Nov 12, 2019
The increased use of connected injection devices, or CIDs, yields potential benefits in terms of improved patient care, but human factors engineering (HFE) approaches require adaptation in order to address these devices.
Connected injection devices (CIDs) typically involve an injection device such as an autoinjector with embedded connectivity to an application hosted on a smartphone, with connection to a cloud-based data storage facility. The resulting system might also provide users with web-based added functionality, such as lifestyle advice and the ability to add sensors from additional devices (e.g., pulse oximeters or spirometers).
Connected injection devices include a variety of features, including:
The claimed benefits to patients of CIDs include improved adherence by the use of reminders, improved injection technique, more rapid “onboarding” of new patients and crucially improved health.
Connected injection devices currently on the market or under development include:
The software-based user interfaces embedded in CIDs confer a requirement on manufacturers to consider usability, and in particular on demonstrating safe use. This is not different in principle to “traditional” injection devices. However, there are a number of challenges when applying human factors engineering approaches to connected injection devices.
Comprehensive human factors engineering calls for testing the whole of the user interface, focusing in particular on those elements that support safe use. The user may interact with one or more elements of the UI whilst using it for its intended purpose.
Connected injection devices extend the user interface to include the app and possibly the interface for cloud-based platforms too. All must be shown to support safe use and to guide users away from potentially harmful use errors.
But for connected devices, developers face a number of questions:
Top tip: Avoid positioning the app as ‘essential for safe use’, unless you are prepared to validate its effectiveness in avoiding harmful use error.
Digital products can be designed extremely rapidly, and development methods such as AGILE are used extensively to shorten iteration cycles and enable a “build fast” methodology. Development cycles are rapid, and excessive documentation could impede progress.
Top tip: Start early to record your Agile activities. Identify the minimum critical design history data that you will need, including the HF data. Embed HF principles in your agile process. Build a body of evidence using a robust method that captures all key design decisions made, and link them to risk.
Combination products achieve their intended therapeutic purpose by facilitating accurate, safe and effective delivery of a drug to its target site. Therefore, users need to be able to use it as intended. So, the usability outcomes of combination products support the clinical outcomes.
Good human factors shape the UI design such that it enhances usability of a product. So for example, we must test that patients can effectively administer a full dose of medication from an autoinjector, because of course that is critical to the effectiveness of the drug.
Combination products require clinical data, generated in clinical studies (at least for the originator brand). So, the version of the user interface (UI) that enters clinical studies must be essentially similar to the UI that is proposed for market launch, and the one that is used in usability trials. If changes are small, a threshold analysis may suffice. If the UI is changed substantially it may be necessary to revalidate it in a HF validation study.
Top tip: Retain a close alignment between the clinical outcomes of your CID and the usability outcomes you validate.
Regulators expect to see evidence that CIDs can be used safely and that critical use errors can be avoided. HF engineering standards such as IEC62366-1:2015 were written for physical devices such as infusion pumps, with long development cycles. This enables a process to be put in place that captures the key design decisions made, the results of testing and brings it together into a “design history” file.
Whilst the principles inherent in the guidance remain, methods will need to be adapted to enable manufacturers to harness new build quick methods whilst providing documentary evidence of safe use.
Regulators will need to adopt a more flexible approach to validating CIDs for safe use, to avoid stifling innovation whilst satisfying themselves that he CID can be used safely. For example FDA have launched a digital health pre-certification program, with the stated aim to:
“help inform the development of a future regulatory model that will provide more streamlined and efficient regulatory oversight of software-based medical devices…”
The focus is on rigorous quality management processes becoming embedded in software development procedures. Such an approach may help manufacturers of CIDs to give confidence to regulators that safe use can be established.
Top tip: Speak to regulators early, and focus on rigorous quality management of software development methods.
Connected injection devices will become more prevalent, driven principally by the move to greater patient engagement in their own treatments to achieve better care, and hence to increasing self-use of devices in a safe and effective manner. Human factors will remain at the heart of ensuring and demonstrating safe use of medical technology. However, the approaches used will need to adapt to a technology that is fast-moving, fluid and multi-faceted. And regulators will need to adapt too, to strike a balance between driving up patient safety whilst not stifling innovation.
Richard Featherstone is Research Director at Emergo by UL’s Human Factors Research & Design division.