Built for the Clinic, Worn at Home

Medical devices for chronic disease management — insulin pumps, continuous glucose monitors, home dialysis systems, CPAP machines, infusion pumps, wound VAC systems — are designed around clinical workflows and clinician mental models, then prescribed for home use by patients who face fundamentally different contexts: no clinical training, no backup equipment, no technical support, variable environments, competing daily priorities, and cognitive load from their illness. FDA adverse event reports show that use-related errors account for approximately 40% of medical device recalls, and the majority occur in home-use settings. The gap between the intended clinical user (trained, focused, in a controlled environment) and the actual home user (untrained, distracted, in a kitchen or bedroom) is the binding design failure.

An estimated 50 million Americans use medical devices at home, and this number is growing as healthcare shifts from hospital to home. Home use errors range from CPAP mask fit problems (causing non-adherence in 30–50% of sleep apnea patients) to insulin pump programming errors (causing hypoglycemic emergencies) to home dialysis errors (causing peritonitis infections). The cost is both clinical — preventable adverse events, emergency department visits, hospitalizations — and equity-related: patients with lower health literacy, limited English proficiency, cognitive impairment, or physical disabilities face disproportionate barriers to device use. The FDA has acknowledged this gap but the regulatory pathway for home-use devices is the same as for clinical devices, with human factors evaluations typically conducted in simulated clinical environments rather than actual homes.

Human factors engineering requirements (IEC 62366) mandate usability testing but allow testing in laboratory simulations of use environments — not actual homes with actual patients. Patient training programs (device manufacturers provide onboarding) address knowledge gaps at setup but don't prevent use errors months later when routines change, conditions worsen, or caregivers rotate. Simplified device interfaces reduce error rates for basic operations but often also reduce the functionality that patients need for non-routine situations (alarm troubleshooting, supply replacement, parameter adjustment). Patient-designed devices and workarounds (the DIY diabetes technology community's open-source artificial pancreas systems) demonstrate that patient-led design produces different and often superior solutions — but these cannot navigate the regulatory pathway because they weren't developed by recognized manufacturers.

Home-contextualized human factors evaluation that requires device testing in actual home environments with actual patient populations — including patients with limited health literacy, cognitive impairment, and physical limitations. Modular device architectures that separate the clinical-grade therapeutic core (requiring full FDA clearance) from the user interface and interaction layer (which patients or their caregivers can customize). Regulatory pathways that recognize patient-generated evidence — incorporating real-world home-use data from patient communities into post-market surveillance and iterative design improvement.

A team could conduct in-home observations of patients using a specific medical device (e.g., CPAP, insulin pump, or nebulizer), documenting all the workarounds, environmental challenges, and use errors that emerge in real home contexts versus what the manufacturer's human factors testing predicted. A design team could prototype an alternative user interface for a common home-use device, designed with patient co-designers rather than clinician input, and conduct comparative usability testing. Relevant disciplines: human factors engineering, industrial design, nursing, health informatics.