Lessons from the Caregiver's Perspective: Essential Usability Principles for Medical Device Design

In 2025, as I supported my husband through his lymphoma journey, I found myself in an unexpected role: the primary user of numerous medical devices I had never encountered before. From feeding pumps to the Sara Stedy transfer aid to straight catheters to on-body infusion pumps used for chemo and more, each day brought new interfaces to learn, new procedures to master, and new challenges to navigate—all while managing the emotional weight of caregiving.

This experience gave me profound appreciation for the medical device manufacturers who had thoughtfully considered usability in their designs. The difference between a well-designed interface and a poorly designed one wasn't just a matter of convenience—it directly impacted my confidence, my husband's comfort, and the quality of care I could provide.

As a human factors professional, I've spent years advocating for user-centered design. But living on the other side of that equation having to learn many new medical devices —as a stressed, sleep-deprived caregiver learning critical medical procedures in real-time—brought those principles into sharp focus in ways no amount of research could replicate.

Seven Essential Principles for Medical Device Usability

Although this is not an exhaustive list, here are the key design principles that made the most significant difference in my experience as a caregiver and device user:

1. Display System Status Clearly

Users shouldn't have to guess what's happening with a medical device. Clear status indicators—whether through displays, lights, or audio cues—provide essential feedback that the device is functioning correctly. When a feeding pump clearly showed bolus given, flow rate, and estimated completion time, I could confidently leave the room for a few minutes. When status was ambiguous, I felt tethered to the device, uncertain whether it was working properly.

2. Prevent Errors Through Smart Interface Design

Disable or gray out selections and submenus that aren't applicable to the current task. This simple design choice prevents confusion and reduces the cognitive load on users who may already be overwhelmed. In high-stress caregiving situations, every potential error path eliminated is one less thing to worry about.

3. Make Correct Use Obvious

Provide functional, cognitive, and physical affordances that help users understand how to operate the device correctly. Design controls and features that clearly signal how they should be used. Schematics on how to feed the tubing, buttons that look pressable, icons indicating the lock features, and connectors that only fit one way—these intuitive design elements reduce training time and minimize use errors.

4. Provide Clear Fault Recovery Instructions

When something goes wrong—and eventually, something will—users need clear, actionable guidance on how to address the problem. Don't expect caregivers to troubleshoot complex fault conditions on their own. Error messages should explain what happened and exactly what steps to take next.

5. Design for the Human Body

Leverage anthropometric data—human body measurements and capabilities data—when designing medical products that interface with the patient's body. Devices that accommodate a range of body sizes, account for limited mobility, or consider varied user strength demonstrate thoughtful design that respects the diversity of patients and users who will use them.

6. Enable Easy Cleaning and Maintenance

Medical devices used in home settings must be designed for easy cleaning to minimize contamination risk and preserve long-term functionality. Caregivers are often managing multiple responsibilities; devices with smooth surfaces, minimal crevices, and clear cleaning instructions make proper maintenance far more achievable in daily practice.

7. Account for Real-World Use Environments

Consider the characteristics of actual use environments: lighting conditions, available space, ambient noise levels, room occupancy, and other contextual factors. A device designed only for well-lit, spacious hospital rooms may become difficult or dangerous to use in a cramped, dimly-lit bedroom at 2 AM. Design choices should minimize perception and action issues that could lead to use errors across the range of realistic use scenarios.

The Human Impact of Thoughtful Design

These principles aren't just theoretical best practices—they have real consequences for real people during some of the most challenging moments of their lives. Well-designed medical devices empowered me to provide better care for my husband. They reduced my anxiety, shortened my learning curve, and allowed me to focus my energy on what mattered most: supporting him rather than struggling with confusing interfaces.

Poorly designed devices, on the other hand, added unnecessary stress, created opportunities for errors, and eroded my confidence at times when I needed it most.

To the medical device designers and human factors professionals working to improve usability: your work matters more than you may realize. Every thoughtful design decision, every usability test with real users, every iteration to make an interface clearer—these efforts ripple out to impact patients and caregivers in profound ways.

As you design your next medical device, I encourage you to remember that your users aren't just healthcare professionals in controlled clinical settings. They're also exhausted family members, anxious patients, and caregivers doing their best in imperfect circumstances. Design with compassion, test with diverse users, and never underestimate the impact of making medical technology truly usable for everyone who depends on it.