Designing Graphical User Interfaces for Medical Devices

By: Alistair Ruff Date: 06/04/2018

Device manufacturers worldwide already recognise that to satisfy regulations their products need to be 'user friendly'. These usability regulations not only cover the physical product, but any interactions required to operate the device.

However, ‘usability’ often falls into the trap of becoming about ticking boxes, paid lip service by device manufacturers with a view to getting a product to market with a piece of paper that calls it 'safe'. In a competitive industry with demanding users, this is not enough.

PDR has been conducting research with medical professionals for over 10 years and the shift in product interaction expectations since the widespread adoption of smartphones and tablet computers has been clear. There have been many occasions when during an interview or paper prototyping session the user has pulled out their phone and simply said that the product should "work like this". Users want devices that hold the same visual appeal and intuitive interaction styles as the consumer products they use daily. This might seem like stating the obvious, but the nature of the medical device market frequently leads manufacturers to fall back on their existing market share and acceptable safety history rather than designing to improve outcomes. 

What should medical device manufacturers be considering?

  • Visual style is not window dressing

  • New interaction styles are not gimmicks

  • Information architecture matters

Of course, these aspects overlap and intertwine.

Visual style is not window dressing

The value placed on pleasing visual design in consumer products is far greater than the average medical product. Consumers, including medical professionals, therefore have much higher expectations for what they perceive to be a quality product. Being exposed every day to the work of talented design teams, pushing the boundaries in terms of visual communication has had an undeniable impact on how discerning an ‘average’ user is.

In this new world of complex information accessed through simple and beautiful interfaces, many current medical products look dangerous, untrustworthy and cheap. The use of visual language in a device communicates a great deal about how this product will work. A product that is visually coherent, with a high standard of design is not only desirable but respected. I trust it, my patient trusts it and their family trusts it.

It is almost impossible to differentiate this enhanced level of visual communication from how it is interacted with. Content is meaningless until a user can access and interpret it to inform their actions.
New Interaction styles are not gimmicks

Technology has enabled a move towards what is described as natural user interfaces. These new interfaces do away with digital metaphors such as the pointers and windows of older interfaces. Capacitive touch screens are commonplace, with gesture and voice developing at pace.

Now, if I want something, I touch it, wave at it or talk to it.

To some, this adds complexity; it makes interfaces more difficult to design. I think this reveals that many involved in developing medical device interfaces have yet to explore how humans naturally interact with objects around us every day.

Many aspects of the retired WIMP (Window, Icon, Menu, Pointer) interfaces have no ‘real life’ reference point. It is removed from my everyday experience and is therefore something I need to learn. ‘Natural’ interactions on the other hand has its roots in everyday life; if I touch something or someone I expect a reaction of some kind. This all opens rich veins of possibility for improving medical device interactions, making them more natural. The essential aspect of this that is often missed is understanding how users think about the device and the tasks they will use it for, this brings us to information architecture.

Information Architecture matters

Current development processes for many medical devices revolve around skinning software with a graphical user interface that minimises error. Whilst good intentioned, it only serves to eliminate errors from a product for which the parameters have already been set. Yes, the product might be safe to use, but does it actually do what the user wants it to?

Interactions, of any sort should be defined by the usage and mental models of users, understood through generative research. This can involve in-context observation of current products in use, detailed task analysis, semi-structured interviews with users and low-fidelity prototyping, amongst other methods. Through this we as designers seek to establish an information architecture, from which we work towards both visual and interactive elements of the design.

Understanding how users structure the tasks they are completing in their own mind is crucial to developing intuitive interactions. This is often differs from what designers or software developers assume (even the end users may not have a defined structure of their usage). The methods mentioned are designed to draw these insights out, generating both quantitative and qualitative data that informs design decisions throughout the rest of the project. This research should be supplemented by further formative tests as the design develops and a final summative test focussed on eliminating error.

Building an information architecture that fits with user’s mental model builds upon the trust that visual communication delivers as well as the natural interaction styles. This results in a product that gives users an excellent experience when being used.

But that’s still about making devices safe isn’t it?

Yes, safety is still an overarching priority, but often our segregation between interfaces, hardware and software results in products that can only be tested to eliminate superficial errors. Instead we should be dealing with the larger underlying problems of the broader user experience. There is a great deal of value to be added to the whole spectrum of medical devices through an improved understanding of how humans understand the tasks they are completing and interpret the products they are using.

Delivering an excellent user experience is not only about ensuring safe usage of a product, but also differentiating product and manufacturer from competition. Companies that seek to include design in their product development process and adopt design thinking principles at their heart have been proven to see great business results, even recognised by the very standards that cover Medical Device Development.

“Using a human-centred approach to design and development has substantial economic and social benefits for users, employers and suppliers. Highly usable systems and products tend to be more successful both technically and commercially.”

ISO 9241-210:2010

Medical devices should be a leading light in adopting design. There are few other industries where the demands on users are so constantly high, with the consequences so severe. This is where the detailed understanding of human interaction should lie, backed up by the ability to deliver outstanding product experiences to aid professionals in the care of patients in every conceivable way.

You can contact me on [email protected] if you would like to find out more or discuss how the team at PDR could help you with the design of your medical devices.