementation of several scenarios where the simulation tool is tested throughout the comparison of theoretical and measurement results. A simplified human body has been also developed with the aim of employing it in different scenarios, performing dosimetric estimations and providing insight on its influence in the electromagnetic power distribution inside an indoor scenario. Finally, obtained results are compared with different guideline thresholds giving an idea of the compliance of the law when usual wireless communication systems are emitting.Programa Oficial de Doctorado en Tecnologías de las Comunicaciones (RD 1393/2007)Komunikazioen Teknologietako Doktoretza Programa Ofiziala (ED 1393/2007

Antenna Development for Radio Frequency Hyperthermia Applications

This thesis deals with the design steps, development and validation of an applicator for radio frequency hyperthermia cancer therapy. An applicator design to enhance targeted energy coupling is a key enabler for preferential temperature increments in tumour regions. A single-element, near-field approach requires a miniaturised solution, that addresses ergonomic needs and is tolerant to patient anatomy. The antenna war-field rriodality and the high-dielectric patient loading introduce significant analytical and computational resource challenges. The antenna input impedance has to be sufficiently insensitive to in-band resonant cletuning and the fields in the tissue can he targeted to selected areas in the patient. An introduction to the medical and biological background of hyperthermia is presented. The design requirements of antennas for medical and in particular for hyperthermia applications are highlighted. Starting from a conventional circular patch, the antenna evolved into a compact circular patch with a concentric annular ring and slotted groundplane, operating at the 434 MHz Industrial Scientific and Medical frequency band. Feed point location is optimized for an energy deposition pattern aligned with the antenna centre. The applicator is assessed with other published approaches and clinically used loop, dipole and square patch antennas. The antennas are evaluated for the unloaded condition and when loaded with a tri-layer body tissue numerical model. This model comprises skin, fat and transverse fiber of muscle of variable thicknesses to account for different body locations and patient. anatomy. A waterbolus containing de-ionized water is added at the skin interface for superficial tissue cooling aud antelina matching. The proposed applicator achieves a penetration depth that supersedes other approaches while remaining compact and an ergonomic fit to tumour areas on the body. To consider the inner and peripheral complex shapes of human bodies, the full human body numerical model developed by Remcom is used. This model was segmented from 1 mm step computed tomography (CT) and magnetic resonance imaging (MRI) cross-sections through and adult male and it comprises twenty-three tissue types with thermal and frequency-dependent dielectric properties. The applicator performance is evaluated at three anatomical body areas of the model to assess its suitability for treatment of tumours at different locations. These three anatomical regions present different aperture coupling and tissue composition. \u27Different conformal waterbolus and air gap thickness values are evaluated. The models used in this work are validated with measurements performed in a phantom containing a lossy liquid with dielectric properties representative of homogeneous human body tissue. The dosimetric assessment system (DASY) is used to evaluaxe the specific absorption rate (SAR) generated for the antenna into the liquid. The measurement setup with the antenna, phantom and liquid are simulated. Simulated and measured results in terrms of specific absorption rate and return loss are evaluated

Smart manufacturing for industry 4.0 using Radio Frequency Identification (RFID) technology

Industry 4.0 (I4.0) presents a unique challenge of efficiently transforming traditional manufacturing to smart and autonomous systems.Integrating manufacturing systems, materials, machinery, operators, products and consumers, improve interconnectivity and traceability across the entire product life cycle in order to ensure the horizontal and vertical integration of networked Smart Manufacturing (SM) systems. Manufacturing functions of Material Handling (MH)-control, storage, protection and transport of raw materials, work in process (WIP) and finished products- throughout a manufacturing and distribution process will need a revamp in ways they are currently being carried in order to transition them into the SM era. Radio Frequency Identification (RFID), an Automated Identification Data Capture (AIDC) technology increasingly being used to enhance MH functions in the (SM) industry, due to opportunities it presents for item tracking, out of sight data capturing, navigation and space mapping abilities. The technology readiness level of RFID has presented many implementation challenges as progress is being made to fully integrate the technology into the preexisting MH functions. Recently, many researchers in academia and industry have described various methods of using RFID for improving and efficiently carrying out MH functions as a gradual transition is being made into I4.0 era. This paper reviews and categorize research finding regarding RFID application developments according to various MH functions in SM, tabulates how various I4.0 enablers are needed to transform various traditional manufacturing functions into SM. It aims to let more experts know the current research status of RFID technology and provide some guidance for future research

Implanted Wireless Sensors For Medical Applications: Exploring the Limits of Inductive Powering.

