1. Definition of the term UOUP (according to IEC 62366)
The IEC 62366-1:2015 (the standard for “Application of usability engineering to medical devices”) introduces the term UOUP and defines it as follows:
A UOUP (User interface of unknown provenance) is a user interface or parts of a user interface with an unknown development process for which suitable records of a usability-oriented development process by IEC 62366-1 are unavailable.
2. What IEC 62366 aims to achieve with the concept of UOUP
Many medical device manufacturers purchase components such as computer mice that have not undergone a usability engineering process by IEC 62366. Or they have had old products on the market for decades without any problems, and would like to make a minor change to the UI.
The manufacturers must now retroactively run the entire process for these user interfaces. This is precisely where the new IEC 62366 comes in: It allows them to run a shortened usability engineering process in which the risks associated with the usability of these components are estimated. This process requires the manufacturer to draw on information already available.
This shortened process can be applied precisely to three scenarios:
- On (legacy) medical devices that are already on the market and that were not developed using the process by IEC 62366:2006 (so-called predecessor medical devices)
- (Legacy) medical devices that have only undergone minor changes and were not developed initially using IEC 62366:2006
- Medical devices that contain a commercially available component that was not developed using IEC 62366:2006. An example was the computer mouse mentioned above.
- What simplifications does the standard allow?
3. What simplifications does the standard allow?
Simplifications provided by IEC 62366:2006
The simplifications consist of omitting some of the steps in the usability engineering process as specified in IEC 62366:2006. This applies in particular to
- the usability specification
- the usability verification
- the usability validation plan
- the usability validation itself.
In return, feedback must be evaluated to determine whether it contains information on risks due to poor usability. Suitable sources of information include:
- Service reports
- Customer complaints
- Reports to and from authorities
- Hotline calls
- Observations
However, manufacturers must not omit the so-called “application specification,” i.e., the intended purpose and determining the primary operating functions.
3.1. Simplifications through IEC 62366-1:2015
According to IEC 62366-1:2015, the simplifications are similar: Here, formative and summative assessment, and even the description of the “use scenarios,” may be omitted, but not the definition of the “use specification.”
4. UOUP: Timing is crucial
An addition by Wolfgang Schneider, usability expert at the Johner Institute and member of the working group on IEC 62366-1:
The standard IEC 62366-1:2015 explicitly refers to the date of publication in its normative Annex C, which should be used to assess whether a UI can be subsumed under UOUP or not—i.e., the year 2015.
4.1. Normative Text
The key statements are as follows:
C.1 General
This annex was created in recognition of the fact that many MANUFACTURERS will be interested in applying the tools defined in this standard to USER INTERFACES or parts of USER INTERFACES that have already been commercialized prior to the publication of this edition of this standard.
[…]
However, if any modifications are made to the USER INTERFACE or its parts, only the unchanged parts of the USER INTERFACE remain UOUP and the changed parts of the USER INTERFACE are subject to 5.1 to 5.8.
4.2. Summary
Therefore, this applies to 2015 if the manufacturer wishes to use the 2015 version of the standard. Furthermore, Annex C is definitely “normative” and not “informative,” unlike Annex B. The publication date, therefore, applies. The new AMD draft also provides for the date 2015 to be added to Annex C, which has not yet been mentioned.
If the manufacturer still wants to use the harmonized previous version, Annex K and the old year 2007 apply.
Therefore, it is likely to be more interesting for manufacturers not to use the “old” publication date and the harmonized standard, but the new one with 2015 and Annex C. This would then cover more products.
Since the standard requires manufacturers to develop UI parts created or modified after publication by the 62366-1 process, they are de facto forced to use the publication date as a criterion.
Note: The process in Annex C can be classified as optional, as the normative part only refers to “may be evaluated according to Annex C.” This means that there is no obligation (“shall”) to use the process in Annex C, which contradicts the standard.
4.3. Conclusionn
The recommendation refers to the current 62366-1 publication date, as stated in Annex C, whereby Annex C is confirmed by the 2016 corrigendum and the new AMD.
5. Further information to UOUP
5.1. UOUP (User Interface of Unknown Provenance) and SOUP (Software of Unknown Provenance)
For these “proven” “user interfaces of unknown provenance,” the approach from IEC 62304, which refers to “software of unknown provenance” (SOUP), has been adopted. For software and user interfaces of unknown provenance, there is no requirement for the documentation that would otherwise be mandatory if they have proven themselves and the manufacturer estimates the risks to be acceptable.
5.2. Consequences
The concept of UOUP is not limited to third-party user interfaces, but can also be applied to your products or user interfaces placed on the market before IEC 62366 existed and have proven themselves in the market. However, as soon as a manufacturer changes these user interfaces, they must again go through the entire usability engineering process prescribed by IEC 62366. This means that documentation errors made in the past are overlooked if they do not pose any risks to patients. However, this is not carte blanche for the further development of medical devices.
5.3. UOUP and FDA
Even before IEC 62366-1:2015 was published, an amendment in the form of Annex K was made. This adds precisely this concept of UOUP, which, incidentally, is endorsed by the FDA. This is good because otherwise, this “concession” would be worthless for all medical device manufacturers who also want to
