It all started more than a decade ago when sports watches “went wireless” to capture what appeared to be a rather narrow market of elite athletes who wanted to monitor their performance with as little fuss as possible.
Sports watches from Polar, Suunto and Garmin bulked up with a wireless RF chip, heart-rate sensors and some Flash memory to store the data. At the end of the workout, the athlete downloaded the data onto a PC or Mac for review and analysis.
Those basic watch-to-PC beginnings have burgeoned into a remarkably broad range of products from watches to headbands to shoes, clothing and even undergarments in all price ranges and with ever-more-sophisticated features. Use scenarios have also evolved – and diverged – to delivering actionable data in real time at the elite end of the market and to providing motivation support using social media for the mass market.
At the leading edge of wearable sensors is a continuous glucose monitor (CGM) prototype designed by California-based Glucovation, which includes not just hardware but sophisticated software to interpret the data. To collect data, the CGM uses a 5-mm micro-needle that is minimally invasive and can be left in the abdomen or an arm for a week without discomfort.
In professional sporting events such as the Tour de France, CGMs could be used to avoid the rapid decline in glucose levels that can quickly drain strength and leave the athlete feeling lightheaded and dizzy. The sensor is not medical-equipment grade, which means that it is considerably less expensive to manufacture. Perhaps more important, it can be used for glucose monitoring in other non-medical applications such as monitoring pre-diabetes conditions.
In sporting events where real-time data is valued, the communications scenario is challenging. While the ultra-low energy consumption of running a Bluetooth Smart protocol on chips from companies such as Nordic Semiconductor and Texas Instruments is good for short to moderate distances, a longer range technology such as Wi-Fi may be necessary for connecting to a control center.
The wearable system can be a two-chip solution comprising an ultra-low power (ULP) wireless chip and an equally low-power 16-bit microprocessor, or, a System-on-Chip (SoC) that integrates a multiprotocol 2.4-GHz radio and a 32-bit ARM Cortex-M0-based processor together with about 256 kB of Flash memory. The processor has to be powerful enough to supervise the SoC’s operation as well as run the CGM algorithm that transforms raw blood glucose data into actionable information.
Wearable, wireless fitness-monitoring technology is not solely the province of the elite athlete. The range of applications is remarkable and often incorporates the web and social media.
Wristband devices such as Fitbit Surge, Basis Peak and Garmin vivoactive are also being incorporated into fitness programs sponsored by corporations for their employees who typically form teams. The social networking aspect supports the most daunting aspect of any fitness program: motivation. Facebook and other social media sites are used to enable support, interactivity and competition.