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Supporting regulators

Key points

  • In direct response to our work, the UK regulator for medical devices has established a programme of work on human factors for device design.
  • Working with the US regulator, the Food and Drug Administration (FDA), we have found previously unknown safety issues in marketed medical devices related to interaction design issues.
  • CHI+MED team members are working with the US regulator to develop theories and tools that regulators can use as the basis of new international standards on the development of medical devices.

Before medical devices, such as infusion pumps, can be marketed they must go through an approval process to ensure that they are safe. The Food and Drug Administration (FDA) is the main regulator for medical devices in the USA. It also has worldwide influence. In the UK the Medicines and Healthcare Products Regulatory Agency (MHRA) is responsible for the approval of such devices in a similar way. Approval typically involves a process in which a manufacturer must provide an argument and evidence that a new device is substantially equivalent to a device that has previously been approved as safe. The regulator has limited time after submission to check the safety of the device and respond.

We have directly supported both the MHRA in the UK and FDA in the United States, helping them understand the importance of a range of human and usability factors that are critical in analysing medical device safety. Ultimately, the regulators provide a major leverage point for instigating long-term transformational change and our work with them is a major step in this regard.


"Anyone with a medical device will be touched by [this] work." - US government stakeholder


Working with the UK regulator
In response to our findings about the 'gaps' between the way devices are approved and clinical practice, and to our work around model-based engineering with the FDA discussed below, the UK regulator, MHRA, has now established a programme of work on human factors for device design. CHI+MED leads, Ann Blandford and Harold Thimbleby, both spoke at the launch meeting in February 2015, with the former giving the keynote. This led to raised awareness of the issues amongst many critical organisations. For example, in the meeting, the representative from NICE, the UK body responsible for providing national advice to improve healthcare, gave a commitment to introducing Human Factors into their assessments of Health Technology. A further direct consequence of the meeting has been that several members of the CHI+MED team were invited to become expert assessors to the MHRA, giving expert advice as part of the premarket review of the software of new devices. The MHRA has also set up a Human Factors "Task and Finish" group involving Ann Blandford and representatives of other key organisations. This will "progress the human factors agenda and create an environment for innovation and improved patient safety in the medical devices field".

Working with the US regulator
We have also had a close research collaboration with the FDA over several years. This collaboration has led to the FDA using CHI+MED research as a reference for quality assessment of user interfaces. CHI+MED analysis has been trialled on medical devices leading to the discovery of previously unknown safety issues in marketed medical devices related to interaction design issues.

Concerned about the number of incidents and recalls of devices, the FDA initiated a programme to improve the safety of infusion pumps. One strand of this, called the 'Generic Infusion Pump Project' was to develop a set of reference specifications for infusion pumps that describe the key elements. The aim is that they can be used by manufacturers to check safety properties of their own devices. CHI+MED provided the expertise to add a missing element of this work: a reference architecture for the user interface software that could be used to ensure its safety. We demonstrated its usefulness by using it to help find problems in commercial infusion pump software. We also used it to identify user interface design issues that explain common problems reported in infusion pump incidents. The official website for the FDA's Generic Infusion Pump project (rtg.cis.upenn.edu/gip/) now links directly to CHI+MED as a source of resources on the safety of infusion pumps.

The FDA has installed CHI+MED developed tools, including our model based prototyping tool, PVSio-web. We demonstrated the effectiveness of our analysis approach on an old submission of a cleared device, finding critical software defects that had not been detected with other methods. As a result, Rick Chapman, Chief of the FDA General Hospital Device Branch, suggested that our analysis methods should be tested on new pre-market submissions and during forensic investigations to see if they can identify issues that manufacturers have missed.

In the longer term the aim is that the FDA will use CHI+MED theories and tools as the basis of new international standards on the development of medical devices to supercede the existing ones. As the FDA has significant influence with manufacturers globally, regulators from other countries may follow their lead. Therefore, our relationship with the FDA is a major leverage point for ongoing transformational impact.

Masci, P. Oladimeji, P. Zhang, Y., Jones, P., Curzon, P. and Thimbleby, H. (2015) "PVSio-web 2.0: Joining PVS to Human-Computer-Interaction." In Computer Aided Verification (CAV2015), Computer Aided Verification: Proceedings of the 27th International Conference, CAV2015, Part 1, Lecture Notes in Computer Science, 9206, pp 470-478, July, San Francisco, California, USA, Springer.

Masci P, Zhang Y, Jones P, Curzon P, Thimbleby H. Formal verification of medical device user interfaces using PVS. In: Gnesi S, Rensink A, editors. Fundamental Approaches to Engineering, 17th International Conference on Fundamental Approaches to Software Engineering (FASE'14), Held as Part of the European Joint Conferences on Theory and Practice in Software, ETAPS, April 5-13, 2014; Grenoble, France. New, York, New York: Springer; 2014. pp. 200-214.

Masci P, Zhang Y, Jones P, Thimbleby H, Curzon P. A generic user interface architecture for analyzing use hazards in infusion pump software. In: Turau V, Kwiatkowska M, Mangharam R, Weyer C, editors. Proceedings of the 5th Workshop on Medical Cyber-Physical Systems (MCPS'14) April 14, 2014; Berlin, Germany. Dagstuhl, Germany: Schloss Dagstuhl-Leibniz-Zentrum fuer Informatik; 2014. pp.1-14. Available from http://drops.dagstuhl.de/portals/oasics/index.php?semnr=14002

Key People
Paolo Masci, Patrick Oladimeji, Ann Blandford, harold Thimbleby, Paul Curzon