May 25, 2021
Medical devices are evolving, often with additional wireless functionality. A consistent way to evaluate the risks due to wireless data transfer is necessary because additional functionality also brings the potential for increased risk to patients and operators. Used together, AAMI TIR69:2017/(R)2020 and IEEE/ANSI C63.27-2017 address this concern by providing a path to evaluate the risk and determine the effectiveness of risk controls.
Wireless test determination
AAMI TIR69, Risk Management of Radio-Frequency Wireless Coexistence for Medical Devices and Systems, provides a method of determining the correct test tier noted in IEEE/ANSI C63.27, American National Standard for Evaluation of Wireless Coexistence, which is then used to evaluate the hazardous situations. When a medical device provides wireless data transfer, AAMI TIR69 provides guidance on items to determine the correct test tier. The standard aligns with the principles outlined in ANSI/AAMI/ISO 14971:2007, Medical Devices - Application of Risk Management to Medical Devices. When reviewing the risk levels, you should consider the data being wirelessly transmitted along with the intended use of the device that will then drive the correct severity level and associated test tier. AAMI TIR69 clearly defines the risk level in Table 1, which is broken down into four categories, with the lowest category not requiring testing.
Wireless data risk evaluation
When evaluating the risk, you should consider the data transmitted for each wireless technology employed, such as Bluetooth™, Wi-Fi, Zigbee, etc., and the hazard associated with each. The standard additionally discusses the things to consider when evaluating the risk, for example data delay, transmission failure, corrupt data, etc. Each wireless technology can have a different risk category. While the standard does not state the compliance criteria specifically, the manufacturer needs to define compliance and provide the exact method that will be used during testing to determine it.
Once you identify the test tier and compliance, a test plan needs to be developed using the test tier along with the test methods specified in IEEE/ANSI C63.27. Additionally, TIR69 provides example test reports that can be used for summarizing the results.
In a separate article, UL experts will discuss the test methods specified in IEEE/ANSI C63.27. If you would like to speak with one of our technical experts, please feel free to contact us.