'Interscatter communication' helps implanted devices communicate via Wi-Fi

Using what’s called “interscatter communication,” small devices such as brain implants, contact lenses, credit cards and wearables can talk to other devices like smartphones and watches. University of Washington researchers have developed a way for these small devices to communicate using Bluetooth signals that convert into Wi-Fi transmissions.

This ability to communicate with implant could have a potential impact on disease management.

“Wireless connectivity for implanted devices can transform how we manage chronic diseases,” said co-author Vikram Iyer, a UW electrical engineering doctoral student, in a report on the tech. “For example, a contact lens could monitor a diabetic’s blood sugar level in tears and send notifications to the phone when the blood sugar level goes down.”

These types of devices tend to be too small, or located in an area that limits the use of conventional wireless transmission. UW engineers and computer scientists have found a way, however, to use standard Wi-Fi transmission so these devices can communicate, without the need for any specialized equipment.

“Instead of generating Wi-Fi signals on your own, our technology creates Wi-Fi by using Bluetooth transmissions from nearby mobile devices such as smartwatches,” said co-author Vamsi Talla in the report. Talla is a recent UW doctoral graduate in electrical engineering who is now a research associate in the Department of Computer Science & Engineering.

The technique they use for the process is called “backscatter.” Devices are able to exchange info by reflecting existing signals. The team is calling the process--which uses Bluetooth signals to create Wi-Fi transmissions--“interscatter,” as it enables inter-technology communication.

Mobile devices like smartphones or laptops serve as both sources and receivers for reflected signals. The report gives an example of the process using a smartwatch and a smart contact lens. The watch sends a “blank slate” Bluetooth signal to the lens’s antenna. The lens receives this as a single tone signal that can be manipulated. Using backscattering, the lens can encode data into a standard Wi-Fi transmission that can be read on a smartphone, tablet or laptop.

“Bluetooth devices randomize data transmissions using a process called scrambling,” explained lead faculty Shyam Gollakota, assistant professor of computer science and engineering, in the report. “We figured out a way to reverse engineer this scrambling process to send out a single tone signal from Bluetooth-enabled devices such as smartphones and watches using a software app.”

A concern for these types of transmissions was the battery life of an implanted device. Replacing a battery requires surgery, which could lead to possible complications. However, co-author Joshua Smith explained that battery usage shouldn’t be a concern. “Interscatter can enable Wi-Fi for these implanted devices while consuming only tens of microwatts of power,” he explained.

- here's the UW report

Related Articles: 
Researchers developing new communication technique for wearable devices
Mayo Clinic, Gentag partner to develop movement sensor patches