Wearable sensors to revolutionise the medical industry?

4 min read

The idea of wearable sensors is really nothing new. Pendants worn around the neck and on wrists have been used for decades.

However, sensing devices have predominantly been used by people considered 'high risk', such as the elderly or those recovering from operations. Wearable sensors allow healthcare providers to monitor patients remotely, meaning many more people are able to stay independent at home. Studies have shown that patient comfort is generally better within their own home, something that has also been shown to aid recovery. In addition, it helps to reduce the burgeoning costs of healthcare by allowing people that don't necessarily need to be in a hospital to stay elsewhere and free up beds for those that need immediate care. "If people could wear something 24/7 the data could be captured and events such as heart attacks predicted before they happen," says Steve LaJeunesse, strategic marketing manager for the medical equipment segment within Maxim Integrated. "This is all about preventative medicine and wellness." Maxim has recently been involved in a project that looked at the development of wearable sensors for health monitoring application. The result was the FIT telemonitoring T-shirt, which integrates a three lead ECG, body temperature and motion sensors, as well as processing technology into a comfortable shirt. The main issues related to mechanical and industrial design, says LaJeunesse. "We had to work out how to get sensors into the shirt and then to get good contact with the body," he says. The solution to that problem came from Orbital Research, which has developed FDA-approved sensors that improve signal pick up by a factor of four. According to Orbital, ECG electrodes tend to rely on an electrolytic gel to conduct bioelectrical signals from the skin to the electrode, which means you only get good signals when there is a high hydration level at the electrode. It developed electrodes which feature surface microstructures that function as the sensing element, removing the need for the electrolytic gel and aggressive skin preparation. These are embedded in the upper layers of the skin, allowing ion transduction. Signal quality, it claims, is maintained irrespective of the type or duration of activity while the electrodes are being worn. "The shirt has to be comfortable to wear," says LaJeunesse. "The mechanical design of the sensors needs to give good skin contact. "We needed to penetrate beneath [the top layers of the skin known as the stratum corneum which comprises dead cells], where there is a lot of electrical activity. The little bumps on the electrodes do a good job in getting better signal pick-up." Many key players in the medical device market are now looking at methods and technologies that will allow sensors to be worn by individuals. Increasing advances in technologies such as smartphones are likely to be leveraged to improve both diagnosis and treatments. This, in conjunction with the increasing influence of the consumer market, is also driving significant change. "Many people now use gym-based sensing devices such as blood pressure and heart rate monitors," says Bill Sermon, a partner at Viadynamics, an innovation consultancy specialising in product and service development. "The fitness side of wearable sensors that work with smartphones are getting increasingly popular. These could start to be used to provide healthcare." Examples of existing 'well-being' monitoring products include the Jawbone Up System and Nike Fuelburn. These are almost permanently worn by users to continually monitor activity. The Jawbone Up comprises a wristband that cleverly houses accelerometers to track movement. It sends data such as how many steps are taken in a day and records sleep patterns to a smartphone. It also allows users to enter diet information and, using some clever algorithms, gives 'insights' in to lifestyle choices. This is being taken even further by the recent launch of a product and company known simply as Basis. This wristwatch-style device uses an array of sensors including three-axis accelerometers, an optical scanner to track blood flow and heart rate, as well as a moisture sensor to measure skin perspiration, and finally temperature sensors to measure both skin and ambient temperature. "People are starting to see that the future is moving to a point where sensors that are mostly used for well-being and fitness could be deployed for other uses," says Sermon. "We could see open platforms where various people can tap in to the same data for different purposes. You could even potentially have a sensor with you from youth through to the end of your life, which you use and leverage for different things at different times." It does paint a powerful picture in terms of health monitoring, and predictive diagnosis. Doctors could be able to download all sorts of historic data, and not just test and treat you on the day. This could help spot harder-to-find health issues and more thoroughly monitor treatment and recovery. GPs could run a diagnosis before you arrive at a surgery or get the sensors in your watch – for example – to log some other parameters. The issue of 'big data' is one that is not unique to wearable sensors. Modern life has led to all of us accumulating reams of data. How it is used, collected, shared and controlled continues to be fiercely debated. And, given the very personal nature of health, this is likely to be a contentious issue for most. "The challenge is really about making an object that people feel is subtle enough that it is not intrusive, but still manages the functions they need," says Sermon. "In many cases, particularly the way in which people are using a mobile phone and using the web, it is moving the controls off the sensing device itself." Many established wearable sensors used for healthcare can be clunky, sterile and overly complicated, with various buttons and functions intended for professional use. However, newer medical devices tend to be much more portable, practical and aesthetically pleasing. "A device that is worn becomes much more a part of the user and they are going to demand much higher standards in terms of aesthetics and ergonomics," says Patrick Hall, development director at Maddison – a product design consultancy specialising in medical and scientific products. "The idea of embedding a sensor in something like a watch and accessing it on something like a smartphone is a very attractive model. However, there may be an issue around different user groups. For example, the elderly are probably not going to be as comfortable using a smartphone, but certainly there are user groups where it could be interesting." This ability to use software to get a sensor to do different things means devices can be changed depending on circumstance. A wearable wrist band that has accelerometers can, for example, be used to record a gym workout but also could be set up to be a fall detector. Design is about creating products and service, but also about accommodating new behaviours. The idea of wearable sensors that provide a bridge between heath, fitness as well as medical care is an emerging behaviour that is increasingly coming under the spotlight for medical device and sensor designers.