Risk-based EMC Approach in Hospital Environment

Abstract

A modern hospital has a wide range of medical devices that can be technologically very advanced and complex in terms of electromagnetic emissions and susceptibility. It is a public environment where people carry communication equipment and/or medical active implants. Therefore, electromagnetic interference among the devices in the hospital environment is not an unfamiliar topic. There is a misconception among engineers that if all medical devices comply with harmonized standards, then the installation of a large number of medical devices altogether would work absolutely fine. However, this is not always true, and so for complex systems, a smarter approach is necessary to assess and control the risks of electromagnetic interference. This paper emphasizes the importance of using the risk-based approach to deal with the often unpredictable factors causing electromagnetic interference in a complex hospital environment.

Studying the Probability of EMI through Time-Variance Behavior of Environment on Medical Devices

“…[1]) are generally communication or treatment devices that are designed to generate electromagnetic radiation, unintentional emitters (MRI, LED lights, leakage of microwave ovens etc. [2]), on the other hand, generates radiation as a byproduct of their intended operation. In order to achieve electromagnetic compatibility (EMC), by efficiently eliminating EMI, medical devices are inspected as per FDA Reviewer Guidance document or the European IEC 60601-1-2 standards [3].…”

Radiated and Conducted EMI by RF Fields at Hospital Environment

“…S INCE the mid-1990s the risk of electromagnetic interference (EMI) due to the increasing number of medical electrical equipment (MEE) in the professional healthcare facility environment has been continuously reported [1]. Despite manufacturers' efforts to enhance the MEE conformity, new challenges are introduced to the electromagnetic compatibility (EMC) based on the newest health technologies [2], [3]. The trend is to define the MEE regulations directly at manufacturers to ensure conformity and EMC.…”

Introduction of Wireless Services and Devices in a Hospital Environment Following a Risk-based EMC Approach

“…In most cases, the equipment is checked for immunity and emissions as a standalone object in laboratory conditions, although it is intended to be used in a densely populated and complex environment. Moreover, the high care spaces such as IC or OT can work as semi-reverberant environments for electromagnetic fields rather than a free space (FS) environment [8]. Presence of different types of reflectors, coated glass mirrors, or other equipment, creates more coupling paths for the reflected waves that further increase the complexity of the environment.…”

“…Furthermore, in an extreme case of an environment as reflective as a reverberation chamber, E can increase even by 20 dB [19]. In this extreme case, the resonating scattered components become stronger than the directly coupled component, which actually makes spatial separation less effective, and it will not follow the exponential decay, as shown in [8]. Due to the very strong statistical variations, the latter effect is not included in Table II and is subject to future studies.…”