Shift from „testing usability” to „designing for usability”
The update of ANSI/AAMI HE75:2025, AAMI’s core human factors and usability engineering standard for medical devices, is more than a technical refresh. It is a clear signal that user-centred design has moved from “nice-to-have” to “regulatory expectation”. According to AAMI, the new edition is intended to guide manufacturers who want to design better devices, write specifications that actually reflect user needs and ensure that usability testing is aligned with FDA expectations. At the same time, its principles dovetail with requirements stemming from the EU MDR, especially those general safety and performance requirements that address usability, ergonomics and minimisation of use error.
A recurring theme in HE75:2025 is the shift from viewing usability as a final test to treating it as a design philosophy. Rather than asking at the end of development whether users can operate the device, the new edition encourages teams to build usability into every design decision. That means user interface layouts, control logic, alarm behaviour, on-device labelling and instructions for use are all driven by a structured understanding of users, their environment and their limitations.
This thinking closely mirrors MDR expectations that risks associated with the use of a device, including risks arising from ergonomic features and human factors, must be reduced as far as possible and not simply controlled through labelling. In practical terms, HE75:2025 gives manufacturers an operational toolbox for turning this legal principle into actionable design guidance.
Structured user research and requirements development
HE75:2025 puts strong emphasis on early and iterative user research. Rather than assuming a generic “healthcare professional”, it calls for clear definition of user groups, including their training, cognitive workload, physical capabilities and likely stressors in the intended use environment. The standard highlights methods for gathering user insights and translating them into design inputs, ensuring that specifications for displays, controls, workflows and training materials actually reflect real-world practice.
For MDR manufacturers, this supports the requirement to define the intended purpose and intended users with enough precision that subsequent risk management and clinical evaluation can be meaningfully anchored to real usage scenarios. Well-documented user research also strengthens the human factors section of the technical documentation and the human factors dossier submitted to regulators or notified bodies.
Anthropometric and biomechanic foundations
One distinguishing feature of HE75 is its extensive use of anthropometric and biomechanic data to inform physical design decisions. The 2025 edition continues this tradition, encouraging designers to base dimensions, forces, reach distances and clearances on empirical data rather than intuition. In practical terms, this can influence handle geometry, button sizes, display readability, weight distribution and the design of workstations or transportable devices.
From a regulatory perspective, designing to anthropometric data directly supports MDR’s requirement to consider the physical characteristics and health status of the intended users, including vulnerable groups. It also helps reduce foreseeable misuse caused by poor fit, excessive force requirements or awkward postures.
Use-related risk management and error-resistant design
A central promise of the new HE75 training is to help participants integrate methods that identify and reduce use-related risk and to design error-resistant medical devices. The standard links usability activities to risk management, ensuring that hazard identification and risk control measures explicitly include use scenarios, task analyses and known user interface failure modes. aami.org
For MDR and IVDR manufacturers, this aligns naturally with risk management obligations under Annex I and the requirement to consider risks arising from ergonomic features and from the interaction between user, device and environment. Instead of relying solely on warnings and training, HE75:2025 encourages design teams to remove or mitigate sources of confusion in the interface itself, for example through clear affordances, feedback mechanisms and consistency across product families.
Usability testing aligned with regulatory expectations
The AAMI training around HE75:2025 specifically addresses expectations for usability testing, particularly those articulated by the FDA for human factors submissions. It emphasises realistic test scenarios, representative users and tasks derived directly from use-related risk analyses. The goal is not only to demonstrate that the device can be used, but to show that critical tasks can be completed safely and effectively under realistic conditions.
Manufacturers working under MDR can leverage the same evidence in clinical evaluation and in their post-market clinical follow-up or post-market performance follow-up, showing that the user interface performs as intended and does not introduce unacceptable residual risk. Over time, repeated usability studies, complaint trends and vigilance data can be integrated into an evolving human factors dossier that reflects real-world performance.
Applying HE75:2025 across device types and use environments
HE75:2025, as described by AAMI, covers design guidance for a broad range of device types: from hand tools and workstations through transportable and home-use devices to integrated systems and combination products. This breadth is particularly relevant under MDR, where devices are increasingly used outside traditional hospital settings and where lay users and caregivers are often involved.
In hospital environments, the standard helps teams design interfaces that support rapid situation awareness, reduce alarm fatigue and facilitate coordination between different roles. In home use, it supports simplified interfaces, robust feedback, clear error recovery and packaging that guides correct setup without direct professional supervision.
Implications for human factors dossiers and technical documentation
For regulatory and quality professionals, HE75:2025 offers a reference framework for building and maintaining a coherent human factors dossier. It provides structure for documenting user research, task analyses, risk control decisions, formative and summative usability tests and design rationales. This documentation, in turn, feeds into the technical documentation required by MDR and into FDA submissions that include human factors data.
By aligning human factors documentation with HE75:2025, manufacturers can show that their usability program is systematic, standard-based and integrated with risk management and design controls. This reduces the likelihood of late-stage surprises when interacting with regulators or notified bodies and supports smoother conformity assessment.
Conclusion
The updated ANSI/AAMI HE75:2025 moves human factors from the margins of device development to its centre. By combining user research, anthropometric data, use-related risk management and structured usability testing, it gives manufacturers a practical roadmap for designing interfaces that are both intuitive and demonstrably safe. For organisations navigating MDR and FDA expectations, adopting HE75:2025 is not only a way to “reinforce the human factors dossier”, but a strategic investment in safer, more usable and more competitive medical devices.