Breathing monitoring with RFID sensing: Tag Antenna Design and Signal Processing

Abstract

Real-time monitoring of respiratory function plays an essential role in both clinical diagnosis and pulmonary rehabilitation. In this work, we proposed a novel respiratory monitoring solution based on ultra-high frequency (UHF) radio-frequency identification (RFID) technology for local measurement of breathing at multiple locations simultaneously. A respiratory monitoring system was built using commercial RFID devices, and a signal processing algorithm was developed to extract respiratory features. The results demonstrate high accuracy in both respiratory rate and temporal pattern compared with a reference piezoelectric (PZT) respiratory belt. Moreover, two compact tag antennas were designed and optimized to operate on the human body. Two different methods, stencil printing and copper tape engraving, were used for tag antenna fabrication, with advantages and challenges analyzed. Overall, our study suggests that RFID technology holds a big potential for non-invasive and localized respiratory monitoring.