The new technology known as Interscatter Communication, works by converting Bluetooth signals into Wi-Fi transmissions over the air.

UW electrical engineering doctoral student Vikram Iyer said: “Wireless connectivity for implanted devices can transform how we manage chronic diseases.

“For example, a contact lens could monitor a diabetics blood sugar level in tears and send notifications to the phone when the blood sugar level goes down.”

Until now, implanted devices, due to power constraints cannot send data using conventional wireless transmissions. The research team and the University have demonstrated that these power-limited devices can communicate with other devices using standard Wi-Fi communication.

This new system no special equipment and works solely in the presence of other devices with wireless communication capabilities. Instead of generating Wi-Fi signals on their own, these devices convert Bluetooth transmission into Wi-Fi signals for communication.

The system relies on a communication technique known as backscatter, which lets devices exchange information by reflecting existing signals.

UW electrical engineering doctoral student Bryce Kellogg said: “That means that we can use just as much bandwidth as a Wi-Fi network and you can still have other Wi-Fi networks operate without interference.”

However, one of the major challenges faced by the team was that the backscatter technology creates unwanted copies of packets of information. To overcome this problem, the team had to create a blank slate on which new information could be written.

The team developed a way to transform the Bluetooth transmission into a ‘single tone’ signal that can be manipulated further and transformed. With backscattering the single tone signal, the contact lens can send encoded data such as health information into a standard Wi-Fi packet which is read by a smartphone or a tablet.

A paper describing the new technology will be presented at the annual conference of the Association for Computing Machinery’s Special Interest Group on Data Communication (SIGCOMM 2016) in Brazil on August 22.


Image: University of Washington researchers develop low power communication system for implanted devices. Photo: Courtesy of Mark Stone/University of Washington.