Niall Redmond, Starfish Medical

Adding the Human Factor to Medical Devices

By Niall Redmond
Niall Redmond, Starfish Medical

Human factors addresses not only the obvious or physical, but also digs deep.

Human Factors and Patient Comfort

There are many ways to design for comfort, but first you need to define what comfort is. The Oxford English dictionary defines comfort as “a state of physical ease and freedom from pain or constraint”. Even by this definition, it is subjective. “Constraint”— what is that? Is a t-shirt constraining? Is a jacket constraining? Is a hammock constraining? Is a head brace constraining? The answer to all of these questions is yes.

Think of putting a dog in a coat for the first time. They shake and scratch and run like, well, mad dogs. But, after a short time they stop. And the next time you put the coat on them they’re fine. People are the same. What differentiates a t-shirt from a head brace in terms of comfort is your mental preparation for what’s about to happen. In medical devices this is very important to remember. If you think something is going to be 25 kg of weight on your chest (Heavy) and it’s only 10 kg, will your brain tell you it’s comfortable?

Industrial designers use formative and summative evaluations in conjunction with design thinking techniques to help them understand the importance and level of mental preparation required and how that pertains to the accepted level of comfort.

Another important criteria while designing for comfort is understanding how long the comfort is required. An analogy I have used in the past: Lying in bed for eight hours is comfortable, but lying in bed for 80 hours is not. In the same light, wearing a medical device for eight hours many not be comfortable but wearing it for eight minutes might be. Remember what the device function is and how long it is required.

Other considerations include how the device will be perceived. Use materials, forms and colors that personify and reinforce a predetermined idea of comfort. Comfort is subjective, so if the patient believes it is comfortable, it’s more likely to succeed.

Design for comfort or any other added value brought by human factors engineering and industrial design is something no mechanical or electrical engineer alone could likely accomplish no matter how well he/she followed the guidelines set out in the regulations.

One of the client requirements for a product recently released to clinical trials was that the device be comfortable. Using the criteria listed above, we were able to qualify and quantify a level of comfort resulting in objective results that could be documented as a proof of comfort.

This is a great example of the added value industrial design and human factors engineering brings to the medical device field. The product of the synergy between these two disciplines is the reason that more medtech companies are hiring more industrial designers and human factors professionals to their teams.

More than just a regulatory requirement, industrial designers touch on all aspects of medical device development, from software to purchasing to mechanical, electrical, human factors and finally, regulatory. At the end of the day, nothing sells a product faster than word of mouth. In today’s market of social media, this has never been truer. Having a human factors and industrial design team at the core of product development enables the product to evolve in a way that is relatable to everybody. The product will tell the story of its creation through form, color and texture using the interactions and affirmations of test subjects, KOLs and internet forums to empower it. The resulting device will be much more than just a fantastically functional and safe device. It will have the human factor.


  1. Wong, K., Tu, J., Sun, Z., and Dissanayake, D. W. (May 29, 2013). “Methods in Research and Development of Biomedical Devices”. World Scientific Publishing.

About The Author

Niall Redmond, Starfish Medical