Compliance & Regulatory Info Sheet Nr. 4 | Wireless Medical Devices & Connected Healthcare Applications | July 2014 Medical device manufacturers are increasingly incorporating radiofrequency (RF) wireless technology into their medical devices. Communication is accomplished using either published IEEE standards or proprietary protocols, many of which operate at unlicensed frequencies in the Industrial, Scientific and Medical (ISM) bands or in the Medical Implant Communication Service (MICS) band. As a result, ensuring wireless coexistence has become a focused effort for regulatory bodies all over the world. In this regards the FDA guidance document “Radio-Frequency Wireless Technology in Medical Devices,” outlines concerns related to RF wireless devices and asks that suppliers specifically address - among others - coexistence for their chosen wireless modality. However, test engineers will find that it is extremely difficult to find procedures that apply to FDA concerns. Although the FDA outlines a limited set of standards to assist in wireless medical device testing, it is still recommended that design teams review coexistence test plans with known experts in the field of product deployment. To address these concerns the IEEE 802.15.2 guideline for coexistence can be considered. This guideline recommends interference analysis criteria for measuring interference between wireless systems. It provides an exhaustive list of coexistence factors in the physical layer and medium access control layer that should be taken into account. It is to be noted that there is a clear distinction between EMC testing and wireless coexistence testing. Wireless Risks IEC 60601-1-2 is the general safety standard for medical electrical equipment and the primary standard used for EMC testing of non-implanted and non-in-vitro diagnostic electrical medical devices. Until recently the major limitation of the IEC 60601-1-2 standard was that RF receivers are exempt from immunity testing in the exclusion band. In other words, a medical device with RF wireless technology operating in the 2.4 GHz ISM band was not required by IEC 60601-1-2 to maintain wireless communication when subjected to RF signals in its passband. To fill this gap, the IEC published early this year IEC 60601-1-2: 4th Edition which reshapes the environment for Medical EMC while implementing considerably increased levels for radiated immunity. In addition the compliance criteria are no longer defined but depend highly on the risk management of the manufacturer. As a result, compliance according to IEC 60601-1-2: 4th Edition requires a close coordination process between the manufacturer and the test laboratory. Find the key changes as follows: • • EM Sources • Naturel (lightning, ESD) Non-Communicating (RF, Inductive charging...) Communications (Cell phones, Wireless data...) Receptors IEC 60601-1-2: 4th Edition (2014) reshapes the medical environment TRADITIONAL EMC WIRELESS COEXISTANCE Unintended (Hearing Aids, Medical Devices...) • • • Communications (Cell phones, Wireless data, RFID...) At present, device manufacturers and test facilities use very different methods of coexistence testing. Until recently the medical device EMC standards did not require test procedures to assess the performance of systems containing RF receivers in the presence of in-band transmitters. Here, test engineers can find answers in „IEEE 1900.2: Recommended Practice for Interference and Coexistence Analysis“ including an extensive overview of coexistence factors to consider during testing and recommends interference analysis criteria for measuring interference between radio systems. Early this year the IEC 60601-1-2:2014 (4th Edition) has been published, implying dramatical changes for the medical industry, in particular the EMC approach for coexistence testing. For more details consult the summary in the right column on this page. CETECOM is ready to support you! Apart from this, various regulatory interest groups are currently elaborating test methods to evaluate wireless coexistence. The IEEE 802.19 Wireless Coexistence Working Group assessing each 802 standard to determine scenarios in which interference may occur. Parallel to this, the American National Standards Institute (ANSI) C63, subcommittee 8 formed a working group to seek solutions, known as C63.27. CETECOM is an active member of this working group. The environment is divided into 3 areas: −Professional healthcare facility environment −Home Healthcare Environment including logistics −Special Environment /military areas The manufacturer must state the suitable environment(s) for use, and design the MEE for emission and immunity accordingly. The radiated immunity has increased the testing frequencies to match the reasonably foreseeable max. level found in the environment Immunity levels are harmonized with IEC 60601-1-11 Immunity testing now follows the same port-by-port convention of IEC 61000-6 of the Generic EMC standards Immunity to proximity fields from RF wireless communications equipment is based on a minimum separation distance of 30 cm Introduction dates • • • In Europe, CENELEC has recognized the 4th edition. The withdrawal date for the 3rd Edition is to be expected in 2017-2018. In the U.S. the FDA will decide on the 4th Edition in July, probably with a 3-year transition period. Unless changes are made that affect its compliance retesting of legacy products is not required. Canada will only review the 4th Edition in 2015, meaning that it will not be adopted before 2015/2016. Questions? Contact CETECOM! We are ready for IEC 60601-1-2: 4th Edition! Coexistence Evaluation Test Planning Analysis Conducted Testing Radiated Testing Consequential Chain Mapping Extrapolation to Field Performance Field Measurements & Monitoring © CETECOM Group 2014 | Contact: [email protected] | www.cetecom.com
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