The ever increasing capabilities of wrist-worn devices – for uses ranging from recording activity and health status to interacting with software applications – brings many challenges and opportunities, but a systematic survey of research in the field was lacking, until now. Drawing on the findings of 54 distinct studies, Rasha M. Al-Eidan and colleagues at King Saud University in Riyadh, Saudi Arabia review the current state of this fast-developing technology in their review, “A Review of Wrist-Worn Wearable: Sensors, Models, and Challenges”, published in Journal of Sensors.
Sensors and signals
Strapping a small computer to the wrist is already an everyday routine for the growing numbers of people who use fitness trackers to record their activity levels and vital signs – including heart rate and blood pressure. Other devices are being used to help care for the elderly, for example by detecting when a person has fallen and then automatically summoning assistance.
More specialist devices monitor highly specific aspects of health, such as detecting blood oxygen levels by firing light pulses through the skin. This means the growing range of medical information that can be gathered now through wearable technology includes sophisticated details of blood, muscle and nerve activity.
Outside of the medical and health fields, researchers are also developing systems that can recognise hand gestures and use them to control software within a wrist-worn device. While others are working on developments to allow groups of users to interact via tiny computers on their wrists to collaborate on documents and presentations.
Al-Eidan and her co-authors describe the range of miniature sensors that can detect many aspects of user activity, and review the research that is broadening these sensors’ capabilities. In addition to biometric data, appropriate sensors can also pick up details of the environment around them, including temperature, atmospheric pressure and light levels.
Challenges for research
As more and more possibilities emerge for wrist-worn sensing and communication, there are nevertheless significant challenges in making the technology sufficiently robust for commercialisation. These include the need to reduce the weight of the devices, the drive to extend battery life, and the current lack of standard systems and networking capabilities across different devices.
Long-term use also raises significant issues of reliability, accuracy and consistency. Consumers will need to be persuaded that the biometric data gathered is accurate before they place their trust in it.
The authors also identify these as concerns that could limit user-acceptance of new wrist-worn technologies. “For example, will people want to have sophisticated devices strapped to their wrist that can send sensitive information about activity and health into the potentially insecure realm of wireless communications?” Al-Eidan asks.
Beyond the wrist
Advances in the field of wearable tech don’t just stop at the wrist, as the authors show. Smart glasses, for example, have already reached the market. More futuristic possibilities currently being researched include sensing and signalling systems incorporated into clothing or in small items of jewellery such as bracelets and earrings. “Wearable technology can be expected to increasingly enter and influence daily life,” Al-Eidan concludes.
Rasha M. Al-Eidan, Hend Al-Khalifa, and Abdul Malik Al-Salman, “A Review of Wrist-Worn Wearable: Sensors, Models, and Challenges,” Journal of Sensors, vol. 2018, Article ID 5853917, 20 pages, 2018. https://doi.org/10.1155/2018/5853917
This blog post is distributed under the Creative Commons Attribution License (CC-BY). The illustration is by Hindawi and is also CC-BY.