The medical device industry is undergoing a fundamental transformation. Devices that once required trained clinical staff are now being designed for use by patients in their own homes. From continuous glucose monitors (CGMs) and insulin pumps to hearing aids and remote cardiac monitors, the migration of medical technology into consumer hands is accelerating rapidly.
This shift is driven by multiple factors: an aging population that prefers to age in place, healthcare systems seeking to reduce costs by minimizing hospital stays, and patients demanding greater control over their own care. The Hospital-at-Home movement, now approved across 400 hospitals in 39 US states, exemplifies this trend.
But this transition creates a profound human factors challenge: how do you design a device that is safe and effective when used by someone with no medical training, potentially limited technical literacy, and no clinical supervision?
When a device is used in a clinical setting, manufacturers can make certain assumptions about the user. Clinicians have been trained on proper technique. They understand sterile procedure. They can interpret warning messages in clinical context. They have colleagues to consult when something unexpected happens. Home users are different. They may be elderly patients with declining vision and dexterity. They may be caregivers who are stressed, sleep-deprived, and juggling multiple responsibilities. They may be patients who are anxious about their condition and prone to misinterpreting feedback from the device.
The use environment has changed too. Clinical settings have controlled lighting, minimal distractions, and easy access to supplies. Homes have pets, children, poor lighting, and interruptions. A task that takes 30 seconds in a clinic might take 5 minutes at home—if it gets completed at all.
Successful home-use device design requires rethinking every aspect of the user interface:
Physical Design: Controls must be operable by users with arthritis or tremors. Displays must be readable by users with presbyopia. Components must be robust enough to survive being dropped on a bathroom floor.
Cognitive Load: Instructions must be understandable without medical terminology. Error messages must tell users what to do, not just what went wrong. The number of steps in any procedure should be minimized.
Training and Support: Unlike clinicians who receive formal training, home users learn from quick-start guides and YouTube videos. The device and its instructions must work together as a complete learning system.
Error Recovery: When errors occur—and they will—users need clear paths back to safe operation. This is especially critical for devices that deliver therapy, where a use error could result in over- or under-dosing.
Formative usability studies are essential for home-use devices, and they must be conducted with representative home users—not clinicians, not company employees, not healthy volunteers who don't match the target patient population.
These studies should be conducted in simulated home environments, not sterile usability labs. They should include realistic distractions and interruptions. They should test the complete out-of-box experience, including unpacking, setup, and first use.
Multiple rounds of formative testing are typically needed. Each round identifies usability issues, the design team addresses them, and the next round validates the improvements while uncovering new issues exposed by the changes.
The FDA has taken notice of the home-use trend. The agency's human factors guidance emphasizes the importance of understanding the intended use environment and user population. For devices with critical tasks—those where use errors could cause serious harm—comprehensive human factors validation is expected. The new FDA draft guidance on human factors submission content introduces a risk-based categorization system. Home-use devices with critical tasks will typically fall into the highest documentation category, requiring full human factors validation study reports.
The migration of medical devices into the home will only accelerate. Manufacturers who invest in robust human factors engineering now will be better positioned to bring safe, effective products to market. Those who treat human factors as an afterthought will face regulatory delays, post-market problems, and—most importantly—patients who cannot use their devices safely. The challenge is significant, but so is the opportunity. Well-designed home-use devices can improve patient outcomes, reduce healthcare costs, and give patients greater autonomy over their own care. Getting the human factors right is the key to realizing that potential.