The standard on the usability engineering process, IEC 62366-1:2015, has been amended several times since it was published in 2015. Corrections were made in 2016 in the form of the corrigendum. With 2020 amendment (AMD1:2020) resulted in significant changes that manufacturers of medical devices now need to familiarize themselves with.
The following article
The usability engineering process described by IEC 62366-1:2015 aims to ensure that risks that may arise when using medical devices are minimized. The target audience for the standard is manufacturers of medical devices and also technical committees that are responsible for the creation of specific standards for medical devices.
IEC 62366-1:2015 is the successor to 62366:2007. To clean up the normative part, the new version of IEC 62366 is made up of two parts:
Since IEC 62366-1:2015 was published, experts have identified a total of 22 problems. These have now been remedied by the corrections.
In summary, the significant changes are as follows:
Links to the standard texts
An overview of the topic of the usability of medical devices can be found in our overview article Usability & IEC 62366.
“Purely physical hazards” deleted, so hazards of any kind are included
3.2 Accompanying documentation
The definitions of accompanying documentation has been expanded
3.20 Use environment/Note 1 to entry
The definition of use environment conditions has been changed
3.29 User profile
Focus placed on the individual characteristics of the user
4.1 General requirements
Training of users introduced as a risk control measure
4.3 Tailoring the usability engineering effort
Changes to the usability engineering effort no longer need to be documented in the UE file
5.7 Establish user interface evaluation
The term “user group” has been introduced
5.7.3 Summative evaluation planning
New requirements for summative usability tests have been introduced, including recording use difficulties
5.9 Performing summative evaluation
Recording of the use difficulties in the summative evaluation is mentioned
Annex A (informative) – general introduction and justification
Rationale for definition 3.11 – primary operating function
Primary operating functions do not need to be determined
Rationale for definition 3.22 – use scenario
The term “critical task” has been introduced
Relationship between IEC 62366-1 and ISO 14971 shown for the types of use
Cooperation between risk management and usability engineering
Changes to hazard-based use scenarios, risk management measures and user interface evaluation
Rationale for Clause 5.7.3 – Summative evaluation planning
Use difficulties and close calls taken into account
Annex B (informative) – examples of possible hazardous situations
Here, the word “physical” in connection with hazards has been removed, so now theoretically subsequent psychological damage can also be included that occurs as a result of use errors.
Clause 3 of IEC 62366-1:2015 sets out terms and definitions. Here, too, there have been some updates.
The definition of “supporting documentation” from Clause 3.2 has been expanded such that it now covers materials containing information about the decommissioning and disposal in addition to those relating to the installation, use, and maintenance of a medical device.
“knowledge, skills, and abilities, which can have a bearing on design decisions”
In the rationale of the primary operating functions in Annex A, it is predominantly the handling of the primary operating functions that has changed. The rationale of Clause 3.11 now clearly states that these do not have to be determined according to IEC 62366-1:2015. Instead, hazard-based use scenarios shall be identified, described, and evaluated.
There are, however, exceptions to this:
In the rationale of the use scenario (3.22) in Annex A, the term “critical task” was also introduced.
This describes a task in a hazard-related use scenario in which a use error could lead to significant damage when the task is completed.
In Clause 4.1.2, which relates to risk management in connection with the design of the user interface, in addition to the existing risk management options [a) “safe design and production”, b) “protective measures”] the option “training of users” has been added in c) in addition to “information on safety”.
Point c) now says:
“Information for safety and, where appropriate, training of users“.
According to Clause 4.3, changes to the usability engineering effort no longer need to be documented in the user engineering (UE) file. This is not an essential requirement in the sense of the standard.
There have also been some changes in Clause 5 on the usability engineering process.
When creating a plan for the user interface evaluation (5.7.1 General), the terminology has changed. If usability tests are part of the plan (formative and summative evaluation), it is necessary to document which user groups are included in the test.
Clause 5.7.3 relates to the planning of the summative evaluation. The requirements for implementing summative usability tests have changed. The requirement is now for
The rationale of 5.7.3 in Annex A addresses the term “use difficulty” in greater detail.
Note 1 on this is also important on this, the wording of which is identical to the close call already mentioned from Annex A:
“A use difficulty where a user almost commits a use error while performing a task, but recovers in time to avoid making the use error is sometimes called a ‘close call’.“
Source: IEC 62366-1:2015+AMD1:2020
A new graphic A.4 was introduced in the informative (informative) Annex A, which explains the relationship between the “type of use” in IEC 62366-1 and the concept of “reasonably foreseeable misuse” in ISO 14971. To some extent this is an expansion of the graphic in the Clause “Terms 3.1 – abnormal use”.
The graphic introduces two updates:
This is a little unclear. Where is the difference to be set between abnormal use and use with errors? Does the user/manufacturer now need to predict potential abnormal use and check for in usability tests. Certainly not. The fact that abnormal use should now be reasonably foreseeable in addition to possible use errors (or maybe not foreseeable) results in a lack of clarity.
Graphic A.5 has also been changed, albeit only minimally. It clarifies the processes and links between risk management and usability engineering steps. There is a new focus on mutual exchange. When identifying hazards, scenarios, and user interface (UI) features relevant to safety, it is sensible to collaborate.
Also in connection with Graphic A.5, we emphasize that the hazard-related use scenarios, risk management measures and the user interface evaluation should be adapted and improved on a continuous (iterative) basis using the results of the formative evaluation.
The most important things first:
Unfortunately, harmonization has come to a halt since quite some time. This applies both to this standard and to other standards that were already harmonized with the MDD and need to be harmonized again.
EN ISO 14971 should be harmonized first to pave the way for other standards on the harmonization list. The current IEC 62366-1 is closely linked to this standard. Efforts are underway for other standards such as IEC 60601. As yet, however, all harmonization efforts have failed due to continuous content-related differences with the European Commission in terms of compatibility with the requirements of the MDR – despite all of the efforts to generate formulations compatible with the MDR in additional annexes.
Unfortunately, the way forward remains unclear, although a start has been made with other standards (as of September 2021). However, the validity and applicability of IEC 62366-1 is not affected by the harmonization process.
More information is available in the updated article Harmonized standards: evidence for medical device manufacturers and in the Regulatory Radar.
Amendment AMD1:2020 in particular introduced numerous changes into IEC 62366-1:2015 that must be taken into account in the usability engineering process. Most of these changes provide helpful clarifications and improvements. Some, such as the changes to Graphic A.4 in Annex A, raise more questions than they answer. The process of harmonizing the usability standard, which is urgently needed, continues to be delayed.
Diploma in Psychology