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Deep Dive: MDR and Usability

Author: Marvin Kolb

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Sep 2022

You are established as a manufacturer of medical devices and are now wondering why you suddenly have to meet some Usability requirements for your product with the introduction of the Medical Device Regulation? What exactly has changed? Where can you find the relevant passages in the MDR and how are they to be interpreted? What exactly is required of you in terms of Usability of your medical device? And how can you comply with all of this?

 

We will get to the bottom of these questions in this article. Here you will find all the relevant passages of the Medical Device Regulation that are important for the Usability of your product. We have not only compiled the passages, but also explained them for you. You will also learn how to comply with these Usability requirements for your medical device.

Introduction

The word “Usability” appears only twice in the MDR once in relation to post-market surveillance and once in relation to device software). So, the question “Do I have to do Usability for my medical device?” is a valid one. Nevertheless, there are some very important Usability requirements for your medical device in the Medical Device Regulation that must be met.

But which parts show you that Usability is relevant? We show you the relevant parts of the MDR and derive the requirements for you as a manufacturer.

Let’s take a closer look at the parts of the Medical Device Regulation that set requirements for the Usability of your medical device. Most of them can be found in Annex 1: “General safety and performance requirements”. These must be fulfilled by all medical devices!

 

Our recommendation for implementing the requirements: The Usability Engineering process according to IEC 62366-1

The MDR makes demands on the Usability of your medical device, but leaves it open how you fulfill them. There are no regulations on this. However, there is a list of harmonized standards that can greatly facilitate implementation. This includes the Usability Engineering process according to IEC 62366-1.

The process helps you to fulfill all MDR requirements for the Usability of your medical device as pragmatically as possible and to provide the necessary evidence for the Notified Body. In addition, the process is also FDA-compliant and thus also an important part for the clearance in America.

Therefore, we will refer to the Usability Engineering process at the appropriate points to show you how it helps you meet the Usability requirements of the MDR. However, it is not mandatory.

 

Annex 1: paragraph 1

Paragraph 1 requires: ” Devices shall achieve the performance intended by their manufacturer and shall be designed and manufactured in such a way that, during normal conditions of use, they are suitable for their intended purpose. They shall be safe and effective and shall not compromise the clinical condition or the safety of patients, or the safety and health of users or, where applicable, other persons, provided that any risks which may be associated with their use constitute acceptable risks when weighed against the benefits to the patient and are compatible with a high level of protection of health and safety, taking into account the generally acknowledged state of the art. ” (source: MDR, Annex I, paragraph 1).

So you need to define:

  • What are normal conditions of use?
  • What is the intended purpose of your product?
  • Who are the users?

The conditions of use are defined by IEC 62366-1 under the term “use environment”. It defines these as “actual conditions and setting in which USERS interact with the MEDICAL DEVICE”. This includes “hygienic requirements, frequency of use, location, lighting, noise, temperature, mobility, and degree of internationalization”, but also “Social characteristics”. Here, IEC 62366-1 lists basic characteristics of the use environment such as “shift duration”, conditions such as “chaos” or “quiet surrounding”. (source: IEC 62366-1:2021-08; 3.20)

The term “intended use” is defined in DIN EN ISO 14971:2022 (the standard for risk management of medical devices) as “application for which a product, process (3.14) or service is intended according to the specifications, instructions and information provided by the manufacturer (3.9)” (source: DIN EN ISO 14971:2022; 3.6).

IEC 62366-1 defines the user as ” person interacting with (i.e. operating or handling) the MEDICAL DEVICE” and makes the addition that there may be multiple users of a device and lists as common users “clinicians, patients, cleaners, maintenance, and service personnel.” (source: IEC 62366-1:2021-08; 3.24)

The Use Specification, which is the beginning of the Usability Engineering process according to IEC 62366-1, provides you here with everything you need for this section of the MDR. IEC 62366-1 specifies: ” The USE SPECIFICATION is an input to determining the INTENDED USE of ISO 14971:2019″ (source: IEC 62366-1:2021-08; 3.23) In addition, the Use Specification defines itself as a ” summary of the important characteristics related to the context of use of the MEDICAL DEVICE”. Named contents include the definitional items required by the MDR: “The intended medical indication”, “USER PROFILE”, “USE ENVIRONMENT” and the “operating principle” of your product. (source: IEC 62366-1:2021-08; 3.23)

In summary: In the course of the Usability Engineering process according to IEC 62366-1, you therefore define the required intended purpose and the normal conditions of use for your medical device. This is done during the creation of the so-called Use Specification.

Your argument for your product’s MDR compliance can be built on this foundation.

