Your entry into the usability of medical devices

What does usability mean?

There is a good definition for this question in IEC 62366-1. According to this, usability describes the characteristics of the user interface that facilitate its use, thereby enabling effectiveness, efficiency and user satisfaction in the intended use environment.

The user interface is the part of the medical device with which the user interacts during use. The use environment is the environment in which the user uses the medical device.

How do you determine usability?

By definition, it's about demonstrating aspects of effectiveness, efficiency and user satisfaction - but none of these are physically measurable. So how do you proceed

As is so often the case in medical technology, a standard comes into play here. The IEC 62366-1 mentioned earlier, to be precise. It specifies different steps of a usability engineering process that have to be passed through and are linked to risk management according to ISO 14971. By applying the standard, the usability can be proven - until the moment when contrary information becomes known. This can happen, for example, if it is discovered during post-market surveillance that there are difficulties with the usability of the product.

For which medical devices is usability relevant?

According to MDR and IVDR, existing risks due to application errors should be reduced as much as possible. For this purpose manufacturers must

• "reduce as far as possible the risks related to the ergonomic features of the device and the environment in which the device is intended to be used (design for patient safety), and
• give consideration to the technical knowledge, experience, education, training and use environment, where applicable, and the medical and physical conditions of intended users (design for lay, professional, disabled or other users) [MDR / IVDR]".

The above requirements are derived from the General Safety and Performance Requirements (GSPRs). As GSPRs are applicable to all medical devices, it must be assessed on a case-by-case basis whether the above requirements are applicable and to what extent.

How is this related to risk management?

Usability is primarily concerned with reducing risks due to application errors as far as possible. The handling of risks of medical devices is regulated in ISO 14971, thus in risk management.

To describe this interface in more detail, we will explain the necessary basics in the blog post "Risk Management - Part 2". In "Usability - Part 2" we will then explain where the two processes exchange information in order to explain the connection between them.