Human Factors and Medical Devices: From regulatory Requirement to Clinical Risk Reduction

From Compliance Exercise to Safety‑Critical Discipline

The medical device sector is evolving rapidly as technological advances, software-rich interfaces, networked systems, and artificial intelligence become increasingly embedded in clinical practice. Historically, human factors (HF) was often viewed as a design‑stage consideration, focused on layout, controls or interface choices. Today, however, it is clear that HF must sit alongside technical performance and regulatory requirements. 

In busy clinical environments, understanding how people interact with technology is just as important as understanding what the technology can do. Research shows that device‑related harm is often linked to use‑related issues rather than technical defects (Sawant et al., 2023), while UK guidance describes HF as an iterative activity that supports risk management and post‑market learning (MHRA, 2025). In practical terms, HF now acts as a core safety mechanism influencing procurement, incident review and ongoing surveillance. 

What has Changed? Evidence From Recent Human Factors Research

Recent studies highlight that many device incidents stem from use‑related factors shaped by design, workflow, environmental pressures and cognitive load, not simply ‘user error’ (Sawant et al., 2023). An example might be similar buttons colated but with very different functions, the ease with which mismatched connectors can be interlocked allowing wrong route administration of infusions (there were six never events related to wrong route administration in England in 2024/5).  This raises important questions about the nature of usability testing, including whether assessments reflect real clinical contexts such as interruptions, PPE use or competing alarms. These are often factors captured in investigations as to why systems of work did not deliver the expected outcome (it’s good people, working hard but the reliance on human behaviours to accommodate design flaws will always be fallible).  

Cultural and behavioural factors also play a role. Established habits, local norms and mental models can significantly influence how users interact with devices. When design assumptions are misaligned with these factors, error risk increases. Evidence also links poor usability with workflow disruption, inefficiency and staff stress – factors associated with burnout and safety risk (Al Harbi et al., 2025). This can lead to slip/lapse errors where the correct action was intended but because of distractions and interruptions there is a missed step. We see this ‘looked but not seen’ errors where perhaps the wrong device is selected from the shelf and the error identified later in the journey.  

Taken together, these insights support the view that usability can serve as a leading indicator of risk. HF challenges often become visible only when design assumptions meet real‑world conditions such as lighting, time pressure and teamwork demands (Sawant et al., 2023; Tandon et al., 2024). Recognising contributory factors, and implementing controls that reduce the likelihood or impact of error, helps strengthen safety at the point of use. These may range from ‘forcing functions’ to ensure a critical safety step is taken, or a ‘silence for safety’ which means a team allows moments free from distraction permitting a conscious effort to safety. 

Human Factors as a Regulatory Expectation in the UK

Modern UK guidance frames HF and usability engineering as evidence‑based processes spanning the entire device lifecycle. The MHRA’s 2025 update emphasises integration of HF with risk management and post‑market surveillance, recognising that important learning often emerges only after devices enter real‑world use (MHRA, 2025).  

The MHRA’s 2021 guidance (v2.0) outlines expectations around identifying intended users and environments, defining and evaluating critical tasks, integrating formative and validation testing, and documenting risk controls. These requirements align with BS EN 62366‑1, the core usability engineering standard (MHRA, 2021; BSI, 2019). Although aimed at manufacturers and approved Bodies, these principles also shape the work of clinical engineers and healthcare scientists. Activities such as gathering post‑market feedback, reviewing incident reports and monitoring configuration changes all contribute to a continuous safety cycle. 

Incident Investigation: From “User Error” to System Insight

When an incident occurs, it can be tempting to categorise it as ‘user error’. HF analysis encourages a broader view, exploring why conditions made the error more likely. This includes examining whether tasks are intuitive, whether critical information is accessible and timely, whether alarms are clear and prioritised appropriately, and whether environmental factors – noise, lighting, interruptions – affected performance. 

This approach shifts the focus from individual blame toward system‑level contributors, consistent with MHRA guidance on learning from use‑related incidents and supporting corrective actions in design, labelling, training and post‑market updates (MHRA, 2025). It will be interesting to see the direction in the future, and whether activities such as procurement will be influenced by a human factor’s mindset and whether safety by design equipment will outweigh the financial implications when selecting the safest equipment 

Key Takeaways for Practice

1. Human factors evidence supports safe systems. Consider design, usability and validation within real‑world conditions to better understand device performance. 
2. Environmental conditions matter. Lighting, noise, simultaneous alarms, PPE and workflow interruptions all influence how devices are used. 
3. Incidents can drive learning. HF methods help identify where design‑induced risks or system constraints contribute to error. 
4. Post‑market information is essential. Capture usability complaints, workarounds and near‑misses and feed them into local governance and PMS processes. 
5. Seek specialist HF expertise. Effective application of human factors and ergonomics requires training, experience and scientific understanding. 

Closing Reflection

The science of human factors is increasingly recognised as a continuous, risk‑based discipline within medical device testing and evaluation. UK guidance reinforces its role throughout the device lifecycle, including after regulatory approval (MHRA, 2025; MHRA, 2021). 

When the principles of human factors are integrated into procurement, acceptance testing, incident analysis and post‑market surveillance, the benefits are tangible: fewer workarounds, reduced cognitive demand, smoother workflows and a lower likelihood of patient harm. Approaching human factors as a supportive patient‑safety measure, rather than a procedural requirement, helps ensure medical devices function safely and effectively in the environments where they are used every day. 

References

• MHRA (2025) Guidance on applying human factors to medical devices
• MHRA (2021) Guidance on applying human factors and usability engineering to medical devices in Great Britain (v2.0)
• BSI (2019) BS EN 62366-1:2015+A1:2019 (Usability engineering standard)
• Sawant et al. (2023) Review of usability testing methods in healthcare devices
• Al Harbi et al. (2025) Usability, human factors engineering, and staff wellbeing
• Tandon et al. (2024) Scoping review of digital health HF/usability (preprint)

Disclaimer. The views and opinions expressed in this article are solely those of the author and do not necessarily reflect the official policy or position of Test Labs Limited. The content provided is for informational purposes only and is not intended to constitute legal or professional advice. Test Labs assumes no responsibility for any errors or omissions in the content of this article, nor for any actions taken in reliance thereon.