What is IEC 62366-1?
In this post, we will zoom in on the IEC 62366 standards which provides requirements for usability engineering for medical devices.
In order to understand what is meant by usability engineering, we first need to understand what is "usability". According to ISO 9241-11:2018 Usability is defined as "The extent to which a product can be used by specified users to achieve specified goals with effectiveness, efficiency and satisfaction in a specified context of use."
User-friendliness and ergonomics play crucial roles in the quality of various products, including medical devices. These characteristics are not only tied to user satisfaction but are also integral to ensuring safety, particularly in the context of medical devices. Manufacturers of medical devices actively address user requirements by implementing relevant measures and enhancements.
Usability is medical devices is therefore defined as "Characteristic of the user interface that facilitates use and thereby establishes effectiveness, efficiency and user satisfaction in the intended use environment."
The main factors to consider are:
How is information perceived
Is the information well understood and can decision be made based on that information
Does the interaction with the medical device allow to achieve specified goals
This should all be evaluated in the correct setting, taking the intended use, intended use environment and the intended user population in account with the ultimate goal of ensuring safe use of the device.
The role of proper usability engineering is a very important factor in ensuring patient safety. So it comes as no surprise that usability is reflected in many different places in the Medical Device Regulation, as well as in different standards.
In the EU 2017/745 Medical Device Regulation, you find mentioning of usability aspects in many of the General Safety and Performance Requirements (GSPR).
A few examples:
GSPR 5: “In eliminating or reducing risks related to use error, the manufacturer shall:
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)”
GSPR 14.1: “If the device is intended for use in combination with other devices or equipment the whole combination, including the connection system shall be safe and shall not impair the specified performance of the devices. Any restrictions on use applying to such combinations shall be indicated on the label and/or in the instructions for use. Connections which the user has to handle, such as fluid, gas transfer, electrical or mechanical coupling, shall be designed and constructed in such a way as to minimise all possible risks, such as misconnection.”
GSPR 14.6: ”Any measurement, monitoring or display scale shall be designed and manufactured in line with ergonomic principles, taking account of the intended purpose, users and the environmental conditions in which the devices are intended to be used.”
GSPR 22.1: ”Devices for use by lay persons shall be designed and manufactured in such a way that they perform appropriately for their intended purpose taking into account the skills and the means available to lay persons and the influence resulting from variation that can be reasonably anticipated in the lay person's technique and environment. The information and instructions provided by the manufacturer shall be easy for the lay person to understand and apply.”
GSPR 22.2: “Devices for use by lay persons shall be designed and manufactured in such a way as to:
Ensure that the device can be used safely and accurately by the intended user at all stages of the procedure, if necessary, after appropriate training and/or information
Reduce, as far as possible and appropriate, the risk from unintended cuts and pricks such as needle stick injuries, and
Reduce as far as possible the risk of error by the intended user in the handling of the device and, if applicable, in the interpretation of the results”
What is IEC 62366?
There are several standards that refer to usability requirements for specific types of devices like e.g the ISO 80369 series. However, IEC 62366 standards are applicable to all medical devices and are as well harmonized in Europe and recognized in the US.
Currently there are:
IEC 62366-1:2015/Amd1:2020: This is the main standard for Application of Usability Engineering to Medical Devices. This is the main standard as compared to the IEC/TR 62366-2
IEC/TR 62366-2:2016: This is a Technical report or guidance document that describes possible ways to implement usability engineering, not only focussing on safety. It should be read in conjunction with ISO 62366-1
Usability Engineering Process according to IEC 62366-1
The definition of Usability Engineering for medical devices is described as “Application of knowledge about human behaviour, abilities, limitations and other characteristics to the design of medical devices (including software), systems and tasks to achieve adequate usability”
Link with ISO 14971
Usability Engineering is a design and development process for the user interface where possible use errors and use-associated risks are identified and reduced. Obviously, there is a strong link between IEC 62366-1 and the ISO 14971 risk management process. In order to define use-associated risks, the barriers for what is considered to be Normal Use should be set and this is done by identifying the intended use.
