An Artificial Nervous System for Communication between Wearable and Implantable Therapeutics

Bioelectronics transformed our capacity to monitor and treat diseases; however, power hungry and bulky communication systems limit their ability to synergistically interact as cohesive in-body networks. Inspired by body’s ionic conductivity, we engineered an artificial nervous system that utilizes the body’s own tissue to pass signals between a wearable hub and multiple implantable therapeutics. When the central hub emits a pulse, it generates a voltage gradient throughout the body that turns on implanted transistor switches when exceeding their gate threshold voltages. We conducted in vivo studies in rats that demonstrate our system’s ability to independently control the motion of hind legs via implantable neurostimulators triggered by wearable strain sensors with 10x greater power efficiency than Bluetooth and near field communication (NFE) and a smaller electronic footprint.

SWANS, the Smart Wearable Artificial Nervous System, allows for simultaneous control of multiple implants by using different transistor switch types, each responding to characteristic electrical pulses generated by the wearable hub. Receiving pad surface area showed minimal influence on harvested voltage, supporting compact device designs (7x1mm) that are over 5x smaller than the communication components of Bluetooth chips. In vivo studies with subcutaneous, intraperitoneal, and intragastric implants confirmed that the propagated electric field extends deep into the body, a potentially important finding in the design of low-power ingestible devices. The SWANS implant successfully triggers when placed across the tissues in various orientations and locations due to the tissue’s natural conductivity and ability to spread the voltage gradient throughout the Leveraging the collected data, we designed the SWANS neurostimulator for implantation in animal models and successfully achieved selective activation of the right and left hind legs, effectively mimicking the function of the body’s nervous system.

Our findings establish SWANS as a scalable and energy-efficient framework for developing cohesive bioelectronic networks, paving the way toward minimally invasive, long-lived therapeutic systems capable of dynamically interfacing with the body.