Embroidered wearable Antenna-based sensor for Real-Time breath monitoring

In this paper we present the design and the validation of a novel fully embroidered meander dipole antenna based sensor integrated into a commercially available T-shirt for real-time breathing monitoring using the technique based on chest well movement analysis. The embroidered antenna-based sensor is made of a silver coated nylon thread. The proposed antenna-sensor is integrated into a cotton T-shirt and placed on the middle of the human chest. The breathing antenna-based sensor was designed to operate at 2.4 GHz. The sensing mechanism of the system is based on the resonant frequency shift of the meander dipole antenna-sensor induced by the chest expansion and the displacement of the air volume in the lungs during breathing. The resonant frequency shift was continuously measured using a Vector Network Analyzer (VNA) to a remote PC via LAN interface in real-time. A program was developed via Matlab to collect respiration data information using a PC host via LAN interface to be able to transfer data with instrumentation over TCP/IP. The measurements were carried out to monitor the breathing of a female volunteer for various positions (standing and sitting) with different breathing patterns: eupnea (normal respiration), apnea (absence of breathing), hypopnea (shallow breathing) and hyperpnea (deep breathing). The measured resonance frequency shift to 2.98 GHz, 3.2 GHz and 2 GHz for standing position and 2.84 GHz, 2.95 GHz and 2.15 GHz for sitting position, for eupnea, hyperpnea and hypopnea, respectively. The area of the textile sensor is 45 x 4.87 mm2, reducing the surface consumption significatively with regard to other reported breath wearable sensors for health monitoring.

Automated summary

This paper presents the design and validation of a new embroidered meander dipole antenna-based sensor integrated into a commercially available T-shirt for real-time breathing monitoring. The sensor operates at 2.4 GHz and measures the resonant frequency shift induced by chest expansion and lung air volume displacement during breathing. The measurements were carried out to monitor breathing patterns in different positions, and the textile sensor showed significant surface consumption reduction compared to other reported wearable sensors.