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The future of wearable medical devices

Published: 30 June 2016 - Sarah Mead

The technological convergence of portable consumer electronics such as smartphones, smart watches and fitness devices with that of professional medical equipment such as pulse oximetry, ECG and Glucose meters as well as ultrasound scanners and kidney diagnostics, is increasingly blurring the lines between equipment designed for practitioners and devices used by consumers. Here, Neil Oliver, technical marketing manager at Accutronics Ltd, explores the trend and looks at the potential consequences.

Your average smartphone now has more processing power than the supercomputers used by NASA circa 1969 when it sent three astronauts to the moon. It's no surprise then, that there has been a growing surge in recent years of start-ups specifically developing peripheral devices to monitor intimate details of one's physical condition.

This trend was highlighted at last year's consumer electronics show (CES), the world's biggest technology exhibition. Held annually in Las Vegas, Nevada, CES was a perfect opportunity for many original equipment manufacturers (OEMs) to exhibit their latest and greatest inventions; from smartwatches that can track your heart rate and sleep quality to armchairs that exercise you in the comfort of your home. There was even a hearing aid developed by Siemens to allow the user to zoom into sounds.

The rise of wearable devices was attributed to a much larger societal disposition towards the Internet of Things (IoT). Although the IoT, as a concept, has been around for many years, it's only recently started to pick up traction. A maturing ecosystem of mobile operating systems (OSs) such as Android and iOS as well as an improving cloud computing infrastructure and the widespread availability of cheap wireless sensors means that OEMs in the consumer electronics sector have glimpsed the profitability of the medical technology (MedTech) sector and they want a piece of the pie.

The ability to create cheap devices that don't require heavy on-board processing, rather outsourcing this to a server in the sky, means that nearly every household object in sight can now be equipped with a sensor and a screen giving up-to-date information on any number of ailments or long term conditions. Diabetics can use a peripheral plug-in gadgets to monitor blood glucose, chronic kidney patients can save time-consuming visits to the doctor by testing at home and patients with a gruelling pill-regime can track their exact intake with a handy smartphone app.

The benefits of wearable and portable medical devices are clear. Wearables make patient data readily accessible and they may reduce the frequency of visits to a doctor and in doing so alleviate the burden on our healthcare system. As well as this, it's becoming cheaper to produce wearable medical devices that fulfil the function traditionally limited to large and expensive medical devices in hospitals.

So surely that's that? Wearable medical devices will revolutionise our lives and we can thank Intel's Gordon Moore for bearing witness to the trend for smaller and smaller electronics? Not quite. You see, many experts in the industry are already raising eyebrows at what they believe to be a bad precedent, an incompatibility between two industries that operate in fundamentally very different ways.

Circle of life

The problem is one of business strategy. The last decade has witnessed unprecedented globalisation, with cross-border trading blocs resulting in international supply chains with highly responsive logistical networks. This has increased competition in the global marketplace and created a price based race to the bottom. As a result, consumer product development life cycles (PDLCs) have shrunk drastically. A typical consumer product life cycle is 12 months. It can stretch to 24 months and be as short as six.

This can be attributed to increased disposable income in emerging economies, more global competition, access to cheap labour and an incessant consumer demand for the next best thing. In contrast to this, medical device PDLCs are much longer, typically 10 years. Due to the lower volume production, higher research and development (R&D) costs, more lucrative healthcare contracts and a desire to yield a higher return on investment (ROI), medical devices are designed to last much longer.

It's no surprise then, that many in the medical industry are sceptical of the long term reliability, safety and quality of wearable medical devices. Add to this, the fact that we're living longer on average, it's vital that the solution is sustainable. Here at Accutronics we've got 40 years of experience in designing, developing and manufacturing batteries and we've seen devices become smaller over the years. As a result so have the batteries that power them.

As batteries get smaller to accommodate the trend for smaller and lighter devices, we begin to see some trade-offs. The Lithium-ion (Li-ion) cells that make up the majority these batteries have a limited gravimetric and volumetric energy density and subsequently, wearable devices inevitably suffer from inadequate runtime. If your smart phone runs out of juice then it is inconvenient, but if the same device is monitoring your health then it is far more concerning.

This reduction in battery quality is a real concern. The lifespan of a rechargeable consumer Li-ion battery averages around 300-500 charge cycles before its capacity drops to an unacceptable level. Because medical devices outlive their batteries they tend to use removable rather than embedded batteries.

To combat this problem for wearables, Accutronics has already developed a credit-card sized battery for use in wearable medical devices. Today, these batteries are being used to power devices that are worn by patients, monitoring their health or providing medication when the patient requires it. Being removable means the battery can be swapped for another when charging is required and the device does not need to be returned to the manufacturer for a battery replacement when the original set of batteries reach end of life.

Although battery quality is a major problem for consumer medical devices, there are deeper concerns when it comes to the manufacture, testing and regulation of the industry as a whole. Because this industry has seen rapid growth over the last three years, many far east manufacturers have taken shortcuts by producing gray market knock-offs, and sometimes outright illegal batteries, that lack the necessary protection circuits that are needed to prevent Li-ion batteries from overcharging, overheating or becoming unstable and potentially catching fire.

Many OEMs have already taken action to protect their intellectual property rights (IPR) against fake, or copycat, batteries by introducing security features such as invisible inks and holograms. Here at Accutronics we've incorporated an advanced software-security algorithm (SHA-1) into our batteries that ensures only authorised batteries are used in medical devices. The host device rejects fake batteries when detected and takes appropriate action, as defined by the vendor, such as failing to power up or notifying the user.

Taking such measures however, is only a reactive response. Although the medical industry is one of the most regulated industries in the world, it has struggled to keep pace with the advent of wearable medical devices. One of the biggest reasons for this is that the very definition of a medical device is becoming blurred.

If your smartphone accompanied by a wearable device is able to measure, diagnose and recommend treatment on any given health condition, then should that be regulated as a piece of IT equipment, under the IEC 60950-1 standard or should it be regulated as a fully blown medical device under the IEC60601-1 standard? These medical standards form the requirement for the commercialisation of an electrical medical equipment in many countries.

It was this ongoing ambiguity that led Apple to consult with the US Food and Drug Administration (FDA) on the use of sensors in its devices, which may ultimately lead to regulatory review by the FDA. Although information-only apps are exempt, any apps taking measurements, for example a glucometer that takes readings, would be considered diagnostic in nature. This conversation led Apple to release Healthkit, its software development kit (SDK) for developers.

Likewise, in Europe, the European parliament has set out directives on the classification of medical and in-vitro medical devices to include a broader range of products including non-corrective contact lenses, aesthetic implants and software used in devices. The regulations will also be more selective in awarding CE markings to high risk devices, which must undergo further clinical trials to assess risk.

In the UK, the Medicines and Healthcare products Regulatory Agency (MHRA) has published guidelines making it clear that, "the manufacturer of a device is responsible for establishing that the device is safe and that it is suitable for its intended purpose. To establish this, manufacturers must implement appropriate controls on the device design and manufacture, and evaluate the safety and performance of the device in its intended application".

It is clear that the world of wearable devices is not all that it seems at first glance. On a deeper exploration it is evident that there are numerous economic, cultural and regulatory changes needed before a sustainable and safe integration of wearable medical devices into our everyday lives. With the right power management, design and production controls and when used under the guidance and on the recommendation of a healthcare professional, wearable devices can become a viable asset in improving the health of our increasingly ageing population.



 
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