 

Annex 1: paragraph 3

Paragraph 3 of the general safety and performance requirements calls for the introduction and documentation of risk management. This is defined as a “continuous iterative process throughout the life cycle of a product” (source: MDR, Annex I, paragraph 3). This also results in requirements for Usability. What exactly they must achieve is shown in the subsections:

Annex 1: paragraph 3 b)

Section b) requires you to “identify and analyse the known and foreseeable hazards associated with each device.” (source: MDR, Annex I, paragraph 3b))

Hazard-related use scenarios, i.e. a “USE SCENARIO that could lead to a HAZARDOUS SITUATION or HARM” (source: IEC 62366-1:2021-08; 3.8) are among these foreseeable hazards mentioned by the MDR. IEC 62366-1 adds “A HAZARD-RELATED USE SCENARIO can often be linked to a potential USE ERROR.” (source: IEC 62366-1:2021-08; 3.8)

In order to identify all known and foreseeable hazardous situations, you can

  • Find out through user research where use errors occur that lead to hazard-related use scenarios
  • Draw on data on the misuse of similar products
  • Use post market surveillance data to find out what incidents occurred
  • Provide a list of all hazard-related Use Scenarios.

The definition and analysis of foreseeable hazards and hazardous situations is thus an integral part of the usability engineering process according to IEC 62366-1. IEC 62366-1 provides all hazard-related use scenarios in the fourth step of the usability engineering process. These contain:

  • All tasks of the scenario.
  • The sequence of tasks.
  • The severity of the associated damage.

(source: IEC 62366-1:2021-08, 5.4)

Annex 1: paragraph 3 c)

This paragraph requires that you “estimate and evaluate the risks associated with, and occurring during, the intended use and during reasonably foreseeable misuse.” (source: MDR, Annex I, paragraph 3c))

This means: You must assess and evaluate the hazards identified and analyzed in section b) in section c). This is about all risks “associated with the intended use and which occur during a reasonably foreseeable misuse”. (source: MDR, Annex I, paragraph 3c))

This can happen in the course of a Use Related Risk Analysis. This term originates from the FDA and the associated Human Factors Engineering process. You can and should integrate this into your Usability Engineering according to IEC 62366-1 to provide the assessment and evaluation of risks required above.

Annex 1: paragraph 3 d)

Paragraph 3 d) requires you to ” eliminate or control the risks referred to in point (c) in accordance with the requirements of Section 4″ (source: MDR, Appendix 1; paragraph (3d)).

Section 4 requires: “eliminate or reduce risks as far as possible through safe design and manufacture” (source: MDR, Annex 1; paragraph 4) This also includes good Usability. In other words, exactly what the Usability Engineering process according to IEC 62366-1 aims to achieve. At the end of the process, you can prove that you have achieved exactly this by means of the summative evaluation, in which you have to test with real users under realistic circumstances and with the Production Equivalent Device. It pays off here if you have considered and tested the Usability of your product beforehand in order to avoid unpleasant surprises in the summative evaluation.

 

Annex 1: paragraph 3 e)

All data on potential hazards and their frequency obtained during the development process and post-market surveillance must be evaluated for risk-benefit ratio.

Here, usability engineering provides important input to risk management. Especially through the data found out in 3c) and the task analysis data obtained in the course of Usability Engineering.

 

Annex 1: paragraph 3 f)

Depending on the data resulting from section e), you may need to take steps to manage the risk.

This is where the (iterative) formative Usability testing of the Usability Engineering process helps. This is not prescribed by the MDR, but can be very helpful, especially with regard to risk control, as it provides the basic data for the development of a product that is safe in terms of use. During iterative testing, new use errors are always identified and possible causes for these errors are eliminated as far as possible by revising the design. And this continues until no more critical use errors occur. You can prove that no more critical use errors occur by means of a summative (i.e., a final) usability evaluation.

 

Annex 1: paragraph 5

This paragraph is particularly important with regard to the Usability of your medical device. This is about the exclusion or reduction of risks due to use errors. You must:

  1. “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)” (source: MDR, Annex 1, paragraph 5).
  2. ” 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)”. Named are: “lay persons, professionals, disabled persons or other users” (source: MDR, Annex 1, paragraph 5).

This means: You must know your users and the use environment and take the resulting requirements into account when designing your product so that it can be used safely by the intended users. In other words: Here, too, you must address the Usability of your product.

The required information about your users is provided by the Usability Engineering process in the course of the use specification. The resulting requirements for your product (and their implementation) are developed in step 2 of the Usability Engineering process: Identify User Interface Characteristics related to safety and potential Use Errors and Step 6: Establish User Interface Specification.

IEC 62366-1 defines Usability Engineering 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”. (source: IEC 62366-1:2021-08; 3.17). The MDR thus indirectly calls for Usability Engineering when it speaks of taking into account the knowledge and experience of users.

