Wearable Sensor for Breath Rate Monitoring

Monitoring of the breath rate is important for assessment of patients' health condition, sleep quality, sports monitoring, operational health, safety and early detection of potential serious respiratory system infections. Despite the need for continuous respiratory rate (RR) monitoring, wearable RR sensors are highly demanded in the relevant application fields. In this article a wearable breath rate sensor based on a planar spiral resonator (SR) is presented. The SR is accommodated on a flexible thin textile substrate allowing the sensor to conform to non-planar surfaces such as the human torso making it suitable for integration in garments. The respiration rate is retrieved by using the SR and a wireless reader probe placed close-by. The working principle is based on tracking the movement of the chest wall or abdomen during inhalation and exhalation that modulates the distance between the reader and the SR. The proposed device is capable of measuring the frequency of respiration by analyzing the modulated signal collected by the probe. The sensing concept was verified via preliminary experimental measurements using a breath simulator.