Page 52 - Safety Risk Management for Medical Devices

CHAPTER 8

Usability Engineering and Risk Analysis

Abstract
Medical devices are providing ever more benefits and at the same time are becoming more com-
plex with user interfaces that are not so intuitive, difficult to learn, and difficult to use. Use-errors
caused by inadequate medical device usability have become an increasing source of adverse safety
events. As healthcare evolves, and more home-use is promoted as a cost-saving measure, less
skilled users including patients themselves are now using medical devices. This chapter examines
the contribution of usability engineering to the safety of medical devices.
Keywords: Use Failure; Use Error; usability engineering; IEC 62366; human factors; user-device
interaction; task analysis

Medical devices are providing ever more benefits and at the same time are becoming
more complex with user interfaces (UIs) that are not so intuitive, difficult to learn,
and difficult to use. Use-errors caused by inadequate medical device usability have
become an increasing source of adverse safety events. As healthcare evolves, and more
home-use is promoted as a cost-saving measure, less skilled users including patients
themselves are now using medical devices.
In this chapter, the terms “Use Failure” and “Use Error” are used interchangeably.
The leading standard for usability engineering is IEC 62366, which in its latest
edition splits into two documents: IEC 62366-1:2015 [14], and IEC TR 62366-
2:2016. This international standard describes a usability engineering process to provide
acceptable safety risks as related to the usability of a medical device. It should be noted
that the scope of usability engineering is larger than safety. Usability engineering is
also concerned with how well and easily the user can interact with the medical device
in order to achieve their desired outcomes. Therefore customer experience and
satisfaction are also influenced by usability engineering.
IEC 62366 [14] provides a process to assess and mitigate risks associated with the correct-
use and use-errors. Malice, and Abnormal use are excluded from the risk management
process. See Sections 8.1 and 8.2 for further elaboration and elucidation of these terms.
It should be noted that the FDA considers Human Factors and Usability Engineering
to be synonymous. See FDA Guidance on HFE [18], par 3.6. Also, the FDA has
replaced the term “user error” with “use error.” This means that use error is
considered by the FDA to be a device nonconformity because human factors should be
considered in the design process.

Safety Risk Management for Medical Devices r 2018 Elsevier Ltd.
DOI: https://doi.org/10.1016/B978-0-12-813098-8.00008-8 All rights reserved. 31