Chris Vincent

Integration of human factors and ergonomics during medical device design and development: It's all about communication

Manufacturers of interactive medical devices, such as infusion pumps, need to ensure that devices minimise the risk of unintended harm during use. However, development teams face challenges in incorporating Human Factors. The aim of the research reported here was to better understand the constraints under which medical device design and development take place. We report the results of a qualitative study based on 19 semi-structured interviews with professionals involved in the design, development and deployment of interactive medical devices. A thematic analysis was conducted. Multiple barriers to designing for safety and usability were identified. In particular, we identified barriers to communication both between the development organisation and the intended users and between different teams within the development organisation. We propose the use of mediating representations. Artefacts such as personas and scenarios, known to provide integration across multiple perspectives, are an essential component of designing for safety and usability.

Patient safety and interactive medical devices: Realigning work as imagined and work as done

Medical devices are essential tools for modern healthcare delivery. However, significant issues can arise if medical devices are designed for ‘work as imagined’ when this is misaligned with ‘work as done’. This problem can be compounded as the details of device design, in terms of usability and the way a device supports or changes working practices, often receives limited attention. The ways devices are designed and used affect patient safety and quality of care: inappropriate design can provoke user error, create system vulnerabilities and divert attention from other aspects of patient care. Current regulation involves a series of pre-market checks relating to device usability, but this assumes that devices are always used under the conditions and for the purposes intended (i.e. work as imagined); there are many reasons for devices being used in ways other than those assumed at development time. Greater attention needs to be paid to learning points in actual use and user experience (i.e. work as done). This needs to inform manufacturers’ designs, management procurement decisions and local decisions about how devices are used in practice to achieve co-adaptation; without these, we foster risks and inefficiencies in healthcare.

The challenges of delivering validated personas for medical equipment design

Representations of archetypal users (personas) have been advocated as a way to avoid designing in isolation. They allow communication of user needs and orient teams towards user experience. One of the challenges for developers of interactive medical devices is that most devices are used by a wide variety of people, and that developers have limited access to those people; personas have the potential to make developers more aware of who they are designing for. But this raises the question of whether it is possible to deliver useful, valid personas of interactive medical device users. The aim of this research was to develop and test a rigorous, empirically grounded process of constructing personas, with the objective of reflecting on that process. Many challenges were encountered: we found that directly linking the personas to a user population was not possible and although personas were a useful tool for supporting communication and elicitation across disciplines, it was hard to make them representative when picking details that were relevant and checking accuracy. Checking the content resulted in disparate, possibly incommensurable, views. Despite this, the personas proved useful in supporting the transfer of knowledge across professional perspectives.

Designing for Safety and Usability User-Centered Techniques in Medical Device Design Practice

The design of systems affects the likelihood and nature of errors that people might make with them, and the ease of error recovery. If developers are to design systems that are less prone to errors propagating, they need to consider the users and user contexts. There are many techniques and resources available to support developers in this. In this paper we report on an interview study involving professionals from major manufacturers of medical devices, to better understand their development practices and the external forces that shape those practices. This identified barriers to user-centered design and corresponding opportunities for support. Results are divided into four themes. These are: collaborative working practices; understanding the user and their situation; providing adequate justification for the adoption of a user-centered approach; and the provision of clear guidance and support. Our findings highlight the importance of ensuring that techniques are adequately justified, applied at the correct time, aligned with the development lifecycle and easy to adopt.

Can Standards and Regulations Keep Up With Health Technology

Technology is changing at a rapid rate, opening up new possibilities within the health care domain. Advances such as open source hardware, personal medical devices, and mobile phone apps are creating opportunities for custom-made medical devices and personalized care. However, they also introduce new challenges in balancing the need for regulation (ensuring safety and performance) with the need to innovate flexibly and efficiently. Compared with the emergence of new technologies, health technology design standards and regulations evolve slowly, and therefore, it can be difficult to apply these standards to the latest developments. For example, current regulations may not be suitable for approaches involving open source hardware, an increasingly popular way to create medical devices in the maker community. Medical device standards may not be flexible enough when evaluating the usability of mobile medical devices that can be used in a multitude of different ways, outside of clinical settings. Similarly, while regulatory guidance has been updated to address the proliferation of health-related mobile phone apps, it can be hard to know if and when these regulations apply. In this viewpoint, we present three examples of novel medical technologies to illustrate the types of regulatory issues that arise in the current environment. We also suggest opportunities for support, such as advances in the way we review and monitor medical technologies.