To prove that your product is actually safe to use by the target users (i.e., that the actions you took from the work in the previous paragraph are correct), you can then do Usability testing. The easiest way to prove this is to do a (successful) summative Usability evaluation.

 

Annex 1: paragraph 14.1

Paragraph 14 of Annex 1 deals with the “Construction of devices and interaction with their environment”. A first issue for the Usability of your medical device can be found directly in paragraph 14.1: here it is required: “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 minimize all possible risks, such as misconnection. “. (source: MDR; Annex 1; paragraph 14.1).

So, you need to identify and eliminate hazards that arise from the interaction of the environment for the use your product. This reduction of hazards is always part of the Usability Engineering process.

If you as a manufacturer use the Usability Engineering process according to IEC 62366-1, the hazards described above due to environmental interactions should already have been identified in step 4. Step 4 asks you to identify and describe the Hazard-Related-Use Scenarios, i.e. all hazard-related use scenarios.

 

Annex 1: paragraph 14.2

This paragraph contains some requirements for the Usability of your medical device! The paragraph deals with the exclusion of the following risks by the product design and manufacture. We have limited ourselves to the sub-items relevant for Usability.

 

Annex 1: paragraph 14.2 a)

“The risk of injury, in connection with their physical features, including the volume/pressure ratio, dimensional and where appropriate ergonomic features” (source: MDR; Annex 1; paragraph 14.2 a)).

Excluding hazards due to ergonomic features of the product are always part of Usability. To exclude these risks, you can resort to Usability testing as part of the Usability Engineering process.

 

Annex 1: paragraph 14.2 b)

“Risks related to reasonably foreseeable external influences or environmental conditions” must be excluded (source: MDR; Annex 1; paragraph 14.2 b))

Here again the environmental conditions identified in 3b) and the known and foreseeable hazardous situations (possibly identified by Usability testing) come into play.

 

Annex 1: paragraph 14.2 f)

Here, it is required that mutual interference from other products used for the respective investigation or treatment be avoided.

These are all sub-issues to consider in your product design. Through targeted user research during the development process, you will find the

  • ergonomic features of your product,
  • the features that pose risks due to external effects or environmental conditions
  • and those that are affected by mutual interference from other products,

that you need to adjust to manage above risks out. User research is not mandatory here, but a very effective and good approach!

 

Annex 1: paragraph 14.6

Paragraph 14.6 requires that “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.” (source: MDR, Annex I, paragraph 14.6).

Find out whether the intended users can use a product correctly, for example, in Usability tests. Be sure to test with real users under realistic conditions (interactions and environmental conditions) whether the display devices can also all be used and interpreted correctly. Otherwise, it will be difficult to argue that you have met the requirements of the MDR.

 

Annex 1: paragraph 23.1

Paragraph 23 of the general performance and safety requirements deals with the “requirements regarding the information supplied with the device” of your product. In 23.1, “General requirements regarding the information supplied by the manufacturer ” are specified. The following are relevant to the Usability of your medical device:

  • For the respective product
  • For its purpose
  • For the technical knowledge of the users
  • The experience, education or training of the intended users

(source: MDR, Annex I, 23.1 a))

In addition, it is explicitly required that the instructions for use are demonstrably written in such a way that they “readily understood by the intended user”. In addition, it is stated that the instructions for use can be supplemented with drawings and diagrams, if necessary. (source: MDR, Annex I, 23.1 a))

For example, you can prove that real users understand the labels and instructions for use correctly by conducting Usability tests. In other words, you confront real users with the instructions for use and check whether they are understood without difficulty.

Class I and IIa medical devices that can be used safely without guidance are exempt. (source: MDR, Annex I, 23.1 d))

 

Section 1: Article 83.3 f)

Outside of the “General Safety and Performance Requirements” of the MDR, there is another section that places requirements on you regarding the Usability of your product: Article 83.3 f) requires you to ensure that the data you are required to collect in post-market surveillance is also used to improve the Usability of your product: Among other things, the data should be used to “for the identification of options to improve the usability, performance and safety of the device” (source: MDR, Section 1, Article 83.3 f))

The word “Usability” is even used explicitly here.

 

Only relevant for the special case of medical device software

Annex 1: paragraph 17.3

Here we are dealing with the special case of medical device software: paragraph 17.3 is composed of the relationship between the specific characteristics of the mobile platform and the external factors of the usage environment.

