Human Factors Engineering in Medtech

In this Q&A, MD+DI took a deep dive into human factors with Velentium’s Albert Rodriguez and discussed its purpose in the design of medical devices.

Katie Hobbins, Managing Editor

March 21, 2023

8 Min Read
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Image Courtesy of Velentium / Graphic Courtesy of MD+DI

Human factors focus on the interaction between users and devices, making the practice a key part of medical device development. To learn more about its importance in the design of medical technology and the steps in which human factors are put into practice, MD+DI sat down with Albert Rodriguez, director of human factors engineering at Velentium.

MD+DI: Velentium has previously stated that introducing fully integrated HFE (Human Factors Engineering) processes from day one of development negates expensive redesign and risk. Can you further explain why this is? Especially as some may see it as an unnecessary, expensive addition.

Rodriguez: For a product to work properly and be considered successful in this industry, it must be able to satisfy its intended end user needs while being used in the environment that it would typically be used. Now, this seems simple enough, but in many instances, engineers are often not aware of the details about those two aspects of the products they are designing. Frequently, clients view the process of identifying this information as costly and unnecessary because the required research effort associated with the human factors engineering processes does not produce the output typically associated with product development.

Without adding in fully integrated HFE processes, the product development team is essentially designing devices with incomplete knowledge of the specifics of how the design should support the function it needs to perform for the specific person who will be performing it. This often leads to products failing to fulfill their intended needs whether it be in clinical trials, research studies, or commercial release. Frequently, however, the failure may not be because the product didn’t correctly perform its intended functions, but because there was a usability issue or user error that caused it to fail. Despite that, headlines just report a failure, and won’t mention the details of the failure. Unfortunately, most people won’t ever read that far. All they pay attention to is the word failure.

Designers then have to go back to the drawing board. They have cost themselves a lot of time and money that could have been saved if they had done the research and considered the end user, task, and environment in their design process. That is what human factors engineering is.

When HFE processes are fully integrated from the beginning, the front end of the design process focuses on identifying three key areas: the intended users of the product, the intended environment in which users will operate the product, and the main tasks and functions that users will perform with the product. Identifying these characteristics early on is important because once these details are known, they will be used to make important design decisions. Designing the product with an understanding of what the product needs to do for the various user groups will greatly facilitate its usability to a larger audience by tailoring its design specifically to each end user’s needs.

A product that is being used by various clinical specialists may need more complex and involved features requiring a larger number of functions and use cases designed to meet each intended user’s needs. But if the intended end-user of a product is a patient or lay person, the products may require a reduced set of features designed in a way that the average person can use correctly for its intended purpose. The environment that the product is used in is important for design decisions too because the product needs to have a design that will function correctly when exposed to that specific environment.

Surgeons, for example, are typically surrounded by very bright lights when they are in the operating room, so if a device is designed to be used in an operating room by a surgeon, and it has a digital display screen, it would need to have design modifications that allow the screen to be viewed under bright lights without washing out the display.

By doing the research and identifying the human factors that apply to a product early on, engineers are able to make more informed design decisions upfront and down the line that reflect these factors. When a product is designed with the specific intended users, environments, and tasks in mind, the risk of having to redesign the product is greatly mitigated, and the chances of success are much higher. In the end, this saves much more time and money, and this is the reason why Velentium chooses to integrate human factors engineering from the beginning.

MD+DI: How has the company balanced the need for simple interfacing with the expectation of sophistication of its products?

Rodriguez: The answer to this question goes back to user needs. You want to phrase and capture user needs in a form specific to the user that you’re representing. For example, a hospital inventory manager needs to be able to quickly and efficiently assess the model, manufacturer, and expiration date of a particular product. This allows them to identify the correct product and take it to where it is going to be used by a specific person for a specific need. The simple interface gives them what they need to succeed. Figure out what the user needs to achieve and why. We have those discussions over multiple aspects of your product. Figure out the goal, the test being performed, the role the user is playing, the key piece of information, or the key results they need to be able to achieve, and that helps you understand the balance of a simple interface with product sophistication. You want to be sensitive to what the user needs to do at the point at which they’re going to interface with a product. Think about your check engine light. It does exactly what it needs to do in a very simple way, right? The intended user is the driver. It gives them a quick, obvious interface that says there is a problem. Then the downstream intended user is the mechanic who will receive the specifics of why the check engine light is on. In each case, the products are designed to provide interfaces that are appropriate to the user’s needs.

MD+DI: How has the integration of smartphone technology changed the way developers think of human factors?

Rodriguez: Smartphones have been around for a long time. Over time design standards principles have been developed, resulting in very consistent interfaces across all apps. Users are familiar with the common interface components and can quickly and easily become proficient users of apps. As designers of medical products, we should leverage this user “training” to present a product that users are quickly familiar with. This will help users quickly grasp how to interact with the app that controls or communicates with the product. It is a net positive for us as designers to leverage the training people have from simply using their phones. If certain aspects of your design are unique or novel from an interface perspective, it will create a new user experience for your users and should be thoroughly evaluated during the design and development process.

MD+DI: What steps are put in place during the design process to help predict how users will interact with a specific product?

Rodriguez: Normally HFE steps begin before the design process starts and are then integrated throughout the process as the product is being designed. The process begins with in-depth research and analysis to find out what the key elements are: intended user, intended environment, and the tasks needed to be performed. At a high level, this information is defined in collaboration with the sales and marketing teams as they are the tip of the spear defining this knowledge. Once the intended users and the environment the product will be used in are identified, the HFE teams perform a task analysis which helps understand and define what kind of tasks need to be performed by the various intended user groups and thus how they will interact with the product.

Throughout the design process, this task analysis and the previously determined user and environment demographics are used to evaluate the various interface aspects of the product’s design to make sure they are in alignment. Once it is understood how the product is going to be used, this factor is considered throughout the entire life cycle of the product and determines design decisions at every step of the process, from early concepts to form factor aspects of the design, to larger-scale manufacturing and deployment.

During the design process, numerous evaluations are performed to observe how users interact with the product. This is usually done by taking the product to the intended users within the intended environments and asking them to evaluate the usability of the product by performing the intended task. For example, engineers will take devices to mock surgery rooms and ask doctors, surgeons, and the users who prescribe, implant, or use the devices to evaluate them, and give their opinion on their usability and performance. Getting down to this level of fidelity and reproducing the use environments helps engineering teams determine if the product works as it needs to and allows them to continue down the correct path or pivot if needed.

The moral of the story is that in order to help predict how users will interact with a product, user-centered design processes and steps must be implemented at every point in the product’s design cycle. Keeping the intended user and environment in mind will help in the understanding of how users will use the product, which then influences the design of all aspects of the product. It’s basically a reoccurring cycle of user intentions and design intentions influencing each other back and forth. As a product’s design gets closer and closer to the end of the process, you must keep going back to the end user, conducting interviews, simulations, evaluations, etc. to see if they are on the right track with usability. This will lead to a much higher likelihood of success down the road.

About the Author

Katie Hobbins

Managing Editor, MD+DI

Katie Hobbins is managing editor for MD+DI and joined the team in July 2022. She boasts multiple previous editorial roles in print and multimedia medical journalism, including dermatology, medical aesthetics, and pediatric medicine. She graduated from Cleveland State University in 2018 with a bachelor's degree in journalism and promotional communications. She enjoys yoga, hand embroidery, and anything DIY. You can reach her at [email protected].

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