# Electromagnetic Assessment of UHF-RFID Devices in Healthcare Environment
## 4 Discussion  
Given the more and more frequent use of the wireless networks within the proximity of medical devices, it will be crucial to determine the points with higher exposure levels. Following the results obtained by the authors, the EMF measured in far-field (sufficiently away from the readers, i.e., at distance of at least 0.5 m away from the readers antenna) are within the limits provided to evaluate the health hazards to exposed humans, that have been due to the thermal effects of the absorption of electromagnetic energy in tissues, as specified for in the applicable laws and regulations and research review reports. At the frequency of 866 MHz, like for the EMF emission from the tested UHF RFID readers, the specific limits aimed to assess the thermal exposure effects, lie within the range of 40-200 V/m, for example: the limit of 88.3 V/m has been delivered to assess the EMF exposure at the work environment, in compliance with the European Directive 2013/35/EU, [36] or the limits of 88.3 V/m and 193.8 V/m were set forth in the ICNIRP 2020 to assess whole body and local occupational exposure, respectively, or accordingly, many-fold lower limits set for the general public exposure at discussed frequency. Nevertheless, what should be emphasized to this extent is the fact that the level of emitted EMF is inversely proportional to the distance from the emitting antenna, and to the reading range of the applied RFID system. Consequently, the closer to the antenna, the more the EMF level rises. At the near-field, within a distance shorter than the wave length (as for the consider RFID readers emitting EMF of an approximate wavelength of 0.3 m), the thermal effects of EMF exposure near the source are to be examined, with the use of SAR computer simulations. The results of the studies carried out for such near-field exposure case (when a manually operated RFID reader is used, or by mistake rather, anyone is present directly close the autonomous reader) show that the electric field strength directly close to the reader may raise significantly exceeding 5 V/m, when in the far-field the EMF exposure level is many-time lower, depending on the distance from the antenna and the reading range of used system. With regard to the average value of the measured E-field, the distances at which these values were obtained and the fact that the exposure would be sporadic near autonomous readers located away from people, the conclusion goes that an operator of the considered manually operated devices or the individuals approaching their proximity may suffer from the exposure at levels comparable to the exposure limits provided to protect against thermal effects of EMF influence on exposed tissues. The results obtained by the authors show that whilst taking the EMF exposure effects in the near-field surrounding UHF RFID readers into consideration, the relevant preventive measures should be undertaken with the aim being to ensure sufficient protection of individuals who may be present there, where the RFID reader emitting over 1 W of electromagnetic radiation is used and the individuals may access the areas that is closer than 30% of reading range of the applied RFID system. However, all guidelines included the notes that the vulnerable individuals may require additional protection, including also the protection against inappropriate operation of electronic devices, at the level of exposure which is formally compliant with international exposure limits--with the foregoing to be of specific significance for medical implants that are more often used in healthcare centers than in public areas. Specifically more attention should be paid to the use of manually operated RFID the application of which is planned at the areas accessible to patients and visitors. The foregoing implies the E-field levels may be considered negligible where autonomous readers are used and located far from space accessible for workers, patients and visitors in healthcare centers.