Key facts
- Georgia Tech researchers developed SWANS, a system for implants to communicate via electrical signals through body tissue.
- SWANS uses ionic conduction, similar to neurons, to transmit signals.
- The system extends implant battery life by over 15 times compared to Bluetooth and NFC.
- Implants are small, measuring 3 by 1.1 by 17 millimeters, and can fit through a 6-gauge needle.
- Tests in rats showed signals could travel over 30 centimeters through tissue.
- The system is designed for passing key information between implants, not large data amounts.
A new networking system called SWANS (Smart Wireless Autonomous Networking System) has been developed by researchers at Georgia Tech, enabling medical implants to communicate with each other by transmitting electrical signals through body tissue. This approach bypasses the limitations of radio-based communication like Bluetooth and near-field communication (NFC), which struggle with power consumption and signal attenuation within the body.
According to co-author Alex Abramson, current radio protocols can significantly reduce an implant's battery life and have a limited range of about one centimeter through tissue. The SWANS system, inspired by the human nervous system, uses ionic conduction to send signals, similar to how neurons communicate. This method allows for much greater signal range and efficiency.
The SWANS system comprises a wearable hub that processes data and emits voltage pulses, a patch with microneedles to deliver these pulses into the body, and syringe-injectable implants containing basic components like receivers and batteries. The implants are designed to be small and energy-efficient, drawing almost no power while idle, which extends battery life by over 15 times compared to existing technologies. The implants react to specific pulse strengths and durations, allowing for targeted communication.
Experiments conducted on pork bellies demonstrated that a single 10-volt pulse could create a detectable voltage gradient over 30 centimeters across the tissue and up to 14 centimeters deep. In live rats, signals successfully reached implants placed in various locations, including the abdominal cavity and stomach, with actuation observed even when the wearable hub was placed on the rat's stomach and the implant on its hind leg. The researchers also successfully demonstrated an implant-to-implant relay based on temperature readings.
While SWANS is not designed for high-data-volume transmission, its developers believe it can facilitate crucial information exchange between different body parts and integrate with existing implants to enable combined therapies, such as synchronized neurostimulation and drug delivery. Preliminary studies in large animals have also shown promising results.