A wireless implantable sensory ring for continuous airway stent migration tracking

Airway stents play a vital role in managing central airway obstruction (CAO) caused by lung cancer and other pulmonary diseases by providing structural support to collapsed airways and restoring airflow. However, complications such as stent migration often require urgent medical intervention while early monitoring is essential to reduce the risk. Regular monitoring through bronchoscopy requires anesthesia in the hospital, which causes pain and an economic burden on patients. Computed tomography involves risky radiation and lacks the ability to provide continuous, real-time feedback outside of hospital settings. Here we report a fundamental mechanism of wireless tracking based on magnetic field in a wirelessly powered sensory ring integrated on an airway stent. The sensory ring is designed for continuous, real-time monitoring of stent position and orientation. This sensory ring, integrating an on-board magnetic sensor, and a wearable magnetic field generation system, enable accurate localization by detecting the magnetic field generated externally. The sensory ring is powered wirelessly via a charging coil, ensuring long-term operation. Our system achieves tracking accuracy of 0.5 mm and 2.2 degrees, with a temporal resolution of 0.2 Hz. Beyond migration monitoring, the sensor also detects airway deformation, offering the potential to sense pathological changes associated with lung cancer and other pulmonary conditions. By eliminating the need for radiation-based imaging or bronchoscopy, this approach enables safe, long-term surveillance of stent patency and surrounding tissue conditions. The proposed sensing mechanism and platform are also adaptable in other organs, such as the esophagus, for monitoring stent migration and deformation.