Infusion device standardisation and dose error reduction software

In 2004, the National Patient Safety Agency (NPSA) released a safety alert relating to the management and use of infusion devices in England and Wales. The alert called for the standardisation of infusion devices and a consideration of using centralised equipment systems to manage device storage. There has also been growing interest in smart-pump technology, such as dose error reduction software (DERS) as a way to reduce IV medication errors. However, questions remain about the progress that has been made towards infusion device standardisation and the adoption of DERS. In this article, the authors report the results of a survey investigating the extent to which the standardisation of infusion devices has occurred in the last 10 years and centralised equipment libraries are being used in practice, as well as the prevalence of DERS use within the UK. Findings indicate that while reported standardisation levels are high, use of centralised equipment libraries remains low, as does DERS usage.

Processing of first-order motion in marmoset visual cortex is influenced by second-order motion.

We measured the responses of single neurons in marmoset visual cortex (V1, V2, and the third visual complex) to moving first-order stimuli and to combined first- and second-order stimuli in order to determine whether first-order motion processing was influenced by second-order motion. Beat stimuli were made by summing two gratings of similar spatial frequency, one of which was static and the other was moving. The beat is the product of a moving sinusoidal carrier (first-order motion) and a moving low-frequency contrast envelope (second-order motion). We compared responses to moving first-order gratings alone with responses to beat patterns with first-order and second-order motion in the same direction as each other, or in opposite directions to each other in order to distinguish first-order and second-order direction-selective responses. In the majority (72%, 67/93) of cells (V1 73%, 45/62; V2 70%, 16/23; third visual complex 75%, 6/8), responses to first-order motion were significantly influenced by the addition of a second-order signal. The second-order envelope was more influential when moving in the opposite direction to the first-order stimulus, reducing first-order direction sensitivity in V1, V2, and the third visual complex. We interpret these results as showing that first-order motion processing through early visual cortex is not separate from second-order motion processing; suggesting that both motion signals are processed by the same system.

AirFlow: designing immersive breathing training games for COPD

Chronic Obstructive Pulmonary Disease (COPD) refers to a collection of lung diseases that result in breathing difficulties. In some cases, the symptoms of COPD can be reduced, by engaging in breathing exercises. Technology can support, and we are developing AirFlow, a suite of interactive computer games, to guide breathing exercises and promote learning. To establish requirements, we interviewed 20 people with COPD, in China, to understand their use of breathing exercises, and learn how technology might fit their lifestyle. The findings informed our design goals. We outline a prototype system, where respiration rate, waveform, and amplitude are captured and used to control a virtual environment. The system will guide users through breathing exercises, and provide training instructions, using a series of games. The immersive environment aims to support a fun and motivating experience, therefore underpinning user confidence.

How do health service professionals consider human factors when purchasing interactive medical devices? A qualitative interview study.

We present findings of a UK study into how those involved in purchasing interactive medical devices go about evaluating usability, the challenges that arise, and opportunities for improvement. The study focused on procurement of infusion devices because these are used by various professionals across healthcare. A semi-structured interview study was carried out involving a range of stakeholders (20 in total) involved in or impacted by medical device procurement. Data was analysed using thematic analysis, a qualitative method designed to support the identification, analysis and reporting of patterns. In principle, health service purchasing was found to accommodate consideration of equipment usability. In practice, the evaluation process was driven primarily by engineering standards; assessment of local needs did not accommodate substantive assessment of usability; and choice was limited by the availability of equipment on the marketplace. We discuss ways in which purchasing could be improved through techniques that account for social circumstances.

Designing and Optimizing a Healthcare Kiosk for the Community

Investigating new ways to deliver care, such as the use of self-service kiosks to collect and monitor signs of wellness, supports healthcare efficiency and inclusivity. Self-service kiosks offer this potential, but there is a need for solutions to meet acceptable standards, e.g. provision of accurate measurements. This study investigates the design and optimization of a prototype healthcare kiosk to collect vital signs measures. The design problem was decomposed, formalized, focused and used to generate multiple solutions. Systematic implementation and evaluation allowed for the optimization of measurement accuracy, first for individuals and then for a population. The optimized solution was tested independently to check the suitability of the methods, and quality of the solution. The process resulted in a reduction of measurement noise and an optimal fit, in terms of the positioning of measurement devices. This guaranteed the accuracy of the solution and provides a general methodology for similar design problems.