Wireless Wearable Sensor to Characterize Respiratory Behavior

A. Chen and J. Chae
Arizona State University, United States

Keywords: wearable, wireless, ultrasound, monitoring breathing

Respiratory behavior contains crucial parameters to feature lung functionality, including respiratory rate, profile, and volume. The current well-adopted method to characterize respiratory behavior is spirometry using a spirometer, which is bulky, heavy, expensive, requires a trained provider to operate, and is incapable of continuous monitoring of respiratory behavior. This work presents a wireless wearable sensor that is capable of continuous monitoring of respiratory behavior and delivering the clinically relevant respiratory information to a smartphone. The sensor, with a footprint of 40×35×6mm3 and weighing 6.5g, including a 2.7g battery. The sensor converts the linear strain at the wearing site to the lung volume change. The temporal lung volume change data is wirelessly transmitted to a smartphone where a custom-designed app computes to show volume-time and flow rate-volume loop graphs, standard respiratory analysis plots. The app analyzes the plots to show the clinically relevant respiratory behavioral parameters, such as forced vital capacity (FVC) and forced expiratory volume delivered in the first second (FEV1). Eight volunteers were recruited to evaluate the sensor, showing FEV1/FVC ratio of ~0.00−4.25% deviation when benchmarked by the spirometer. The continuous measurement of respiratory behavioral parameters helps track the progression of the respiratory status as well as diseases.