Patient monitors, dialysis machines, intravenous infusion pumps, glucose meters, and insulin pen injectors are just a few examples of medical devices that clinicians and sometimes laypersons use to treat medical conditions. Enabling people or “users” to interact safely with such devices is the work of human factors engineers.

Michael Wiklund, General Manager of UL’s Human Factors Engineering (HFE) practice, has been working with his teammates to improve the quality of user interactions with medical devices for several decades.

Acquired by UL in 2012, his team helps clients who are predominantly located in the United States, Europe, and Asia to apply HFE to produce devices well matched to user needs and preferences and also to help prevent potentially harmful mistakes such as user errors. Wiklund also teaches at Tufts University where he shares his knowledge on showing the value of applying HFE to medical technology.

Many industries outside of healthcare have practiced HFE for decades with the central goal being to improve safety. Significant progress has occurred in the transportation and power generation sectors, for example. Its widespread application in healthcare is a relatively recent development as people and regulators have realized that HFE can help prevent some medical errors.

A 2016 Johns Hopkins study determined that medical errors were one of the leading causes of death in the U.S. following heart disease and cancer. The death rate is estimated to be in the hundreds of thousands per year, with many more severe consequences and tremendous costs resulting from errors. While many errors are strictly related to medical practice, a significant portion is due to people making mistakes when using medical devices.

UL’s HFE specialists tackle the problem of user error by applying their knowledge of human capabilities and limitations to help manufacturers develop devices that account for them. When a product is designed with HFE in mind, people can perform tasks they do best, while automating other tasks. Users can then make critical judgments as needed for tasks that do not require robotic perfection.

“HFE focuses on how systems and devices work with naturally fallible human beings at the controls and attempts to design them so that users have an accurate sense of the system’s or device’s status and the proper actions to take at the right time,” Wiklund says. When mistakes occur during simulated use tests, UL’s human factors engineers help determine their root causes and assess the user interface, which may have hardware, software, and other media elements, to prevent future mistakes.

When helping a client who is developing a new product, UL’s human factors engineers often perform the following steps:

  1. Determine who would be using the product (intended user) and research to find out their needs and preferences. For example, if the expected user were a nurse, he or she would have different experience and training in administering a medication than if the product was intended for “home use.”
  2. Use the research results to determine the requirements for how the person would use the device safely. For example, the requirements could specify size and shape of the buttons or controls, size of the fonts on labels or screens, colors and contrast for readability of relevant information, etc.
  3. Take their years of collective experience to support the manufacturer with designing their user interface so that the product meets these requirements, is intuitive to use, and innovative in its field.
  4. Conduct a series of user interface design evaluations, including recruiting actual users to participate in usability tests, to help the client fine-tune the design to be error-resistant, easy-to-use, and appealing. If a mistake is made during these tests, the HFE team member will ask the user why they think the error was made and document the answer. They also ask the user to assess whether the instructions for use are legible and clear.
  5. Conduct what’s called a “validation usability test” and take the results to generate a report on the use-safety and effectiveness, which can be included in applications to regulators such as the U.S. FDA for approval for sale.

Wiklund and his coworkers (Jonathan Kendler, Allison Strochlic, Andrea Dwyer, and Erin Davis) published two books to help people appreciate what HFE has to offer and to learn how to practice it effectively. The books are titled Usability Testing of Medical Devices and Medical Device Error – Root Cause Analysis.

In addition to assisting clients with their system and device development, UL’s HFE team teaches workshops to corporations and helps them develop HFE procedures that are central to quality assurance.

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