By Caroline Hayes, Senior Editor
Initial momentum in fitness and wellness may be surpassed by growth in the infotainment market. But challenges lie ahead.
Wearable technology can be divided into three groups – fitness and wellness, infotainment, and healthcare and medical (used by professionals, these wearable devices need legislation and approval, making them a separate category). Caroline Hayes looks at the growth, challenges and prospects of wearable technology.
The fitness and wellness market has seen initial momentum, with activity monitors like Nike FuelBand and Fitbit trackers. However, the infotainment market is now one of high interest and growth, with smart watches and GoogleGlass projects. This type of wearable technology can be used for augmented reality and gaming as well as providing a second screen to a smartphone, and making the smartphone even more ubiquitous than it is already. David Maidment, mobile segment marketing manager, ARM believes that the ability to integrate multiple functionality into a single platform is the key to its appeal, adding: “We are used to technology on our wrist,” he reasons, “so the consumer is already familiar with the [smartwatch] idea”.
Challenges
The first innovation was the fitness band, which ‘hit its stride’ in 2012-2013. The nature of the wristband means that the semiconductors used have to be a very small form factor. In addition, the battery has to last a long time on a single charge. The wearable technology in this category is paired with a smartphone and with cloud services. When a wearable device is paired and tethered to a smartphone, the phone acts like a personal hub, providing access to cloud services, for example websites where personal charts and tables are stored for review. The need for low power connectivity, means that Bluetooth Smart is used.
The ability to take disparate sensors, add algorithms that aggregate and make sense of the collected data adds functionality
In addition to ultra low power, low power connectivity, Maidment identifies a third criteria – connectivity of MEMS sensors. Wearable technology is about monitoring the data from the sensor, he says. This means that the device has to be always-on. Using Sensor Fusion, or Sensor Hub, the ARM® Cortex®-M processor in these devices will monitor the data and choose when to push the refined data to the cloud. This is important for wearable technology, as every bit of data sent costs power.
Sensor Fusion
For Maidment, the game-changer is Sensor Fusion, or Sensor Hub technology. The ability to take disparate sensors, add algorithms that aggregate and make sense of the collected data adds functionality but also exploits the low power performance of ARM 32bit architecture, he says. This provides more sophisticated data that is sent to the cloud following monitoring and analysis from various sources. “Sensor Fusion, smart aggregation and always-on power are at the heart of wearable technology”, he says, whether it is via the Nike Fuelband to log in to the cloud to review the day’s exercise data, or whether, in the future, it will be to log in to check blood glucose data following a blow-out and eating that forbidden burger.
Software
Sensor Fusion underpins everything, according to Maidment, as an always-on core is always needed. Another essential factor is contextual awareness. With gesture control, the flick of a wrist can accept a call or display a message. Sensor Fusion allows the watch to be always monitoring and waiting for the wearer to do something to which it can react.
Sensor Fusion is also the basis for Siri-style voice recognition. A microphone is a sensor after all, and so the microprocessor has to be left permanently on to detect voice commands and background noise for contextural awareness.
ARM and its partners are working together to develop this Sensor Hub (or Sensor Fusion). In the near future, he says the level of interpretation will allow the smartwatch to sense when the wearer is holding a steering wheel and driving a car, by the angle of the wrist and the background (i.e. engine) noise. This is why, he says the 32bit architecture is used over 8- and 16bit ones, says Maidment, referring to its power performance.
Analog Device’s Tony Zarola, strategic marketing manager, healthcare, agrees that power consumption is a significant hurdle in wearable technology design. “The main challenge is to meet the power consumption target that makes the end device useable for more than a few minutes, whilst maintaining the level of performance to make the device useful from a measurement perspective.” He quotes the example of a device that measures heart rate unreliably in order to conserve energy is of no use and, equally, unstable in a practical sense, he says is the example of a heart rate monitor that only operate continuously for an hour or so.
Time for smartwatches
The smartwatch market is still in the early stages, with the Pebble smartwatch using STMicroelectronics’ STM32 F2 microcontroller, with an ARM Cortex-M3 core. It also has the STMicroelectronics LIS3DH MEMS digital-output motion sensor (see Figure). The total wearable technology market will be $20billion by 2017, according to Future Source, as designs integrate the Internet of Things and connectivity of smart devices. Data on specific wearable devices is not available, but Maidment estimates that there were around 200,000 smart watches sold in 2013. ARM has over 60 design in progress or in the market today. This figure is expected to “explode” this year, through ARM partners.
Figure: Pebble smartwatch uses STMicro and ARM cores complemented with MEMS sensors.
Innovation is king, in the early stages of a technology, he says. Adapting and evolving the same sensors used in fitness bands, and the same low power, black and white displays for smartwatches.
Everyone agrees low power operation is vital. Wearable devices are expected to last a week on a single charge, while acting as both an activity monitor and a second screen for a smartphone, as alerts and SMS messages are pushed to the watch. All of this has to be in a small, unobtrusive form factor and the software has to be equally unobtrusive, hence the small, micro-kernel ARM Cortex-M3, says Maidment.
Some smartwatches connect to the cellular network, making them more of a mini smartphone (for example, the Omate TrueSmart, which runs on Android and is billed as a standalone smartwatch, working independently from a smartphone). Samsung has also recently introduced the Galaxy Gear, Android-based smart watch. Connecting directly to the cellular network untethers the watch from the smartphone, says Maidment, and allows data to be pushed directly to the cloud and cloud services.
The smartwatch as a smartphone on a wrist has its own limitations. A color display and/or touchscreen, for example, means that battery life is only one to two days. The ultimate goal, says Maidment, is to optimise the power; running always-on Sensor Fusion and increasing the complexity of software in a low power, footprint.
There are opportunities to bring the two modes of smart watch together, he says, with ARM-like power efficiencies, clever system level design, power gating and clock management.
For Zarola, as well as connectivity and power, it is the format of wearable technology that needs to be addressed. It demands a small footprint. This, he believes, can, to some extent, be addressed through novel packaging techniques.
All of the enabling technology for always-on, connected, wearable technologies, across all three groups is available now. Many believe that this year is the top of the curve for wearable technology and that innovation will continue to a thrive, as consumers demand more connectivity, more analysis and monitoring of data, more access to the cloud in a small, discreet form factor.