Device testing is required for a wide array of variables in the development of a medical device. When it comes to devices used directly by the patient, however, it is critical to test the patient/device “relationship.” This article looks at examining and testing the human factor when it comes to the handling of a medical device and how the design can be improved to enhance that relationship.
For any product on the market, a measure of success is the consumer’s ability to use that product effectively. In the healthcare arena, a successful delivery system must be easy to use, intuitive, efficient, and effective. In addition, any system must be safe for the patient or caregiver to use in the environment for which the product was intended, which could include the home setting. Pharmaceutical and packaging manufacturers must work together to ensure ease-of-use and mitigate risk, while helping to improve dosing adherence rates with a device or system that considers the needs of the patient as well as the drug.
To do so requires that the patient be taken into consideration during the design process. Human factors engineering (HFE) is an integral component of a user-centered design process, and can help to ensure that the device or delivery system meets the cognitive, physical, and emotional needs of the end user. Incorporating HFE principles and methods early in the design process enables manufacturers to identify and define patient needs in detail and examine the point where a product intersects with the intended user.
At the core of HFE and the mitigation of user-based risk lies a common sense approach that considers design options in the context of human interaction with the world. Understanding how the human factors world defines and evaluates human capabilities is only part of the puzzle for pharmaceutical delivery device manufacturers. Design experts must also understand that the human condition, which must be considered in the design, is not static but rather a series of evolutions defined by the changing disease state. By understanding the needs and desires of the patient at various times during treatment, human factors experts can mitigate user-based error, and control or reduce any lapses in therapy associated with improper device use.
The FDA has provided recommendations for medical device design optimization through human factors analysis, testing, and validation. The methods offer an effective way to understand use-related hazards and optimize how people interact with the technology, as it relates to the three major components of the device-user system:
- Device users
- Device-use environments
- Device and/or device-user interfaces
In-depth statistical analysis, data aggregation, and synthesis techniques can yield actionable opportunities for innovation and a thorough understanding of the potential users’ behaviors, motivation, and needs.
Since there are many tools available, engineers should engage human factors experts to help preliminarily define and prioritize the needs of the intended users and determine what else needs to be learned about user and device interaction before selecting the best method. Common methods include:
- Qualitative, such as interviews, ethnographic observation, contextual inquiry, and concept evaluation
- Quantitative, including questionnaires, in-person surveys, and user-based performance testing
- Analysis and synthesis outputs, such as affinity diagramming, product adoption road maps, and habits and ideal scenarios
- Human factors/ergonomics, including human error and risk analysis, usability testing, and heuristic analysis (encouraging a person to use the device on his/her own)
Discovery research, usability testing, and directional and preference testing offer a strong framework for the development process. Customers’ needs and desires can be confirmed through discovery. Directional research allows users to evaluate product concepts, and usability testing helps to ensure that the delivery solution is user-appropriate. For a more robust testing framework, four major components of user capability must be considered. These components are inextricably linked in the context of understanding what “usability” means. They are:
- Physical Abilities—Anthropometry (the measure of bodies, such as heights or the size of hands), biomechanics [what can be accomplished physically (e.g., how much weight can be lifted, how firmly something can be grasped)], and sensory abilities (vision, hearing, tactile sense, etc.)
- Cognitive Abilities—How people process information, the capabilities of memory, the manner in which humans learn new things, and how habits are developed
- State of Being—The general health of the expected user, disease states and co-morbidities the patients are likely to be challenged with, mental and emotional states, and motivation for learning new things
- Experiences—Educational background, knowledge of a particular disease state, and lifelong experiences with objects that will guide behavioral interactions with any delivery system
Each of these components helps make important connections in the relationship between the user and the device. It is also helpful for human factors experts to interview the user in the proper context or environment of use. Someone sitting in a conference room will have a different user experience than a stay-at-home mother who is also taking care of an aging parent. It may be helpful for human factors experts to see the user in the midst of daily distractions, such as children, pets, ambient noise, temperature, and lighting. This will help human factors experts get the most relevant data and better understand how the patient will use a device, as well as the many factors that may affect use. Usability may also change over time as the patient becomes more accustomed to a device.
To get the richest data, human factors experts must follow the patient on his or her journey—from diagnosis to end of therapy—and then translate the multitude of qualitative and quantitative data into features of a product that will not only provide a patient with safe and effective delivery, but also meet the emotions, needs, and desires of the user at different stages of disease management.
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