However, 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.

A group of University of Arizona researchers has set out to change that with a wearable monitoring device system that can send health data up to 15 miles—much farther than Wi-Fi or Bluetooth systems can—without any significant infrastructure. Their device, they hope, will help make digital health access more equitable.

The researchers introduce novel engineering concepts that make their system possible in the journal Proceedings of the National Academy of Sciences.

Philipp Gutruf, an assistant professor of biomedical engineering and Craig M. Berge Faculty Fellow in the College of Engineering, 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.

Designed for ease, function and future

The COVID-19 pandemic, and the strain it placed on the global health care system, brought attention to the need for accurate, fast and robust remote patient monitoring, Gutruf said. 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 main-line 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 system the Gutruf Lab developed uses a low power wide area network, or LPWAN, that offers 2,400 times the distance of Wi-Fi and 533 times that of Bluetooth. The new system uses LoRa, a patented type of LPWAN technology.