Here’s one I made earlier: getting your hands dirty for good medical device design

31 Jan 2017 10min read

My professional career in design began in the mid-90s, having spent the previous four years mostly studying product design at Glasgow School of Art; an institution perhaps more famous for fine art and architecture, but nonetheless a reputable and enviable place to study design.

However, my aspirations for becoming a product designer materialised more than a decade earlier when I started designing and making a range of bespoke money boxes for my rapidly growing collection of 20p pieces which had just been introduced. Made out of empty cereal boxes and UHU glue, these were no ordinary money boxes with a slot on the top and a means for subsequent pilfering underneath.

Of course, they had to keep my stash safe from my three marauding brothers, but they were Heath Robinson works of art. Most comprised an elaborate pick-up mechanism which then channelled my newly acquired 20p down a concealed shaft, rotated some gearing to make a whirring sound before dispensing said piece of silver onto the growing stockpile of bounty within.


Cunningly disguised, some of my other creations did look like a Kellogg’s cereal box, but these had a rotary combination lock also made out of cardboard. If my brothers knew my date of birth (d’oh!) they would have cracked the safe in seconds. It didn’t occur to me though that throwing the entire creation into a warm bath to soften the cardboard was a much easier way to access the booty.

Alas, I have not designed and built any more cardboard money boxes since, but the sheer pleasure and satisfaction of designing and creating something with my own hands from everyday materials, seeing my ideas evolve, transform and delight (and not forgetting the highly toxic glue vapours) remain with me to this day. Not only that, but it forms an essential part of me and my ethos that good design starts life as a collage of ideas, inspirations and what-ifs, and more often than not is made from cardboard, pipe cleaners and stickybacked plastic.

Evaluating early ideas by making simple, cheap, low-fidelity mock-ups should be an essential element of the early design development process, as it not only inspires innovation but is an extremely efficient method of understanding the real challenge as well as highlighting areas of potential risk. This is vital in the field of medical device development where a solid design foundation is essential not only for the commercial success of the product but more importantly, the safety and well-being of the end user.

Mock-up [mok-uhp] noun 1. a model, often full-size, of something that has not yet been built, showing how it will look or operate

As a designer with a practical hands-on approach to problem solving, there is no more effective way for me to innovate.

Every new design prospect comes with a challenge. We would not be in employment if there was no need for products to be safer, or easier to use, or to be more effective, or to be smaller and portable, or to be appealing to both children and the elderly, or to have enhanced functionality at half the cost… The list goes on.

Problem solving is not easy, in fact it can be bloody difficult. Literally. One of the patents on which I am a named inventor is a cannula insertion device; a sharp, pointed and potentially lethal cannula insertion device. The design started life as a bare 40 mm long needle. After countless ‘percutaneous exposure incidents’ (or as my older brothers would often say ‘painful little pricks’) you quickly appreciate the challenge at hand and the absolute necessity for needle safety. It was through fabricating a series of mock-ups, increasing in fidelity, and going through repeated cycles of evaluation and iteration that a simple idea for improved needle safety evolved into an innovative and commercially successful product.

Producing physical mock-ups need not be complicated, timely or costly. On the contrary, the simpler the better and the easier they are to adapt, to evolve the concept and explore different ideas. It is like brainstorming in three dimensions.

Scribbles on Post-it notes become physical representations of thought; simple mechanisms come alive to demonstrate the principle behind an idea – good or bad. (There is no bad idea until it starts costing time and money.) Being able to demonstrate a reason to believe in your idea at the earliest opportunity increases the likelihood of future success as well as highlighting areas of potential risk that can be managed at an early stage.

Establish the right design at the outset and a sound engineering and usability product development process will ensure the design is right at the end.

There are many advantages to producing mock-ups as early as possible:

• They are powerful design tools, yet low cost and quick to produce;

• They inspire innovation;

• They allow us to fully comprehend the challenges at hand and define the problem;

• They quickly highlight ideas which are not so good;

• They ground our ideas in reality;

• They highlight potential risk areas early on.