Wireless medical implant powering is an emerging sector for future healthcare applications. It enhances the healthcare safety level and the prospects of a better life. The main theme of this research is to design a wireless power budgeting for the medical implants. A proper link between an external source to the implant is established by an inductive coupling for a particular physiological parameter monitoring. A battery-free implant device requires sufficient power supply for active monitoring. The main target of this research is to develop a wearable and external antenna design for transferring sufficient power to the implant for its activation without violating the regulations of specific absorption rate limits. In addition, there is another goal of improving the implant depth. In this research, two different models (link model and SAR model) are used for the assessment in the virtual environment. Previously, a two-turns antenna is used for power transmission but in this research, several antenna structures are studied such as – the circular two-turns with a capacitor loaded loop, benzene shape, rectangular shape, octagonal shape, and circular spiral shape. Among these structures, circular spiral shape, with the combination of same and counter directions of spiral loops, shows satisfactory results. Through the proper optimization approach, the circular spiral antenna is capable of providing 25% more power at the implant with respect to the two-turns antenna. For 16 mm link distance, the circular spiral antenna can transmit 686 mW whereas a two-turns antenna is efficient up to 452 mW. Even the implant can be placed 2.5 mm more depth without interrupting the power transmission link between antennas. The circular spiral antenna is able to transfer significant power up to 9 mm skull thickness whereas 6.4 mm is the average width. Two experimental setups are developed for antenna performance analysis such as “air gap testing”, and “pigskin and air gap testing”. In the experiments, the effect of parasitic elements over the link power efficiency is identical to both the experiments. The results of “in vitro” testing of the newly developed wearable external antenna inspires for future implementation in the monitoring of intracranial pressure. From the performance analysis, in both the virtual environment and experimental setup, the circular spiral antenna has enough potentiality to use in inductive powering for further research and development

Implanted Wireless Sensors For Medical Applications: Exploring the Limits of Inductive Powering.

Wireless medical implant powering is an emerging sector for future healthcare applications. It enhances the healthcare safety level and the prospects of a better life. The main theme of this research is to design a wireless power budgeting for the medical implants. A proper link between an external source to the implant is established by an inductive coupling for a particular physiological parameter monitoring. A battery-free implant device requires sufficient power supply for active monitoring. The main target of this research is to develop a wearable and external antenna design for transferring sufficient power to the implant for its activation without violating the regulations of specific absorption rate limits. In addition, there is another goal of improving the implant depth. In this research, two different models (link model and SAR model) are used for the assessment in the virtual environment. Previously, a two-turns antenna is used for power transmission but in this research, several antenna structures are studied such as – the circular two-turns with a capacitor loaded loop, benzene shape, rectangular shape, octagonal shape, and circular spiral shape. Among these structures, circular spiral shape, with the combination of same and counter directions of spiral loops, shows satisfactory results. Through the proper optimization approach, the circular spiral antenna is capable of providing 25% more power at the implant with respect to the two-turns antenna. For 16 mm link distance, the circular spiral antenna can transmit 686 mW whereas a two-turns antenna is efficient up to 452 mW. Even the implant can be placed 2.5 mm more depth without interrupting the power transmission link between antennas. The circular spiral antenna is able to transfer significant power up to 9 mm skull thickness whereas 6.4 mm is the average width. Two experimental setups are developed for antenna performance analysis such as “air gap testing”, and “pigskin and air gap testing”. In the experiments, the effect of parasitic elements over the link power efficiency is identical to both the experiments. The results of “in vitro” testing of the newly developed wearable external antenna inspires for future implementation in the monitoring of intracranial pressure. From the performance analysis, in both the virtual environment and experimental setup, the circular spiral antenna has enough potentiality to use in inductive powering for further research and development

Wearable sensors for respiration monitoring: a review

This paper provides an overview of flexible and wearable respiration sensors with emphasis on their significance in healthcare applications. The paper classifies these sensors based on their operating frequency distinguishing between high-frequency sensors, which operate above 10 MHz, and low-frequency sensors, which operate below this level. The operating principles of breathing sensors as well as the materials and fabrication techniques employed in their design are addressed. The existing research highlights the need for robust and flexible materials to enable the development of reliable and comfortable sensors. Finally, the paper presents potential research directions and proposes research challenges in the field of flexible and wearable respiration sensors. By identifying emerging trends and gaps in knowledge, this review can encourage further advancements and innovation in the rapidly evolving domain of flexible and wearable sensors.This work was supported by the Spanish Government (MICINN) under Projects TED2021-131209B-I00 and PID2021-124288OB-I00.Peer ReviewedPostprint (published version

Design, Analysis and Applications of Wearable Antennas: A Review

Wearable antennas are the vital components for Body Centric Communication (BCC). These antennas have recently gained the attention of researchers and have received a great deal of popularity due to their attractive characteristics and opportunities. They are fundamental in the Wireless Body Area Networks (WBANs) for health care, military, sports, and identification purposes. Compared to traditional antennas, these antennas work in close proximity to the human body, so their performance in terms of return loss, gain, directivity, bandwidth, radiation pattern, efficiency, and Specific Absorption Rate (SAR) is influenced by the coupling and absorption of the human body tissues. Additionally, in the design of these antennas, size, power consumption, and speed can also play a paramount role. In most cases, these antennas are integrated into the clothes, or in some cases, they may be fixed over the skin of the users. When these characteristics are considered, the design of wearable antennas becomes challenging, particularly when textile materials are examined, high conductivity materials are used during the manufacturing process, and various deformation scenarios have an impact on the design’s performance. To enhance the overall performance of the wearable antennas and to reduce the backward radiation towards the human body, metamaterial surfaces are introduced that provide a high degree of isolation from the human body and significantly reduce the SAR. This paper discusses the state-of-the-art wearable/textile/flexible antennas integrated with metamaterial structures composed of wearable/flexible substrate materials, with a focus on single and dual band antenna designs. The paper also reviews the critical design issues, various fabrication techniques, and other factors that need to be considered in the design of wearable/textile/flexible antennas. All the designs presented in this work are of the recent developments in wearable technology