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What is design?
This module goes into more depth about design principles and processes that are important for creating medical devices, especially iterative design processes. To introduce this topic, let’s look at what design actually means in this context.
Design is often misunderstood as a superficial activity that is applied to a product once the hard work of developing the product has been completed. In reality, the design process should start right at the beginning of product development and should be treated as of equal importance to other areas such as research and engineering.
“Most people make the mistake of thinking design is what it looks like. People think it’s this veneer – that the designers are handed this box and told, “Make it look good!” That’s not what we think design is. It’s not just what it looks like and feels like. Design is how it works.”
– Steve Jobs
For us, this famous quote doesn’t go far enough. Design isn’t just how something works, it is what something is. That might sound overly philosophical right now, but thinking about design in this way has some useful and important implications later.
There are lots of different design disciplines: user experience design, content design, interaction design, graphic design, product design and new ones are created all the time. Each of these disciplines is a specialised way of approaching design and requires a certain amount of skill and expertise to do well. However, there is a core activity common to all forms of design that is more general and can help demystify things: Design is a process of making proposals.
To practice design you don’t need to consider yourself to be a designer or get a fancy degree (although that helps a lot!). The only requirement is to feel comfortable making design proposals.
Design proposals
There are two parts to a design proposal. The first is an assertion that something about the world could be different than it is right now. This might be a difference at a small scale, for example: “what if we added feature X to improve this product?”; or it could be a difference in larger scale: “what if we made a product that solved problem X?”.
The second part of a design proposal is the medium you choose to communicate the assertion. This could be anything from a simple statement like the “what if” questions (as in the previous examples) to a drawing, mockup or functional prototype.
Design process
When you create a design proposal, you’ll inevitably receive feedback from many sources (for example: users, experts, peers, even yourself through a process of reflection). It might not always be useful, but constructive feedback will tell you what is good about your design and what could be improved. You will then be able to update the design proposal reflecting the feedback you have received, which will be the starting point to develop an improved design.
Iterative design
A good design process can help you obtain the right feedback at the right point in time to help you spend your time usefully. Therefore a good design process is iterative.
Receiving more or less constructive feedback will depend on the medium through which you communicate your design proposal. Generally, the higher the fidelity of the medium you choose, the easier it will be for people to understand your proposal and respond constructively. However, higher-fidelity media like prototypes, mockups and models require more time to be produced. Therefore, in each design iteration it is important to find the right balance between the time you spend on communicating your design proposal and the type of feedback you need.
It is important to take time to think and plan your design process. We’ll go into more detail about planning design process in the next section.
Designing medical devices
Design is rightfully understood as a creative activity. Medicine is a field where progress is made through careful collection and analysis of evidence, rather than by following someone’s creative urge. However, this does not mean design is less important when it comes to developing medical devices. Poor design can result in confusing user experiences and poor product affordances - affordance means whether people can work out what a product’s for and work out how to use it. This can lead to safety issues that can be harmful and even life threatening.
Reading the FDA’s list of device recalls is instructive, as many of these recalls are due to design mistakes that could have been easily avoided with the right feedback at the right time.
Risks of poor design
Even when poor design doesn’t lead to risk of harm, it can still degrade the utility and experience of using a medical device unnecessarily. Medical devices are often used by expert users who may have no choice but to persevere with a badly designed product. Poor design can often be compensated for with additional training which is why perhaps there is a much higher tolerance for bad design in the domain of medical devices. However, in order to create a more personalised medicine, it will be necessary to involve the patient, their informal carers, family and friends. Medical devices must offer a much higher ratio of value to inconvenience for these types of users.
Waterfall design process
One of the key reasons behind this high prevalence of poor design is the waterfall product development process. We will cover this in more detail in Module 3.3. Waterfall prioritises rigour of process in an attempt to create a high-quality product that is free from defects. Although this development process makes complying with regulations easier, it also decreases the quality of the final product. This is because the implications of poor decisions don’t become apparent until it’s too late to correct them and they end up impairing the design of the product.
Designing software as medical device
A lot of the best practices for developing medical devices, and the regulations that enforce them, have evolved with a focus on hardware devices. There are a lot of assumptions baked into the regulations that don’t apply to software-as-medical-device.
Hardware medical devices will necessarily have a manufacturing step before the product is released. This means the design and production of a device are two distinct processes. The factory does not begin production before the design is complete.
When it comes to software as medical device, it is possible to think of design (UX and UI) being distinct from production (software engineering). However, we find it helpful for the design, research and engineering teams to work together very closely in agile teams.
This type of development process blurs the line between the design proposal and its implementation as working software. The two areas merge, which leads to more efficiency and better results. However, it makes it more difficult to comply with regulations, specifically with the regulatory requirement of Design Controls. In chapter 3.3. we’ll cover the reasons why and describe our approach to dealing with this these complications.