When granting regulatory approvals for medical devices, both IEC 62366 and the FDA have emphasized the importance of applying human factors and user-centered design activities to the development process to ensure medical device safety and improve usability. The development of mobile medical apps (MMAs) is no exception. Developers of an MMA aren’t just building another Angry Birds or Candy Crush app, they are building a medical device in the form of a mobile app that keeps up with a user’s health, perhaps even diagnosing symptoms and preparing users for unforeseen medical emergencies.
So, it is up to the developers of MMAs to build well-integrated, easy-to-use apps, which meet the needs and expectations of the intended users while reducing the risks for user errors. Doing so will not only facilitate the CE and FDA approval processes, but will also increase customer adoption and satisfaction.
When planning for product development of a mobile medical application, here are 5 user-centered design activities for improving the user experience and customer satisfaction of your MMA.
1. Understand the Intended Use Environment and User Needs
User research allows the MMA development team to understand what users need and the clinical problem the mobile medical app will intend to solve. User research involves directly observing potential users while in their intended use environment. When developing a mobile medical app, it may be beneficial to include a medical expert as a member of the development team. Developing medical apps can require specific and extensive medical knowledge that is not understood by most product developers. By understanding the user needs and environments, developers will have a better chance of including all the necessary functions and information that will make the app beneficial.
The results of the observational research are documented in user scenarios and task analyses. A user scenario is a short narrative story about a specific user with a specific goal. Task analysis provides a detailed description of the human requirements to perform the steps required to accomplish a user scenario. These are written in plain language to provide development team members as well as stakeholders a common understanding, and are referenced often during the remaining user-centered design activities.
2. Analyze Possible Use Risks and User Errors
The development team should perform use risk analysis concurrently with conventional system risk analysis to determine specific potential risks related to intended uses and reasonably foreseeable misuses of the app, in the context of the use scenarios. Safety-critical tasks, related to possible use risks will be identified, as will essential tasks, which are those tasks necessary for successful use of the mobile medical app for its intended clinical purpose.
Designers have a responsibility to create workflows and interaction designs that prevent use errors from occurring. If users do make an error, the workflow and design of the MMA should allow them to recover quickly. Consideration should be given to the fact that the input methods available for mobile devices are different from those for desktop computers and may take some time to become familiar to new users. Differences in age, mental ability, lifestyle, and digital and health literacy levels of the intended users will influence their proficiency using the mobile app, and may influence the likelihood of use errors. If the intended users include young, healthy, and technology savvy users as well as older or disabled users, developers need to make sure it can be effectively used by both groups.
3. Design to Model Expected User Task-Flows and Paradigms
App designers need to ensure the app’s design accommodates the users’ workflow by:
- focusing on how a user will complete the primary functions and essential tasks,
- supporting the task at hand efficiently and intuitively, with minimal cognitive burden,
- limiting the display, features, and number of steps to the minimum required for the user to achieve their objective.
Many users will already be familiar with non-medical mobile apps and will have expectations of consistency in navigation and interaction. App developers benefit from following current industry-accepted mobile UI design navigation and interaction paradigms. Consistent paradigms provide an intuitive and straightforward experience; they are easy to learn and to remember. It is well understood that users won’t invest time to learn new intricate interactions, and that users rarely read a user manual or help pages, especially in a mobile situation.
Involving designers who understand the concepts of responsive design is also vital to an efficient mobile interaction design effort. Responsive design enables users to access and use the app from many devices providing a consistently optimal viewing experience and clear navigation. Responsive design improves the user experience. It minimizes panning and resizing, and adjusts for a wide range of screen sizes giving the user convenient navigational control.
4. Iterate on the Design (Prototype, Test, Refine, and Repeat)
Following an iterative design approach supports the opportunity to make the MMA user interface intuitive and easy to use. It also controls or mitigates potential use-related risks. Iterative design is a repetitive process of prototyping, testing, analyzing, and refining a design to provide early insight and feedback.
It is important to do this as early as possible so any issues can be quickly addressed, allowing design iterations and adjustments before arriving at the final design. Since prototypes can be created and updated in a fairly short amount of time, several iterations can take place to allow improvements in the user interface and interactions. Iterations are repeated until errors and issues have been reduced to an acceptable low-risk level.
The usability testing conducted to collect the feedback on the prototypes from potential real users can be relatively short and conducted with a small number of participants. They don’t require extensive time or documentation. These formative evaluations are essential to provide critical insights into how a representative user would use the application. Initial testing can quickly identify a significant percentage of potential design issues.
5. Validate Clinical Efficacy
Summative validation testing demonstrates that the product is safe and effective for the intended uses, users and use environments. It also shows that the design does, in fact, minimize use-related risks. Summative testing is conducted using the intended final design and the complete product, in a simulated use environment with representative users. Representative users should include a sample of all user groups of the MMA being tested, which may include health care providers, administrators, patients, and care-givers.
The summative test is not an exploratory effort for obtaining inputs on design features – that was already obtained as part of the iterative design activity. The summative testing should really function as a final demonstration of safe use of the device, since the use scenarios that are tested should focus on critical and essential tasks from a risk perspective.
User centered design activities should be conducted throughout all phases of your MMA development including preliminary user research, task and risk analysis, iterative design and evaluation, and final summative validation testing in simulated use environments. While this may require a much more in-depth development path than building the next Angry Birds or Candy Crush, doing so will facilitate regulatory approvals of your medical app, reduce the risk of user errors, and increase customer satisfaction.