“Software referred to in this Section that is intended to be used in combination with mobile computing platforms shall be designed and manufactured taking into account the specific features of the mobile platform (e.g. size and contrast ratio of the screen) and the external factors related to their use (varying environment as regards level of light or noise).” (source: MDR; Annex 1; paragraph 17.3)

So, the key question here is: do the size, contrast ratio, etc. of the platform fit the changing environment (light incidence, noise level, etc.)? To check your design solutions in this respect, Usability testing can help you to prove that the features of your product’s mobile platform are also safe to use in the appropriate use environment (or before that, it can help you to check what you still need to improve until this is achieved).

Through Usability Engineering, you can develop important information for the design solution of your product very early in the development process that considers the points required above. In the course of the Use Specification (step 1 of the process), you can collect and define important information about the use environment here (including the parameters mentioned, such as light incidence and noise level). You then include these in the User Interface Specification in step 6.

 

Only relevant for the special case of a medical device with lay user:

Annex 1: paragraph 21.3

In 21.3, it is specified that the function of operating and display devices must be clearly indicated on the product.

“The function of the controls and indicators shall be clearly specified on the devices. Where a device bears instructions required for its operation or indicates operating or adjustment parameters by means of a visual system, such information shall be understandable to the user and, as appropriate, the patient.” (source: MDR; Annex 1; paragraph 21.3)

Once again, the issue here is that use by the intended users (in this case laypersons) must be safe. In other words, adequate Usability must be ensured.

Whether lay users can interpret the visual displays mentioned above without errors can be found out (or proven, if so) in Usability tests with real users, for example.

 

Only relevant for the special case of a medical device with lay user:

Annex 1: paragraph 22.1

Paragraph 22 of the Medical Device Regulation’s Generall Safety and Performance Requirements addresses “Protection against the risks posed by medical devices intended by the manufacturer for use by lay persons”.

Therefore, if your medical device is to be used by laypersons, the following paragraphs are particularly exciting for you. In paragraph 22.1, the following requirements are placed on your product:

  • The product must be designed and manufactured in such a way that it can fulfill its intended purpose ” taking into account the skills and the means available to lay persons”
  • The ” the influence resulting from variation that can be reasonably anticipated in the lay person’s technique and environment” must also be taken into account here.
  • All information and instructions you include with your medical device must be “easy for the lay person to understand and apply.”

(source: MDR, Annex I, paragraph 22.1)

So, the following requirements concerning the Usability of your product are in this paragraph:

  • They must consider the skills of lay users in product design
  • You must demonstrate that your product can fulfill its intended purpose under laypersons use
  • You must demonstrate that information and instructions can be interpreted without error by lay users

Here again, the Usability Engineering process can help you. Already in the course of user research for the use specification, you can gain very important data about the users and the use environment and take them into account in initial design implementations.

You can then prove (for example) that lay users can use your product as described in paragraph 22.1 by conducting Usability tests with real users of the target group. However, these are not mandatory. You can also provide proof in other ways.

 

Only relevant for the special case of a medical device with lay user:

Annex 1: paragraph 22.2

This subitem requires that the product design reduce the following risks when your product is used by non-professionals:

  • The product must be able to be used “safely and accurately by the intended user at all stages of the procedure”. If necessary, after appropriate training or education. (source: MDR, Annex I, paragraph 22.2)
  • Risks from accidental cutting or stabbing must be reduced.
  • The ” possible the risk of error by the intended user in the handling of the device and, if
  • applicable, in the interpretation of the results” must be minimized. (source: MDR, Annex I, paragraph 22.2)

Wrong handling and all described risks can be found out in Usability Research early in the Usability Engineering process. This allows you to adapt your product design at an early stage and make your product safer. Again, through Usability Engineering you can comply with the above requirements of the MDR.

 

Only relevant for the special case of a medical device with lay user:

Annex 1: paragraph 22.

If you have a device that is intended to be used by a layperson, the Medical Device Regulation requires you to have laypersons

  • be able to verify independently whether ” that, at the time of use, the device will perform as intended by the manufacturer” (source: MDR, Annex I, paragraph 22.3)
  • “if applicable, is warned if the device has failed to provide a valid result”. (source: MDR, Annex I, paragraph 22.3)

You can (but you don’t have to) find out whether both are given with your product through Usability testing and prove it if necessary.

 

Conclusion

The MDR significantly increases the relevance of Usability for your medical device: Necessary is the analysis and control of risks related to the use of a medical device. This is mainly required in the “General Safety and Performance Requirements”. This means: This must be demonstrated for all medical devices.

Usability Engineering according to IEC 62366-1 offers an established procedure for meeting the requirements. Here you have a structured process at hand to systematically fulfill the many requirements. Without Usability Engineering, it will be very difficult to fulfill the passages of the MDR explained in the text.

How do the MDR Usability requirements affect your product? What is your specific case? Comment on this post or get in touch via our contact form. We look forward to hearing from you.

 

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