Making the Most of Human Factors for Medical Devices
By Reade Harpham
Most medical device developers are familiar with the field of human factors, but few fully understand its impact to the safety, efficacy and acceptance of their product. During 2008, the Association for the Advancement of Medical Instrumentation (AAMI) will release a new standard document—HE-75: Human Factors for Medical Devices, a set of best practices that brings a far sharper focus and application of human factors to medical device development. This is because the area of use-error risk consistently has been overlooked in device development. HE-75 attempts to clarify our vision on what makes a medical user-interface error tolerant.
The FDA has been strident in emphasizing to device developers the importance of demonstrating that they have incorporated use-error risk management into their development programs. Those who remain hesitant or skeptical of the benefits human factors bring to the development process now might ask themselves the following question: “Do I want my medical device to enjoy a smooth and timely approval process or risk FDA rejection and an extended process?” As part of the process outlined in ISO 14971, Risk Management in Medical Devices, the FDA requires medical device developers to identify and control the risks of use error in their design process. The major set of methods for controlling this risk lies within human factors techniques. When used to its full potential, HE-75 will represent an invaluable resource for medical device human interface design and use-error risk management.
The field of human factors has been around for decades but recently has been a high-profile area of interest for the FDA. According to Robert North, chief scientist for Agilis Consulting, “...there was no watershed moment that grabbed the attention of the FDA, but rather a slowly increasing sense of urgency as the adverse event statistics began to show the effects of use error.” Starting with the Institute of Medicine’s report that alluded to the medical industry's hidden risks of medical error in 1998, the tone was set for the “human factor” to be examined “with less attribution of guilt to the caregiver.” The next operating force was data from the field, which continued to point to use errors as the root cause of incidents, while mechanical and electrical failure instances decreased. Although these use-error attributions have been treated with a shrug of the shoulders by the device industry, the FDA began to view them as inexcusable and worthy of specialized attention, just like other risks. In other words, overlooking human factors in device development is the same as overlooking a significant area of risk.
What Does This Mean to Me?
For device developers, this new dimension of risk management translates into another discipline that should be involved in the development process. While the amount of involvement is scalable to the inherent risk of the device, it is essential for a systematic process of use-error risk management to be a part of the overall risk management program. Human factors professionals, knowledgeable about human capabilities and skilled in user-interface design, are well suited to conduct such analyses and evaluations. While this presence may translate into increased cost at the beginning of a program, it can be significantly less than the costs associated with re-design and re-validation of a device that failed FDA approval, and exponentially less than having a product recalled due to adverse events linked to use errors.
Where Do I Start?
If you already have a robust human factors capability in your company that is fully integrated into your development process, consider yourself one of the fortunate few. If you do not fall into this category, there are ways to maximize the value of human factors without having to build the capability from scratch. Depending on the project, one place to start is by contacting any of the human factors consultants who contributed to the development of AAMI’s HE-75. As authors of this standard, these experts have firsthand experience in the unique field of human factors for medical devices and can help you safely navigate this territory.
If you are looking for a complete outsource partner for your development program, there are a handful of experienced, full-service device development partners in the market. When choosing a partner, it is critical to verify the company is certified to ISO 13485 and understands the unique characteristics of human factors engineering enough to have fully integrated it into the company’s development process. Another important but frequently overlooked characteristic is a proven track record for specifically developing medical devices. While many product design and development firms have entered the medical device arena, few have the experience or resources necessary to understand and implement the processes required to compete in the highly regulated field of medical device development. Personal experience has shown that medical device clients who started their programs with these types of design firms eventually had to partner with a new company after it became apparent their current partner was under-qualified and lacked experienced in the nuances of medical device development. Depending on the stage of the development program, this necessary change in direction can have a substantial impact on the scope of the program, time necessary to meet milestones and total cost to complete.
What Will Be Different?
When involving human factors professionals in the development process, you can expect a primary focus on how the user will interact with the device. However, due to the nature of medical devices, you can expect their efforts to focus on “foreseeable misuse,” rather than the ubiquitous “ease of use.” On the surface, this may seem like a minor change in focus, but it represents a fundamental shift in the traditional application of human factors. Foreseeable misuse will challenge your development teams into patterns of thought off the usual track, focusing on how the device failed to support error-free use and how to mitigate those errors. Understanding misuse provides greater insight into potential hazards and allows those hazards to be mitigated pro-actively—before your product goes off for FDA approval or ever hits the market.
How Can I Maximize the Benefit?
The simplest and most effective way to maximize the benefit of a human factors engineer (HFE) is to involve him/her from the project’s inception. While the overall presence on programs will fluctuate, early involvement assures the product requirements will reflect the needs of the user from the onset. Paring an HFE with an industrial designer is another successful way to maximize the impact of an HFE, especially in the initial concept development phase of a program. The analytical, process driven focus of an HFE is symbiotic with the insightful and visually oriented nature of industrial designers. This unique paring can produce a broad, yet relevant array of user-focused product concepts.
Industrial designers and HFEs also should collaborate to develop any models, prototypes and simulations to be used for early usability testing. Typically part of the core development team, industrial designers can quickly integrate any insights directly into the development process.
How Can I Assure Success?
The most important management challenge may be to convince your team of skilled engineers and designers that they don’t have all the answers when it comes to designing equipment that will be easy to use and error tolerant. This is a major trap for most design teams. Bringing users in early and often to interact with the emerging user-interface design, often referred to as usability evaluations, usually convinces the team once it watches end users misinterpret instructions and make unexpected button presses. Aspects that the design team thought were “sure things” very often are “foreign concepts” for the end-user.
Finally, create an environment for success—one that welcomes change. Adding new members to a team, especially those with different professional skills and focus, may upset “the way we do things around here.” Managers have a strong obligation to communicate the importance of human factors to all development projects and offer strong support for HFE design factors in all product outputs. Without a management buy-in and repetitive support of human factors implementation, development teams will treat this focus as a passing trend—and your next device will face more risk and expense than your budget can take.