Identification of different respiratory rate by a piezo polymer based nasal sensor

In this paper, we present a new nasal sensor system developed using Polyvinylidene fluoride (PVDF) piezo polymer in cantilever configuration and its applicability for measuring human Respiration Rate (RR). Two identical PVDF nasal sensors are mounted on a headphone such that they are located below Right Nostril (RN) and Left Nostril (LN), in such a way that the nasal airflow during inspiration and expiration impinge on sensors. Due to nasal airflow, piezoelectric natured PVDF nasal sensors generate corresponding voltage signals. The RR is the number of breaths per minute (bpm). The RR was determined from the filtered respiratory signals, by computing a power spectral density (PSD) spectrum using Welch method of averaged periodograms. The developed PVDF nasal sensors were capable of identifying different RR corresponding to normal (18.5±1.5 bpm), tachypnea (34.5±4 bpm), and bradypnea (10.5±2.2 bpm) similar to `Gold standard´ Respiratory Inductance Plethysmograph (RIP) method and Nasal Prongs (NP).