Wearable device that can send health data up to 24 km

International researchers have developed a wearable monitoring device that can send health data 2400 times the distance of Wi-Fi without significant network infrastructure.

Wearables currently require significant infrastructure — such as satellites or arrays of antennas that use cell signals — to transmit data, making many of those devices inaccessible to rural and under-resourced communities, according to University of Arizona researchers. They introduced the novel engineering concepts that make their system possible in a paper in the journal Proceedings of the National Academy of Sciences.

The device can send health data up to 15 miles (24 kilometres) — much farther than Wi-Fi or Bluetooth systems can. It is said to charge wirelessly and hopes to make digital health access more equitable.

The COVID-19 pandemic, and the strain it placed on the global healthcare system, brought attention to the need for accurate, fast and robust remote patient monitoring, said Philipp Gutruf, an assistant professor of biomedical engineering and Craig M. Berge Faculty Fellow in the College of Engineering, who directed the study in the Gutruf Lab.

Co-lead authors are Tucker Stuart, a UArizona biomedical engineering doctoral alumnus, and Max Farley, an undergraduate student studying biomedical engineering.

Non-invasive wearable devices currently use the internet to connect clinicians to patient data for aggregation and investigation.

“These internet-based communication protocols are effective and well-developed, but they require cell coverage or internet connectivity and mainline power sources,” said Gutruf, who is also a member of the UArizona BIO5 Institute. “These requirements often leave individuals in remote or resource-constrained environments underserved.”

In contrast, the Gutruf Lab system uses a low power wide area network, or LPWAN, that offers 2400 times the distance of Wi-Fi and 533 times that of Bluetooth. It uses LoRa, a patented type of LPWAN technology.

To make the device almost imperceptible to the wearer, the lab also enables recharge of its batteries over 2 metres of distance. The soft electronics, and the device’s ability to harvest power, are the keys to the performance of this first-of-its-kind monitoring system, Gutruf said.

“Our device allows for continuous operation over weeks due to its wireless power transfer feature for interaction-free recharging — all realised within a small package that even includes onboard computation of health metrics,” Farley said.

Gutruf, Farley and Stuart plan to further improve and extend communication distances with the implementation of LoRa wireless area network gateways that could serve hundreds of square miles and hundreds of device users, using only a small number of connection points.

The wearable device and its communication system have the potential to aid remote monitoring in underserved rural communities, ensure high-fidelity recording in war zones, and monitor health in bustling cities, said Gutruf, whose long-term goal is to make the technology available to the communities with the most need.

“This effort is not just a scientific endeavour,” he said. “It’s a step toward making digital medicine more accessible, irrespective of geographical and resource constraints.”

Image credit: iStock.com/ALLVISIONN