Wearable data acquisition for heartbeat and respiratory information using NAM (non-audible murmur) microphone

We are aiming at to establish the technology for measuring heartbeat and respiration without placing excessive load on subjects in daily situations. In this paper, we focus on the NAM (non-audible murmur) microphone, a small skin-attached microphone developed to record NAMs. The device can simultaneously work as an acoustic sensor for sounds that are related to the user´s physiological signs. We confirm the existence of the heartbeat and respiratory information in the NAM sounds and discuss the possibility of extracting these indices.