When designing, it is very tempting to jump headlong into 3D CAD after only a few sketches, thinking we understand the challenges, brimming with confidence of how we are going to solve the problem and come up with a fantastic looking product. It is also very easy and relatively cheap to produce rapid prototypes from 3D CAD models to evaluate the early design concepts. In my opinion, this is missing a fundamental part of good practice in design development. How else can you derive a deep understanding of the problem/challenge without first getting your hands dirty?

“They are powerful design tools, yet low cost and quick to produce”

I have worked on numerous medical device development projects in which the key challenge has been the handling and/or controlled delivery of a ‘substance’ from a new ‘device’. The substances in question have had a wide variety of properties: wet, dry, fibrous, viscous, sticky, UV sensitive and sometimes hazardous.

With appropriate safety precautions in place, getting our hands dirty and ‘playing’ with the stuff with simple mock-ups was the only way to really appreciate how it behaves, how it moves, how it clumps together, how it expands with heat, how it adheres to a surface (or not), how it reacts with water, how hard it is to dispense from a syringe, how it eats plastic – all of these things. You can read all the technical data sheets in the world but nothing compares to rolling up your sleeves and playing with the stuff, understanding the problems and making things to work through the possibilities.

Over-eagerness to jump into 3D CAD to produce photo-realistic images of a concept before the basic principle of the idea has been considered is not only setting ourselves up for a fall, but is creating a disconnect between the design and the designer. Design is emotive – How do we feel about a product? How do we feel when we use it? How do we feel it adds value to our lives? To feel (in the true sense of the word), we need to touch. To touch we need something physical. If we don’t have something physical how can we feel emotion towards it?

If you have designed a product that is hand-held or otherwise manually operated, and you did not start by carving out a foam model by hand, shame on you. All too often I have witnessed young designers develop an idea from the sketch book straight into 3D CAD, and then struggle with the limitations of the CAD software to the point of compromising their design intent. Design should not be limited by the 3D modelling package. Instead, the design intent should be realised in the physical form, starting with a computer numerically controlled (CNC)-machined basic 3D form as a physical underlay if necessary.

“You can read all the technical data sheets in the world but nothing compares to rolling up your sleeves and playing with the stuff”

The use of modelling clay is not restricted to the automotive industry and is a great material to achieve the subtle surface detail that was not possible in 3D CAD. Physical models, once right, can always be 3D scanned and the digital surface imported back into the 3D modelling package for refinement.

Another innovative medical device I worked on required the controlled delivery of a topical treatment for the scalp. One of the first mock-ups I made to test an idea comprised an empty bottle of hair dye, the lid from a Ketchup bottle, shampoo as a placebo, and my wife in the shower. Of course I was merely an observer of this first user trial, but once assembled and filled with shampoo (the mock-up, not my wife) she proceeded to easily apply the contents of the modified bottle directly to her scalp in a controlled and repeatable manner. Result! (although my wife didn’t appreciate the blue tint to her hair for a few days afterwards).

When I first started in consultancy, 3D CNC machining was in its infancy and there was no rapid prototyping; not in west London at any rate. All physical representations of the product design had to be made by hand; from early foam models and mock-ups, all the way to final prototypes. The software and technologies readily available to us today, and project budgets and schedules restrict the making of visual models and functional prototypes entirely by hand for obvious reasons. But there is no reason for not making early mock-ups and foam models by hand and evolving the design out of these early manifestations.

The value in the more traditional ways of designing, sculpting foam and evaluating early ideas with mock-ups, has stood me in good stead. I am a strong advocate of hands-on design and encourage the younger generation to see the value in it. Long may I continue to not only contribute to the commercial success of our clients but to help make a tangible difference to the lives of the end users we are ultimately designing for.

Join the conversation

Looking for industry insights? Click below to get our opinions and thoughts into the world of
medical devices and healthcare.