A heartbeat and respiration rate sensor based on phonocardiogram for healthcare applications

This paper presents a system to monitor heartbeat and respiration rate based on phonocardiogram by developing a mini wireless acoustic sensor. The developed sensor including two capacitor microphones, which one for recording the heartbeat by using a bell-shaped stethoscope and another one for respiration rate, a microcontroller and a transceiver which operates at the frequency of 2.54 GHz and Industrial, Scientific and Medical (ISM) band. The presented system was tested on the several volunteers and the obtained results are compared to a gold standard to determine accuracy of the system. The results showed that root mean square errors (RMSEs) are obtained less than 2.27 beats per minutes and 0.92 breaths per minutes for the heartbeat and respiration rate, respectively. Also, the results reveal that the standard deviation of the errors (SDs) is determined less than 1.26 and 0.63 for heartbeat and respiration rate in turn. The system can be used for continuous vital sign monitoring in healthcare applications.