The necessity of HF within medical device development: Echo Kirk
Echo is the latest addition to our Human Factors team. With almost a decade of consulting experience, and a specialism in medical devices, we’re thrilled to have her on board and hear her thoughts on the prevalence of Human Factors within the medical industry…
“My first exposure to Human Factors work inspired me to make it my career. It was a presentation at my university’s for-profit HF consultancy business on campus in which graduate students do the work. The director at the time took us on a journey through the different types of projects on which she’d worked, and one of them caught my eye – observing a day in the life of a paramedic, which revealed a problem. Paramedics had to guess which size neck brace would fit a patient in an emergency situation, and there were four choices. Could you imagine the pain if the wrong size was initially selected? The solution? An adjustable neck brace; simple, elegant, brilliant.
The primary problem was a compromise of patient safety. Extrapolating beyond the neck brace, what is happening in an emergency situation? Time is of the essence to ensure that patient survives on the way to the hospital, in some cases. The paramedic’s need for a split-second decision, the time to try a different one if needed—you can imagine the situation.
“Human Factors empowers medical device manufacturers to develop safer, more effective, and user-friendlier devices."
Stories like this are why incorporating HF into the medical device development process is crucial to device development. Oh yeah, it’s also required by the US FDA, European regulatory authorities, and others.
Medical device companies need to submit documentation with evidence of incorporating HF throughout the process. When HF isn’t engrained into the process and documented thoroughly, submitting these supporting documents becomes a time-consuming process of back-engineering the project in a time-crunch before submission.
When you submit these documents, you are claiming that you have completed the following activities (not an exhaustive list, but the core), starting before you develop a concept for your device:
User profiles: Understanding the strengths and limitations of the people who will use your device, as well as those receiving the treatment (if not self-administered). Some user groups are highly educated, like medical specialists. Others have a limited educational background and, therefore, might not understand technical terms and sophisticated language. Some conditions, like diabetes, often cause visual limitations.
Use environment profiles: Understanding what about the use environment might affect use of your device. Will it be used in a brightly lit room where screen glare might make medical decisions more difficult? Is it a noisy environment like an operating room, in which your alarm sound might get lost in the shuffle? Will everyday people who happen to have medical conditions need to inject in a dimly lit environment?
Known use problems search and analysis: What kinds of issues already exist in the use of similar devices or devices with similar interactions? What is our plan to address these already identified problems when we’re designing our device? What, in the end, did we do?
Hazards: Identifying what about the device could affect use, considering the user’s background and experience, as well as the use environment. Continuously updating this list as new hazards are identified through formative HF evaluations. Users do things you never would have imagined—that’s why you need to observe them throughout the design/development process and understand the pain points (literally and figuratively).
Use error: What would the user have to do for the previously identified characteristics to introduce a problem?
“At the core of HF is empathy - we observe and interview people with various backgrounds, and each of them has a story to tell."
Hazardous situations: What kind of situation does the use error cause? Will it lead to harm of the user, other people, or the environment? What has to be true for that to happen?
Harms: What are the clinical consequences—medical conditions—that could happen to the patient or user if that happened?
Severity: What level of medical intervention, if any, is involved? Would it lead to patient or user death?
Mitigations/risk control: Determining in early, conceptual phases how you can design your device to decrease the burden on the user or eliminate the hazard.
Evaluations: When you put your device into the hands of the users, does your mitigation work to stop or deter them from committing the use error?
- Note that the requirement is to conduct iterative testing throughout the design cycles (early to late) to ensure you provide evidence you have made an exhaustive effort to mitigate the risk.
Evidence of mitigation effectiveness: At the end, when your device and all accessories and accompanying documentation is finished and production-equivalent, you have conducted an HF validation test to confirm your mitigations’ effectiveness.
Residual risk: Use errors always occur in HF validation tests, full stop. What is your team’s multidisciplinary (read: design, development, medical expert/specialist, regulatory, others) assessment of the residual risk? Does your team think it is an acceptable level of risk? Then, the regulatory authorities say: Convince me. Provide a sound, logical argument regarding why you find it acceptable to potentially expose patients and users to this risk. Does the benefit of your device or drug outweigh this potential risk? Why?
These HF requirements were put into place to bring everything back to the patient and users. Developing a stellar drug for the treatment of multiple sclerosis is great – inserting it into a device that requires significant hand-eye coordination and coming up with a dosing regimen that requires the patient to remember date/time of last dose or remember to write it down? Not so great for the patient, who might inadvertently press the dose button while experiencing hand tremors, forget s/he lost the dose, and assume s/he took the medication (for example).
HF empowers medical device manufacturers to develop safer, more effective, and user-friendlier devices. Remember—your mother, sister, spouse, child, best friend, co-worker could need to use your device someday. Wouldn’t you do everything you can to make sure they’re okay and receive the treatment they require?
If you’re having trouble relating to the user, bring in HF experts. IEC 62366 says just that—the people doing the HF work need to be formally trained in the process. The HF background of human perception and cognition as they relate to the design of products and processes is a unique blend.
At the core of HF is compassion—we observe and interview people with various backgrounds, and each of them has a story to tell. The conditions people live with every day can be de-motivating, exhausting, scary. But medical device manufacturers have an opportunity to lighten patients’ load—HF work ensures that opportunity is harnessed in meaningful ways.”