Wearable medical technology is caught up in a perfect storm of surging advances, changing healthcare delivery paradigms and evolving consumer demands. The sensor, or multiple sensors, behind every product intertwine the future of medicine with innovation.
Sensor sophistication and power are steadily improving, which bodes well for medical applications. Device developers face the exciting challenge of harnessing the power of such equipment to help healthcare providers meet the needs of consumers accustomed to anywhere/anytime access to information and services. Whether they are healthy, ill or in recovery, demand for personalised, convenient and cost-effective healthcare will only increase.

While wearables are on the rise in multiple industries, healthcare is a particularly promising market. A forecast by market research firm IDTechEx projects the ‘healthcare, medical, fitness, wellness’ sector will account for more than $21 billion of a marketplace worth $70 billion overall by 2025.

"This increasingly merging sector has the greatest potential of all of the application sectors we looked at," said IDTechEx technology analyst James Hayward.

Common sense

Sensors are used in healthcare to measure everything from ambient air temperature to heart rates. Placing them on specific parts of the body enables them to detect physiologic variables. The sensor system processes the raw signals, typically relying on algorithms to synthesise and translate data into meaningful metrics. For example, when motion is detected, a related algorithm can interpret the readings into caloric expenditure.

In its report, ‘Sensor Trends 2014: Trends in Future-Oriented Sensor Technologies’, the AMA Association for Sensors and Measurement defined sensors as follows: "The term ‘sensor’ is variously interpreted. In this study, it is used as a superordinate term describing any component that generates a usable electrical signal from a measured physical parameter. In its simplest form, a sensor consists merely of a naked sensor element. For instance: an unhoused pressure sensor element made of silicon, mounted on a substrate, no more than a few millimetres exterior dimension."

"Device developers face the exciting challenge of harnessing the power of sensors to help healthcare providers meet the needs of consumers accustomed to anywhere/anytime access to information and services." 

Sensors have been used in the healthcare industry for many years. They are found in pulse oximeters, electrocardiogram leads, thermometers, blood pressure monitors, and other devices and instruments.

Traditionally, many of these devices have relied on wires, tubes and hoses to connect them to power sources, data processors and computer networks. Today, many of them operate wirelessly.

Modern sensors must meet demanding criteria. In its aforementioned report, the AMA Association for Sensors and Measurement listed the following eight basic user requirements and wishes for sensors:

  • minimal measuring uncertainty
  • constant availability of physical
  • and chemical data from all systems and processes
  • measurements are to be performed with minimal impact on the processes involved
  • real-time measuring
  • the ability to function without maintenance, calibration, or adjustment, and with minimal interference/care
  • low costs (including sensor systems)
  • integrated on-board diagnostics.

The three most important requirements in medicine are installed size, energy consumption and minimal impact on measurement parameters, the report said.

In a very important trend for wearable wellness and medical devices in general, sensors are getting smaller, more energy-efficient and increasingly powerful. The AMA Association’s report estimates the typical medical technology/life sciences sensor consumes less than 0.01W and occupies less than 5cm3, with measurement uncertainty between 1% and 5%. In the future, these sensors are expected to have a surface area of less than 0.5cm2.

Track to the future

The wearables boom is creating fertile ground for the future of medical products. At the 2015 International Consumer Electronics Show – which can be taken as a barometer of technology trends – a huge area was devoted to digital health exhibitors. It’s clear that body-worn wellness and fitness trackers have reached the mainstream. Whether people are working at the office, exercising at the gym, running laps or running errands, it’s not unusual to see them wearing Fitbits and Jawbones, and Apple Watches will soon surely be ubiquitous. Wal-Mart even has dedicated displays for wellness trackers.

Consumer electronics firms, medical device makers and other players are approaching wearables in different ways. A product’s perceived value often depends on consumer expectations. Some wearables, such as fitness sensors built into watches and bracelets, are designed to be worn daily. Like other mobile devices, they typically require recharging, and their measurement accuracy can vary.

As The Wall Street Journal reported in January, "Researchers at Iowa State University recently tested the accuracy of eight activity trackers in measuring energy expenditures and found that most were off by 10-15% compared with a precise laboratory measurement." Still, their accuracy might suit those who simply want to set goals for healthier lifestyles.

Other body-worn sensors are designed for short-term use to capture a precise snapshot of an individual’s wellness. For example, the sensing device of the Metria IH1 Lifestyle Assessment System is worn directly on the skin, around the clock, for up to one week.

The product is disposable, and requires no recharging. The system, developed by Vancive Medical Technologies, measures calories burned, and the level and duration of physical activity and sleep metrics. Collected data is analysed by a variety of algorithms, and the results are presented in several UI configurations. The combination of multiple sensors, and the fact it adheres directly to the skin, enables high compliance and accuracy.

"Improvements are happening every day: there are better sensors, better networks, better ways of communicating data, stronger data protection and more intuitive user interfaces for patients and providers." 

Accuracy is a greater focus for the emerging second generation of wearable technology. In its report, ‘Beyond Wristbands: a Vision of Next-Generation Wellness Technology’, LEK Consulting said, "Unlike the first-version consumer devices, these next-generation MedTech devices will probably attract greater FDA scrutiny and will need to be able to demonstrate their reliability."

We care a lot

Medical wearables development is tied to the move toward shared accountability for individual healthcare – before, during and after illness. Wearables will probably be marketed to cater to each of these three health states. As the healthcare industry evolves, there will be a greater exchange of information between patients, their families, healthcare providers and others along the care continuum, including device developers, insurance companies, pharmacies and social networks. All will rely more on data from body-worn sensors, a physical connection to the patient that can transcend traditional boundaries to continuous care.

While sensor advances and the applications of wearables are sprinting ahead, it will take time for developments to become entrenched in the healthcare industry. One of the biggest challenges to widespread adoption is the need for stringent, proven privacy and security protocols. Protection of information is critical when vast amounts of individual health data are collected from sensor systems, communicated across digital networks and shared among providers, patients and other stakeholders.

Just as importantly, medical wearable devices must provide results just as reliable if not more so than traditional devices and methods – at a cost on par, or less than, the current care protocol.

Improvements are happening every day in all of these areas. There are better sensors, better networks, better ways of communicating data, stronger data protection, and more intuitive user interfaces for patients and providers. With increasingly powerful sensors in their corner, medical device developers are poised for an amazing era of innovation in wearables.

Market outlook: sensor technology

Sensors and measuring devices have become all but indispensible in practically every branch of industry and many aspects of modern life. They enable products to be manufactured with unique features, without significantly increasing production costs. Europe is the world leader in this high-tech area, not only with regard to technological standards, but also in terms of global market share. As for turnover, a comparison between commercial studies regarding the demand and the results of the polls carried out by the AMA Association regarding the supplier market, shows that European suppliers cover about 35% of the worldwide demand on sensor products. The number of manufacturers of industrial sensors and measuring systems in Europe alone is estimated to comprise almost 1,000 enterprises. Overall, approximately 3,000 companies, from makers to retailers, from engineering consultants to specialised service providers, are active in European sensor technology.

The market for sensor technology is very hard to segment, even for those involved. There is, however, a noticeable shift from the market for capital goods to that of consumer goods, with an increasing importance on end products. New applications with considerable growth rates are found in household appliances, safety and security technology, medical equipment for diagnosis and therapy, and automotive engineering.