The FDA requires user interface specifications for medical devices. But your user interface specification can and should be more than a requirement or regulatory box to check.

After all, a robust specification establishes design specs, which inform the experience users ultimately have with your product and overall brand. In a way, your user interface is the connection between humans (your users) and a machine (your product).

Not to mention the commercial success of your medical device — and thus your company — is largely dependent on a positive user experience.

So while the FDA’s user interface directives (and most medical device companies) focus chiefly on the safety and efficacy of products, you have the opportunity to leverage your specification as a more meaningful tool. One that leads you to develop a device that makes people’s lives easier and better on top of being safe and effective.

What Is a User Interface?

Before we discuss user interface specifications, we need to define user interface. In IEC standard 62366-1, they state:

The user interface is the means by which the user and the medical device interact. User interface includes all the elements of the medical device with which the user interacts including the physical aspects of the medical device as well as visual, auditory, tactile displays and is not limited to a software interface.

It’s important to call out, as the IEC does above, that user interface and digital interface are not synonymous.

Touchscreen devices have invaded all aspects of our lives. As a result, the term ‘user interface’ has become generic and mostly associated with digital user interfaces — like smartphone touchscreens. However, the medical device industry and the applicable standards it adheres to refer to these digital user interfaces as graphical user interfaces — or GUI for short.

The term GUI might seem outdated or even clunky to contemporary designers. Still, we advise everyone in the healthcare industry to adopt the IEC and FDA terminology to avoid miscommunication, confusion, and conflation.

What Is a User Interface Specification?

We’ve established that a user interface encompasses all the ways a user and a device interact. IEC 62366-1 defines a user interface specification as:

A collection of specifications that comprehensively and prospectively describe the user interface of a medical device.

The operative word here is ‘collection.’ Your user interface specification will likely be integrated into other documents found in your use specification and/or usability engineering file, not in its own singular document or place. We still recommend keeping a master document called ‘user interface specification.’ Even if this document mainly refers to the individual documents that make up the umbrella concept of user interface specifications, it will organize your team.

The first step is to gather and document your user interface requirements before generating your user interface specification. As defined in IEC 62366-2, user interface requirements ensure your user interface ascribes to good usability engineering principles and meets needs identified by user research. Both the United States (21 CFR part 820.30) and the international community (ISO 13485) mandate these requirements.

At MPE Inc., we have a form and process for documenting these user interface requirements. Once the user needs for both the physical and graphical user interfaces are translated into requirements (design inputs), the user interface specification creation and design can commence.

How Most Medical Device Companies Approach User Interface Specifications

As mentioned, a lot of medical device developers view their user interface specifications as nothing more than a regulatory box to check on their path to market.

Why? Because, in general, medical device companies are led by technical people with technical mindsets. As such, everyone stays laser-focused on designing, engineering, and optimizing the technology and product itself — the tangible aspects of development.

The user interface is the connection between humans and machines. But for all intents and purposes, this connection doesn’t exist until after a product is developed, approved by the FDA, and on the market. It’s intangible during development, as are user experience and many other aspects of human factors engineering.

This intangibility explains why it’s often difficult for medical device companies founded on and consumed by technological advancement and innovation to devote time to this seemingly soft, fuzzy human-to-machine connection fostered by the user interface.

Why You Should Approach User Interface Specifications Differently

We keep mentioning the importance of the user interface as the connection between a person and your product. But why does this matter?

Think about it this way: If a user can’t successfully interact with your product’s interface, they can’t successfully use your device to complete their tasks. These users are doctors, nurses,  patients, etc. An interface (and entire medical device, for that matter) that doesn’t center on user experience is hindering someone from treating a sick person, preventing illness, easing burdens — the list goes on.

Your user interface specification single-handedly determines whether your product is designed to solve an engineering, technology, or science problem — or to actually meet the needs of real users. Those physicians, patients, and so many others.

If that’s not enough to convince you user interface specifications matter, consider how the shift from hospital care to home health will push many medical devices to adopt a user-centric approach to design. At-home users demand intuitive products in a way medical staff traditionally have not.

The FDA is on the right track. They include the user interface specification as a requirement for medical device manufacturers, as noted. They also put it in a term, ‘specification,’ that even the most technically minded engineers are accustomed to using during all aspects of development. In some ways, this has cajoled medical device companies to chart and solve for user needs.

Still, most medical device firms haven’t gone far enough to take the user interface specification from a rote FDA to-do to a guidebook for delivering a world-class product that, again, connects human and machine.

To Get Your User Interface Specification Right, You Need Human Factors Experts

It’s not a bad thing for engineers and technologists to be technically minded. It’s not in their job descriptions to consider the UX of the interface. Despite this, a common pitfall in medical device development is for the engineering team — mechanical, electrical, or software — to try and design the user interface. It seems like a natural progression for many technical professionals.

But in reality, an expert team of user-centric industrial designers, graphical user interface designers, user experience designers, and human factors engineers (HFE) should be responsible for all aspects of the user interface requirements, specifications, and design.

It is the HFE team’s job to actively create specs that will contribute to a usable medical device and then collaborate closely with technical teams through implementation.

We understand why many medical device companies don’t hire human factors professionals or focus on user experience. Mid-sized and larger companies are understaffed. They’re forced to focus on regulation to get their products out the door. Meanwhile, startups are notoriously cash-strapped. They understandably cannot hire full-time human factors professionals. And often, neither can justify having a full-time human factors engineer on staff when they’re only releasing a new medical device every few years.

That’s why we offer human factors engineering on a consultative basis. Our team can add bandwidth to yours to ensure you’re keeping the end users’ needs in mind, including with your user interface specification.