Normal use consists of both correct use as well as use errors. Abnormal use on the other hand is when a device is intentionally used incorrectly. This is beyond the scope of the usability engineering process. However, it is important to note that reasonably foreseeable misuse should still be considered in the risk management process.
IEC 62366-1 provides requirements for the process of usability engineering.
Usability Engineering Process
According to IEC 62366-1, the usability engineering process should consider the entire time the user is in contact with the medical device. This user might be different over time. There can be users that need to interact with the device during transportation, during installation, during use, during cleaning, while servicing and for the disposal. These could all potentially be different users, but also different use environments.
1. Use Specifications
The first step in the usability engineering process is to perform user research and define use specifications. These Use Specifications should be based on:
the intended medical indication
the intended patient population
the intended part of the body or type of tissue applied to or interacted with
the intended user profile
the use environment
the operating principle
Knowing the what, how, who and when of the interactions with the medical device is key according to IEC 62366-1. Based on this, the associated risks can be defined.
2. Identify User Interface characteristics related to safety and potential use errors
Secondly, the UI characteristics that are linked to safety need to be identified. This should be done as part of the risk analysis performed in compliance with ISO 14971. Based on these characteristics, potential use errors related to the user interface can be identified.
3. Identify known or foreseeable Hazards and Hazardous situations
As described in our post about ISO 14971 (link to post), the identification of hazards and hazardous situations is part of the risk analysis. When it comes to usability engineering, the potential hazards and hazardous situations linked to the use specifications (see step 1), the possible use errors (see step 2) and available information about hazards and hazardous situations for existing user faces of medical devices of a similar type need to be taken into account to identify hazards and hazardous situations.
4. Identify and describe Hazard-related use scenarios and make a selection for summative evaluation
The next step according to IEC 62366-1, is to define reasonably foreseeable hazard-related use scenarios based on the identified hazards and hazardous situations. This must as well include all tasks and their sequences, as well as the severity linked to the associated harm. Once these use scenarios have been defined, a selection (including justification of the selection) should be made for further summative evaluation.
Once the UI characteristics and the associated risks have been defined, UI specifications need to be established according to the IEC 62366-1 usability engineering process.
Establish User Interface specification
In this step of the IEC 62366-1 usability engineering process, the UI specifications need to be established as testable technical requirements. Risk control measures, required accompanying documentation and specific training requirements should as well be taken into account.
It's important to make sure these specifications are:
correct and unambiguous
6. User Interface Evaluation Plan
IEC 62366-1 requires planning for the UI evaluation. This plan should be established early in the process.
It should contain:
methods for formative evaluation
methods for summative evaluation
usability tests to be performed, including
involvement of representative users/user profile
test environment and conditions
The formative evaluation is part of the design process and is intended to explore UI design strengths, weaknesses and unanticipated errors.
The summative evaluation takes place at the end of the UI development and is intended to obtain objective evidence that the user interface can be used safely. As mentioned earlier in this post, this is done based on selected hazard-related use scenarios.
Usability testing is done on the final device by representative users. It should be performed using defined use cases and in realistic settings. This kind of testing provides information on usability, user experience and objective evidence regarding risk reduction.
Usability Engineering File
Throughout the IEC 62366-1 standard many time it is stated: "compliance is checked by inspection of the usability engineering file". This file contains the results of the Usability Engineering Process and should at least contain a reference to the applicable records. IEC 62366-1 does not require to duplicate information. The actual records can be part of other documents and files such as e.g. the Risk Management File.
Adopt IEC 62366-1 best practices to enhance usability with Matrix Requirements
As IEC 62366-1 is generally accepted as the reference standard when it comes to usability engineering for medical devices, it's important to integrate its requirements in the design of your medical device. One of the key aspects is to ensure usability is fully integrated in both the requirements as well as the risk management of your device. MatrixALM is a tool that can help you with properly documenting these requirements and risks. It is designed to allow you to ensure traceability throughout the design of your device and to extract all needed information into the documentation needed for your regulatory submissions.
If you would like to explore how MatrixALM can help you save time on integrating usability engineering in your design, don't hesitate to book a demo!