Designing Usable Medical Devices for Home Use

I live at home with my family, a number of pets and luckily for myself and my family, very few medical devices. But as I age, I expect to be bringing home from hospitals and pharmacies more home-use medical devices – especially if hospital care is shifting towards home-based treatments and rehabilitation. This I do not fear, but what I do think about is the point in time when I, or my family members are completely managed by medical devices – such that our freedom in life is constrained by them. The rise of artificially-intelligent software and person-to-person communication will mean soon that medical devices will start to control our intake of medicines, treatments and schedules for therapies. The future is very digital and safe, but there are human factors that can unhinge the use of medical devices in the home – and they include interacting with the biggest risk of all – us, as human beings.As we age, become ill, have injuries and diminish, and we expect to become more and more dependent on medicines and medical devices. Nowadays, people don’t just die – they die of something. We are labelled in death and increasingly, labelled in life – with a disease, a condition, an injury or deficiency. Once labelled, we are prescribed medicines and medical devices to manage the medicines, assist in recovery, or use to manage ourselves or our families – and more so in the home environment. Where in past times, if you were not well, you were managed in hospitals, clinics and care facilities, in current climates, this is financially unsustainable and so healthcare is transferred to the home environment – and some studies prove this assists with healing (a good thing!)With this trend of home healthcare, does this mean that we are turning our homes into mini-hospitals? Quite possibly! The bedroom is not a place just to sleep, it will become a place to recover, heal, relax (especially for the bed-bound) and as such, it becomes a “mini-hospital” – a storage facility, a healing facility, with the personal touch of the bedroom user. A hospital or clinic is unable to be personalised easily due to infection control procedures and sustainability. A bedroom can be completely variable and personalised for its user(s). This can create issues to overcome in the development of home-use medical devices since the product has to fit into the home environment. If it does not fit in, there is a chance the patient has less compliance for safe and clinically effective use of the device. This is not what we want – we all want to be healthy.Is this part of medical device development we understand? I would hope so. We all live in apartments, flats, houses (some castles!) and care-homes, with a family, on our own, with friends and with pets. Some of us have children, dependents, carers, and other people who help us live our lives, and all who could potentially interact with a medical device intended for one of the household. Yet, are these people considered during medical device development? I fear, that all too often they are not. It is not often we see the home environment characterised, understood and documented in medical device developments.A human factors and usability engineering process is obviously very focused on users and interactors of the medical device. In a clinical setting, this is very controlled – by experience, speciality, pay grade, qualification and training. In the home setting, what controls exist? Well, there are controls, but they are more variable in outcome. Generally training is given to the users, caregivers and their appropriate interactors (non-users such as a spouse, parent, child, friend, carer) but again, this is minimal and does not always take into consideration the learning capabilities of the home users and interactors. Luckily many medical device companies and pharmaceutical organisations have help facilities – call centres for telephone assistance, on-line resources for information and speciality clinicians to assist with the management of the device. The medical device itself, or the system it may be part of, is a control, and understanding how much control it generates is critical when developing it. All controls can lead to safe use of a medical device, and with control, you can reduce the variability and risk of mis-use.Human beings are really, the largest risk with using medical devices in the home environment. As a human being, I have behaviours that are not ideal – all of us do. We are often lazy, controlling, suspicious, cautious, arrogant and emotional. When we are unwell, these behaviours can be escalated, either due to our condition, disease, injury or aging, and the way we think can change significantly if we are disturbed from our normal routines by being unwell. A good example is when we are in pain, this can really escalate how we perceive, comprehend and use normal products, let alone medical devices. The state of the user is an important human factor that should be understood when characterising the typical user.When we look at the level of detail recorded in the design history of a medical device, or in the usability or human factors engineering file, the home-use environment, the users and interactors are not often characterised in detail and translated into the device development. Surely to develop a product, something that cares for you, manages you, assists in your healing, manages your intake of medicines should be designed and developed to fit into your life, family, and your home? This is part of human factors – understanding the intended use environment and how it has to be set up for safe use of the medical device, and whether the medical device prevents as far as possible mis-use or abnormal use. It’s all too easy to label a medical device “not for use by children”, but is labelling enough – can the risk be designed out? Only if you have thought about it in the first place.An example of where human factors are not optimised in medical device design at present is the very common, blue-coloured inhaler (which contains Ventolin). Everyone who uses one knows it is a medical device and that we are trusted to use is safely and compliantly when needed. But do we always? Imagine that I am prescribed one of these inhalers for control of asthma as a rescue medication. Where would I carry it? Probably in the pocket of my jeans. Where would I store it? Likely to be somewhere in my home where I know my pets can’t get to it like on a mantelpiece or sideboard. I would likely lose the cap as it is a rescue medicine and in a moment of panic I may not be worrying about the cap, until I wish to store the inhaler again in my jeans or on the sideboard. When would I dispose of it? Possibly never! An expiry is printed on the labelling, but would I actively seek a replacement for it prior to the expiry – not unless it was empty. I would surmise that many people actually use expired medicines without knowing it. I would of course check that I was using it correctly, but I would rely on the training I had with the respiratory nurse, and not the instructions for use that came with it. That will probably be in the bin along with the box it was supplied in. Why would I keep an empty box for the months/years the inhaler is valid for?Just by asking a few questions, even with my own potential personal situation, a number of issues have arisen around using a medical device in a home environment, to fit into my life. Trend this with a reasonable sample size of possible users and you have data that is very valuable, and could have a significant effect on the design and development of the medical device. Taking it a step further and ethnographically researching people living with medical devices currently will likely show some very basic reasons why they become non-compliant, unsafe, or continue to not heal or have quality of life. People are by nature variable, but also we are often predictable. Human factors research can at least guide the development of a medical device down a route based upon a level of prediction, based upon current real life.A home-use medical device should fit into the home of the user, and also ideally fit into the life of the user. Not forgetting the interactors where the medical device may have influence from. It should promote safe use and prevent mis-use. When predicting the mis-use that could potentially occur in the home, it is prudent to follow a risk-based approach since many types of risk assessment focus on hazards – which in the home, there may be many. And ideally you want to be finding them out before the medical device is launched, since if an unforeseen hazard is realised, and it causes harm, then that could be a customer complaint or an adverse incident – neither of which you want. Thus, understanding the human factors around the use of a home-based medical device is important if you wish to prevent post market events from occurring – all of which can damage the reputation of a brand, the manufacturer or distributor, but more importantly, make the design of the medical device fail its intended use. After all, medical devices are here to help us!