Jul 16, 2021Industry standards group AIM Global has released the latest version of its standard for the testing of non-implantable wireless medical devices, to help users and manufacturers better determine if they are immune to emission from RFID technology. AIM's 7351731 standard provides companies with guidance to test medical devices and determine whether RFID transmissions pose any risk to their operability. The standard offers test protocols for 125 kHz LF and 13.56 MHz HF RFID compliant with ISO 15693, as well as UHF RFID transmissions and both active and passive technologies.
AIM is a global industry association that offers networking, education and advocacy to promote and standardize automatic-identification technologies. It covers RFID, barcoding and smart devices used in Internet of Things (IoT), real-time location system (RTLS) and blockchain applications. The organization's latest healthcare standard revision, which it announced in June of this year, provides updates to the previous version of the standard, which was developed by AIM's healthcare initiative workgroup, within the RFID Experts Group (REG HCI), according to Mary Lou Bosco, the COO of AIM and AIM North America.
Mary Lou Bosco
RFID is frequently used in healthcare environments for asset and inventory management, as well as for patient and personnel tracking. For instance, RFID tags can be applied to high-value equipment, laptops, carts and medications, as well as to packaging for surgical implants and tools. RFID-enabled wristbands and badges can be worn by hospital personnel, in addition to both adult and infant patients.
Test labs have been testing against the standard for several years, Bosco reports, and some have provided suggestions for improving the testing protocols to the AIM working group. This third version of the standard is intended to reflect the latest testing needs, and to be easier to implement than previous iterations. The update is part of regular review and revisions that AIM provides for all of its standards, "AIM periodically reviews these documents," Bosco states, "to make sure all the information is up to date and conforms with the most recent technology advancements."
Several ISO/IEC documents have been revised since the release of the initial standard, and AIM thus updated its standard to accommodate those changes. The working group adjusted the standard according to requests from RFID solution designers, Bosco says, as well as from medical facility engineers and administrators. All of the previous groups have performed the test methods and test levels for evaluating the electromagnetic immunity of non-implantable medical electrical equipment and systems to electromagnetic emissions from RFID readers. AIM has been working with these parties, she says, "to give as clear guidelines as possible with how to perform the testing."
The changes, which include clarification of some figures to make them easier to interpret, take into account updates to several ISO/IEC documents, as well as comments from the labs that performed the testing in the standard. "The specially appointed workgroup thought that enough new information was available to update the standard," Bosco says, "and make testing methodologies clearer for those reading and implementing the standard."
The standard guides medical device manufactures and end users on how to evaluate their devices' immunity to emissions as RFID readers interrogate tags within the vicinity. The test procedures are based on experimental results from several AIM members and testing labs that performed the standard's test methods, Bosco says. Working together, these parties reached an agreement on how testing should be performed and the verbiage that should be used to specify the standard's testing requirements.
Test protocols are included for the major commercial implementations of RFID. The standard is designed for testing existing medical electrical equipment and systems. For the purposes of this standard, Bosco notes, other technologies, such as Wi-Fi and ultra-wideband, are not considered. Instead, she says, LF, HF and UHF represent the most common RFID technologies currently deployed in healthcare environments.
While there is no official certification process for devices that pass testing, AIM has encouraged those that have carried out testing to contact the association with their results so that it may continue to collect a list of those who claim they can perform the test. The standard guidelines can also offer guidance for RFID solution designers, to help them determine during the designing stage whether medical electrical equipment and an RFID solution environment are compatible. Immunity to RFID reader testing is required by the FDA for medical devices.
According to the FDA, the use of RF wireless technology offers advances in healthcare, but because airways are shared, the function of a wireless medical device could be affected by the presence of other wireless devices within the vicinity. One example might be losing data or experiencing disruption in operation. The FDA advises healthcare facilities to consider the selection of wireless technology, quality of service, coexistence and security when choosing RFID and other wireless technologies.
