User-Centered Design of Medical Devices

July 9, 2020

l

Satu Peltonen

Beijing sky scraper & cctv tower

User-centered design of medical devices positions the user and human factors in the heart of the design process to enhance the usability, safety and effectiveness of the medical device, where usability testing is a critical component of the human factors engineering process.

Introducing Human Factors, Usability and Design Thinking

In recent years medical technology has taken a trend towards creating personalized care while seeking ways to enhance quality for patients and to lower healthcare costs. At the same time developers have to keep in mind the ease of use of the devices and gaining regulatory approval for them in the highly internationalized market.

Capturing user profiles and use environments across nations and cultures needs more creative, wide-reaching, and complex problem-solving approaches than conventional preference of scientific and technological advancement.

Even so, it is not uncommon to observe medical technology developers to concentrate rather on engineering than on user needs and usability, although human factors have been identified as particularly important aspect of the risk management plan for medical device safety. 

 So why to put user in the center of medical technology development?

Leaving the fact aside that usability requirements have been addressed by FDA and MDR in regulatory requirements and guidelines to enhance device performance and safety, the most profound reason is to protect people from injury and death due to use errors as they arise from a poorly realized fit between the user and device. One sadly famous example is the programming of infusion pumps, where a simple decimal error of 50 instead of 5.0 – example-wise – could lead to a fatal drug dose delivery. This error has been so frequent that the industry has coined the expression “death-by-decimal point” to initiate use correction processes to address this particular medical error.

To highlight how broad this issue is, it is estimated that thousands of people die due to errors involving medical devices each year. By reviewing FDA’s MAUDE (Manufacturer and User Facility Device Experience) and MDR (Medical Device Reporting) databases it can be seen that several hundred thousand medical devices are being reported on a yearly basis.

To put it simply: From a manufacturers point of view a medical device can be optimized toward safety as long as it remains within the domain of engineering, but once the device has entered the market its safety is dependent on the user. User types and environments of use range widely and even among medical professionals’ differences of sophistication cause a great deal of variety in the user experience, not to mention differences between nations and cultures.

While market for medical technology is getting more and more international it is not enough to consider questions like “who will use this device?” or “what are the expectations of each user group?”, instead questions like “what are the color and symbol code comprehensions?” come into the picture while considering if the design should be universal and free of any special cultural specifics or specially designed for one specific culture.

Such issues and considerations bring a whole new challenge to defining user profiles and use environments, but also emphasizes the need for more user-centered design process. Entering design thinking, which is a human-centered iterative approach for creative and critical problem solving that works well hand in hand with human factors research investigating human characteristics and use environment to translate this into medical device usability and to integrate this into the whole medical device life cycle.

The advantages of design thinking tools are the use of diverse and multidisciplinary teams that tackle to re-define unknown or ill-defined problems by focusing what is most important for the user and their interactions in their real-life environment. The aim is to break the naturally developed patterns of thinking to produce unconventional and original ideas and to bring diverse voices and user-driven criteria into the design process.

As designing for another culture is less intuitive and designers are easily swayed by assumptive thinking in the process it is even more important to seek understanding of the user journey where designers need to break out of their cultural bubbles. It is not about designing for certain languages or traditions, but for different cultural dimension, color and symbol psychology but also for different mental models.