Social distancing is currently one of the best ways to prevent Covid-19, but maintaining six feet can be challenging. Georgia Tech researchers have created a custom wearable device that helps users stay safely apart in public places.
The device, called 6Fit-A-Part, performs wireless localization using ultra-wideband radios to determine if two or more devices are in close proximity. Within seconds of contact, the device emits a red light and a beep to alert the wearer. It can be worn by users or placed on objects in hospitals, schools, grocery stores, warehouses, and similar locations.
Pairing Wireless Networking and Sensing
6Fit-A-Part uses ultra-wideband radios, a relatively new technology gaining popularity in the latest smartphones. Radio waves are ideal for estimating distances because they travel at a fixed speed that can be measured. To determine which device the radio waves sensed the researchers rely on distributed ranging protocol, a wireless networking concept that extends the reach of a signal.
“We have previously explored various ways to measure distance between two wireless devices by exchanging special ranging packets,” said School of Computer Science (SCS) assistant professor Ashutosh Dhekne. “We identified that similar distance measurements can help us raise an alarm if two or more devices come in close proximity to each other.”
In operation, 6Fit-A-Part invites all neighboring devices to exchange wireless ranging packets to determine distance. Messages are limited, so each round of distance measurements isn’t time-consuming. For example, 10 nearby devices can calculate all-to-all distances within a second. The distance is accurate within 10 centimeters if there are no human or building obstructions.
The device’s merging of wireless networking techniques and wireless sensing technology also makes it more precise than other comparable devices. Instead of alerting a user any time devices are in range, 6Fit-A-Part can distinguish if there is a physical barrier between devices, such as a wall, that would prevent close contact.
It can also observe the received signal and its echoes from nearby objects to determine if there was a human blocking the signals. It can then compensate for the distance accordingly. This prevents false negatives when two people are too close to each other, but their bodies obstruct the signals from their devices.
Contact Prevention Better than Contact Tracing
Although many organizations are using contact tracing applications, the focus on social distancing makes 6Fit-A-Part a preventative measure before users are exposed to the virus. Users also don’t need a specific app downloaded or Bluetooth enabled to receive the benefits.
It protects privacy better, according to researchers.
“6Fit-A-Part reminds everyone to maintain physical distancing, which reduces the possibility of infection without constantly tracking a person’s whereabouts,” said SCS Ph.D. student Yifeng Cao. “This allows complete protection of the user’s privacy by not associating a particular person with the device.”
The researchers hope to test 6Fit-A-Part in additional real-world environments to understand how the device influences human behavior. Dhekne and Cao wrote the paper, 6Fit-A-Part: A Protocol for Physical Distancing on a Custom Wearable Device, with SCS Professor Mostafa Ammar. They presented the research at the 28th IEEE International Conference on Network Protocols in October.