Regulatory frameworks for usability testing

IEC 62366-1:2015 is an international standard that specifically covers the application of usability engineering to medical devices. It’s important to note that the IEC specifies that the standard covers assessment and mitigation of risk associated with normal use and use errors of the device. It doesn’t cover abnormal usage; however, it can be used to identify such risks.

IEC 62366-1 is the overlapping standard for FDA, the European Commission, and other regulatory bodies.

European union medical device regulation (EU MDR) is a little less specific about usability requirements, as this is covered largely in part in the General Safety and Performance Requirements.

MDR does include requirements for product validation and usability-related activities, of which must be documented in a manufacturer’s technical file. Additionally, the regulation emphasizes the need to collect and evaluate usability data as part of a manufacturer’s post-market monitoring and evaluation process.

The FDA describes its requirements for human factors engineering in two documents:

1. Applying Human Factors and Usability Engineering to Medical Devices(Feb 2016, final version)
2. Content of Human Factors Information in Medical Device Submissions(Dec 2022, draft)

Components of the Usability Engineering File:

The Usability Engineering File comprises several essential components, each of which plays a crucial role in ensuring the usability and safety of medical devices. These components include:

1. Descriptions of intended device users, uses, use environments, and training
2. Description of device user interface
3. Summary of known use problems
4. Analysis of hazards and risks associated with the use of the device
5. Summary of preliminary analyses and evaluations
6. Description and categorization of critical tasks
7. Details of human factors validation testing.

FDA requires usability testing, which is called human factors validation testing, “to demonstrate that the device can be used by the intended users without serious errors or problems, for the intended uses, and under the expected use conditions.”

Basic understanding of the steps and processes involved in human factors validation testing, adhering to FDA guidance, which sets forth the following requirements:

• The test participants represent the intended (actual) users of the device.
• All critical tasks are performed during the test.
• The device user interface represents the final design.
• The test conditions are sufficiently realistic to represent actual conditions of use.

The MDR’s Usability Testing Requirements

The new MDR 2017/745 comes with numerous usability testing requirements for Medical devices. They are:

• Devices must be suitable for their intended purpose

This intended purpose should not just define the intended medical purpose, it should also define the intended users and the environment in which the device is intended to be used. IEC 62366-1 calls this the “use specification”.

• Analysis of foreseeable misuse

It requires manufacturers to have a risk management system. They must use it to “estimate and evaluate the risks associated with, and occurring during, the intended use and during reasonably foreseeable misuse”.

• Measures to eliminate or reduce risks related to use errors

MDR makes it mandatory for manufacturers to define measures for all identified risks related to usability. Manufacturers must first aim for inherent safety, then aim for protection measures and, only after that, provide information for safety.

Examples of these measures are:

• Inherent safety: a switch that does not exist cannot be used incorrectly.
• Protection measure: a switch that has a flap to prevent it being pressed accidentally.
• Information for safety: a warning, e.g., in the instructions for use, regarding the consequences of pressing the switch by mistake.

• Specific risks from use in combination with other devices

 Risks resulting from the interaction of devices with their environment to be controlled. These risks are also, in part, related to usability

These usability requirements in the MDR should already have been met if the manufacturer has considered all use scenarios, including scenarios in which their device is combined with and connected to other devices. The MDR also demands here, as of a measure, inherent safety against faulty connections as far as possible.

• Specific risks resulting from inadequate ergonomic features

It requires risks relating to the design of the device to be controlled not risks resulting from misuse. The MDR refers to “ergonomic features”.

• Ergonomics of displays

Measuring, control or display devices are designed and manufactured in such a way that they comply with ergonomic principles with regard to the intended purpose, the intended users and the environmental conditions under which the products are to be used.

• Understandability of displays

In addition to ergonomic requirements, the MDR also requires displays to be understandable:

The function of operating and display devices is clearly stated on the products. If the instructions for use of the product are attached to the device itself or if the operating or control parameters are visually displayed, this information must be understandable to the user and, where applicable, the patient.

• Lay persons

The specific and extensive requirements contained in the MDR regarding safe use by lay persons are new in this form.

Because the requirements are so extensive, here is a summary:

• Manufacturers must take the “variation that can be reasonably anticipated in the layperson’s technique and environment” into account.
• In any case, the risks must be minimized. The lay person must be able to use the device “safely and accurately at all stages of the procedure”.
• This may require “appropriate training and/or information”.
• Instructions and information must be “easy for the lay person to understand and apply”.

These requirements have a direct effect on the design of the device, as well as on the design of training courses and the evidence required, e.g., in the form of usability tests.

• Annex II: Technical Documentation

Annex II establishes contents of the technical documentation as a direct reference to the usability. This should include the definition of intended users, a description which describes that which devices will be connected to the particular device and tests and its results. For software, these tests must be performed in an actual or a simulated user environment. For the device to be connected to other device, proof should be given that the device to be connected must conform to general safety and performance requirements.

For further information on MDR’s Usability Testing Requirements, please reach out to MakroCare today!